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Environmental competitiveness evaluation by life cycle assessment for solid fuels generated from Sida hermaphrodita biomass
Abstract
As part of a comprehensive evaluation of the use of Sida hermaphrodita (hereafter referred to as Sida) biomass as a solid biofuel, a life cycle assessment (LCA) according to ISO 14040/14044 was carried out by means of a suitable cradle-to-gate system design. The supply and use of chips, pellets and briquettes was studied by internal and external comparisons to show competitiveness and improvement options. The results show fewer differences within the Sida process chain designs but larger distinctions to compared alternative biofuels such as wood or Miscanthus pellets. A major finding is that Sida process chains cause lower environmental impacts in comparison with alternative biofuels. The study identified hot spots within the Sida process chains and starting points for further improvement. A sensitivity analysis of important parameters, such as specific yield or heating values was performed. Because there are no similar investigations on the environmental impact of Sida used as a biogenic solid fuel to date this manuscript presents first results. So far, the results indicate that Sida provides a more sustainable option for the use of biomass in combustion processes in relation to environmental impacts.
... It concluded that if waste-to-energy scenarios are included with the agribusiness sector, it could reduce environmental impacts and Global warming potential = 913 kg CO2 eq/t seed-corn through combustion Endpoint indicators: human health, ecosystem quality, resource depletion Global warming potential = 797 kg CO2 eq/t seed-corn through gasification Schonhoff et al. (2021) Global warming (including biogenic carbon), global warming (excluding biogenic carbon), acidification, freshwater eutrophication, terrestrial eutrophication, marine eutrophication, human toxicity (carcinogens), human toxicity (non-carcinogens), land use, particulate matter formation, water depletion, freshwater ecotoxicity, ionising radiation, photochemical zone formation, abiotic depletion potentials ...
... Generally recognised contentious issue to produce biofuels was land use which could occur due to natural land, agricultural and urban land transformation. This was highlighted by the fact that 7% of the studies used land use as a functional unit (Fig. 5); furthermore, about 15% of the reviewed studies analysed impacts on land use (Aberilla et al. 2019;Chung et al. 2019;Ubando et al. 2020;Aristizábal-Marulanda et al. 2021;Brassard et al. 2021;Schonhoff et al. 2021). It was also noted that the use of perennial energy crops is an interesting approach towards mitigation of greenhouse gas emissions; however, it could result in loss of biodiversity for the European Union and UK (EU-27 + UK) (Di Fulvio et al. 2019) (Table 11). ...
... Other studies focused on water depletion and concluded that while producing biofuels can mitigate greenhouse gas emissions, it is also necessary to compute water depletion during crop production and biomass processing (Aberilla et al. 2019;Quispe et al. 2019;Ubando et al. 2020;Aristizábal-Marulanda et al. 2021;Schonhoff et al. 2021). In fact, Zhu et al. (2019) concluded that water depletion for biofuel production from cotton straws was lower than biooil power generation, however, much greater than observed for other renewable sources of energy (such as geothermal, solar photovoltaic and wind power). ...
The global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.
... In recent decades, Virginia Mallow has been cultivated mainly as an energy crop. Recent studies on Virginia Mallow have shown that its biomass is useful as a solid fuel, with the advantage of good processability (harvesting, pelleting, briquetting), good combustion properties, high ash melting point, and a generally good comprehensive life cycle assessment [17][18][19]. The most promising application of Virginia Mallow appears to be in the production of biogas for energy purposes [13]. ...
The current increase in energy demand, along with the deepening climate crisis, has led to the need for alternative energy sources. One of these is the cultivation of energy crops. In turn, issues related to the deepening problem of soil salinization are an important aspect of environmental protection on a global scale. New species and innovative solutions are sought to support the effective cultivation of energy crops, including in saline areas. The purpose of the study was to evaluate the effect of the foliar application of an aqueous quercetin solution applied in different doses (1%, 3% and 5%) on the physiological properties of Virginia Mallow plants subjected to salt stress conditions. The experiment was carried out as a pot experiment. The results obtained were related to two types of plants treated as a control sample. In one case, they were grown with the addition of quercetin alone, without salt stress. The other group was grown without quercetin and without salt. Quercetin is a phenolic compound that plays an important physiological and biochemical role in plants. Salinity caused a significant decrease in physiological indices in Virginia Mallow leaves. Foliar application of an aqueous quercetin solution mitigated the negative impact of salt on plants, the most stimulating effect being demonstrated at a dose of 5.0%.
... Sida showed that Sida biomass is very suitable as a solid fuel, with the advantage of good processability (harvesting, pelleting, briquetting), good combustion properties, a high ash melting temperature, and an overall good comprehensive life cycle assessment [4,5]. In an earlier study, the use of Sida biomass for biogas production was also investigated, but the energy yield is clearly inferior to that of its use as a solid fuel, considering the dry biomass [6]. ...
The long-term performance of perennial energy crops and their elimination is important for long-term planning and use of agricultural land. In this study, the elimination of a six-year-old Sida hermaphrodita (hereafter referred to as Sida) stock for agricultural reclamation was investigated over three years. Crop rotation using maize, winter wheat, and sugar beet, a catch crop, as well as mechanical–chemical treatments were employed according to agricultural practices. After soil grubbing at the beginning of the experiment and prior to further treatments, on half of the former Sida planting area, visible Sida roots were manually removed in addition to determining their potential effect on total resprouting. Prior to each crop harvest, resprouted Sida plants were counted. At harvest, by the end of the first year, 476 versus 390 resprouted Sida plants were found in the investigated areas of 315 m² each, where preceding manual root removal either took place or not, respectively. This accounted for 76% and 62% of the initial Sida planted. In the second year, the overall number of resprouted Sida declined significantly, accounting for 15 and 11 plants (i.e., 2.4% and 1.8% of initially planted), and in the third year, only two and four residual plants (i.e., 0.3% and 0.6%) were found, representing an almost 100% Sida elimination rate. We conclude that additional root removal did not result in a significant difference in Sida regrowth compared to the mechanical–chemical treatments only. No impediments to harvesting and no loss of yield in any crops were observed due to resprouted Sida in the existing field crops. No Sida plants were found outside the initial field, indicating a low dispersion potential and invasiveness. The results show that successful recultivation of an established Sida stock is possible through common agricultural practices and that resprouting Sida plants did not negatively affect the subsequent crops.
... Biomass transport constitutes a significant portion of the final price of biomass intended for energy, and the transport itself requires fuel, the combustion of which increases greenhouse gas emissions. Schonhoff et al. [90], based on expert interviews, conducted a techno-economic analysis of biomass transport for major forest wood products in Switzerland (firewood and wood chips). Their research found that the transport of forest wood is more efficient than the transport of, for example, manure. ...
The article examines the potential utilization of forest biomass in bioenergy production in Europe, taking into account limiting and developmental factors. The methodology includes a strategic analysis and the use of PEST analysis to evaluate the market for wood biomass. In the context of the current geopolitical situation and the decarbonization goals of the EU, the authors recommend accelerating energy transformation and highlighting forest biomass as an alternative within renewable energy sources. A literature review indicates the need to revise EU assumptions to enable the use of wood for bioenergy production, taking into account the needs of the wood industry. The analysis of economic factors shows competitiveness of forest biomass against coal, yet challenges arise regarding resource availability and competition with other energy sources. Emphasis is placed on the necessity of sustainable forest resource management and technological innovation. In the context of an energy crisis, the article underscores the role of innovation and recycling in alleviating shortages in energy markets. Conclusions highlight the imperative to develop a sustainable energy strategy for forest resource management and engage EU countries in the development of new biofuel and renewable energy sources for energy security and environmental protection.
... Microalgae 1 MJ (Schonhoff et al., 2021) Germany Comparison of environmental impacts of three different processing routes for Sida biomass used as a solid fuel Sida biomass 100 GJ thermal energy China Comparison between the energetic, environmental, and economic performances of three household-based bioenergy. ...
Developing countries suffer from both lack of resources and appropriate solid waste management systems. Therefore, the introduction of alternative options for waste valorisation is imperative. The current research introduces an environmental Life Cycle Assessment (LCA) of waste-based briquettes produced with 80 % of non-recyclable cardboard waste from separate collections and 20 % sawdust from sawmills in Bolivia. The aim is to compare the environmental impacts generated within the briquette's life cycle with conventional fuels. Primary data from a development project implemented in La Paz in 2021 were collected for building the inventory. SimaPro9.0 was employed to conduct the analysis, with IMPACT2002+ as the impact assessment method. Re-sults' normalization, contribution evaluation, interval assessment, and sensitivity analysis were carried out, and the results were compared with conventional fossil fuels, namely: coal, methane, and LPG. Results suggest that briquettes' life cycle contributes to seven of fifteen impact indicators, with global warming, use of non-renewable energy, and respiratory inorganics, the most important. The global warming potential ranges from 23.9 to 26.7 gCO 2-eq. MJ − 1 , lower than about 485 % compared to coal and 185 % to methane. Considering the avoided impacts from wood and methane substitution, global warming potential can decrease to about 20.0 and 18.9 gCO 2-eq. MJ − 1 respectively. On balance, compared to other fuels for heating and cooking, waste-based briquettes always have better environmental performance transporting the briquettes to about 100-130 km from the production plant. These results suggest that waste-based briquettes can contribute to mitigating environmental impacts and carbon footprint at a global level.
... Also, environmental impacts evaluated the preparation of activated carbons from cocoa pods (Tiegam et al., 2021). Furthermore, in other research the potential environmental impacts of processing different types of biomass has been estimated, in electricity production (Puig-Samper Naranjo et al., 2021;Zhang et al., 2021), biogas (Boschiero et al., 2016;Ioannou-Ttofa et al., 2021) and biofuel (Abbas and Handler, 2018;Schonhoff et al., 2021). Many studies have assessed the environmental performance of producing biofuels by thermochemical conversion. ...
A life cycle assessment was performed to compare the sustainability of gasification and fast pyrolysis processes for producing bio-oil using agricultural wastes from biomass. The objective was to carry out the environmental analysis associated with the production of 1 MJ bio-oil using different agricultural wastes biomasses for both thermochemical processes to determine which process is more respectful with the environment. The life cycle assessment revealed that gasification was more detrimental to the environment for all agricultural biomasses under study. In addition, greenhouse gas emissions over a 100-year time horizon were calculated, thereby demonstrating that CO2 yield emissions were higher than those for CH4 and N2O in both thermochemical processes. Furthermore, to gain a comprehensive overview, both thermochemical processes were divided into different equipment blocks to evaluate their individual impacts. Almond shell, pistachio shell and olive stone were identified as the biomasses for which minor amount of feed was needed to produce 1 MJ bio-oil. This assessment determined that the gasification stage of the gasification process and the separation stage for fast pyrolysis, were the main contributors to all mid-point impact categories. Finally, fast pyrolysis was the most environmentally friendly option for producing 1 MJ bio-oil.
Bioenergy is one of the renewable energy sources with high expectations in terms of its potential for greenhouse gas (GHG) emissions mitigation, and thus has been included in most global warming limiting strategies and pathways. However, within this context, a state-of-the-art and comprehensive understanding of the environmental performance of currently available bioenergy technologies is still missing. Hence, we conduct this critical review on life cycle assessment (LCA) studies regarding a wide portfolio of bioenergy technologies to deal with this lack of knowledge. Our critical review of exhaustively searched literature identified commonly existing limitations and difficulties in the selected LCAs in terms of essential aspects of LCA, i.e., system boundaries, functional unit (FU), multifunctionality, and impact categories. Key findings of our review are as follows: inconsistency of system boundary definitions, incomparability of LCA results due to various FU definitions, incomprehensiveness of impact categories, as well as a lack of uncertainty and sensitivity analysis. Finally, in view of the above findings, we present a generic guideline for future studies with the purpose of overcoming the identified shortcomings.
There is an urgent need to switch from fossil to bio-based fuels in the transport sector, particularly in shipping and aviation. The growth of the world's population has resulted in a significant impact on passenger transport, with a noticeable increase in greenhouse gas emissions, depletion of fossil resources and associated risks in all three pillars of sustainability. In this context, new policies, standards and targets have been developed to reduce this environmental damage, which is mainly caused by the use of fossil fuels. Therefore, the alternative of using biofuels seems to be the most appropriate solution, to the extent that important targets have been set and specific directives have been developed for the integration of biofuels in the maritime and aviation sectors. However, to demonstrate that switching to biofuels is indeed beneficial, it is necessary to evaluate new biofuel scenarios from a life-cycle perspective, with particular emphasis on analyses that provide information beyond the present, such as prospective life-cycle assessments. To this end, the focus of this review is on the current trends in the production of biofuels for the marine and aviation sectors, taking into account the main targets set, the existing regulations and directives on the subject, and an analysis of the type of technologies used for their production. It also addresses biofuel Life Cycle Assessment (LCA) scenarios and future LCA approaches, and how these analyses should be carried out to be effective. Finally, key policies, standards and certifications are analyzed. The trends and bottlenecks discussed in this review concerning the actual and future development of the biofuels sector could be used by policy makers and stakeholders to identify efforts that favor the integration of biofuels into the value chain. Furthermore, it could be concluded that the evaluation of the guidelines foreseen in the development of competitive scenarios based on emerging technologies, as well as the adoption of policies and restrictions on the use of fuels, are key conditions to establish the roadmap for the widespread implementation of biofuels.
Perennial nectar‐producing wild plant species (WPS) cultivation for biogas production helps improve ecosystem services such as habitat functioning, erosion mitigation, groundwater protection, and carbon sequestration. These ecosystem services could be improved when WPS are harvested in late winter to produce pellets and briquettes as solid energy carriers for heat production. This study aims for gaining first insights into the use of WPS biomass as resource for pellet and briquette combustion with focus on two perennial WPS common tansy (Tanacetum vulgare L.) and mugwort (Artemisia vulgaris L.), and two biennial WPS yellow melilot (Melilotus officinalis L.) and wild teasel (Dipsacus fullonum L.). All WPS are found economically viable for pellet combustion. The main drivers are i) low cultivation costs, ii) subsidies, and iii) low pellet production costs due to low moisture contents. However, high ash contents in WPS biomass justify the need of i) blending with woody‐biomass or ii) supplementing with additives to attain international standards for household stoves. This approach appears technically feasible providing a research field with significant potential impacts. As 70% of the pellet market is demanded as household level, public concern about the legal framework of alternative plant biomass pellets must be overcome to develop this market.
Due to an increased awareness of climate change and limited fossil resources, the demand of alternative energy carriers such as biomass has risen significantly during the past years. This development is supported by the idea of a transition to a bio‐based economy reducing fossil‐based carbon dioxide emissions. Based on this trend, biomass for energy is expected to be used in the EU mainly for heating until the end of the decade. The perennial herbaceous mallow plant Sida hermaphrodita (L.) Rusby (“Sida”) has high potential as an alternative biomass plant for energy purposes. Different density cultivation scenarios of Sida accounting for 1, 2, or 4 plants m‐2 resulted in a total biomass yield of 21, 28, and 34 tons dry matter ha‐1, respectively, over a three‐year period at agricultural conditions, while the overall investment costs almost doubled from 2 to 4 plants m‐2. Subsequently, Sida biomass was used as SI) chips, SII) pellets, and SIII) briquettes for combustion studies at pilot plant scale. Pellets outcompeted chips and briquettes by showing low CO emission of 40 mg Nm‐3, good burnout and low slagging behavior, however with elevated NOx and SO2 levels. In contrast, combustion of chips and briquettes displayed high CO emissions of >1300 mg Nm‐3, while SO2 values were below 100 mg Nm‐3. Contents of HCl in the flue gas ranged between 32 and 52 mg Nm‐3 for all Sida fuels tested. High contents of alkaline earth metals such as CaO resulted in high ash melting points of up to 1450 °C. Life Cycle Assessment results showed the lowest ecological impact for Sida pellets taking all production parameters and environmental categories into consideration, showing further advantages of Sida over other alternative biomasses. Overall, the results indicate the improved applicability of pelletized Sida biomass as a renewable biogenic energy carrier for combustion.
In Poland, unutilised land occupies approximately two million hectares, and it could be partly dedicated to the production of perennial crops. This study aimed to determine the environmental impact of the production of giant miscanthus (Miscanthus x giganteus J.M. Greef & M. Deuter). The experiment was set up on a low-fertility site. The crop was cultivated on sandy soil, fertilised with digestate, and mineral fertilisers (in the dose of 85 and 170 kg ha−1 N), and was compared with giant miscanthus cultivated with no fertilisation (control). The cradle-to-farm gate system boundary was applied. Fertilisers were more detrimental to the environment than the control in all analysed categories. The weakest environmental links in the production of miscanthus in the non-fertilised treatment were fuel consumption and the application of pre-emergent herbicide. In fertilised treatments, fertilisers exerted the greatest environmental impact in all the stages of crop production. The production and use of fertilisers contributed to fossil depletion, human toxicity, and freshwater and terrestrial ecotoxicity. Digestate fertilisers did not lower the impact of biomass production. The current results indicate that the analysed fertiliser rates are not justified in the production of giant miscanthus on nutrient-deficient soils.
Purpose
Soil organic carbon (SOC) plays a key role in soil functioning and in greenhouse gas exchange with the atmosphere. Land use and land use changes can critically affect SOC. However, despite various methodological developments, there is still no scientific consensus on the best method to assess the holistic impact of land use and land use change within LCA. The SOCLE project aimed to review how SOC contribution to climate change is accounted for in LCA and to test the feasibility and sensitivity of best methodological options.
Methods
In total, five crop products (annual/perennial, temperate/tropical) and two livestock products were investigated through 22 scenarios of land use changes (LUC) and agricultural land management changes (LMC). Three methods were applied: IPCC Tier 1-2 (2006), Müller-Wenk and Brandaõ (2010) and Levasseur et al. (2012). We also carried out a sensitivity analysis on key variables, notably carbon stocks, reference states, and regeneration times.
Results and discussion
The accounting for LUC and LMC influenced greatly the results on the climate change impact. Compared to the impact of other GHG emissions, (i) LUC impacts ranged from − 23 to + 1702% with the IPCC method and from − 5 to + 336% with the Müller-Wenk and Brandaõ method, and (ii) LMC impacts from − 130 to + 54% and from − 31 to + 11%, respectively. The sensitivity analyses stressed the critical influence of all methodological and data choices on final results.
Conclusions
Based on the project results, we recommend accounting systematically for the impact of LULUC on climate change by applying, a minima, the comprehensive IPCC Tier 1 approach (2006), which provides default factors for SOC accounting. Where available, case-specific data should be used (e.g., Tier 2) for SOC stocks but also C:N ratio in order to model the degressive impact over 90% of the time period needed to reach equilibrium.
In recent years, black locust has been receiving special attention as a potential energy crop. Conversely, straw, which constitutes a waste product, is mainly used for energy purposes. The aim of this study was to perform the Life Cycle Assessment of straw pellet and black locust logs production. The environmental effects were investigated according to the Ecoindicator’99 and Global Warming Potential 100a methods. The single score for the functional unit of black locust logs equals 5.47 Pt, and for cereal straw pellets is between 23.37 and 30.49 Pt. The minor value of the indicator for wood results from higher density and net calorific value, which in this study was equal to 17.72 MJ/kg for black locust and 14.9 MJ/kg for cereal straw pellets. Moreover, greenhouse gas emission was calculated and equals 94.7 kgCO2eq for black locust logs and between 365.9 and 588.3 kgCO2eq for cereal straw pellets. Obtained results allow to compare the processes of biomass production. Black locust logs have a smaller potential of affecting the environment than pellets due to lower energy intensity of the production process, especially lower electricity consumption. Furthermore, logistic improvement may significantly decrease the environmental impact of discussed products.
Novelty or Significance: The presented study includes the comparison of two biomass products (cereal straw pellets and black locust logs) based on the Life Cycle Assessment of their production. The originality of the comparison is based both on the detailed inventory and the applied impact assessment method (Ecoindicator'99). The broadened scope of the study allowed for the assessment of both production of materials and pellets, which brings the novel contribution into the existing state of knowledge pertaining to the biomass life cycle described by points of Ecoindicator and greenhouse gas emission. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 163–170, 2019
Lignocellulosic ethanol represents a renewable alternative to petrol. Miscanthus, a perennial plant that grows on marginal land, is characterised by efficient use of resources and is considered a promising source of lignocellulosic biomass. A life cycle assessment (LCA) was performed to determine the environmental impacts of ethanol production from miscanthus grown on marginal land in Great Britain (Aberystwyth) and an average‐yield site in Germany (Stuttgart) (functional unit: 1 GJ). As the conversion process has substantial influence on the overall environmental performance, the comparison examined three pretreatment options for miscanthus. Overall, results indicate lower impacts for the production in Stuttgart in comparison to the corresponding pathways in Aberystwyth across the analysed categories. Disparities between the sites were mainly attributed to differences in biomass yield. When comparing the conversion options, liquid hot water treatment resulted in the lowest impacts, followed by dilute sulphuric acid. Dilute sodium hydroxide pretreatment represented the least favourable option. Site‐dependent variation in biomass composition and degradability did not have substantial influence on the environmental performance of the analysed pathways. Additionally, implications of replacing petrol with miscanthus ethanol were examined. Ethanol derived from miscanthus resulted in lower impacts with respect to greenhouse gas emissions, fossil resource depletion, natural land transformation, and ozone depletion. However, for other categories, including toxicity, eutrophication and agricultural land occupation, net scores were substantially higher than for the fossil reference. Nevertheless, the results indicate that miscanthus ethanol produced via dilute acid and liquid hot water treatment at the site in Stuttgart has the potential to comply with the requirements of the European Renewable energy directive for greenhouse gas emission reduction. For ethanol production at the marginal site, carbon sequestration needs to be considered in order to meet the requirements for greenhouse gas mitigation.
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Improving fertility of marginal soils for the sustainable production of biomass is a strategy for reducing land use conflicts between food and energy crops. Digestates can be used as fertilizer and for soil amelioration. In order to promote plant growth and reduce potential adverse effects on roots because of broadcast digestate fertilization, we propose to apply local digestate depots placed into the rhizosphere. We grew Sida hermaphrodita in large mesocosms outdoors for three growing seasons and in rhizotrons in the greenhouse for 3 months both filled with marginal substrate, including multiple sampling dates. We compared digestate broadcast application with digestate depot fertilization and a mineral fertilizer control. We show that depot fertilization promotes a deep reaching root system of S. hermaphrodita seedlings followed by the formation of a dense root cluster around the depot-fertilized zone, resulting in a fivefold increased biomass yield. Temporal adverse effects on root growth were linked to high initial concentrations of ammonium and nitrite in the rhizosphere in either fertilizer application, followed by a high biomass increase after its microbial conversion to nitrate. We conclude that digestate depot fertilization can contribute to an improved cultivation of perennial energy-crops on marginal soils.
The cultivation of perennial biomass plants on marginal soils can serve as a sustainable alternative to conventional biomass production via annual cultures on fertile soils. Sida hermaphrodita is a promising species to be cultivated in an extensive cropping system on marginal soils in combination with organic fertilization using biogas digestates. In order to enrich this cropping system with nitrogen (N) and to increase overall soil fertility of the production system, we tested the potential of intercropping with leguminous species. In a 3-year outdoor mesocosm study, we intercropped established S. hermaphrodita plants with the perennial legume species Trifolium pratense, T. repens, Melilotus albus, and Medicago sativa individually to study their effects on plant biomass yields, soil N, and above ground biomass N. As a control for intercropping, we used a commercial grass mixture without N2-fixing species as well as a no-intercropping treatment. Results indicate that intercropping in all intercropping treatments increased the total biomass yield, however, grass species competed with S. hermaphrodita for N more strongly than legumes. Legumes enriched the cropping system with fixed atmospheric nitrogen (N2) and legume facilitation effects varied between the legume species. T. pratense increased the biomass yield of S. hermaphrodita and increased the total biomass yield per mesocosm by 300%. Further, the total above ground biomass of S. hermaphrodita and T. pratense contained seven times more N compared to the mono-cropped S. hermaphrodita. T. repens also contributed highly to N facilitation. We conclude that intercropping of legumes, especially T. pratense and T. repens can stimulate the yield of S. hermaphrodita on marginal soils for sustainable plant biomass production.
Purpose
Life cycle assessment (LCA) has become one of the most widespread environmental assessment tools during the last two decades. However, there are still impacts that are not yet fully integrated, including climate impacts of land use. This study contributes to the development process by testing a selection of recently proposed climate impacts assessment methods, some more focused on the impact of land use and others more focused on a product’s carbon life cycle.
Methods
Several assessment methods have been proposed in recent years, with their development still being in progress. Of these methods, we selected three methods that are more focused on the product’s carbon life cycle, and two methods more focused on the impact of land use. We applied the methods to an LCA study comparing biomass-based polyethylene (PE) packaging via different production routes in order to identify their methodological and practical challenges.
Results and discussion
We found that including the impact of land use and carbon cycles had a profound effect on the results for global warming impact potential. It changed the ranking among the different routes for PE production, sometimes making biomass-based PE worse than the fossil alternative. Especially, the methods accounting for long time lags between carbon emissions and uptake in forestry punished the wood-based routes. Moreover, the variation in the results was considerable, showing that although assessment methods for climate impact can be applied to biomass-based products, their outcomes are not yet robust.
Conclusions
We recommend efforts to harmonize and reconcile different approaches for the assessment of climate impact of biomass-based products with regard to (1) how they consider time, (2) their applicability to both short and long rotation crops and (3) harmonization of concepts and terms used by the methods. We further recommend that all value laden methodological choices that are built into the methods, such as the choice of reference states/points, are made explicit and that the outcomes of different modelling choices are tested.
This article reviews the scholarly literature dealing with the perennial multipurpose crop Virginia mallow (Sida hermaphrodita (L.) Rusby; Sida in the following). In regions dominated by intensive agricultural management practices, growing Sida holds the potential to combine ecosystem services such as decreasing soil erosion, reducing nitrate leaching as well as enhancing biodiversity, with economic profit for the farmer. After promising biomass yields of Sida were reported from studies performed in Poland about 15 years ago, the interest in this plant species has continuously increased, and different utilization pathways were examined, predominantly by researchers in Poland and Germany. At present, however, a comprehensive overview that summarizes the different lines of research performed regarding the use of Sida is lacking. This review aims at closing this gap. After providing background information on Sida, we summarize the main results obtained from investigations concerning biomass yields, fertilization effects, key findings concerning direct combustion, biogas production, steam gasification, phytoremediation, and alternative utilization pathways. Thereafter, we highlight important aspects of Virginia mallow cultivation practices, including first estimates regarding the costs involved. Finally, we point to existing research gaps. Summarizing the available literature on Sida, we aim at raising the interest of scientists and farmers in this plant species further and to show where future research might tie in with, as the successful cultivation of Sida might represent a worthwhile strategy to transform current agricultural practices in Central Europe into approaches that are more sustainable and resilient against future challenges.
Perennial non-food energy crops are currently discussed as a more sustainable alternative to conventional energy
crops like maize. As they can be cultivated on marginal soils, they reduce the risk of land use and food vs. fuel
conflicts. In this study, we evaluated the perennial energy crop Sida hermaphrodita for its potential to be cultivated
on marginal substrate and conventional agricultural soils over a three-year field and mesocosm experiment
at agricultural conditions. Furthermore, we aimed for a closed nutrient loop by fertilizing plants with biogas
digestate and using the carbon fraction of the digestate as soil amendment to ameliorate the overall soil fertility.
As controls, plants were either untreated or fertilized with an equivalent amount of mineral NPK fertilizer. We
found S. hermaphrodita to give highest DM yields of up to 28 t ha−1 under favorable soil conditions when
fertilized with mineral NPK. However, on marginal substrate digestate fertilization resulted in a clear biomass
yield advantage over NPK fertilization. An increased soil carbon content, water holding capacity and basal soil
respiration indicated improved soil fertility in the marginal substrate. These results demonstrate the great potential
of S. hermaphrodita to be cultivated on marginal soil in combination with organic fertilization via biogas
digestate.
Growing energy crops in marginal, nutrient-deficient soils is a more sustainable alternative to conventional cultivation. The use of energy-intensive synthetic fertilizers needs to be reduced, preferably via closed nutrient loops in the biomass production cycle. In the present study based on the first growing season of a mesocosm experiment using large bins outdoors, we evaluated the potential of the energy plant Sida hermaphrodita to grow in a marginal sandy soil. We applied different fertilization treatments using either digestate from biogas production or a commercial mineral NPK-fertilizer. To further increase independence from synthetically produced N-fertilizers, the legume plant Medicago sativa was intercropped to introduce atmospherically fixed nitrogen and potentially facilitate the production of additional S. hermaphrodita biomass. We found digestate to be the best performing fertilizer because it produced similar yields as the NPK fertilization but minimized nitrate leaching. Legume intercropping increased the total biomass yield by more than 100% compared to S. hermaphrodita single cropping in the fertilized variants. However, it negatively influenced the performance of S. hermaphrodita in the following year. We conclude that a successful establishment of S. hermaphrodita for biomass production in marginal soils is possible and digestate application formed the best fertilization method when considering a range of aspects including overall yield, nitrate leaching, nitrogen fixation of M. sativa, and sustainability over time.
The performance and biomass yield of the perennial energy plant Sida hermaphrodita (hereafter referred to as Sida) as a feedstock for biogas and solid fuel was evaluated throughout one entire growing period at agricultural field conditions. A Sida plant development code was established to allow comparison of the plant growth stages and biomass composition. Four scenarios were evaluated to determine the use of Sida biomass with regard to plant development and harvest time: (i) one harvest for solid fuel only; (ii) one harvest for biogas production only; (iii) one harvest for biogas production, followed by a harvest of the re-grown biomass for solid fuel; and (iv) two consecutive harvests for biogas production. To determine Sida's value as a feedstock for combustion, we assessed the caloric value, the ash quality, and melting point with regard to DIN EN ISO norms. The results showed highest total dry biomass yields of max. 25 t ha−1, whereas the highest dry matter of 70% to 80% was obtained at the end of the growing period. Scenario (i) clearly indicated the highest energy recovery, accounting for 439,288 MJ ha−1; the energy recovery of the four scenarios from highest to lowest followed this order: (i) >> (iii) >> (iv) > (ii). Analysis of the Sida ashes showed a high melting point of >1500 °C, associated with a net calorific value of 16.5–17.2 MJ kg−1. All prerequisites for DIN EN ISO norms were achieved, indicating Sida's advantage as a solid energy carrier without any post-treatment after harvesting. Cell wall analysis of the stems showed a constant lignin content after sampling week 16 (July), whereas cellulose had already reached a plateau in sampling week 4 (April). The results highlight Sida as a promising woody, perennial plant, providing biomass for flexible and multi-purpose energy applications. This article is protected by copyright. All rights reserved.
Soil organic carbon (SOC) change can be a major impact of land use change (LUC) associated with biofuel feedstock production. By collecting and analyzing data from worldwide field observations of major LUCs from cropland, grassland and forest to lands producing biofuel crops (i.e., corn, switchgrass, Miscanthus, poplar and willow), we were able to estimate SOC response ratios and sequestration rates and evaluate the effects of soil depth and time scale on SOC change. Both the amount and rate of SOC change were highly dependent on the specific land transition. Irrespective of soil depth or time horizon, cropland conversions resulted in an overall SOC gain of 6-14% relative to initial SOC level, while conversion from grassland or forest to corn (without residue removal) or poplar caused significant carbon loss (9-35%). No significant SOC changes were observed in land converted from grasslands or forests to switchgrass, Miscanthus or willow. The SOC response ratios were similar in both 0-30 and 0-100 cm soil depths in most cases, suggesting SOC changes in deep soil and that use of top soil only for SOC accounting in biofuel life cycle analysis (LCA) might underestimate total SOC changes. Soil carbon sequestration rates varied greatly among studies and land transition types. Generally, the rates of SOC change tended to be the greatest during the 10 years following land conversion, and had declined to approach 0 within about 20 years for most LUCs. Observed trends in SOC change were generally consistent with previous reports. Soil depth and duration of study significantly influence SOC change rates and so should be considered in carbon emission accounting in biofuel LCA. High uncertainty remains for many perennial systems and forest transitions, additional field trials and modeling efforts are needed to draw conclusions about the site- and system-specific rates and direction of change.This article is protected by copyright. All rights reserved.
The wood energy conversion into power and heating processes concerning the chips and pellets production chain is analyzed. An exergy analysis and a life cycle assessment are performed, considering the wood chips for electricity generation in a central power plant and wood pellets for distributed generation. The consumption of diesel oil, electricity and biomass itself were carried out along both production chains. The results showed the best way to avoid exergy destruction and environmental impacts based on carbon dioxide emissions. Considering the same energy conversion plant efficiency, the exergetic performance and the environmental impact are very close when both the technological routes are compared. However, taking into account a distributed generation and the high efficiency characteristic of micro cogeneration plants (combined heat and power), the pellets technological route presents a better exergetic and environmental performance. Also, a sensitivity analysis along the production chain stages have demonstrated that large variations of about 50% on the specific fuel consumption represents a very small influence on the overall exergetic efficiency, in order of just 1.5%.
The use of biomass pellets as fuel is emerging as a suitable alternative to fossil resources for mitigating climate change. A considerable number of articles have applied Life Cycle Assessment (LCA) to quantify and to compare the environmental performance of biomass pellets but a wide variation of results can be found in the literature. This work reviews 84 articles on LCA of biomass pellets, focusing on identifying trends in methodological choices and on understanding the influence of those choices on life cycle impacts, in particular global warming and non-renewable primary energy. Most of the reviewed articles assess woody pellets and most of the cradle-to-grave studies focus on heat generation. The methodological choices vary widely between articles with respect to approach (attributional or consequential), functional unit, system boundaries, procedure to deal with multifunctionality and allocation, biogenic carbon modelling, inclusion of greenhouse gases other than carbon dioxide, life cycle impact assessment method, impact categories, and presence of sensitivity analysis. The results for global warming and non-renewable primary energy were assessed, showing a correlation between them. Moreover, a high variability is found for global warming, with impacts ranging from −18 to 488 g CO2 eq/ MJpellets. The main causes (technological features, assumptions, methodological choices) for this high variability are analysed and discussed.
The aim of this study was to quantify and compare the environmental impact of the heat of grape stalk pellets with that of wood pellets and other sources, using the Life Cycle Assessment methodology. The study was carried out using the ISO 14040/44 series standard. The inventory analysis and, subsequently, the impact analysis were performed using the software SimaPro8.4.0. The method chosen for this environmental impact assessment was CML-IA baseline. The results show that heat from grape stalk pellets is more environmentally friendly than heat from wood pellets for 7 out of 11 impact categories, including marine aquatic ecotoxicity, which is considered the most important impact category. A global reduction of 1.6 × 10⁴ or 1.14 × 10⁶ or 1.9 × 10⁶ tonne of CO2 eq emissions could be achieved if the global potential production of grape stalk pellets replaced wood pellets or light fuel oil or hard coal briquettes, respectively, contributing to the achievement of the EU’s objectives.
Full text online: https://www.tandfonline.com/doi/full/10.1080/00207233.2018.1446646
Lignocellulosic crops can be a significant source of feedstock for the chemical industry. They can be grown on poorer soils, but fertilisation should be applied to achieve a considerable yield. The aim of the study was to determine the environmental impact of the production of Virginia mallow (Sida hermaphrodita Rusby L.) biomass fertilised with digestate: wet (WD), dried (DD) and torrefied (TD), obtained from an agricultural biogas plant and fertilised with mineral fertilisers (MF) and non-fertilised (C). All the fertilisers were applied at a rate equivalent to 85 and 170 kg ha⁻¹ N. The system boundaries covered the production and use of digestate and mineral fertilisers, preparation of a field, growing Virginia mallow, harvest and transport of biomass from the field to the farm. The life cycle impact assessment of cultivation was done using the ReCiPe Midpoint method. The most beneficial effect on climate change was observed for utilisation of dried and torrefied digestate. The most adverse effect on human toxicity was observed when the TD was applied at both fertilisation rates. Higher particulate matter formation for all the growing options than for C resulted from production of fertilisers and use of machines. The lowest impact on terrestrial acidification was observed in the MF 85 option and the highest was in TD 170, which resulted mainly from high field emission. The use of digestates and mineral fertilisers resulted in an increased effect on freshwater eutrophication (30–56-fold). Torrefaction of digestate had the largest impact on terrestrial ecotoxicity. The greatest impact on fossil depletion was found for MF 170. The impact category with the highest normalized score was freshwater eutrophication. The production of Virginia mallow intended for bioproducts can fulfil the condition of low GHG emission. The application of fertilisation in all forms affected the environment more in the other impact categories than the base scenario. The application of WD 85, WD 170 and DD 85 could be recommended for Virginia mallow instead of mineral fertilisers, whereas DD 170 and TD at both rates had the most adverse environmental effect.
The idea of LCA was conceived in the 1960s when environmental degradation and in particular the limited access to resources started becoming a concern. This chapter gives a brief summary of the history of LCA since then with a focus on the fields of methodological development, application, international harmonisation and standardisation, and dissemination. LCA had its early roots in packaging studies and focused mainly on energy use and a few emissions, spurring a largely un-coordinated method development in the US and Northern Europe. Studies were primarily done for companies, who used them internally and made little communication to stakeholders. After a silent period in the 1970s, the 1980s and 1990s saw an increase in methodological development and international collaboration and coordination in the scientific community and method development increasingly took place in universities. With the consolidation of the methodological basis, application of LCA widened to encompass a rapidly increasing range of products and systems with studies commissioned or performed by both industry and governments, and results were increasingly communicated through academic papers and industry and government reports. To this day, methodological development has continued, and increasing attention has been given to international scientific consensus building on central parts of the LCA methodology, and standardisation of LCA and related approaches.
In the years 1996-1998 in the sewage treatment plant in Hajdów an experiment was set up in order to determine the optimal number of plants and the method of proliferation of Sida hermaphrodita R. on sewage sludge. The cultivation of Sida was carried out on especially prepared plots with an added 50 cm thick layer of sewage sludge. Two methods of plantation establishing (propagation) were used -generative and vegetative. Three plant densities were used per 1 ha: 3 kg of seeds or 33,000 seedlings; 6 kg of seeds or 50,000 seedlings; and 9 kg of seeds or 100,000 seedlings. A higher yield of stems and greater amounts of Fe extracted from the sludge were obtained from vegetative plant propagation. In the conditions of greater number of plants, considering stem yield, Sida took from the sludge more Co, Fe, and Ni. The three-year cultivation of Sida hermaphrodita caused positive changes in the structure of the sewage sludge.
Concerns over non-renewable fossil fuel supply and climate change have been driving the Renaissance of bio-based materials. To substantiate environmental claims, the impacts of bio-based materials are typically quantified by applying life cycle assessment (LCA). The internationally agreed LCA standards provide generic recommendations on how to evaluate the environmental impacts of products and services but do not address details that are specifically relevant for the life cycles of bio-based materials. Here, we provide an overview of key issues and methodologies explicitly pertinent to the LCA of bio-based materials. We argue that the treatment of biogenic carbon storage is critical for quantifying the greenhouse gas emissions of bio-based materials in comparison with petrochemical materials. We acknowledge that biogenic carbon storage remains controversial but recommend accounting for it, depending on product-specific life cycles and the likely time duration of carbon storage. If carbon storage is considered, co-product allocation is nontrivial and should be chosen with care in order to: (i) ensure that carbon storage is assigned to the main product and the co-product(s) in the intended manner and (ii) avoid double counting of stored carbon in the main product and once more in the co-product(s). Land-use change, soil degradation, water use, and impacts on soil carbon stocks and biodiversity are important aspects that have recently received
attention. We explain various approaches to account for these and conclude that substantial methodological progress is necessary, which is however hampered by the complex and often case- and site-specific nature of impacts. With the exception of soil degradation, we recommend preliminary approaches for including these impacts in the LCA of bio-based materials. The use of attributional versus consequential LCA approaches is particularly relevant in the context of bio-based materials. We conclude that it is more challenging to prepare accurate consequential LCA studies, especially because these should account for future developments and secondary impacts around bio-based materials which are often difficult to anticipate and quantify. Although hampered by complexity and limited data availability, the application of the proposed approaches to the extent possible would allow obtaining a more comprehensive insight
into the environmental impacts of the production, use, and disposal of bio-based materials.
At the Experimental Farm of University of Life Sciences in Lublin (central-eastern Poland), two single-factor trials were conducted with two dedicated bioenergy crops. Virginia fanpetals (Sida hermaphrodita L. Rusby) – perennials, and basket willow (Salix viminalis L).In the first set of experiments, the influence of seed dressing on the height of Virginia fanpetals’ yields, from the third to fifth year of research (2005–2007) was examined. Seed dressing of Virginia fanpetals led to significant increase in biomass yield (2 t/ha) and production of energy per hectare (18.5%), in comparison to the control plot (without dressing).In the second set of experiments, the yields of Virginia fanpetals, reproduced by root cutting, and two willow clones were examined, from the fourth to sixth year of research (2006–2008). Willow’s plots were planted with dormant, unrooted cuttings.Based on averages from three years of tests, significantly higher yields (5 t/ha) of dry matter and more production of energy per hectare (30.5%), were obtained from Virginia fanpetals’ trials, than that of the tested willow.
This paper presents a LCA study about household heat from Short Rotation Coppice wood pellets combustion. The overall process, from field growth to ash disposal, was considered; environmental analysis was carried out using a LCA software programme (Simapro 7.0) and adopting the EcoIndicator 99 model for the evaluation of the global burden; analysis with EPS 2000 and EDIP methodologies were also carried out, in order to compare the different approaches. For the pellet production process, mass and energy flows were measured on an existing Italian plant, while other data were obtained from the Literature; a comparison between results obtained using only data from Literature and using data from the existing plant was made, showing for the pelleting phase a value of about 23% lower if measured data are used. The LCA study showed that agricultural operations account for most of the environmental impact if evaluated both with EcoIndicator 99 and EPS 2000; EDIP gave results that were not very reliable for this chain, due to the high weight given to the infra-structures and machinery construction. The comparison between data obtained consid-ering and not considering the infra-structures contribution in the LCA analysis with EcoIndicator 99 showed a modest contribution of infra-structures on the final score (about 2%). The overall impact evaluated with EcoIndicator 99 is considerably less than the one caused by natural gas heating. The Energy Return Ratio was finally calculated; a value of 3.25 was found, good if compared to the one for the methane combustion, equal to 6.
Energiepflanze mit hohem Potenzial
- Borkowska
Ecoinvent report No. 6-IX - Holzenergie
- Bauer
The European Person Equivalent: measuring the personal environmental space
- Hauschild
Miscanthus: anbau und Nutzung - informationen für die Praxis
- Fritz