Article

# Determination of biogenic and fossil CO2 emitted by waste incineration based on (CO2)-C-14 and mass balances

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

## Abstract

A field application of the radiocarbon ((14)C) method was developed to determine the ratio of biogenic vs. fossil CO(2) emissions from waste-to-energy plants (WTE). This methodology can be used to assign the Kyoto relevant share of fossil CO(2) emissions, which is highly relevant for emission budgets and emission trading. Furthermore, heat and electricity produced by waste incinerators might be labelled depending on the fossil or biogenic nature of the primary energy source. The method development includes representative on-site CO(2) absorption and subsequent release in the laboratory. Furthermore, a reference value for the (14)C content of pure biogenic waste (f(M,bio)) was determined as 1.130+/-0.038. Gas samples for (14)CO(2) analysis were taken at three WTEs during one month each. Results were compared to an alternative approach based on mass and energy balances. Both methods were in excellent agreement and indicated a fraction of biogenic CO(2) slightly above 50%.

## No full-text available

... As MS is greatly affected by the knowledge of the sorting person and available facts about the waste compounds, the uncertainties of this method can hardly be calculated [26,27]. Despite the high analytical precision of the 14 C-Method, uncertainties for this method are introduced by the choice of a 14 C-reference value [28,29]. -The aBM is far less time-and cost-intensive than MS or the 14 C-Method. ...
... The latter depends on the type of biomass and on the period of growth, and dominates the uncertainty of the method. This is due to the changing radiocarbon content in the atmosphere in the past century caused by nuclear weapon tests [28,29,39,41]. However, the 14 C-Method is regarded as a reliable method for the determination of the biomass content in secondary fuels as it has the lowest analytical uncertainty (accelerator mass spectrometry AMS < 3-7% relative [29,[42][43][44]). ...
... This is due to the changing radiocarbon content in the atmosphere in the past century caused by nuclear weapon tests [28,29,39,41]. However, the 14 C-Method is regarded as a reliable method for the determination of the biomass content in secondary fuels as it has the lowest analytical uncertainty (accelerator mass spectrometry AMS < 3-7% relative [29,[42][43][44]). Liquid Scintillation Counting (LSC) can also be applied to analyze the 14 C content [25,41]. ...
Article
Today different types of wastes are used as refuse-derived fuels (RDF) either in waste-to-energy plants or as fuel substitutes in energy-intensive industrial processes. In order to quantify their greenhouse-gas relevance (fossil carbon content), reliable and practical analytical methods are required, which allow differentiation between biogenic and fossil organic carbon. In the present paper, an alternative method to determine the fossil share in RDFs is examined and validated. The so-called “adapted Balance Method” (aBM) is applied to three different RDFs and the results are compared to three standardized methods, namely the Radiocarbon Method (¹⁴C-Method), the Selective Dissolution Method (SDM), and the Manual Sorting Method (MS). The aBM is based on the distinctly different elemental composition of water-and-ash-free biogenic and of fossil matter (TOXBIO and TOXFOS). Within the study, these compositional data are derived by manual sorting of the RDFs. The results show that the values obtained by the aBM are in excellent agreement with the results of the ¹⁴C-Method (considered as reference method). Mean deviations between the two methods of −0.9 to +1.9% absolute for the share of fossil carbon are found which are statistically insignificant. High trueness and reliability of the aBM can be expected, independent of the RDF type. In contrast, the reliability of the other standardized methods (SDM and MS) appears to strongly depend on the type and composition of the RDF. The results further indicate that the generation of RDF-specific data on TOXFOS is important for the aBM if significant shares of polymers with comparably high oxygen content might be present in the RDF and if low uncertainties of the results (<3% relative) are required. The findings demonstrate that the alternative method has advantages compared to standardized methods with respect to reliability and/or costs.
... Previous studies have reported various values for CO 2 emissions and emission factors from waste incinerators. Many of them presented FCF values for each composition of waste or fossil origin CO 2 fraction along with emission factors (Astup et al., 2009;Jones et al., 2014;Mohn et al., 2008Mohn et al., , 2012Palstra and Meijer, 2010). A study conducted by Choi et al. (2017a) estimated N 2 O and CO 2 emission factors using hourly measured concentration data and compared variabilities in N 2 O emission factors with CO 2 emission factors in terms of waste type, incinerator type (i.e., stoker, fluidized bed), and deNOx technology to characterize N 2 O emission factors by category. ...
... Astrup et al. (2009) presented FCF f of 0.33 for a European MSW (Astrup et al., 2009). The FCF f emitted from a waste incinerator in Switzerland were 0.47 and 0.48 when determined by 14 CO 2 and mass balance (Mohn et al., 2008), respectively in accordance to results of a long-term study for the same incinerator (Mohn et al., 2012). In the Netherlands, a similar share of FCF f was determined for a waste incineration facility (average value of 0.51 based on 14 C analysis of flue gas CO 2 from 13 samples) (Palstra and Meijer, 2010). ...
Article
Climate-relevant CO2 emissions from waste incineration were compared using three methods: making use of CO2 concentration data, converting O2 concentration and waste characteristic data, and using a mass balance method following Intergovernmental Panel on Climate Change (IPCC) guidelines. For the first two methods, CO2 and O2 concentrations were measured continuously from 24 to 86 days. The O2 conversion method in comparison to the direct CO2 measurement method had a 4.8% mean difference in daily CO2 emissions for four incinerators where analyzed waste composition data were available. However, the IPCC method had a higher difference of 13% relative to the direct CO2 measurement method. For three incinerators using designed values for waste composition, the O2 conversion and IPCC methods in comparison to the direct CO2 measurement method had mean differences of 7.5% and 89%, respectively. Therefore, the use of O2 concentration data measured for monitoring air pollutant emissions is an effective method for estimating CO2 emissions resulting from waste incineration.
... The Radiocarbon method ( 14 C-method) is based on the distinctly different concentration of 14 C isotope in fossil carbon sources (where 14 C is completely decayed) and in modern (biogenic) carbon sources, which exhibit in a first approximation the current 14 C atmospheric levels. Thus, the 14 C-concentration in the emitted CO 2 when a waste mixture is combusted is directly proportional to the fraction of biogenic carbon in the combusted sample (Mohn et al., 2008). However, owing to anthropogenic activities the background level of 14 C levels in the atmosphere was altered, which complicates the calculation as it requires reference basis to be recalculated for each grow year of biomass (Fellner and Rechberger, 2009). ...
... However, owing to anthropogenic activities the background level of 14 C levels in the atmosphere was altered, which complicates the calculation as it requires reference basis to be recalculated for each grow year of biomass (Fellner and Rechberger, 2009). Yet, the method is regarded as very reliable method for the determination of the biomass content in secondary fuels as it has the lowest analytical uncertainty (accelerator mass spectrometry <1% relative; Mohn et al., 2008). ...
... F 14 C of wood burning is higher than that because a significant fraction of carbon in the wood burned today was fixed during times when atmospheric 14 C/ 12 C ratios were substantially higher than today. Estimates of F 14 C for wood burning are based on tree-growth models (e.g., Lewis et al., 2004;Mohn et al., 2008) and found to range from 1.08 to 1.30 (Szidat et al., 2006;Genberg et al., 2011;Gilardoni et al., 2011;Minguillón et al., 2011;Dusek et al., 2013). When F 14 C is measured on OC and EC separately, contributions from non-fossil and fossil sources to carbonaceous aerosols can be separated. ...
... 2.5 Source apportionment methodology using 14 C F 14 C of EC (F 14 C (EC) ) was converted to the fraction of biomass burning (f bb (EC)) by dividing with F 14 C of biomass burning (F 14 C bb = 1.10 ± 0.05; Lewis et al., 2004;Mohn et al., 2008;Palstra and Meijer, 2014) given that biomass burning is the only non-fossil source of EC, to eliminate the effect from nuclear bomb tests in the 1960s. EC is primarily produced from biomass burning (EC bb ) and fossil fuel combustion (EC fossil ), and absolute EC concentrations from each source can be estimated once f bb (EC) is known: ...
Article
Full-text available
Sources of organic carbon (OC) and elemental carbon (EC) in Xi'an, China, are investigated based on 1-year radiocarbon and stable carbon isotope measurements. The radiocarbon results demonstrate that EC is dominated by fossil sources throughout the year, with a mean contribution of 83±5% (7±2µg m⁻³). The remaining 17±5% (1.5±1µg m⁻³) is attributed to biomass burning, with a higher contribution in the winter ( ∼ 24%) compared to the summer ( ∼ 14%). Stable carbon isotopes of EC (δ¹³CEC) are enriched in winter (−23.2±0.4‰) and depleted in summer (−25.9±0.5‰), indicating the influence of coal combustion in winter and liquid fossil fuel combustion in summer. By combining radiocarbon and stable carbon signatures, relative contributions from coal combustion and liquid fossil fuel combustion are estimated to be 45% (median; 29%–58%, interquartile range) and 31% (18%–46%) in winter, respectively, whereas in other seasons more than one half of EC is from liquid fossil combustion. In contrast with EC, the contribution of non-fossil sources to OC is much larger, with an annual average of 54±8% (12±10µg m⁻³). Clear seasonal variations are seen in OC concentrations both from fossil and non-fossil sources, with maxima in winter and minima in summer because of unfavorable meteorological conditions coupled with enhanced fossil and non-fossil activities in winter, mainly biomass burning and domestic coal burning. δ¹³COC exhibited similar values to δ¹³CEC, and showed strong correlations (r² = 0.90) in summer and autumn, indicating similar source mixtures with EC. In spring, δ¹³COC is depleted (1.1‰–2.4‰) compared to δ¹³CEC, indicating the importance of secondary formation of OC (e.g., from volatile organic compound precursors) in addition to primary sources. Modeled mass concentrations and source contributions of primary OC are compared to the measured mass and source contributions. There is strong evidence that both secondary formation and photochemical loss processes influence the final OC concentrations.
... F 14 C (EC) can be converted to the relative contribution of biomass burning to EC (f bb (EC)) by dividing by the F 14 C of biomass burning (F 14 C bb = 1.10 ± 0.05; Lewis et al., 2004;Mohn et al., 2008;Palstra and Meijer, 2014) to eliminate the effect from nuclear-bomb tests in the 1960s. F 14 C bb represents F 14 C of biomass burning, including wood burning and crop residue burning. ...
... F 14 C of wood burning is higher than that and varies with the age of the tree. Estimates of F 14 C for wood burning are based on tree-growth models (e.g., Lewis et al., 2004;Mohn et al., 2008) and found to range from 1.08 to 1.30 relative to the wood age and felling date (Heal, 2014, and references therein). The lower limit of F 14 C bb corresponds to burning of young wood (tree that is 5-10 years old harvested between 2010 and 2015) and crop residues as main sources of EC, and the upper end of F 14 C bb corresponds to older wood (30-60 years old tree) combustion as the main source of EC. ...
Article
Full-text available
To investigate the sources and formation mechanisms of carbonaceous aerosols, a major contributor to severe particulate air pollution, radiocarbon (14C) measurements were conducted on aerosols sampled from November 2015 to November 2016 in Xi'an, China. Based on the 14C content in elemental carbon (EC), organic carbon (OC) and water-insoluble OC (WIOC), contributions of major sources to carbonaceous aerosols are estimated over a whole seasonal cycle: primary and secondary fossil sources, primary biomass burning, and other non-fossil carbon formed mainly from secondary processes. Primary fossil sources of EC were further sub-divided into coal and liquid fossil fuel combustion by complementing 14C data with stable carbon isotopic signatures. The dominant EC source was liquid fossil fuel combustion (i.e., vehicle emissions), accounting for 64 % (median; 45 %–74 %, interquartile range) of EC in autumn, 60 % (41 %–72 %) in summer, 53 % (33 %–69 %) in spring and 46 % (29 %–59 %) in winter. An increased contribution from biomass burning to EC was observed in winter (∼28 %) compared to other seasons (warm period; ∼15 %). In winter, coal combustion (∼25 %) and biomass burning equally contributed to EC, whereas in the warm period, coal combustion accounted for a larger fraction of EC than biomass burning. The relative contribution of fossil sources to OC was consistently lower than that to EC, with an annual average of 47±4 %. Non-fossil OC of secondary origin was an important contributor to total OC (35±4 %) and accounted for more than half of non-fossil OC (67±6 %) throughout the year. Secondary fossil OC (SOCfossil) concentrations were higher than primary fossil OC (POCfossil) concentrations in winter but lower than POCfossil in the warm period. Fossil WIOC and water-soluble OC (WSOC) have been widely used as proxies for POCfossil and SOCfossil, respectively. This assumption was evaluated by (1) comparing their mass concentrations with POCfossil and SOCfossil and (2) comparing ratios of fossil WIOC to fossil EC to typical primary OC-to-EC ratios from fossil sources including both coal combustion and vehicle emissions. The results suggest that fossil WIOC and fossil WSOC are probably a better approximation for primary and secondary fossil OC, respectively, than POCfossil and SOCfossil estimated using the EC tracer method.
... Facilities can be divided into fossil, biomass, and waste CHP plants. These categories are not mutually exclusive, as many plants can indeed alternate between fuels in the short and long terms (Emmenegger et al., 2012;Johnke, 2003;Mohn et al., 2008). A third economic activity often seen as promising for BECCS is large-scale bioethanol production (Pacca et al., 2016). ...
Chapter
Full-text available
Chapter 2 (“BECCS in Climate Scenarios”) discusses the carbon budgets for the 1.5°C and 2.0°C targets and their relationship to BECCS. The chapter also gives an overview of the role of BECCS in the IPCC’s Fifth Assessment Report (AR5) and in Shared Socioeconomic Pathway (SSP) scenarios provided by integrated assessment models (IAMs). It will also discuss the main assumptions regarding BECCS made in such models.
... MSW generation is heterogeneous and has different fractions like biogenic, fossil, and inert matter (Mohn et al., 2008). The derived SRF from the waste of MSW, commercial waste, and other bulky waste which mostly contain biogenic components like paper, wood, cardboard, etc. and they range from 40% to 80% by weight (Luz et al., 2015). ...
Article
The current study was carried out to focus on the issues of municipal solid waste (MSW) in Pakistan for two urban centers through an energy waste management approach. An eco-friendly fuel was produced from the MSW of both cities, termed solid recovered fuel (SRF). The proximate and ultimate analysis was performed to determine its energy contents and economic benefits. The calorific value of the SRF was found 90% closer to coal and 80% to that of wood as it contains 98% of carbon. The replacement of SRF with furnace oil, natural gas, coal, and wood would cause cost-saving up to 41% calculated on monthly basis for the local industries in Pakistan. The developed SRF is clean and environmentally friendly as compared with coal and wood in terms of its cost, availability, and emissions. The adoption of SRF as fuel will minimize direct dumping, which will cause the encouragement of forestation.
... The best known application for measuring the concentration of the radioactive 14 C isotope is carbon dating. Determining the 14 C/ 12 C-ratio can also be used to differentiate between biogenic and fossil emission, since in the latter the 14 C concentration is depleted [6]. The current standard for sensitive detection of 14 C is accelerator mass spectrometry (AMS), but it requires large and costly facilities to operate. ...
Article
Full-text available
We report a photoacoustic spectroscopy setup with a high-power mid-infrared frequency comb as the light source. The setup is used in broadband spectroscopy of radiocarbon methane. Owing to the high sensitivity of a cantilever-enhanced photoacoustic cell and the high-power light source, we can reach a detection limit below 100 ppb in a broadband measurement with a sample volume of only a few milliliters. The first infrared spectrum of CH414 is reported and given a preliminary assignment. The results lay a foundation for the development of optical detection systems for radiocarbon methane.
... The best known application for measuring the concentration of the radioactive 14 C isotope is carbon dating. Determining the 14 C/ 12 C-ratio can also be used to differentiate between biogenic and fossil emission, since in the latter the 14 C concentration is depleted [6]. The current standard for sensitive detection of 14 C is accelerator mass spectrometry (AMS), but it requires large and costly facilities to operate. ...
Preprint
Full-text available
We report a photoacoustic spectroscopy setup with a high-power mid-infrared frequency comb as the light source. The setup is used in broadband spectroscopy of radiocarbon methane. Due to the high sensitivity of a cantilever-enhanced photoacoustic cell and the high power light source, we can reach a detection limit below 100 ppb in a broadband measurement with a sample volume of only a few milliliters. The first infrared spectrum of $^{14}\text{CH}_4$ is reported and given a preliminary assignment. The results lay a foundation for the development of optical detection systems for radiocarbon methane.
... Modelling studies from recent years confirm that wood burning emissions are important in 131 wintertime Europe, and that such emissions seem to be severely underestimated in many regions 132 (Simpson et al., 2007;Bergström et al., 2012;Genberg et al., 2013). Denier van der Gon et al. (2015a) 133 pointed at inconsistent emission factors as a major problem (some countries report mainly solid 134 emissions, whereas others include substantial amounts of condensed semi-volatile OC, SVOC), and 135 produced a new bottom-up emission inventory for residential wood burning emissions of OC and EC, 136 using a consistent methodology across Europe (see also Genberg et al., 2013 (Mohn et al., 2008). ...
Article
Full-text available
Source apportionment (SA) of carbonaceous aerosol was performed as part of the EMEP Intensive Measurement Periods (EIMPs), conducted in fall 2008 and winter/spring 2009. Levels of elemental carbon (EC), particulate organic carbon (OCp), particulate total carbon (TCp), levoglucosan and ¹⁴C in PM10, observed at nine European rural background sites, were used as input for the SA, whereas Latin Hypercube Sampling (LHS) was used to statistically treat the multitude of possible combinations resulting when ambient concentrations were combined with appropriate emission ratios. Five predefined sources/subcategories of carbonaceous aerosol were apportioned: Elemental and organic carbon from combustion of biomass (ECbb and OCbb) and from fossil fuel (ECff and OCff) sources, as well as remaining non-fossil organic carbon (OCrnf), typically dominated by natural sources. The carbonaceous aerosol concentration decreased from South to North, as did the concentration of the apportioned carbonaceous aerosol. OCrnf was more abundant in fall compared to winter/spring, reflecting the vegetative season, and made a larger contribution to TCp than anthropogenic sources (here: ECbb, OCbb, ECff and OCff) at four of the sites, whereas anthropogenic sources dominated at all but one sites in winter/spring. Levels of OCbb and ECbb were typically higher in winter/spring than in fall, due to larger residential wood burning emissions in the heating season, whereas there was no consistent seasonal pattern for fossil fuel emissions. Biomass burning (OCbb+ECbb) was the major anthropogenic source at the Central European sites in fall, whereas fossil fuel sources dominated at the southernmost and the two northernmost sites. In winter/spring, biomass burning was the major anthropogenic source at all but two sites. Addressing EC in particular, fossil fuel sources dominated at all sites in fall, whereas there was as shift towards biomass burning in winter/spring for the southernmost sites. Influence of residential wood burning emissions was substantial already in the first week of sampling in fall, constituting 30–50% of TCp at most sites, showing that this source can be dominating even at a time of the year when the ambient temperature in Europe is still rather high. Model calculations were made, attempting to reproduce LHS-derived OCbb and ECbb, using two different residential wood burning emission inventories. Both simulations strongly under-predicted the LHS-derived values at most sites outside Scandinavia. Emissions based on a consistent bottom-up inventory for residential combustion (and including intermediate volatility compounds, IVOC) improved model results at most sites compared to the base-case emissions (based mainly on officially reported national emissions), but at the three southernmost sites the modelled OCbb and ECbb concentrations were still much lower than the LHS source apportioned results. The current study shows that natural sources is a major contributor to the carbonaceous aerosol in Europe even in fall and in winter/spring, and that residential wood burning emissions can be equally large or larger than that of fossil fuel sources, depending on season and region. Our results suggest that residential wood burning emissions are still poorly constrained for large parts of Europe. The need to improve emission inventories is obvious, with harmonization of emission factors between countries likely being the most important step to improve model calculations, not only for biomass burning emissions, but for European PM2.5 concentrations in general.
... Facilities can be divided into fossil, biomass, and waste CHP plants. These categories are not mutually exclusive, as many plants can indeed alternate between fuels in the short and long terms (Emmenegger et al., 2012;Johnke, 2003;Mohn et al., 2008). A third economic activity often seen as promising for BECCS is large-scale bioethanol production (Pacca et al., 2016). ...
Chapter
Full-text available
Chapter 3 (“Views of BECCS Among Modelers and Policymakers”) moves from exploring the magnitude of BECCS deployment in climate scenarios to outlining caveats raised by modelers themselves. The chapter addresses how modelers navigate the landscape of political and academic pressures to deliver timely, insightful, and relevant policy advice despite inherent and crucial uncer- tainties and increasing model complexity. Based on interviews with modelers, the chapter discusses perspectives on uncertainty, the communication of IAM results, and the models’ relationship to reality. The chapter also discuss views of BECCS among policymakers whom generally want to give relatively low prior- ity to investments in BECCS. Failing to invest in the future delivery of BECCS, combined with today’s lack of mitigation ambition, limits future generations’ maneuvering room to resolve the climate crisis.
... Facilities can be divided into fossil, biomass, and waste CHP plants. These categories are not mutually exclusive, as many plants can indeed alternate between fuels in the short and long terms (Emmenegger et al., 2012;Johnke, 2003;Mohn et al., 2008). A third economic activity often seen as promising for BECCS is large-scale bioethanol production (Pacca et al., 2016). ...
Book
Full-text available
This book explores the role of bioenergy with carbon capture and storage (BECCS) in climate governance. It starts by discussing BECCS’ global mitigation potential, as depicted in the idealized world of climate scenarios. Chapter 2 shows that almost all climate scenarios compatible with the high likelihood of limiting global warming to 2°C deploy BECCS. While excluding BECCS from these models’ technology portfolios does not necessarily make 2°C compatible scenarios impossible, it does mean that the projected cost of meeting that goal increases. In this context, based on interviews with integrated assessment modelers, chapter 3 illustrates how the use of the word “projected” is deliberate and significant. The modelers insist that they are dealing with projections, not predictions. At the same time, this modesty is contrasted to a core willingness to wield political influence. Chapter 4, which applies a crude method to map European point sources of biogenic CO2, indicates that the scenarios for Europe can be associated with factual potentials. The European pulp and paper industry emitted approximately 60–66 Mt of biogenic CO2 in 2015. To a lesser extent, there is also potential to capture biogenic CO2 from the production of electricity, heat, and biofuels. While R&D into BECCS has previously been framed as a “slippery slope” triggering objectionable consequences, for example, concerning food security, chapter 5 argues that realizing BECCS should instead be seen as an uphill struggle. This conclusion gains support in chapter 6, which maps existing policy incentives for BECCS. This exercise reveals an almost complete lack of political initiatives to deploy BECCS, indicating that the climate scenarios’ large-scale deployment of BECCS could be seen as detached from reality. The book ends with chapter 7, which illustrates how UN and Swedish climate policy objectives have indeed influenced companies to get involved in planning for negative emissions, but also shows how the lack of policy incentives has put “sticks in the wheel” when it comes to affirmative investment decisions. While some funding sources for R&D and capital expenditures are highlighted, the primary concern is the lack of market pull that would provide revenues to cover operational expenditures. This book highlights the many caveats involved in moving from the theoretical potentials identified at the global scale to economically viable potentials facing investors at the business scale. It concludes that overcoming the challenges associated with realizing the theoretical potentials will be daunting, a true uphill struggle. Yet, with appropriate policy incentives, BECCS may still come to play an important role in the struggle to limit global warming to well below 2°C.
... The calculated end member value from this auxiliary study (+102.5‰) is similar to a published wood smoke end member value (+107.5‰) which was de- rived from a tree growth model by averaging 10-85 year old wood fractions ( Mohn et al., 2008). The 14 C value of +28.1‰ corresponds to biomass burning of annual sources including combustion of grass, pruning, and agricultural waste, as well as meat cooking (Zotter et al., 2014b). ...
Article
We examined long-term aerosol optical depth (AOD) trends over 53 sites across the globe which comprise 49 sites from the Aerosol Robotic Network (AERONET) and 4 sites from the Sky radiometer Network (SKYNET) during 1995–2018. Most of these sites are located in remote and isolated aged-background regions, and few are in urban/semi-urban sites having averaged AOD ∼0.1 at 500 nm. These selected sites have a global distribution including tropical, mid-latitudes, high-latitudes and Polar regions. Among them, there are 14 high-altitude stations (∼1028–5050 m amsl), including Himalayan and Polar regions. The main objective of the present work is to evaluate the AOD trends over the aged-background sites across the globe. We found that significant number of sites located in North-South America, Europe, Arctic and Australia have statistically significant and negative trends varied from −6.3x to −1.0x AOD year−1. The negative trends over these sites could be attributed to reduction in anthropogenic emission. Furthermore, there are mixed trends of positive as well as negative over Asian and southern oceanic regions including Antarctica. Some of the trends are weak and statistically non-significant, probably due to non-availability of long-term ground based data. However, the AOD trends over these regions show increasing tendency with statistically significant trends of 8.0x to 4.7x AOD year−1. The present study has also many important aspects on global and regional climate change at high-mountain and aged-background sites in particular, where the satellite based measurements are inaccurate and biased due to extremely low AOD.
... The best estimate and ranges of F 14 C(WSOC) is presented in Fig. S2 and Table S1. F 14 C(EC) can be converted to the relative contribution of biomass burning to EC (fbb(EC)) by dividing with F 14 C of biomass burning (F 14 Cbb = 1.10 ± 0.05; (Lewis et al., 2004;Mohn et al., 2008;Palstra and Meijer, 2014), to eliminate the effect from 15 nuclear bomb tests in the 1960s. Analogously, the relative contribution of non-fossil sources to OC, WIOC and WSOC (i.e., fnf(OC), fnf(WIOC) and fnf(WSOC), respectively) can be estimated from their corresponding F 14 C values and F 14 C of nonfossil sources (F 14 Cnf =1.09 ± 0.05; Lewis et al., 2004;Levin et al., 2010;Y. ...
Article
Full-text available
To investigate the sources and formation mechanisms of carbonaceous aerosols, a major contributor to severe particulate air pollution, radiocarbon (¹⁴C) measurements were conducted on aerosols sampled from November 2015 to November 2016 in Xi'an, China. Based on the ¹⁴C content in elemental carbon (EC), organic carbon (OC) and water-insoluble OC (WIOC), contributions of major sources to carbonaceous aerosols are estimated over a whole seasonal cycle: primary and secondary fossil sources, primary biomass burning, and other non-fossil carbon formed mainly from secondary processes. Primary fossil sources of EC were further sub-divided into coal and liquid fossil fuel combustion by complementing ¹⁴C data with stable carbon isotopic signatures. The dominant EC source was liquid fossil fuel combustion (i.e., vehicle emissions), accounting for 64 % (median; 45–74 %, interquartile range) of EC in autumn, 60 % (41–72 %) in summer, 53 % (33–69 %) in spring and 46 % (29–59 %) in winter, respectively. An increased contribution from biomass burning to EC was observed in winter (~ 28 %) compared to other seasons (warm period; ~ 15 %). In winter, coal combustion (~ 25 %) and biomass burning equally contributed to EC, whereas in the warm period, coal combustion accounted for a larger fraction of EC than biomass burning. The relative contribution of fossil sources to OC was consistently lower than that to EC, with an annual average of 47 ± 4 %. Non-fossil OC of secondary origin was an important contributor to total OC (35 ± 4%) and accounted for more than half of non-fossil OC (67 ± 6%) throughout the year. Secondary fossil OC (SOCfossil) concentrations were higher than primary fossil OC (POCfossil) concentrations in winter, but lower than POCfossil in the warm period. Fossil WIOC and water-souble OC (WSOC) have been widely used as proxies for POCfossil and SOCfossil, respectively. This assumption was evaluated by (1) comparing their mass concentrations with POCfossil and SOCfossil, and (2) comparing ratios of fossil WIOC to fossil EC to typical primary OC to EC ratios from fossil sources including both coal combustion and vehicle emissions. The results suggest that fossil WIOC and fossil WSOC are probably a better approximation for primary and secondary fossil OC, respectively, than POCfossil and SOCfossil estimated using the EC tracer method.
... Facilities can be divided into fossil, biomass, and waste CHP plants. These categories are not mutually exclusive, as many plants can indeed alternate between fuels in the short and long terms (Emmenegger et al., 2012;Johnke, 2003;Mohn et al., 2008). A third economic activity often seen as promising for BECCS is large-scale bioethanol production (Pacca et al., 2016). ...
Chapter
Full-text available
Chapter 5 (“Governing BECCS: “Slippery Slope” or “Uphill Struggle”?”) highlights how BECCS and other large-scale interventions in the Earth’s climate system, proposed to moderate anthropogenic global warming, are commonly portrayed as threatening to initiate a “slippery slope” from research to deployment. The argument suggests that governance should constrain or even proscribe research into BECCS on the grounds that allowing it to proceed unchecked could lead to a chain of events resulting in deployment and the undesirable consequences that this might bring. This chapter begins by critically examining the slippery slope argument as articulated in relation to BECCS. It then draws on the empirical findings of an expert scenario method designed to explore how far BECCS might develop in the future and under what governance arrangements. Rather than a slippery slope, the scenarios instead illustrate what might best be described as an “uphill struggle,” in which BECCS innovators confront manifold technical, political, and societal challenges to deployment. The chapter concludes by seeking to reframe the governance task as one of responsible incentivization, rather than one of constraint or proscription.
... Facilities can be divided into fossil, biomass, and waste CHP plants. These categories are not mutually exclusive, as many plants can indeed alternate between fuels in the short and long terms (Emmenegger et al., 2012;Johnke, 2003;Mohn et al., 2008). A third economic activity often seen as promising for BECCS is large-scale bioethanol production (Pacca et al., 2016). ...
Chapter
Full-text available
Chapter 6 (“Multilevel Policy Incentives for BECCS in Sweden”) builds on the high potential for BECCS in Sweden identified in chapter 4, summarizing the current policy incentives for BECCS research, development, demonstration, and diffusion (RDD&D). It examines the given policy drivers and obstacles at multiple scales (e.g., international, supranational, and national) and in terms of various forms of instruments (e.g., economic, regulatory, and informational).The chapter concludes that current policy instruments mostly fail to incentivize BECCS RDD&D in Sweden. The instruments partly favor R&D yet fail to provide incentives covering operational costs. Under current circumstances, BECCS is unlikely to reach demonstration scale in Sweden.
... In this context the development of methods for measuring and assessing the proportion between fossil and biogenic carbon dioxide in flue gases from industrial sources (for instance WTE: Waste to Energy Plants) received significant attention in recent times (Mohn et al. 2008;Palstra and Meijer 2010;Calcagnile et al. 2011). Indeed the clear difference in terms of 14 C isotopic signature between fossil and biogenic material makes accelerator mass spectrometry (AMS) a very powerful tool in this field. ...
Article
The determination of the proportion between the biogenic and the fossil-derived fraction in carbon dioxide emissions from industrial stationary sources is a relevant aspect in the frame of the worldwide efforts to reduce greenhouse gas emissions into the atmosphere. In this field the ¹⁴ C-based method has gained importance over the years and has been included in standard protocols accepted at both the national and international levels. The advantages of the method, based on the large difference in terms of ¹⁴ C signature between fossil and biogenic carbon, are reviewed as well as some critical aspects related to its application. In particular the results of a study aimed at validating the method by analyzing synthetic gas mixtures produced in a dedicated plant and with a tuneable proportion between fossil and biogenic carbon dioxide are presented.
... The calculated end member value from this auxiliary study (+102.5‰) is similar to a published wood smoke end member value (+107.5‰) which was derived from a tree growth model by averaging 10-85 year old wood fractions (Mohn et al., 2008). The 14 C value of +28.1‰ corresponds to biomass burning of annual sources including combustion of grass, pruning, and agricultural waste, as well as meat cooking (Zotter et al., 2014b). ...
Article
Full-text available
Ambient black carbon (BC) has detrimental effects on both human health and near-term global warming. To mitigate these negative effects, there have been significant efforts to reduce emissions of BC from anthropogenic and biomass burning sources in California's Bay Area since the 1960s. Recent reductions in BC have mainly been from fossil fuel combustion sources such as diesel but additional reductions may be needed for contemporary carbon sources like biomass burning and meat cooking. In this study, PM10 (particulate matter with aerodynamic diameter of less than or equal to 10 μm) samples were collected at seven sites across the San Francisco Bay Area from November 2011 to October 2012 to create winter and non-winter composites for each site. Radiocarbon (14C) abundance and chemical mass balance (CMB) modeling were used for source apportionment of ambient elemental carbon (EC, a proxy for BC). The 14C abundance in the EC fraction was used to quantify the relative contributions of fossil carbon and contemporary carbon sources. The average biomass burning contributions are 48 ± 8% and 41 ± 5% for winter and non-winter seasons, respectively, across the Bay Area. Ambient concentrations of EC are approximately two to three times higher during the winter compared to the non-winter season, except for Cupertino. A CMB model, using bulk aerosol composition and select inorganic compounds, was used to understand the contributions of natural gas combustion, gasoline exhaust, and diesel exhaust to fossil carbon as well as the contribution of biomass burning and meat cooking to contemporary carbon. The different apportionment methods for EC (14C and CMB analysis) agree within 16 ± 12% for fraction fossil and biomass burning for both winter and non-winter seasons. The contemporary contribution to EC is much higher than estimated by current emission inventories, suggesting that the inventories may overestimate the contribution from fossil fuels, particularly diesel exhaust. The results from this study are compared to literature values from other 14C-EC or BC studies from across the world.
... The contamination is typically smaller than 2 μgC (Prokopiou, 2010). 25 2.5 Source apportionment methodology using 14 C F 14 C of EC (F 14 C(EC)) was converted to the fraction of biomass burning (fbb(EC)) by dividing the conversion factor of 1.10 ± 0.05 for EC (Lewis et al., 2004;Mohn et al., 2008;Palstra and Meijer, 2014), to eliminate the effect from nuclear bomb tests in the 1960s. EC is primarily produced from biomass burning (ECbb) and fossil fuel combustion (ECfossil), and absolute EC concentrations from each source can be estimated once fbb(EC) is known : 30 Atmos. ...
Article
Full-text available
Sources of organic carbon (OC) and elemental carbon (EC) in Xi’an, China are investigated based on one-year radiocarbon and stable carbon isotope measurements. The radiocarbon results demonstrate that EC is dominated by fossil sources throughout the year, with a mean contribution of 83 ± 5 % (7 ± 2 µg m−3). The remaining 17 ± 5 % (1.5 ± 1 µg m−3) is attributed to biomass burning, with higher contribution in the winter (~ 24 %) compared to the summer (~ 14 %). Stable carbon isotopes of EC (δ¹³CEC) are enriched in winter (−23.20 ± 0.35 ‰) and depleted in summer (−25.94 ± 0.46 ‰), indicating the influence of coal combustion in winter and liquid fossil fuel combustion in summer. By combining radiocarbon and stable carbon signatures, relative contributions from coal combustion and liquid fossil fuel combustion are estimated as 45 % (29–58 %, interquartile range) and 31 % (18–46 %) in winter, respectively, whereas in other seasons more than one half of EC are from liquid fossil combustion. In contrast with EC, the contribution of non-fossil sources to OC is much larger, with an annual average of 54 ± 8 % (12 ± 10 µg m−3). Clear seasonal variations are seen in OC concentrations both from fossil and non-fossil sources, with maxima in winter and minima in summer, because of unfavourable meteorological conditions coupled with enhanced fossil and non-fossil activities in winter, mainly biomass burning and domestic coal burning. δ¹³COC exhibited similar values with δ¹³CEC, and showed strong correlations (r² = 0.90) in summer and autumn, indicating similar source mixtures with EC. In spring, δ¹³COC is depleted (1.1–2.4 ‰) compared to δ¹³CEC, indicating the importance of secondary formation of OC (e.g., from volatile organic compound precursors) in addition to primary sources. Modelled mass concentrations and source contributions of primary OC are compared to the measured mass and source contributions. There is strong evidence that both secondary formation and photochemical loss processes influence the final OC concentrations.
... ( (Levin et al., 2010) and a tree growth model (Mohn et al., 2008). ...
Article
Full-text available
Water-soluble organic carbon (WSOC) is a large fraction of organic aerosols (OA) globally and has significant impacts on climate and human health. The sources of WSOC remain very uncertain in polluted regions. Here we present a quantitative source apportionment of WSOC, isolated from aerosols in China using radiocarbon (¹⁴C) and offline high-resolution time-of-flight aerosol mass spectrometer measurements. Fossil emissions on average accounted for 32–47 % of WSOC. Secondary organic carbon (SOC) dominated both the non-fossil and fossil derived WSOC, highlighting the importance of secondary formation to WSOC in severe winter haze episodes. Contributions from fossil emissions to SOC were 61 ± 4 and 50 ± 9 % in Shanghai and Beijing, respectively, significantly larger than those in Guangzhou (36 ± 9 %) and Xi'an (26 ± 9 %). The most important primary sources were biomass burning emissions, contributing 17–26 % of WSOC. The remaining primary sources such as coal combustion, cooking and traffic were generally very small but not negligible contributors, as coal combustion contribution could exceed 10 %. Taken together with earlier ¹⁴C source apportionment studies in urban, rural, semi-urban and background regions in Asia, Europe and the USA, we demonstrated a dominant contribution of non-fossil emissions (i.e., 75 ± 11 %) to WSOC aerosols in the Northern Hemisphere; however, the fossil fraction is substantially larger in aerosols from East Asia and the eastern Asian pollution outflow, especially during winter, due to increasing coal combustion. Inclusion of our findings can improve a modelling of effects of WSOC aerosols on climate, atmospheric chemistry and public health.
... The biogenic fractions of CO 2 emissions have been studied this way [5,6], successfully demonstrating the suitability of the 14 C technique. Building on these studies, the first demonstration of 14 C for determining the biogenic fraction of blended biogas and natural gas mixtures was reported by Palstra and Meijer [7]. ...
Article
Full-text available
A tunable laser absorption spectrometer (TLAS) was developed for the simultaneous measurement of δ13C and δD values of methane (CH₄). A mid-infrared interband cascade laser (ICL) emitting around 3.27 µm was used to measure the absorption of the three most abundant isotopologues in CH₄ with a single, mode-hop free current sweep. The instrument was validated against methane samples of fossil and biogenic origin with known isotopic composition. Three blended mixtures with varied biogenic content were prepared volumetrically, and their δ13C and δD values were determined. Analysis demonstrated that, provided the isotopic composition of the source materials was known, the δ13C and δD values alone were sufficient to determine the biogenic content of the blended samples to within 1.5%.
... 14 C(TC p ) values are given as fractions modern (F 14 C), i.e., as the 14 C/ 12 C ratios of the samples related to the isotopic ratio of the reference year 1950 (Reimer et al., 2004). For determination of the non-fossil fraction of TC p (i.e., f nf (TC p ) from 14 C(TC p ) determinations, a reference F 14 C value of pure non-fossil emissions of 1.08 ± 0.04 was used to consider the different impacts of excess 14 C from atmospheric nuclear bomb tests to fresh biomass and tree wood (Mohn et al., 2008). This is based on the assumptions that 50 % of non-fossil TC originates from fresh biomass and 50 % from burning of wood, whereof the latter includes 10-, 20-, 40-, 70-, and 85-year old trees with weights of 0.2, 0.2, 0.4, 0.1, and 0.1, respectively. ...
Article
Full-text available
Carbonaceous aerosol (total carbon, TCp) was source apportioned at nine European rural background sites, as part of the European Measurement and Evaluation Programme (EMEP) Intensive Measurement Periods in fall 2008 and winter/spring 2009. Five predefined fractions were apportioned based on ambient measurements: elemental and organic carbon, from combustion of biomass (ECbb and OCbb) and from fossil-fuel (ECff and OCff) sources, and remaining non-fossil organic carbon (OCrnf), dominated by natural sources. OCrnf made a larger contribution to TCp than anthropogenic sources (ECbb, OCbb, ECff, and OCff) at four out of nine sites in fall, reflecting the vegetative season, whereas anthropogenic sources dominated at all but one site in winter/spring. Biomass burning (OCbb + ECbb) was the major anthropogenic source at the central European sites in fall, whereas fossil-fuel (OCff + ECff) sources dominated at the southernmost and the two northernmost sites. Residential wood burning emissions explained 30 %–50 % of TCp at most sites in the first week of sampling in fall, showing that this source can be the dominant one, even outside the heating season. In winter/spring, biomass burning was the major anthropogenic source at all but two sites, reflecting increased residential wood burning emissions in the heating season. Fossil-fuel sources dominated EC at all sites in fall, whereas there was a shift towards biomass burning for the southernmost sites in winter/spring. Model calculations based on base-case emissions (mainly officially reported national emissions) strongly underpredicted observational derived levels of OCbb and ECbb outside Scandinavia. Emissions based on a consistent bottom-up inventory for residential wood burning (and including intermediate volatility compounds, IVOCs) improved model results compared to the base-case emissions, but modeled levels were still substantially underestimated compared to observational derived OCbb and ECbb levels at the southernmost sites. Our study shows that natural sources are a major contributor to carbonaceous aerosol in Europe, even in fall and in winter/spring, and that residential wood burning emissions are equally as large as or larger than that of fossil-fuel sources, depending on season and region. The poorly constrained residential wood burning emissions for large parts of Europe show the obvious need to improve emission inventories, with harmonization of emission factors between countries likely being the most important step to improve model calculations for biomass burning emissions, and European PM2.5 concentrations in general.
... Analogously, the fraction of non-fossil OC, mvOC and mrOC (i.e., fnf(OC), fnf(mvOC) and fnf(mrOC), respectivly) can be estimated from their corresponding F 14 C values and F 14 C of non-fossil sources (F 14 Cnf ). F 14 Cbb and F 14 Cnf are estimated as 1.10 ± 0.05 and 1.09 ± 0.05 (Lewis et al., 2004;Mohn et al., 2008;Palstra and Meijer, 2014), respectively, based on tree-growth models and the assumption that wood burning dominates biomass burning. ...
Article
Full-text available
Sources of particulate organic carbon (OC) with different volatility have rarely been investigated despite the significant importance for better understanding of the atmospheric processes of organic aerosols. In this study we develop a radiocarbon (¹⁴C) based approach for source apportionment of more volatile OC (mvOC) and apply to ambient aerosol samples collected in winter in six Chinese megacities. mvOC is isolated by desorbing organic carbon from the filter samples in He at 200 °C in a custom-made aerosol combustion system for ¹⁴C analysis. Evaluation of this new isolation method shows that the isolated mvOC amount agrees very well with the OC1 fraction (also desorbed at 200 °C in He) measured by a thermal optical analyzer using the EUSAAR_2 protocol. The mvOC, OC and elemental carbon (EC) of thirteen combined PM2.5 samples in six Chinese cities are analyzed for ¹⁴C to investigate their sources and formation mechanisms. The relative contribution of fossil sources to mvOC is 59 ± 11 %, consistently larger than the contribution to OC (48 ± 16 %) and smaller than that to EC (73 ± 9 %), despite large differences in fossil contributions in different cities. The average difference in the fossil fractions between mvOC and OC is 13 % (7 %–25 %; range), similar to that between mvOC and EC (13 %; 4 %–25 %). SOC concentrations and sources are modelled based on the ¹⁴C-apportioned OC and EC, and compared with concentrations and sources of mvOC. SOC concentrations (15.4 ± 9.0 μg m⁻³) are consistently higher than those of mvOC (3.3 ± 2.2 μg m⁻³), indicating that only a fraction of SOC is accounted for by the more volatile carbon fraction desorbed at 200 °C. The fossil fraction in SOC is 43 % (10 %–70 %), lower than that in mvOC (59 %; 45 %–78 %). Correlation between mvOC and SOC from non-fossil sources (mvOCnf vs. SOCnf) and from fossil sources (mvOCfossil vs. SOCfossil) are examined to further explore sources and formation processes of mvOC and SOC.
... These standards describe, respectively, the 14 C method, the selective dissolution method, and the balance method, as the methods to analyze the biomass fraction. Numerous previous studies have employed these methodologies to analyze biomass fraction [16][17][18][19][20][21][22][23]. ...
Article
Full-text available
In this study, greenhouse gas (GHG) differences due to the application of biomass content are compared at a sewage sludge incinerator. The result of the comparison shows that the differences between the methods of GHG emission estimation based on biomass fraction analysis (sewage sludge analysis and sewage sludge flue gas analysis) were not substantial. On the other hand, the GHG emission estimated from the method in this study showed a difference of 8–9 ton CO2eq/day from the currently used method in Korea. This implies that the latter underestimates the GHG emissions because CO2 emission was not taken into account upon estimating the GHG emission from sewage sludge. Therefore, it has been determined that, from now on, emissions due to CO2 should be reflected in the estimation of GHG emission from sewage sludge.
... F 14 C of non-fossil sources (F 14 C nf ). F 14 C nf is estimated as 1.09 ± 0.05 for OC and 1.10 ± 0.05 for EC (see details in Ni et al., 2019b) using a tree growth model and the contemporary atmospheric 14 CO 2 over the past years (Lewis et al., 2004;Mohn et al., 2008;Levin et al., 2010) with the assumption that biomass-burning OC and biogenic OC contribute to 85 % and 15 % of total OC, respectively. Once f nf (OC) and f bb (EC) are known, carbon concentrations can be apportioned into EC and OC from non-fossil sources (EC bb , OC nf ) and fossil sources (EC fossil , OC fossil ) (Eqs. ...
Article
Full-text available
To mitigate haze pollution in China, a better understanding of the sources of carbonaceous aerosols is required due to the complexity in multiple emissions and atmospheric processes. Here we combined the analysis of radiocarbon and the stable isotope 13C to investigate the sources and formation of carbonaceous aerosols collected in two Chinese megacities (Beijing and Xi'an) during severe haze events of a “red alarm” level from December 2016 to January 2017. The haze periods with daily PM2.5 concentrations as high as ∼ 400 µg m−3 were compared to subsequent clean periods (i.e., PM2.5 less than median concentrations during the winter 2016/2017) with PM2.5 concentrations below 100 µg m−3 in Xi'an and below 20 µg m−3 in Beijing. In Xi'an, liquid fossil fuel combustion was the dominant source of elemental carbon (EC; 44 %–57 %), followed by biomass burning (25 %–29 %) and coal combustion (17 %–29 %). In Beijing, coal combustion contributed 45 %–61 % of EC, and biomass burning (17 %–24 %) and liquid fossil fuel combustion (22 %–33 %) contributed less. Non-fossil sources contributed 51 %–56 % of organic carbon (OC) in Xi'an, and fossil sources contributed 63 %–69 % of OC in Beijing. Secondary OC (SOC) was largely contributed by non-fossil sources in Xi'an (56±6 %) and by fossil sources in Beijing (75±10 %), especially during haze periods. The fossil vs. non-fossil contributions to OC and EC did not change drastically during haze events in both Xi'an and Beijing. However, compared to clean periods, the contribution of coal combustion to EC during haze periods increased in Xi'an and decreased in Beijing. During clean periods, primary OC from biomass burning and fossil sources constituted ∼ 70 % of OC in Xi'an and ∼ 53 % of OC in Beijing. From clean to haze periods, the contribution of SOC to total OC increased in Xi'an but decreased in Beijing, suggesting that the contribution of secondary organic aerosol formation to increased OC during haze periods was more efficient in Xi'an than in Beijing. In Beijing, the high SOC fraction in total OC during clean periods was mainly due to an elevated contribution from non-fossil SOC. In Xi'an, a slight day–night difference was observed during the clean period with enhanced fossil contributions to OC and EC during the day. This day–night difference was negligible during severe haze periods, likely due to the enhanced accumulation of pollutants under stagnant weather conditions.
... Moreover, determining the radiocarbon content is an ideal solution for verification of biofraction in combusted materials that are mixed from multiple sources. 26,27 Recently, the use of laser absorption spectroscopy was reported in quantifying biofraction in biofuels, where the method proved to be suitable for such applications. 28 On-line radiocarbon monitoring at atmospheric concentrations with high temporal and spatial resolution can give invaluable information on the origin of atmospheric carbon dioxide. ...
Article
Full-text available
There are currently no suitable methods for sensitive automated in situ monitoring of gaseous radiocarbon, one of the main sources of radioactive gas emissions from nuclear power plants. Here, we present a transportable instrument for in situ airborne radiocarbon detection based on mid-infrared cavity ring-down spectroscopy and report its performance in a 1-week field measurement at the Loviisa nuclear power plant. Radiocarbon is detected by measuring an absorption line of the ¹⁴CO2 molecule. The time resolution of the measurements is 45 min, significantly less than the few days’ resolution of the currently used technique, while maintaining a comparable sensitivity. The method can also assess the prevalence of radiocarbon in different molecular species in the airborne emissions. The optical in situ monitoring presented is a completely new method for monitoring emissions from nuclear facilities.
... Eine weitere Möglichkeit der Validierung ist der Vergleich mit einer anderen, unabhängigen Messmethode. Dies erfolgte mit der sogenannten Radiokarbonmethode ( 14 C-Methode) an drei Schweizer MVA (Mohn et al. 2008; Abbildung 2, oben). Die Radiokarbonmethode ist bekannt aus der Altersbestimmung in der Archäologie. ...
... The C4 source was excluded in the equations for 3-source apportionment. The emissions from fossil sources are 14 C-free, whereas non-fossil emissions contain the contemporary 14 C content (F 14 C fossil = 0, F 14 C non-fossil = 1.10 ± 0.05) (Lewis et al., 2004;Mohn et al., 2008;Palstra and Meijer, 2014;Ni et al., 2019b). The 13 C source signatures of EC are determined by this study and can be different for different geophysical areas. ...
Article
Carbon isotope signatures are used to gain insight into sources and atmospheric processing of carbonaceous aerosols. Since elemental carbon (EC) is chemically stable, it is possible to apportion the main sources of EC (C3/C4 plant burning, coal combustion, and traffic emissions) using a dual ¹⁴C-¹³C isotope approach. The dual-isotope source apportionment crucially relies on accurate knowledge of ¹³C source signatures, which are seldom measured for EC. In this work, we present ¹³C signatures of organic carbon (OC) and EC for relevant sources in China. EC was isolated for ¹³C analysis based on the OC/EC split point of a thermal-optical method (EUSAAR_2 protocol). A series of sensitivity studies were conducted to investigate the EC separation and the relationship of the thermal-optical method to other EC isolation methods. Our results show that, first, the ¹³C signatures of raw materials and EC related to traffic emissions can be separated into three groups according to geographical location. Second, the ¹³C signature of OC emitted by the flaming combustion of C4 plants is strongly depleted in ¹³C compared to the source materials, and therefore EC is a better tracer for this source than total carbon (TC). A comprehensive literature review of ¹³C source signatures (of raw materials, of TC, and of EC isolated using a variety of thermal methods) was conducted. Accordingly, we recommend composite ¹³C source signatures of EC with uncertainties and detailed application conditions. Using these source signatures of EC in an example dual-isotope source apportionment study shows an improvement in precision. In addition, ¹³C signatures of OC were measured at three different desorption temperatures roughly corresponding to semi-volatile, low-volatile, and non-volatile OC fractions. Each source category shows a characteristic trend of ¹³C signatures with desorption temperature, which is likely related to different OC formation processes during combustion.
... ± 1.4‰) comes from Ni et al. (2018) and references therein. The emissions from fossil sources are 14 C-free, whereas non-fossil emissions contain the contemporary 14 C content (F 14 C fossil = 0, F 14 C non-fossil = 1.10 ± 0.05; Lewis et al., 2004;Mohn et al., 2008;Palstra and Meijer, 2014;Ni et al., 2019). ...
Article
We describe and thoroughly evaluate a method for ¹³C analysis in different fractions of carbonaceous aerosols, especially elemental carbon (EC). This method combines a Sunset thermal-optical analyzer and an isotope ratio mass spectrometer (IRMS) via a custom-built automated separation, purification, and injection system. Organic carbon (OC), EC, and other specific fractions from aerosol filter samples can be separated and analyzed automatically for ¹³C based on thermal-optical protocols (EUSAAR_2 in this study) at sub-μgC levels. The main challenges in isolating EC for ¹³C analysis are the possible artifacts during OC/EC separation, including the premature loss of EC and the formation of pyrolyzed OC (pOC) that is difficult to separate from EC. Since those artifacts can be accompanied with isotope fractionation, their influence on the stable isotopic composition of EC was comprehensively investigated with various test compounds. The results show that the thermal-optical method is relatively successful in OC/EC separation for ¹³C analysis. The method was further tested on real aerosols samples. For biomass-burning source samples, (partial) inclusion of pOC into EC has negligible influence on the ¹³C signature of EC. However, for ambient samples, the influence of pOC on the ¹³C signature of EC can be significant, if it is not well separated from EC, which is true for many current methods for measuring ¹³C on EC. A case study in Xi'an, China, where pOC is enriched in ¹³C compared to EC, shows that this can lead to an overestimate of coal and an underestimate of traffic emissions in isotope-based source apportionment.
... The performance of the 45 keV myCADAS makes it useful in a set of applications where low background levels are not the primary objective, e.g. quantification of fossil fuel emission [67,68]. The myCADAS is equipped with an ETH hybrid ion source [69,70] that allows a measurement of directly injected CO 2 gas from various sources when equipped with the corresponding feeding system [71]. ...
Thesis
Full-text available
... For both WIOC and WSOC, carbon from biomass burning and oceanic organic matter can potentially introduce a reservoir effect (sources of aged carbon). The mixed age of trees in Swiss forests today is estimated to be slightly less than 40 years (Mohn et al., 2008). Back in time, prior to extensive human forest management, the mixed age of trees in Europe was likely older, and the mean age of old-growth-forest wood ranged from around 70 to 300 years depending on the region, i.e. the tree species present (Gavin, 2001;Zhang et al., 2017). ...
Article
Full-text available
High-alpine glaciers are valuable archives of past climatic and environmental conditions. The interpretation of the preserved signal requires a precise chronology. Radiocarbon (14C) dating of the water-insoluble organic carbon (WIOC) fraction has become an important dating tool to constrain the age of ice cores from mid-latitude and low-latitude glaciers. However, in some cases this method is restricted by the low WIOC concentration in the ice. In this work, we report first 14C dating results using the dissolved organic carbon (DOC) fraction, which is present at concentrations of at least a factor of 2 higher than the WIOC fraction. We evaluated this new approach by comparison to the established WIO14C dating based on parallel ice core sample sections from four different Eurasian glaciers covering an age range of several hundred to around 20 000 years; 14C dating of the two fractions yielded comparable ages, with WIO14C revealing a slight, barely significant, systematic offset towards older ages comparable in magnitude with the analytical uncertainty. We attribute this offset to two effects of about equal size but opposite in direction: (i) in-situ-produced 14C contributing to the DOC resulting in a bias towards younger ages and (ii) incompletely removed carbonates from particulate mineral dust (14C-depleted) contributing to the WIOC fraction with a bias towards older ages. The estimated amount of in-situ-produced 14C in the DOC fraction is smaller than the analytical uncertainty for most samples. Nevertheless, under extreme conditions, such as very high altitude and/or low snow accumulation rates, DO14C dating results need to be interpreted cautiously. While during DOC extraction the removal of inorganic carbon is monitored for completeness, the removal for WIOC samples was so far only assumed to be quantitative, at least for ice samples containing average levels of mineral dust. Here we estimated an average removal efficiency of 98±2 %, resulting in a small offset of the order of the current analytical uncertainty. Future optimization of the removal procedure has the potential to improve the accuracy and precision of WIO14C dating. With this study we demonstrate that using the DOC fraction for 14C dating not only is a valuable alternative to the use of WIOC but also benefits from a reduced required ice mass of typically ∼250 g to achieve comparable precision of around ±200 years. This approach thus has the potential of pushing radiocarbon dating of ice forward even to remote regions where the carbon content in the ice is particularly low.
... The distinct 14 C age between modern biomass and fossil fuel is a powerful method for identifying whether the BC is derived from biomass burning or fossil fuel combustion . However, the relatively high error and demanding conditions of energy and instrument make it hard to be widely used ( Mohn et al., 2008 ). The stable isotopic compositions of riverine PBC and DBC were generally distributed in the range of products derived from C 3 plants and fossil fuel combustion ( Drake et al., 2020 ;Qi et al., 2020 ;Wang et al., 2016 ), because the isotopic compositions of these sources are similar, which prevented the accurate source apportionment of riverine BC simply based on isotopic mass balance. ...
Article
Rivers transport abundant terrestrial carbon into the ocean, constituting a fundamental channel between terrestrial carbon pools and oceanic carbon pools. The black carbon (BC) derived from biomass and fossil fuel combustion is an important component of the riverine organic carbon flux. A recent study estimated that approximately 17 ~37 Tg C of BC was delivered in suspended particle phase by rivers per year. The particulate black carbon (PBC) in river systems has rarely been investigated and its controlling factors have remained largely unknown. The stable isotopic compositions of PBC in Xijiang River during the wet season are reported in this study. We found that the PBC/particulate organic carbon (POC) ratio in Xijiang River was slightly higher than that of other rivers, which may be a result of the mobility difference between POC and PBC, aerosol BC input and riverine biogenic effect. We found that the isotopic compositions of PBC depleted 13 C compared with those of POC and dissolved organic carbon (DOC). This divergence may be derived from the fractionation during soil organic matter production and biomass burning or fossil fuel combustion BC particles input with different isotopic compositions. The MixSIAR model indicated that most of the PBC in the study area was derived from fossil fuel combustion (~80%), the contribution of C4 plants burning was limited. Our result highlights that in the watershed without wildfire impact, the aeolian transport and deposition of the particles from fuel oil, coal combustion, and vehicle exhaust could significantly affect the BC flux in rivers.
... The official test methods include 14 C methods, Selective Dissolution Methods, and Balance Methods. In addition, many related studies use other relevant methodologies to analyze biomass contents [1,14,15,17,20]. ...
Preprint
Full-text available
According to the IPCC guidelines, CO2 emissions from biomass should be excluded from the entire amount of CO2 emissions when calculating CO2 emissions and should be separately reported due to the “carbon neutrality.” Sewage sludge is one of the representative biomass fuels. And it is mixed with fossil fuels in terms of greenhouse gas reduction or is used as fuel to replace fossil fuels by itself. According to the results of this study, biomass contents of both the sewage sludge and the sewage sludge incineration exhaust gases did not amount to 100%. At present, in many countries(South Korea, Japan, and Germany), when calculating greenhouse gas emissions from sewage sludge incinerator, all CO2 emissions from sewage sludge are judged to be biomass and only those greenhouse gas emissions that correspond to Non-CO2 gases are calculated as greenhouse gas emissions. However, since, according our results, the content of sewage sludge is not 100% biomass, if CO2 emissions are excluded according to the existing greenhouse gas emission calculation method, the amount of emissions may be underestimated. Therefore, to accurately calculate greenhouse gas emissions from sewage sludge incinerator, CO2 emissions should be calculated in consideration of the fossil carbon contents of sewage sludge.
... Analogously, the fraction of nonfossil OC, mvOC and mrOC (i.e., f nf (OC), f nf (mvOC) andf nf (mrOC), respectively) were estimated from their corresponding F 14 C values and F 14 C of nonfossil sources (F 14 C nf ). F 14 C bb and F 14 C nf are estimated as 1.10 ± 0.05 and 1.09 ± 0.05 (Lewis et al., 2004;Mohn et al., 2008;Palstra and Meijer, 2014), respectively, based on tree-growth models and the assumption that wood burning dominates biomass burning. F 14 C bb for EC is slightly bigger than F 14 C nf for OC because, besides biomass burning, biogenic emissions also contribute to OC but have a smaller F 14 C than that of biomass burning. ...
Article
Full-text available
Sources of particulate organic carbon (OC) with different volatility have rarely been investigated, despite the significant importance for better understanding of the atmospheric processes of organic aerosols. In this study we develop a radiocarbon-based (¹⁴C) approach for source apportionment of more volatile OC (mvOC) and apply to ambient aerosol samples collected in winter in six Chinese megacities. mvOC is isolated by desorbing organic carbon from the filter samples in helium (He) at 200 ∘C in a custom-made aerosol combustion system for ¹⁴C analysis. Evaluation of this new isolation method shows that the isolated mvOC amount agrees very well with the OC1 fraction (also desorbed at 200 ∘C in He) measured by a thermal–optical analyzer using the EUSAAR_2 protocol. The mvOC, OC and elemental carbon (EC) of 13 combined PM2.5 samples in six Chinese cities are analyzed for ¹⁴C to investigate their sources and formation mechanisms. The relative contribution of fossil sources to mvOC is 59±11 %, consistently larger than the contribution to OC (48±16 %) and smaller than that to EC (73±9 %), despite large differences in fossil contributions in different cities. The average difference in the fossil fractions between mvOC and OC is 13 % (range of 7 %–25 %), similar to that between mvOC and EC (13 %, with a range 4 %–25 %). Secondary OC (SOC) concentrations and sources are modeled based on the ¹⁴C-apportioned OC and EC and compared with concentrations and sources of mvOC. SOC concentrations (15.4±9.0 µg m⁻³) are consistently higher than those of mvOC (3.3±2.2 µg m⁻³), indicating that only a fraction of SOC is accounted for by the more volatile carbon fraction desorbed at 200 ∘C. The fossil fraction in SOC is 43 % (10 %–70 %), lower than that in mvOC (59 %, with a range of 45 %–78 %). Correlation between mvOC and SOC from nonfossil sources (mvOCnf vs. SOCnf) and from fossil sources (mvOCfossil vs. SOCfossil) is examined to further explore sources and formation processes of mvOC and SOC.
... Whereby TOx is the calculated water-and-ash-free (total organic) value of a respective element ( 1)). Once those values are determined, the two unknowns x B and x P are calculated by means of non-linear data reconciliation (Mohn et al., 2008). TOx input values of the pure biogenic and plastic fraction are found in Table S2. ...
Article
Plastics are crucial for our modern lifestyle and yet pose a major threat to our environment. Rising levels of microplastics (MP) in rivers and oceans are a big challenge for our economy and regulatory institutions as well as from a scientific point of view. Smaller microplastic particles, in particular, are especially hard to identify and even harder to quantify in environmental samples. Hence, we present a novel and inexpensive approach to quantify microplastics (MP) on a weight basis, relying on a thermoanalytical method. The Elemental Analysis combined with Overdetermined Equation Method (EA-OEM) was originally developed for determining the plastic content of refuse-derived fuels. It makes use of the distinct differences in the organic elemental composition (C, H, N, S, O) of plastics, biogenic and inorganic materials to calculate the (micro)plastic content on a detailed weight base. The study presented provides the first experimental results yielded from the application of the EA-OEM and two different laboratory approaches to the analysis of polyethylene (PE) and polypropylene (PP) MP content in industrial effluent samples from one source. In this way, it was possible to ensure that the polymer composition was known and the MP content therein (10-29%) could be derived. Further, the study reveals good MP recovery rates when applying the methodology to PE/PP-spiked samples.
Article
This study investigates the sources and atmospheric processes of size-resolved carbonaceous aerosols in winter 2018 in urban Beijing, based on analysis of dual-carbon isotopes (i.e., radiocarbon and the stable isotope 13C). We found a size dependence of fossil source contributions to elemental carbon (EC), but no clear size dependence for organic carbon (OC). Comparable fossil source contributions to water-insoluble OC (WIOC; 55 ± 3%) and to water-soluble OC (WSOC; 54 ± 4%) highlight the importance of secondary aerosol formation, considering that fossil sources emit only small amounts of primary WSOC. OC concentrations increased during high PM2.5 pollution events, with increased fossil and non-fossil WSOC concentrating at larger particles (0.44-2.5 µm) than WIOC (0.25-2.5 µm), highlighting the aqueous-phase chemistry as an important pathway for OC production. The ratio of 13C/12C (expressed as δ13C) of total carbon (-27.0‰ to -23.3‰) fell in the range of anthropogenic aerosol, reflecting small biogenic influence. δ13C of OC increased with desorption temperature steps (200 °C, 350 °C and 650 °C). The strongly enriched δ13COC,650 (-26.9‰ to -20.3‰) and large mass fraction of OC650°C in total desorbed OC, both increasing with the increase of particle sizes, were caused by photochemical aging, especially during low and moderate PM2.5 pollution events, when regional, aged aerosol played an important role. During low pollution events, higher δ13COC,650 and WSOC/OC ratios reflect a larger contribution and more extensive chemical processing of aged aerosol. In contrast, relatively low δ13COC,200 (-27.2‰ to -25.7‰) suggests the influence of secondary OC formation on the more volatile OC desorbed at 200 °C. δ13COC,200 was similar for all particle sizes and for different pollution events, pointing to an internal mixture of local and aged regional OC. Our results show that the organic aerosol in Beijing arises from a mixture of various sources and complex formation processes, spanning local to regional scales. Particle sizes < 250 nm show strong contribution from local secondary OC formation, whereas refractory OC in particles around 1 µm shows strong evidence for regional aging processes. In summary, primary emission, secondary and aqueous-phase formation, and (photo-)chemical aging all need to be considered to understand organic aerosol in this region and their importance varies with particle size.
Article
Full-text available
Der Einsatz von alternativen Brennstoffen – wie aus Abfall hergestellte Ersatzbrennstoffe (EBS) – kann in industriellen thermischen Verwertungsanlagen (beispielsweise in Zementwerken) neben der Einsparung von Primärrohstoffen auch zu einer Reduzierung der klimarelevanten CO2-Emissionen führen. Um diese CO2-Einsparungen nachzuweisen, bedarf es einer Methode, die der Heterogenität der Abfallgemische gerecht wird und den fossilen Kohlenstoffanteil bzw. den fossilen CO2-Emissionsfaktor der EBS zuverlässig bestimmen lässt. Die Studie befasst sich mit der Erprobung einer alternativen Bestimmungsmethode, der sogenannten adaptierten Bilanzenmethode (aBM), die auf der Bestimmung der Elementarzusammensetzung des EBS beruht. Insgesamt wurden sechs verschiedene EBS auf ihre Klimarelevanz mittels aBM untersucht und mit Ergebnissen standardisierter Verfahren verglichen. Dabei zeigte sich eine sehr gute Übereinstimmung der aBM-Werte mit denen der Radiokarbonmethode (¹⁴C-Methode), die als Vergleichsmethode herangezogen werden kann. Die mittlere Abweichung von der ¹⁴C-Methode lag bei 0,6 ± 1,4 %absolut bezogen auf den mittleren fossilen Kohlenstoffanteil. Für die zwei weiteren standardisierten Methoden (Selektive Lösemethode und Manuelle Sortierung) zeigten sich beim Vergleich der Ergebnisse deutliche methodische Einschränkungen in Abhängigkeit von der Zusammensetzung der EBS. Die aBM ist damit neben der analytisch aufwendigen ¹⁴C-Methode das einzige Bestimmungsverfahren, das unabhängig vom EBS-Typ zuverlässige Werte zur Klimarelevanz generiert. Zudem weist die Praktikabilität (Zeit- und Kostenaufwand) der aBM, insbesondere bei Routineanwendungen, Vorteile gegenüber standardisierten Verfahren auf. Einzig bei erstmaliger Anwendung ist eine Ermittlung von EBS-spezifischen Eingangswerten zur Elementarzusammensetzung der enthaltenen biogenen und fossilen Materialien notwendig, welche mit erhöhtem Aufwand verbunden sein kann.
Article
Biomass burning (BB) significantly influences the chemical composition of organic aerosols (OAs) in the East Asian outflow. The source apportionment of BB-derived OA is an influential factor for understanding their regional emissions, which is crucial for reducing uncertainties in their projected climate and health effects. We analyzed here three different classes of atmospheric sugar compounds (anhydrosugars, primary sugars, and sugar alcohols) and two types of biogenic secondary organic aerosol (BSOA) tracers (isoprene- and monoterpene-derived SOA products) from a year-long study that collected total suspended particulate matter (TSP) from an island-based receptor site in Gosan, South Korea. We investigate the seasonal variations in the source emissions of BB-derived OA using mass concentrations of anhydrosugars and radiocarbon (14C-) isotopic composition of organic carbon (OC) and elemental carbon (EC) in ambient aerosols. Levoglucosan (Lev) is the most abundant anhydrosugar, followed by galactosan (Gal), and mannosan (Man). Strong correlations of Lev with Gal and Man, along with their ratios (Lev/Gal is 6.65±2.26; Lev/Man is 15.1±6.76) indicate the contribution from hardwood burning emissions. The seasonal trends revealed that the BB impact is more pronounced in winter and fall, as evidenced by the high concentrations of anhydrosugars. Likewise, significant correlations among three primary sugars (i.e., glucose, fructose, and sucrose) emphasized the contribution of airborne pollen. The primary sugars showed higher concentrations in spring/summer than winter/fall. The fungal spore tracer compounds (i.e., arabitol, mannitol, and erythritol) correlated well with trehalose (i.e., a proxy for soil organic carbon), suggesting the origin from airborne fungal spores and soil microbes in the East Asian outflow. These sugar alcohols peaked in summer, followed by spring/fall and winter. Monoterpene-derived SOA tracers were most abundant compared to isoprene SOA tracers. Both BSOA tracers were dominant in summer, followed by fall, spring, and winter. The source apportionment based on multiple linear regressions and diagnostic mass ratios together revealed that BB emissions mostly contributed from hardwood and crop residue burning. We also found significant positive linear relationships of 14C-based nonfossil- and fossil-derived organic carbon fractions with Lev C, along with the comparable regression slopes, suggesting the importance of BB and coal combustion sources in the East Asian outflow.
Article
Full-text available
In-situ monitoring of radiocarbon emissions are challenging due to the lack of a suitable method for sensitive on-line detection of this isotope. Here we report on a complete system for automatised continuous in-situ monitoring of radiocarbon gaseous emissions from nuclear facilities. By combining radiocarbon detection using mid-infrared cavity ring-down spectroscopy and an advanced sampling system, elevated amount of radiocarbon in an atmospheric-like gas matrix was detected. Radiocarbon was detected in the form of ¹⁴CO2 after extraction of the carbon dioxide from the air sample. The system is also able to discriminate between radiocarbon in organic or inorganic molecular form by converting ¹⁴CH4 into ¹⁴CO2. This work lays the groundwork for further use of this technology in nuclear facilities for on-line on-site monitoring of radioactive gaseous emissions, as well as future work on in-situ monitoring of atmospheric radiocarbon.
Article
In this study, the temporal variations of sources of black carbon (BC) concentrations were evaluated in the metropolitan area of Milan, Italy, during three distinct seasons over 2017–2018. We measured BC concentrations using Aethalometers at two sampling sites, one in the city center of Milan, and one in the less densely populated suburb of Bareggio, approximately 14 km to the west of Milan's urban center. PM samples were also collected for elemental carbon (EC) and ¹⁴ C analyses. The Aethalometer model was used to apportion BC concentrations to the fossil fuel combustion (BC ff ) and biomass burning (BC bb ) originated BC. Additionally, radiocarbon ¹⁴ C analysis was performed on the PM samples, allowing us to refine our estimates of the contributions of both BC ff and BC bb to total BC concentrations and assess the dependence of the mass absorption cross section (MAC) of BC on its source. Overall, our results indicated that the annually averaged BC concentrations were higher at the Bareggio site (2763 ± 1050 ng m ⁻³ ) than at the Milan site (1921 ± 876 ng m ⁻³ ). The Aethalometer model results demonstrated that in all of the sampling seasons, fossil-fuel-originated BC (BC ff ) concentrations were slightly higher in Milan (e.g., a summertime average of 1045 ± 150 ng/m ³ ) than in Bareggio (e.g., a summertime average of 940 ± 89 ng/m ³ ); however, black carbon (BC bb ) concentrations from biomass burning were considerably higher at Bareggio (e.g., a wintertime average of 3284 ± 713 ng/m ³ ) than in Milan (e.g., a wintertime average of 1154 ± 103 ng/m ³ ). Diurnal variation plots indicated that both in Milan and Bareggio, BC ff peaked during the morning and, to a lesser extent, afternoon traffic rush hours, while BC bb peaked during nighttime when residential wood burning for heating purposes is prominent. Our results also highlight the significant impact of residential wood burning on ambient BC concentrations in the Milan metropolitan area.
Article
Full-text available
Carbonaceous aerosols are related to adverse human health effects. Therefore, identification of their sources and analysis of their chemical composition is important. The offline AMS (aerosol mass spectrometer) technique offers quantitative separation of organic aerosol (OA) factors which can be related to major OA sources, either primary or secondary. While primary OA can be more clearly separated into sources, secondary (SOA) source apportionment is more challenging because different sources – anthropogenic or natural, fossil or non-fossil – can yield similar highly oxygenated mass spectra. Radiocarbon measurements provide unequivocal separation between fossil and non-fossil sources of carbon. Here we coupled these two offline methods and analysed the OA and organic carbon (OC) of different size fractions (particulate matter below 10 and 2.5 µm – PM10 and PM2.5, respectively) from the Alpine valley of Magadino (Switzerland) during the years 2013 and 2014 (219 samples). The combination of the techniques gave further insight into the characteristics of secondary OC (SOC) which was rather based on the type of SOC precursor and not on the volatility or the oxidation state of OC, as typically considered. Out of the primary sources separated in this study, biomass burning OC was the dominant one in winter, with average concentrations of 5.36 ± 2.64 µg m⁻³ for PM10 and 3.83 ± 1.81 µg m⁻³ for PM2.5, indicating that wood combustion particles were predominantly generated in the fine mode. The additional information from the size-segregated measurements revealed a primary sulfur-containing factor, mainly fossil, detected in the coarse size fraction and related to non-exhaust traffic emissions with a yearly average PM10 (PM2.5) concentration of 0.20 ± 0.24 µg m⁻³ (0.05 ± 0.04 µg m⁻³). A primary biological OC (PBOC) was also detected in the coarse mode peaking in spring and summer with a yearly average PM10 (PM2.5) concentration of 0.79 ± 0.31 µg m⁻³ (0.24 ± 0.20 µg m⁻³). The secondary OC was separated into two oxygenated, non-fossil OC factors which were identified based on their seasonal variability (i.e. summer and winter oxygenated organic carbon, OOC) and a third anthropogenic OOC factor which correlated with fossil OC mainly peaking in winter and spring, contributing on average 13 % ± 7 % (10 % ± 9 %) to the total OC in PM10 (PM2.5). The winter OOC was also connected to anthropogenic sources, contributing on average 13 % ± 13 % (6 % ± 6 %) to the total OC in PM10 (PM2.5). The summer OOC (SOOC), stemming from oxidation of biogenic emissions, was more pronounced in the fine mode, contributing on average 43 % ± 12 % (75 % ± 44 %) to the total OC in PM10 (PM2.5). In total the non-fossil OC significantly dominated the fossil OC throughout all seasons, by contributing on average 75 % ± 24 % to the total OC. The results also suggested that during the cold period the prevailing source was residential biomass burning while during the warm period primary biological sources and secondary organic aerosol from the oxidation of biogenic emissions became important. However, SOC was also formed by aged fossil fuel combustion emissions not only in summer but also during the rest of the year.
Article
Full-text available
This study aimed to measure the fossil carbon fraction in industrial waste incineration facilities to determine its characteristics and the optimal time cycle for measurement. The analysis of the fossil carbon fraction in the industrial waste incineration facilities in Korea showed that the fraction in industrial waste incineration facility A was in the range of 51.58–68.18%, while the fraction in industrial waste incineration facility B was in the range of 40.00–64.66%. In this study, it was shown that a non-parametric method of statistical analysis was most suitable for the data of fossil carbon fraction in the industrial waste incineration facilities. The Kruskal–Wallis test indicated the same distribution of the mean for the monthly, quarterly, semiannual, and annual data from both industrial waste incineration facilities, suggesting that the optimal cycle for measuring fossil carbon fraction in the industrial waste incineration facilities is the annual cycle, corresponding to the longest cycle for measurement. This study provided fundamental data of fossil carbon fraction in industrial waste incineration facilities that can be used as a reference for emission estimation. Additionally, the significance of the study includes suggesting a statistical method for determining the optimal cycle for the measurement of fossil carbon fraction and having determined the optimal cycle.
Article
In this study, we compared the results of biomass and biocarbon content analysis of Solid Refuse Fuels using ¹⁴C method and selective dissolution method. Solid Refuse fuel Samples for biomass and biocarbon contents analysis were each collected from the silos and stack of the respective three facilities. Samples collected for 1, 10, 20, and 30 days for each method were analyzed. The analysis data were grouped into sample period, type and method and the optimum method for the detection of the biomass and biocarbon content was estimated. The biomass and biocarbon content showed a partially normal distribution. However, it does not satisfy equal variance. Therefore, we applied the parametric statistics Welch's ANOVA test and the nonparametric statistics Kruskal-Wallis test to compare the means of each sample group. The results of the Kruskal-Wallis test showed that sapmles collected over 20 days at Facility A had the same mean value. Therefore, when analyzing biocarbon content using the ¹⁴C method, conducting analyses by collecting exhaust gases for more than 20 days reduces errors in the results.
Preprint
Full-text available
Biomass burning (BB) significantly influences the chemical composition of organic aerosols (OA) in the East Asian outflow. Source apportionment of BB-derived OA is an influential factor for understanding their regional emissions, which is crucial for reducing uncertainties in their projected climate and health-effects. We analyzed here three different classes of atmospheric sugar compounds (anhydrosugars, primary sugars, and sugar alcohols) and two types of biogenic secondary organic aerosol (BSOA) tracers (isoprene- and monoterpene derived SOA products) in a year-long collected total suspended particulate matter (TSP) from an island-based receptor site in South Korea, the Gosan. We investigate seasonal variations in the source-emissions of BB-derived OA using mass concentrations of anhydrosugars and radiocarbon (14C-) isotopic composition of organic carbon (OC) and elemental carbon (EC) in ambient aerosols. Levoglucosan (Lev) is the most abundant anhydrosugar, followed by galactosan (Gal) and/or mannosan (Man). Strong correlations of Lev with Gal and Man as well as their high mass ratios such as Lev/Gal (6.7 ± 2.2) and Lev/Man (15.0 ± 6.7), indicate the contribution from hardwood burning emissions. The seasonal trends revealed that the biomass-burning impact is more pronounced in winter and fall, as evidenced from the high concentrations of anhydrosugars. Likewise, significant correlations were observed among three primary sugars (i.e., glucose, fructose, and sucrose), emphasizing the contribution from airborne pollen. The primary sugars showed higher concentrations in spring/summer than winter/fall. The fungal spore tracer compounds (i.e., arabitol, mannitol, and erythritol) correlated well with trehalose (i.e., a proxy for soil organic carbon), suggesting the origin from airborne fungal spores and soil microbes in the East Asian outflow. These sugar alcohols peaked in summer, followed by spring/fall and winter. Monoterpene-derived SOA tracers were most abundant compared to isoprene-SOA tracers. Both BSOA tracers were dominant in summer, followed by fall, spring, and winter. The source apportionment based on multiple linear regressions, diagnostic mass ratios, and positive matrix factorization analysis altogether revealed that biomass burning (41.9 %) and biogenic SOA (21.1 %) mostly dictates the OA loading in the ambient aerosols from East Asian outflow. We also found significant positive linear relationships of 14C-based nonfossil- and fossil-derived organic carbon fractions with Lev-C along with the comparable regression slopes, suggesting the importance of BB and coal combustion sources in the East Asian outflow.
Article
The factor required for estimating greenhouse gas emission, i.e. the fossil carbon fraction, excludes the biomass fraction of incinerated waste and can be applied as a major factor in estimating greenhouse gas emissions. In Korea, the amount of greenhouse gases emitted from waste incineration facilities is calculated by using a solid waste incinerated amount default values (biomass fraction, content of dry matter, etc.) provided by the Intergovernmental Panel on Climate Chang (IPCC). However, this method cannot reflect the characteristics of Korea. This method is likely to overestimate or underestimate the amount of greenhouse gas emissions. This study aims to investigate the difference in emissions between the actual values of the biomass content based on the exhaust gas standard and the IPCC defaults applied in the calculation of the national emissions. The comparative result indicates that the amount of greenhouse gas emissions calculated using the solid waste composition method is 70.71 tons CO2/day and using the flue gas analysis is 56.92 tons CO2/day. This verifies that the former method overestimates the amount of greenhouse gas emissions compared with the latter method. The difference is caused by applying both factors in estimating greenhouse gas emissions and the basic values provided in the IPCC guideline. In addition, although the IPCC reported 10% of biomass content, it is 41.06% as a result of actual analysis, and hence, it is considered that there will be a difference depending on the biomass content. Thus, to increase the reliability of the calculated greenhouse gas emissions, these should be estimated by considering national characteristics.
Article
According to the latest waste-to-energy concept, the corporate operators of urban heating systems (UHS) in European Union (EU) should replace fossil fuels by incineration of mixed municipal solid waste (MMSW, following 2008/98/EC Waste Framework Directive that implements mandatory waste separation system for at least paper, plastic, glass, and metal packaging since 31 of December 2014). However, there are indications that MMSW incineration will be counterproductive to the existing Directive on reducing national emissions of certain atmospheric pollutants. Material flow analysis for comparing the environmental impacts of the incineration of lignite, natural gas, and waste in UHS was carried out on a commercial scale. Results showed that replacing lignite by MMSW can lead to an increase in emissions of nitrogen oxides and other negative environmental impacts. However, it is proposed that co-combustion MMSW with natural gas could be a better alternative.
Article
To verify the feasibility of using radiocarbon detection for the measurement of the biomass-coal blending ratio in co-firing heat and power plants, ¹⁴C activity detection technology that uses benzene synthesis as the sample preparation method and a liquid scintillation counter as the detection instrument was studied. A benzene synthesis system was built to enrich carbon in the combustion flue gas in the form of benzene. The benzene sample was mixed with scintillator (butyl-PBD) and ¹⁴C activity was measured using a liquid scintillation counter (Quantulus 1220). Three kinds of coal and six kinds of biomass were tested repeatedly. The measured ¹⁴C activity was 0.3365 DPM/gC in Zhundong lignite, 0.2701 DPM/gC in Shenmu bitumite, and 0.3060 DPM/gC in Changzhi anthracite. These values were much higher than the instrument background activity. For the co-fired experiment, we used groups with biomass ratios (based on the carbon) of 6.51%, 12.95%, and 20.75%. A modified empirical expression to determine the biomass, coal blending ratio based on the ¹⁴C activity measured in the co-firing flue gas, was proposed by analyzing and verifying measurement accuracy. From the ¹⁴C measurements of the co-fired samples, the corresponding estimated biomass ratios were (5.54±0.48)%, (12.31±0.67)%, and (19.49±0.90)%. The absolute measurement error was around 1% for a typical biomass-coal co-firing application.
Chapter
Waste disposal is a major problem in most of the countries. Thus, waste to energy conversion will fulfill the future energy demand as well as resolve the pollution issues. This work mainly involved in the extensive study on pyrolysis and gasification of biomass and hazardous e-waste into useful energy and its impact on the environment. Microwave-assisted pyrolysis (MAP) technique has attracted the research society because of its energy efficient process and more viable route for converting the waste into potential products. Similarly, this chapter provides the assessment of biomass and e-waste volarization route to produce syngas using different gasification strategies. In addition, this study focused on the pyrolysis and gasification parameters like temperature, equivalence ratio, and particle size, which influence the product yield and emission formation. In general, pyrolysis and gasification of biomass and e-waste produce the volatile products, and it leaves the solid residue like char and ash. As an implementation, this study explained the conversion of waste residue from pyrolysis and gasification into useful products like activated carbon, silicon carbide, and zeolite, which can be used as the catalyst in microwave process and some other applications. At the end, the study covers the utilization of pyrolysis fuel and syngas in compression ignition engines with advanced technologies like CRDI and dual fuel strategies. CRDI and dual fuel mode combustion are the appropriate methods to reduce the engine emissions and enhance the engine efficiency.
Article
The lack of reliable schemes for measuring biomass-coal blending ratios hinders the development of biomass-coal co-combustion. In this study, the accuracy and sensitivity of the ¹⁴C method were verified on a free-fall reactor with blending ratios of 0.99 ∼ 10.93%. Comparison between accelerator mass spectrometry (AMS)-graphitization and liquid scintillation counting (LSC)-benzene synthesis was performed in terms of accuracy, precision and costs. Based on these, a complete scheme for measuring the blending ratios in industrial power plants was established and applied in a power plant for verification. The results on the free-fall reactor perfectly agreed with actual ratios (less than 0.43%, 5.69% of absolute and relative errors); LSC with higher cost-effectiveness was capable of measuring the blending ratios accurately. Blending ratios less than 3% in the power plant were accurately measured with the established scheme (less than 0.22%, 10.68% of absolute and relative errors). Factors affecting the accuracy, especially the ¹⁴CO2 contamination, should be considered for improvement of the accuracy.
Article
Full-text available
A preliminary investigation of the biocarbon fraction in carbon dioxide emissions of power plants using both fossil- and biobased fuels is presented. Calculation of the biocarbon fraction is based on radiocarbon content measured in power plant flue gases. Samples were collected directly from the chimneys into plastic sampling bags. The 14 C content in CO 2 was measured by accelerator mass spectrometry (AMS). Flue gases from power plants that use natural gas, coal, wood chips, bark, plywood residue, sludge from the pulp factory, peat, and recovered fuel were measured. Among the selected plants, there was one that used only fossil fuel and one that used only biofuel; the other investigated plants burned mixtures of fuels. The results show that 14 C measurement provides the possibility to determine the ratio of bio and fossil fuel burned in power plants.
Article
Full-text available
Article
Full-text available
Radiocarbon Vol.49 Nr.2, 325 - 330 A preliminary investigation of the biocarbon fraction in carbon dioxide emissions of power plants using both fossil and biobased fuels is presented. Calculation of the biocarbon fraction is based on radiocarbon content measured in power plant flue gases. Samples were collected directly from the chimneys into plastic sampling bags. The 14C content in CO2 was measured by accelerator mass spectrometry (AMS). Flue gases from power plants that use natural gas, coal, wood chips, bark, plywood residue, sludge from the pulp factory, peat, and recovered fuel were measured. Among the selected plants, there was one that used only fossil fuel and one that used only biofuel; the other investigated plants burned mixtures of fuels. The results show that 14C measurement provides the possibility to determinate the ratio of bio and fossil fuel burned in power plants. A preliminary investigation of the biocarbon fraction in carbon dioxide emissions of power plants using both fossil and biobased fuels is presented. Calculation of the biocarbon fraction is based on radiocarbon content measured in power plant flue gases. Samples were collected directly from the chimneys into plastic sampling bags. The 14C content in CO2 was measured by accelerator mass spectrometry (AMS). Flue gases from power plants that use natural gas, coal, wood chips, bark, plywood residue, sludge from the pulp factory, peat, and recovered fuel were measured. Among the selected plants, there was one that used only fossil fuel and one that used only biofuel; the other investigated plants burned mixtures of fuels. The results show that 14C measurement provides the possibility to determinate the ratio of bio and fossil fuel burned in power plants.
Article
Full-text available
Long-term atmospheric 14CO2 observations are deployed to quantify fossil fuel derived CO2 concentrations at a regional polluted site, and at a continental mountain station in south-west Germany. Fossil fuel CO2 emission rates for the relevant catchment areas are obtained by applying the Radon-Tracer-Method. They are shown to compare well with statistical emissions inventories but reveal a larger seasonality than assumed earlier, thus contributing significantly to the observed CO2 seasonal cycle over Europe. Based on the present approach, emissions reductions on the order of 5-10% are detectable for catchment areas of several hundred kilometres radius, as anticipated within a five-years commitment period of the Kyoto Protocol. Still no significant change of fossil fuel CO2 emissions is observed at the two sites over the last 16 years.
Article
Full-text available
This paper identifies six broad groups of drivers for development in waste management. Public health led to the emergence of formalized waste collection systems in the nineteenth century, and remains a key driver in developing countries. Environmental protection came to the forefront in the 1970s, with an initial focus on eliminating uncontrolled disposal, followed by the systematic increasing of technical standards. Today, developing countries seem still to be struggling with these first steps; while climate change is also emerging as a key driver. The resource value of waste, which allows people to make a living from discarded materials, was an important driver historically, and remains so in developing countries today. A current trend in developed countries is closing the loop, moving from the concept of 'end-of-pipe' waste management towards a more holistic resource management. Two underpinning groups of drivers are institutional and responsibility issues, and public awareness. There is no, one single driver for development in waste management: the balance between these six groups of drivers has varied over time, and will vary between countries depending on local circumstances, and between stakeholders depending on their perspective. The next appropriate steps towards developing a sustainable, integrated waste management system will also vary in each local situation.
Article
Full-text available
In this article we study the generalization abilities of several classifiers of support vector machine (SVM) type using a certain class of kernels that we call universal. It is shown that the soft margin algorithms with universal kernels are consistent for a large class of classification problems including some kind of noisy tasks provided that the regularization parameter is chosen well. In particular we derive a simple su#cient condition for this parameter in the case of Gaussian RBF kernels. On the one hand our considerations are based on an investigation of an approximation property---the so-called universality---of the used kernels that ensures that all continuous functions can be approximated by certain kernel expressions. This approximation property also gives a new insight into the role of kernels in these and other algorithms. On the other hand the results are achieved by a precise study of the underlying optimization problems of the classifiers. Furthermore, we show consistency for the maximal margin classifier as well as for the soft margin SVM's in the presence of large margins. In this case it turns out that also constant regularization parameters ensure consistency for the soft margin SVM's. Finally we prove that even for simple, noise free classification problems SVM's with polynomial kernels can behave arbitrarily badly.
Article
A comprehensive tropospheric 14 CO 2 data set of quasi-continuous observations covering the time span from 1959 to 2003 is presented. Samples were collected at 3 European mountain sites at height levels of 1205 m (Schauinsland), 1800 m (Vermunt), and 3450 m asl (Jungfraujoch), and analyzed in the Heidelberg Radiocarbon Laboratory. The data set from Jungfraujoch (1986–2003) is considered to represent the free tropospheric background level at mid-latitudes of the Northern Hemisphere, as it compares well with recent (yet unpublished) measurements made at the marine baseline station Mace Head (west coast of Ireland). The Vermunt and Schauinsland records are significantly influenced by regional European fossil fuel CO 2 emissions. The respective Δ 14 CO 2 depletions, on an annual mean basis, are, however, only 5 less than at Jungfraujoch. Vermunt and Schauinsland both represent the mean continental European troposphere.
Article
A high-precision tree-ring record of the atmospheric C-14 levels between 1820 and 1954 is presented. Good agreement is obtained between measured and model calculated 19th and 20th century atmospheric delta C-14 levels when both fossil fuel CO2 release and predicted natural variations in C-14 production are taken into account. The best fit is obtained by using a box-diffusion model with an oceanic eddy diffusion coefficient of 3 sq cm/s, a CO2 atmosphere-ocean gas exchange rate of 21 moles/sq m yr and biospheric residence time of 60 years. For trees in the state of Washington the measured 1949-1951 atmospheric delta C-14 level was 20.0 + or - 1.2% below the 1855-1864 level. Model calculations indicate that in 1950 industrial CO2 emissions are responsible for at least 85% of the delta C-14 decline, whereas natural variability accounts for the remaining 15%.
Article
Radiocarbon (14C) measurements performed on PM-2.5 samples collected near Nashville, TN from June 21 to July 13, 1999, showed high levels of modern carbon, ranging from 56% to 80% of the total carbon in the samples. Radiocarbon measurements performed on dichloromethane extracts of a subset of the samples showed modern carbon levels that were on average only 9% smaller than those for total carbon. A new approach based on the Chapman–Richards model of tree growth was used to define the quantitative relationship between measurements of percent modern carbon' and inferred percent biogenic carbon'. The results of this study contribute to a growing body of evidence (including measurements of radiocarbon, organic carbon to elemental carbon ratios and organic tracer species, as well as results from chemical mass balance and air quality simulation modeling) in support of the importance of biogenic secondary organic aerosol in the Southeastern US during summer.
Article
The technical and operational details of the Zurich AMS system are discussed and an overview of new developments which have improved efficiency, sensitivity and accuracy of the measurements is given. The numerous applications associated with these measurements will not be covered.
Article
A comprehensive tropospheric 14CO2 data set of quasi-continuous observations covering the time span from 1959 to 2003 is presented. Samples were collected at three European mountain sites at height levels of 1205m (Schauinsland), 1800m (Vermunt) and 3450 m a.s.l. (Jungfraujoch), and analysed in the Heidelberg Radiocarbon Laboratory. The data set from Jungfraujoch (1986-2003) is considered to represent the free tropospheric background level at mid latitudes of the Northern Hemisphere as it compares well with recent (yet unpublished) measurements made at the marine baseline station Mace Head (west coast of Ireland). The Vermunt and Schauinsland records are significantly influenced by regional European fossil fuel CO2 emissions. The respective Delta14CO2 depletions, on an annual mean basis, are, however, only less than 5 permil compared to Jungfraujoch. The Vermunt and Schauinsland sites are considered to represent well the mean continental European troposphere.
Article
New directives of the European Union require operators of waste-to-energy (WTE) plants to report the amount of electricity that is produced from renewable sources in the waste feed. Until now, the standard method to determine the portion of renewable electricity is sorting the wastes into defined fractions of fossil organic and biogenic waste components and determining the lower heating value of these fractions. Out of it the amount of electricity production from renewables is calculated. This practice is labor and cost intensive. Therefore, it is usually carried out once a year which provides only a snapshot analysis of limited significance. This paper proposes a method to calculate the portion of electricity produced from renewable materials in waste continuously by solving a set of equations. All data required are either available from literature or from operating data routinely measured in WTE plants. The advantages are statistically derived uncertainty of the result, temporal resolution of the result down to daily mean values, low implementation efforts, and virtually no operational costs. An example of the implementation of the method to a 60 000 tons per year WTE plant is given.
A novel approach for independent budgeting of fossil fuel CO 2 over Europe by 14 C-(CO 2 ) observations Radiocarbon measurement of the biogenic contribution to summertime PM-2.5 ambient aerosol in
• I Levin
• B Kromer
• M Schmidt
• H Sartorius
Levin, I., Kromer, B., Schmidt, M., Sartorius, H., 2003. A novel approach for independent budgeting of fossil fuel CO 2 over Europe by 14 C-(CO 2 ) observations. Geophys. Res. Lett. 30 (23), 2194. Lewis, C.W., Klouda, G.A., Ellenson, W.D., 2004. Radiocarbon measurement of the biogenic contribution to summertime PM-2.5 ambient aerosol in Nashville, TN. Atmos. Environ. 38 (35), 6053– 6061.
Switzerland's greenhouse gas inventory Measurement of biocarbon in flue gases using 14 C
• K M Hämälä
• H Jungner
• O Antson
• J Räsä
• K Tormonen
• J Roine
FOEN, 2007. Switzerland's greenhouse gas inventory 1990–2005. Federal Office for the Environment FOEN, Berne, p. 58. Hämälä, K.M., Jungner, H., Antson, O., Räsä, J., Tormonen, K., Roine, J., 2007. Measurement of biocarbon in flue gases using 14 C. Radiocarbon 49 (2), 325–330.
Brennstofftechnische Charakterisierung von Haushaltsabfällen
• T Kost
Kost, T., 2001. Brennstofftechnische Charakterisierung von Haushaltsabfällen. Dresden Technical University, Dresden. Levin, I., 2007. Personal communications.
Vier Jahre routinemässiges Monitoring an der MVA Spittelau -Resultate und Erfahrungen aus der Praxis
• L S Morf
• E Reil
• E Ritter
Morf, L. S., Reil, E., Ritter, E., 2004. Vier Jahre routinemässiges Monitoring an der MVA Spittelau -Resultate und Erfahrungen aus der Praxis. In: DepoTech 2004, Abfall-und Deponietechnik, Altlasten, Abfallwirtschaft, Loeben, Austria, pp. 497-504.
Federal Office for the Environment FOEN
• Nr Schriftenreihe Umwelt
Schriftenreihe Umwelt Nr. 356. Federal Office for the Environment FOEN, Berne, p. 67.
Incineration and Open Burning of Waste
• Sabin Guendehou
• G H Koch
• L Pipatti
• M Eggleston
• H S Buendia
• L Miwa
• K Ngara
Sabin Guendehou, G.H., Koch, M., Hockstad, L., Pipatti, R., Yamada, M., 2006. Incineration and Open Burning of Waste. In: Eggleston, H.S., Buendia, L., Miwa, K., Ngara, T., Tanabe, K. (Eds.), 2006 IPCC Guidelines for National Greenhouse Gas Inventories. IGES, Hayama, Japan, p. 26 (Chapter 5).
Bauabfä Schweiz – Mengen, Perspektiven und Entsorgungswege. Federal Office for the Environment FOEN, Berne, p. 97. ASTM, 2006. D 6866-06a Standard Test Method for Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis
• M Arioli
• M Haag
Arioli, M., Haag, M., 2001. Bauabfä Schweiz – Mengen, Perspektiven und Entsorgungswege. Federal Office for the Environment FOEN, Berne, p. 97. ASTM, 2006. D 6866-06a Standard Test Method for Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis. American Society for Testing and Materials ASTM, pp. 725–738.
Verfahren zur Ermittlung der Anteile biogener und fossiler Energieträger sowie biogener und fossiler Kohlendioxidemissionen beim Betrieb von Abfallverbrennungsanlagen (article 9312)
• H Rechberger
• J Fellner
• O Cencic
Rechberger, H., Fellner, J., Cencic, O., 2007. Verfahren zur Ermittlung der Anteile biogener und fossiler Energieträger sowie biogener und fossiler Kohlendioxidemissionen beim Betrieb von Abfallverbrennungsanlagen (article 9312). In: Bilitewski, B., Schnurer, H., Zeschmar-Lahl, B. (Eds.), Mü llhandbuch, vol. 4, pp. 1-21.
Method for determining the relationship of renewable to non-renewable sources of energy. European Patent Office
• P J Kneissl
Kneissl, P.J., 2005. Method for determining the relationship of renewable to non-renewable sources of energy. European Patent Office, WO 2002/006730, p.
TS 15443 -Solid Recovered Fuels -Methods for Laboratory Sample Preparation
CEN, 2006c. TS 15443 -Solid Recovered Fuels -Methods for Laboratory Sample Preparation. European Committee for Standardization CEN, Brussels, p. 31.
D 6866-06a Standard Test Method for Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis
ASTM, 2006. D 6866-06a Standard Test Method for Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis. American Society for Testing and Materials ASTM, pp. 725-738.
• M Hü Gi
• P Gerber
Hü gi, M., Gerber, P., 2006. Abfallstatistik 2004. Federal Office for the Environment FOEN, Berne, p. 104.
DIN Fachbericht CEN TR 15591 Solid Recovered Fuels -Determination of the Biomass Content based on the 14 C Method
CEN, 2007. DIN Fachbericht CEN TR 15591 Solid Recovered Fuels -Determination of the Biomass Content based on the 14 C Method. European Committee for Standardization CEN, Brussels, p. 36.
Switzerland's greenhouse gas inventory
FOEN, 2007. Switzerland's greenhouse gas inventory 1990–2005. Federal Office for the Environment FOEN, Berne, p. 58.
Erhebung der Kehrichtzusammensetzung 2001/02; Schriftenreihe Umwelt Nr. 356. Federal Office for the Environment FOEN
• U Steiger
Steiger, U., 2003. Erhebung der Kehrichtzusammensetzung 2001/02; Schriftenreihe Umwelt Nr. 356. Federal Office for the Environment FOEN, Berne, p. 67.
Bauabfälle Schweiz -Mengen, Perspektiven und Entsorgungswege. Federal Office for the Environment FOEN
• M Arioli
• M Haag
Arioli, M., Haag, M., 2001. Bauabfälle Schweiz -Mengen, Perspektiven und Entsorgungswege. Federal Office for the Environment FOEN, Berne, p. 97.
Switzerland's greenhouse gas inventory 1990-2005. Federal Office for the Environment FOEN
• Foen
FOEN, 2007. Switzerland's greenhouse gas inventory 1990-2005. Federal Office for the Environment FOEN, Berne, p. 58.
Method for determining the relationship of renewable to non-renewable sources of energy
• P J Kneissl
Kneissl, P.J., 2005. Method for determining the relationship of renewable to non-renewable sources of energy. European Patent Office, WO 2002/006730, p. 9.
Erhebung der Kehrichtzusammensetzung
• U Steiger
Steiger, U., 2003. Erhebung der Kehrichtzusammensetzung 2001/02;