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Energy and carbon footprint assessment of production of hemp hurds for application in buildings

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Abstract

Construction is considered as one of the most relevant sectors in terms of environmental impacts, due to the significant use of raw materials, fossil energy consumption and the consequent Greenhouse Gases emissions. The use of unconventional and environmentally-friendly materials and technologies is worldwide recognised as a key factor to enable the decrease of material and energy consumption in buildings. Between natural/sustainable materials, those using hemp products and by-products (fibres and hurds) have rapidly widened their field of application in the building industry, mainly because of their good hygrothermal and acoustic insulation properties. Moreover, the usage of these materials allows high carbon storage due to the CO2 sequestration during the agricultural phase. This study represents an energy and environmental assessment of hemp crop cultivation in France, carried out through a Life Cycle Assessment approach, showing positive and negative contribution related to the different life cycle phases. The total CF evaluated through the IPCC, 2013 GWP 100 method (IPCC, 2013) is equal to 0.975 kgCO2eq, in view of a CO2 uptake of −1.29 kgCO2eq. So, it is understood that the total CF results therefore lower than the CO2 uptake due to the biogenic carbon captured and stored during hemp growth. The total Energy Footprint, instead, was calculated in 17.945 MJ. The Upstream phase came out as the main contributor to the impacts. A sensitivity analysis was performed to explore changes in results related to main inputs assumptions and, in particular, the environmental benefits associated with the replacement of conventional fertilisers (ammonium sulphate) with organic matter were highlighted.

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... Construction is one of the most relevant sectors in terms of environmental impacts, due to the significant use of raw materials, fossil energy consumption and the consequent Greenhouse Gases emissions. The use of unconventional and environmentally-friendly materials and technologies is worldwide recognised as a key factor to allow the decrease of material and energy consumption in buildings [3]. Indeed, the traditional materials commonly ...
... However, up to date there is few sustainability studies based on the LCA methodology, and some of them are focused only on the agricultural phase of hemp cultivation. Scrucca et al. [3], for example, evaluated the carbon footprint of the hemp cultivation, through Life Cycle Assessment. The total carbon footprint resulted lower than the absorption of CO2, due to the carbon captured and stored during the growth of hemp. ...
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Environmental issues, especially those related to the over-exploitation of natural resources, are leading towards considering alternative solutions and new approaches, such as the circular economy. Currently, some key elements of the circular economy approach are sustainable procurement of raw materials, improvement of production processes and ecological design, adoption of more sustainable distribution and consumption models, development of secondary raw material markets. This work aims to analyse the use of hemp as a building material, replacing traditional construction materials, but respecting at the same time the thermal, insulating and acoustic characteristics required in the construction of a building. The methodology used was Life Cycle Assessment (LCA), which considered the hemp cultivation phase and the production phase of hemp-lime (“hempcrete”) walls. The hempcrete product was compared with two different solutions: a hemp and lime block, and a traditional perforated brick block with external insulation in polystyrene. In particular, the differences among the products in terms of embodied energy and net CO 2 emissions were analysed. Results showed that the hempcrete wall had better environmental performances than the other two solutions.
... Therefore, the utilisation of those materials is recognised to be a key aspect in sustainable construction, as it enables decreasing material and energy consumption in buildings [1, 12,13]. In particular, natural and bio-based construction materials are identified as one of the most promising solution for optimizing buildings' environmental sustainability [14,15] and the benefits of using them instead of synthetic materials is well known and documented in the literature. ...
... Glaser diagram: trend of saturation and vapour pressures throughout wall 1.Energies 2021,14, 5508 ...
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The urgent need to make buildings more performant in energy and environmental terms has led to the increasing study of recycled and natural materials as viable solutions. In this context, the present study aims at comparing the energy performance of innovative wall-sample solutions (with recycled polyethylene-terephthalate panels or durum-wheat straw bales) with a basic one. Energy evaluations were performed in Piazza Armerina (a city of Sicily–Italy), where the chosen material is widespread, by applying two calculation methods: a monthly average-energy-calculation approach, mandatory by Italian regulations (UNI TS 11300), and an hourly energy-calculation procedure (EN 52016). The results documented that: (i) the new innovative wall-sample allows for significantly reducing heat loss (heating of 4–10% and cooling of 40–50%) (ii) a lower primary-energy demand was obtained by adopting the new calculation procedure of EN 52016 (energy decreasing of 20–24%); (iii) significant differences in terms of heat-loss (of 10–36%) and heat-gain (up to 75%) calculations were found for the two calculation methods. This puts emphasis upon the importance of properly selecting a calculation method by accounting for all of those key variables and features that are representative of the energy system being investigated.
... Focussing on building thermal insulation materials, the market leaders (such as EPS, XPS, stone wool, and glass wool) are the most studied in terms of LCA in the literature [25][26][27], but natural and renewable materials also attract attention for life cycle evaluations [28][29][30], with LCA that is generally used to compare different materials as well as to identify environmental hotspots in their life cycle. LCA is therefore considered and used as a powerful tool to support decisions for the choice of more environmentally friendly thermal insulation materials. ...
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Energy efficiency and greenhouse gas reduction have become two of the most important issues to address in fighting climate change. Focused strategies have been implemented aiming at reducing the energy consumption of buildings since it is one of the most energy-intensive sectors, but they are mainly concerned with energy reduction without considering their environmental impact. The present work therefore aims at assessing the energy and environmental impacts of the use of insulation materials for building envelope refurbishment as the thermal coating. Reference buildings were used to perform energy simulations in representative cities of Italy and energy and environmental impacts of the most common and sustainable insulation materials were thus evaluated. Relevant outcomes have been focused on defining a new Economic and Environmental Sustainability Index (EESI) capable of considering both economic and environmental aspects; particularly, sustainable materials (such as cellulose fiber) can have the same affordability as traditional ones (such as polystyrene foam slab, glass wool, or stone wool) if environmental impact is also taken into account, despite their higher cost. However, according to EESI, the affordability of traditional insulation materials remains evident in the warmest climatic zones because of the lower energy needs of buildings.
... In the results, the recycled aggregate concrete achieved a decrease of up to 2.175 x 105 kg CO 2 in carbon footprint, compared to natural aggregate concrete. There are also works wich are not linked to the more traditional materials used in construction, with the aim of investigating new possibilities for reducing the carbon footprint at the material manufacturing stage, such as the research by Scrucca, F. et al. [27], about the use of sustainable materials, such as hemp, due to its good hygrothermal and acoustic insulation properties. ...
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Building sector is a major contributor to the emissions of pollutant gases, which are responsible for health-damaging effects of climate change. To quantify and reduce these emissions. This comparative study is presented between two buildings that could have a sanitary or any other type of use. Both buildings have similar characteristics, except for their structures, one made of metal and the other of concrete. The design, structural calculation and three-dimensional dimensioning were performed using Building Information Modeling (BIM). The budget and the product carbon footprint study were also carried out, to calculate the level of emissions of each building. The study determined higher emissions for the metal-structured building, with 621.234 tCO2/tmaterial compared to 446.707 tCO2/tmaterial for the concrete building. To reduce these emissions, measures related to the replacement of the previously selected materials, by other materials with lower emission rates and identical functionality were presented, such as the replacement of metal building roof polyurethane, or the composition of cement for the concrete building. Both actions represented a reduction of 84.61% CO2 emissions for metal envelope building and 31.765% for the concrete structure. The results of this work will help to select more sustainable materials to use in the renovation of existing buildings, or in the construction of new buildings. For example, health-related buildings, currently in high demand, given the current pandemic situation caused by COVID-19.
... Processing has been found a major contributor to the GWP of bamboo flooring (Gu et al., 2019). Unlike bamboo and timber, cultivation is the main GWP hotspot for hemp insulation (Scrucca et al., 2020;Zampori et al., 2013). As indicated in Table 6, only three studies, all on bioconcrete, have assessed other LCA impacts in addition to GWP. ...
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Negative emissions technologies (NETs) are expected to play a significant role in mitigating climate change. However, there are also concerns that a large scale deployment of NETs may cause various environmental impacts due to the use of land, water and energy resources. A number of studies have assessed the environmental performance of various NETs; however, a comprehensive review comparing a range of different NETs is not available in the literature. To address this research gap, this paper compares life cycle assessment (LCA) studies of the following options for which the data were available in the literature: bioenergy with carbon capture and storage (BECCS), biochar incorporation into soil, afforestation and reforestation, soil carbon sequestration, building with biomass, direct air carbon capture and storage (DACCS), enhanced weathering and mineral carbonation. It is evident from this review that these technologies can have net negative life cycle GHG emissions, ranging from −603 kg CO2 eq./t CO2 removed for building with biomass to −1173 kg CO2 eq./t CO2 removed for biochar incorporation into soil. However, the estimates of GHG removal potentials vary widely among the studies for each technology as well as among the NETs owing to technological differences, methodological choices and differing assumptions. For example, the net global warming potential (GWP) of biochar varies among the reviewed studies between a net positive impact of 1710 to a net negative GWP of 3300 kg CO2 eq./t CO2 removed, depending upon the feedstock, pyrolysis technology and the assumptions for credits for co-products and co-benefits. Overall, biochar used as soil amendment has the lowest GWP per tonne of CO2 removed, followed by soil carbon sequestration, while building with biomass ranks last. The review also reveals that the removal of CO2 by these technologies could lead to a significant increase in other environmental impacts. Especially, the use of energy in non-bio NETs (DACCS, enhanced weathering and mineral carbonation) leads to relatively high fossil depletion, acidification and human toxicity. These impacts can be reduced if the energy demand of NETs is met by renewables instead of fossil fuels. The paper also identifies several methodological issues and challenges in conducting LCA of NETs and provides recommendations to address them.
... Olivito et al. [120] claimed that the internal reinforcement of a masonry wall with flax fibers, provided enhanced formation anchorage sites within the matrix, in addition to improving the ductility of the element, which was in contrast with reinforcements fabricated using glass fibers. This study has provides an opportunity for the development of new materials for application in masonry components, which has a higher performance and sustainability than those currently used, in terms of the significant advantage of these materials with their lower carbon footprint [151]. Claramunt et al. [148] manufactured ventilated facade panels using cement reinforced with fabric flax fibers, which were lighter components with good mechanical performance. ...
Article
The need for sustainable building materials has progressively increased the interest in the use of vegetable fibers as reinforcements in cementitious matrix composites. These fibers are renewable, inexpensive, and offer other advantages, such as lightness, stiffness, biodegradability, and high impact resistance. This review presents research conducted in this field over the last 20 years. For this purpose, the most commonly used fibers and the treatments used to improve the mechanical properties of composites were identified. Moreover, the effect of fiber length on the mechanical properties of the reinforced composites was discussed. Some applications of vegetable-fiber-reinforced composites in structural and nonstructural elements have been highlighted. Based on the results, the treatment used the most was highlighted, which was matrix modifications that reduce the cementitious paste alkalinity by improving the fiber interactions within the composite. Furthermore, short fibers significantly increased the flexural and tensile strengths, and toughness of fiber-reinforced cementitious composites (FRCC), whereas long fibers, used as external reinforcement, increased the compressive strength of textile-reinforced cementitious composites (TRCC) by limiting lateral concrete expansion and abrupt failure. Despite the enhanced mechanical properties of fiber-reinforced composites, information related to fiber durability in cementitious matrices is limited thus far, which has restricted their application in primary structural elements that have high force demands.
... Concerning the material level, multiple solutions may be selected depending on the building material. For instance, hemp-based materials were recently proposed [4]; dealing with concrete, solutions based on geopolymer [5], plants [6], and recycled aggregates [7] are increasingly popular. Dealing with unreinforced masonry, solutions implementing hemp fibers and other bio-natural materials are often used [8,9], while innovative applications of composite materials can be envisaged for exposed masonry, especially in heritage constructions [10]. ...
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This paper presents an innovative methodology to assess the economic and environmental impact of integrated interventions, namely solutions that improve both structural and energy performance of existing masonry buildings, preventing out-of-plane modes and increasing their energy efficiency. The procedure allows the assessment of the environmental and the economic normalized costs of each integrated intervention, considering seismic and energy-saving indicators. In addition, the work introduces in relative or absolute terms two original indicators, associated with seismic displacement and thermal transmittance. The iso-cost curves so derived are thus a powerful tool to compare alternative solutions, aiming to identify the most advantageous one. In fact, iso-cost curves can be used with a twofold objective: to determine the optimal integrated intervention associated with a given economic/environmental impact, or, as an alternative, to derive the pairs of seismic and energy performance indicators associated with a given budget. The analysis of a somehow relevant case study reveals that small energy savings could imply excessive environmental impacts, disproportionally increasing the carbon footprint characterizing each intervention. Iso-cost curves in terms of absolute indicators are more suitable for assessing the effects of varying acceleration demands on a given building, while iso-cost curves in terms of relative indicators are more readable to consider a plurality of cases, located in different sites. The promising results confirm the effectiveness of the proposed method, stimulating further studies.
... Porous bio-based materials have moisture hygroscopic properties, while PCMs have thermal inertia properties. Also, CO 2 emissions are minimal during production and utilization of such materials [8][9][10]. ...
Article
This paper deals with the experimental investigation of hygrothermal behavior of wooden-frame building envelope. The experiment was based on in-situ monitoring of a full size experimental monozone house built at the University of Lorraine. Variations in temperature and relative humidity inside and outside the envelope were logged simultaneously with local meteorological data. Results showed the high coupling between temperature and relative humidity variations within the envelope materials. An overall hygrothermal response of the wall highlighted an interesting hygrothermal dynamic behavior of the envelope which may contribute to mitigate variations of relative humidity inside the building. Nevertheless, relative humidity evolves within a range of values that can lead to mold growth at a certain position which may alter wooden envelope life.
... In high-density cities like Hong Kong, buildings account for 90% of carbon emissions from electricity consumption in the operation phase (Environment Bureau, 2017). In order to achieve a green global economy, lifecycle assessment (LCA) is increasingly adopted to realize low carbon transition of the building industry (Nematchoua et al., 2019;Scrucca et al., 2020). LCA is applied to evaluate the energy use and environmental impacts of material production, construction, operation, and end-of-life phases. ...
Article
Modular construction has attracted increasing attention due to its energy and environmental benefits. Digital technologies such as building information modelling (BIM) have also been explored to generate and manage data through the lifecycle of buildings. Although research has been performed in the area of integrating BIM and modular construction, BIM-based automated lifecycle assessment (LCA) of prefabricated buildings remains unexplored. This study therefore aims to develop a BIM-based LCA method for prefabricated buildings incorporating different assessment levels with unique system boundaries and functional units. The developed approach can support automated assessments through all lifecycle phases of a prefabricated building. It is achieved through an automated process of creating parameters to merge LCA data into the building model, systematic zoning, model setup and impact estimation. This approach is applied to evaluate the energy and environmental performances of a case building in Hong Kong. The case study validated the efficiency of the developed BIM-based LCA method in providing a systematic and detailed assessment of modularly designed buildings. This study extends the knowledge in automated BIM-based LCA by addressing specific characteristics of prefabrication and promotes the incorporation of comprehensive and detailed LCA data into BIM models for improved design robustness and holistic performances of buildings. This validated approach will enhance the willingness of designers to apply LCA during the design stages for minimizing the energy and environmental impacts of both new and renovated buildings with prefabrication.
... Porous bio-based materials have moisture hygroscopic properties, while PCMs have thermal inertia properties. Also, CO 2 emissions are minimal during production and utilization of such materials [8][9][10]. ...
Article
Bio-based materials have strong hygrothermal behavior and phase change materials (PCMs) have high thermal inertia, but they have usually been studied separately in most research. In this paper, the hygrothermal behavior of a multilayer building envelope integrating hemp lime concrete (HLC) and PCM was investigated at experimental level. The envelope was flanked by a climate chamber and the laboratory ambient to imitate the outdoor and indoor environments, respectively. Four envelope configurations comprising a reference (without PCM) and three configurations with PCM (PCM placed on the outdoor and indoor side, in the middle of the envelope) were considered in order to study the effect of PCM and its position on the hygrothermal behavior of the envelope. The results showed that the PCM had a significant effect on the hygrothermal behavior of HLC, based on the high coupling between temperature and relative humidity. The characteristic time was considered to quantitatively evaluate temperature and relative humidity trends, and their value was increased with the participation of PCM. Moreover, PCM increased the heat store/release capacity linearly with its position. The closer the PCM was to the outdoor, the higher the heat store/release capacity and the lower the heating/cooling load from the envelope to the indoor environment. These phenomena were closely related to the PCM's temperature distribution and its corresponding specific heat capacity. Therefore, due to the envelope's thermal and hygric inertia on the indoor environment and the building's energy saving potential, it was recommended that the PCM be placed close to the outdoor side.
... The forest industry, associated with the production of current panels, is responsible for high energy consumption and environmental pollution [134], through the emission of formaldehyde and volatile organic compounds during the production, use, and later disposal of the panel product. Moreover, building sector plays an essential role in the global energy scenario, and its environmental impact could be reduced by introducing more sustainable materials [135,136]. For instance, in a recent review, Maraveas [157] deeply analysed the use of agro-waste in construction materials sector, showing how the use of these resources help to meet sustainability challenge. ...
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Fiberboards are readily available components which can be used in construction for various functions such as furniture, insulation, or soundproofing. Research in the field of fiberboards has developed considerably in trying to match the practical needs of the construction element together with the new environmental challenges, that favour the production of panels in using by-products without adhesives. This review article presents an overview on fiberboard production and may offer a way to establish all the necessary steps to make binderless fiberboards attractive on the market, by considering economic and sustainable issues. Feedstock procurement is analysed, considering the effect of chemical composition of raw material on fiberboard quality. Lignin represents the most important component for bonding ability. However, at the same time, the need to use a by-product, which may result in choosing a material with less lignin and more hemicelluloses, will worsen dimensional stability, and therefore, a pre-treatment of lignocellulosic material may be necessary. Many pre-treatments have been studied and optimised in recent years. This paper analyses mechanical, chemical, hydrothermal and biological ones, and considers the pros and cons of each one of them. The choice of pre-treatment depends on which result is to be achieved. Some applications are considered to conclude the production chain. What emerges is that the application phase is not yet fully developed and scaling up from laboratory to the industrial stage is not yet achieved.
... During hemp fiber separation, hemp crops also produce large amount of byproducts: hemp and dust (González-García et al. 2012). Hurds are non-fiber components obtained by retting hemp stem (Scrucca et al. 2020). The chemical contents of hemp hurds are very close to that of wood species, with a high portion of cellulose and hemicellulose. ...
Article
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The presence of contaminants of emerging concern (CECs) in wastewater treatment plant effluents is a significant underlying health risk and environmental concern. CECs consist of a wide variety of contaminants, including pharmaceuticals and personal care products, hormones, steroids, alkyl-phenols, flame retardants and pesticides. Their impact is of particular relevance to agricultural settings due to CEC uptake and accumulation in food crops and consequent diffusion into the food-chain. Meanwhile, marijuana reform is accelerating in the US, based on the scope and pace of legalization efforts and on wider acceptance in polls of voters. In this review, the effectiveness of industrial hemp (Cannabis sativa L.) in phytoremediation and hyperaccumulation of organic contaminants (e.g., benzo(a) pyrene, Naphthalene, and Chrysene) and heavy metal (e.g., Selenium and Cobalt) from either aqueous solutions or contaminated soils has been reviewed. The potential of industrial hemp as a renewable resource to biodegrade and/or decontaminate CECs is explored. Disposal strategies of this new phytoremediation crop that promote circular economy are also discussed. According to this current review, we believe the use of industrial hemp for phytoremediation is promising to have a sustainable, environmentally friendly and economically viable future.
... Recently, some researchers have also developed bio-degradable CAI materials e.g. sheep wool [30,31] hemp [32], flax [33] and jute [34] and corn stalk [35][36][37]. These bio-materials are sustainable and propose hygroscopic and capillary active properties. ...
Article
This paper studies the influence of a new bio-based capillary active insulation (CAI) materials (corn stalk based vegetal derived concrete namely CS-1 and CS-2) and two traditional insulation materials (aerated autoclaved concrete (AAC) and aerated insulation brick (IB)) on the hygrothermal properties of multilayer wall. The reference wall consists of solid brick masonry plastered on the internal and external sides. Walls based on CAI materials consist of an extra layer of insulation and weather-resistive barrier (WRB) on the façade surface. Simulations were performed under the natural climatic condition of hot-humid and cold regions. Optimum thickness for the bio-based CAI materials to be used as internal insulation was 100 mm beyond which higher insulation thickness triggered the risk of mould growth. All walls based on CAI insulation materials (CS-1, CS-2, AAC, and IB) showed the mould index (MI) within the acceptable range. Bio-based CAI materials showed considerable improvement in the temperature and relative humidity at the interior surface. CAI materials reduced the heat losses through the wall by 58-69% as compared to the reference wall. Drying behavior of the wall was significantly improved with the combination of CAI and WRB and no risk of condensation was observed in the walls.
... However, due to the fact that it has been replaced by the ReCiPe method, the use of this method is proposed. The literature of the subject also uses assessment methods whose assessment result is presented in CO2 equivalent (e.g., IPCC 2013 GWP 100a or Greenhouses Gas Protocol) [27,28]. However, due to the way the results were presented, the ReCiPe endpoint (E) assessment method was used. ...
Article
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Energy saving is at the heart of sustainable development in the context of climate change. Saving energy is not only the amount of energy that we save, but also reducing emissions of pollutants to the atmosphere, as well as reducing the consumption of energy resources that are used to produce energy. Reducing pollutant emissions and the use of energy resources can be achieved by increasing the use of renewable energy sources, but at present, this method of obtaining energy in the world is not representative. It should be noted that renewable energy devices throughout the life cycle generate environmental impact. Similar to this situation, the building's thermo-modernization, which is focused on reducing the pressure on the environment of the building's user, also has an impact on the environment throughout the building's life cycle. Determining this environmental impact and ecological or economic benefits or costs is the purpose of the following article. Thermo-modernization of the building, for the purposes of the article, is understood as thermal insulation of walls and replacement of the heat source for heating the building and preparation of hot utility water. The need to replace the heat source with a much more ecological one results in Poland from provincial legal regulations announced by virtue of a resolution. In the study, data from the Ecoinvent data library included in the SimaPro computer program was used for the LCA (Life Cycle Assessment) analysis. As a result of thermo-modernization of the representative buildings, large ecological benefits were obtained, while economic costs remain at a high level.
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In this study, the thermal, energy, economic, and environmental perspectives of a smart Cannabis plantation are investigated. A commercial R-32 air conditioning at a cooling capacity of 12,300 BTU/h is implemented for the 5-lighting sets. One 300 We-violet-light-emitting diode (LED) and two 100 We-daylight-LEDs are designed for one lighting set at a photosynthetic photon flux density of 100 µmol/m²⋅s. A smart watering system is designed to automatically control a watering period of 62 hours, an operating time of 40 minutes, and a watering rate of 41.5 L/time. The smart Cannabis plantation can produce a fresh inflorescence of 250 g and a dried inflorescence of 46.3 gdy, respectively. A power consumption of 126.9 kWh/plant is mainly driven the environmental impacts of a climate change of 6.22E+02 kg CO2 eq/kgdy. The economic result of a levelized cost is approximately 262.85 USD/kgdy.
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The thermal performance of the building envelope must be adjusted to promote sustainability, reduce energy consumption, and reduce greenhouse gas emissions. In this case, the elements' thermal resistance and heat storage capacity are critical. Due to their high energy density and ability to absorb/release heat under nearly isothermal conditions, phase change materials are extremely competitive and have a wide range of applications. The effectiveness of using PCM in the building envelope is studied in this investigation under exceptionally hot climatic conditions. A thermal model is developed based on the nonlinear transient heat conduction equation to predict the time-dependent thermal response of a multilayer building envelope wall. The enthalpy formulation is used to account for the phase change process, and the mathematical model is solved numerically using the finite element method. A typical exterior multilayer wall's thermal performance is studied and utilized as a benchmark. Then, at various points throughout the wall, a PCM layer is incorporated. The effect of the PCM on wall temperature distribution, heat movement into the interior area, and the fraction of molten material in the PCM layer is investigated. Optimization analysis is used to establish the suitable PCM melting temperature interval, with the heat flow at the internal surface of the wall as the objective function to be minimized. The thermal energy flow into the internal space can be reduced by approximately 50% when the PCM settings are improved. The findings of this investigation demonstrate that the suggested computational model is effective in calculating the optimal PCM, resulting in a significant improvement in the external wall's thermal performance. Integrating PCM into the building envelope is a viable technique for the region, as it has the potential to reduce the amount of heat entering the building, hence lowering the air conditioning load and lowering energy consumption.
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In today’s world, global warming is at its peak and the materials are being excessively used by the industry leading to an adverse effect on the environment. This made leaders all over the globe to work on halting global warming, and thus invention led to the rehabilitation of building materials made of agro-waste concrete, which has the additional benefits of carbon restoration, renewability and low embedded energy. Concrete mixes consist of agro-wastes, such as rice husk, coconut shell, wheat straw, sugarcane bagasse, maize cob, bamboo leaf, Hemp etc. In India, research on Hemp concrete has not been done so far on large scale therefore this surface new opportunity of different outcome on Hemp concrete. The purpose of this paper is to review the research on finding the self-curing properties (Hygrothermal properties), mechanical properties, and light weight properties of hemp concrete so that it can be used as a construction material, with the goal of recognizing research gaps that will guide the future research into its execution in the rapidly increasing green building industry. Several gaps were identified in the research regarding the strength, light weight and the self-curing properties of the Hemp concrete. The article closes with a discussion of the direction and necessity of upcoming research to enhance Hemp concrete's manufacturing methods and mechanical performance in order to expand its use in the construction sector.
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Greenhouse gas emission rate in peat soil under oil palm plantation comes to attractive interest to control the environment. Revealing the indirect emission of the applied input of oil palm cultivation in peat soil in the area, would contribute on the improvement of the greenhouse gas emission data exposure. The objective of this study was to determine greenhouse gas emissions generated from the oil palm cultivation applied inputs. Field observation was conducted in Labuhan Batu, North Sumatra, Indonesia, in 2013-2014, at both corporate and smallholder farmers as well. CO 2 -eq emission of the applied agricultural inputs was calculated by means of MILCA- JEMAI© application software. CO 2 equivalent emissions from applied inputs of corporate peatland oil palm plantation was calculated based on data in 2012 amounted to 1013.7 kg CO 2 -eq ha ¹ year ¹ . On smallholder farmers, it showed a 40 lower emission rate but with higher variability at 604 ± 238 kg CO 2 -eq ha ¹ year ¹ . At the oil palm corporate, inorganic fertilizer application contributed a higher emission rate, followed by fuel use and pesticide applications. CO 2 -eq emission rate at smallholder farmers showed a similar pattern for inorganic fertilizer use. However, it showed higher emission from pesticide application rather than fuel use.
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Background Global targets for reducing resource use have been set by organizations such as the International Resource Panel and the European Commission. However, these targets exist only at the macro level, e.g., for individual countries. When conducting an environmental analysis at the micro level, resource use is often neglected as an indicator. No sum parameter indicating all abiotic and biotic raw materials has been considered for life cycle assessment, as yet. In fact, life cycle assessment databases even lack some of the specific input flows required to calculate all abiotic and biotic raw materials. In contrast, the cumulative energy demand, an input-based indicator assessing the use of energy resources, is commonly used, particularly when analyzing energy-intensive product systems. Methods In view of this, we analyze the environmental relevance of the sum parameter abiotic and biotic raw material demand, which we call the material footprint. First, we show how abiotic and biotic raw material demand can be implemented in the Ecoinvent life cycle assessment database. Employing the adapted database, the material footprint is calculated for 12 individual datasets of chosen materials and crops. The results are compared to those of the cumulated energy demand and four selected impact categories: climate change, ozone depletion, acidification, and terrestrial eutrophication. ResultsThe material footprint is generally high in the case of extracted metals and other materials where extraction is associated with a large amount of overburden. This fact can lead to different conclusions being drawn compared to common impact categories or the cumulative energy demand. However, the results show that both the range between the impacts of the different materials and the trends can be similar. Conclusions The material footprint is very easy to apply and calculate. It can be implemented in life cycle assessment databases with a few adaptions. Furthermore, an initial comparison with common impact indicators suggests that the material footprint can be used as an input-based indicator to evaluate the environmental burden, without the uncertainty associated with the assessment of emission-based impacts.
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Purpose This discussion article aims to highlight two problematic aspects in the International Reference Life Cycle Data System (ILCD) Handbook: its guidance to the choice between attributional and consequential modeling and to the choice between average and marginal data as input to the life cycle inventory (LCI) analysis. Methods We analyze the ILCD guidance by comparing different statements in the handbook with each other and with previous research in this area. Results and discussion We find that the ILCD handbook is internally inconsistent when it comes to recommendations on how to choose between attributional and consequential modeling. We also find that the handbook is inconsistent with much of previous research in this matter, and also in the recommendations on how to choose between average and marginal data in the LCI. Conclusions Because of the inconsistencies in the ILCD handbook, we recommend that the handbook be revised.
Article
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The aim of this article is to develop a methodological approach allowing to assess the influence of parameters of one or more elementary processes in the foreground system, on the outcomes of a life cycle assessment (LCA) study. From this perspective, the method must be able to: (1) include foreground process modeling in order to avoid the assumption of proportionality between inventory data and reference flows; (2) quantify influences of foreground processes’ parameters (and, possibly, interactions between parameters); and (3) identify trends (either increasing or decreasing) for each parameter on each indicator in order to determine the most favorable direction for parametric variation. These objectives can be reached by combining foreground system modeling, a set of two different sensitivity analysis methods (each one providing different and complementary information), and LCA. The proposed method is applied to a case study of hemp-based insulation materials for buildings. The present study will focus on the agricultural stage as a foreground system and as a first step encompassing the entire life cycle. A set of technological recommendations were identified for hemp farmers in order to reduce the crop's environmental impacts (from –11% to –89% according to the considered impact category). One of the main limitations of the approach is the need for a detailed model of the foreground process. Further, the method is, at present, rather time-consuming. However, it offers long-term advantages given that the higher level of model detail adds robustness to the LCA results.
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For buildings applications, an optimum material solution would have the essential structural properties of concrete but with lower thermal conductivity. The reduced thermal conductivity provides a better thermal insulation system that consumes less energy for cooling and heating in the use phase. In the present study, thermal conductivity analysis and environmental analysis were carried out for various materials that are intended for use as external walls for buildings. Life Cycle Assessment (LCA) methodology was applied to evaluate the environmental impacts of four different proposed systems. An eco-sandwich material containing cork, flax fibres and bio-based epoxy resin as natural materials was manufactured and tested in order to evaluate the thermal conductivity. The use of the eco-sandwich in building structure seems to bring several advantages in terms of innovation, good insulation properties and light-weight structures. The LCA results show that when the eco-sandwich is used, the environmental performance is lower compared to other traditional materials, in the manufacture phase. Nevertheless, impacts due to material transportation and installation could be lowered due to the light weight and handling of the eco-sandwich.
Article
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Acoustical sustainable materials, either natural or made from recycled materials, are quite often a valid alternative to traditional synthetic materials. The production of these materials generally has a lower environmental impact than conventional ones, though a proper analysis of their sustainability, through Life Cycle Assessment procedures, has to be carried out.Airborne sound insulation of natural materials such as flax or of recycled cellulose fibres is similar to the one of rock or glass wool. Many natural materials (bamboo, kenaf, coco fibres) show good sound absorbing performances; cork or recycled rubber layers can be very effective for impact sound insulation. These materials also show good thermal insulation properties, are often light and they are not harmful for human health. Furthermore, many of these materials are currently available on the market at competitive prices.There is however a need to complete their characterization, both from an experimental and a theoretical point of view, and especially to propose a standard and unique procedure to evaluate their sustainability.The paper presents an updated survey on the acoustical properties of sustainable materials, both natural and from recycled materials, including mixed and composite materials and systems such as green roofs and green walls, and is completed by a wide selection of recent related bibliography.
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This paper advocates a shift for green building rating tools (GBRTs) from energy-oriented towards human-oriented through incorporating the concept of biophilia. A biophilic framework has been derived to address human sensorial experience and related health benefits via indoor-outdoor and building-nature connections. Six representative GBRTs and their credits have been standardized and categorized for a detailed comparison with the biophilic framework. The relationship between GBRTs and biophilia is disclosed through a series of credit-strategy pair analyses. GBRT credits except for those on Energy are closely related to 85% of biophilic strategies. However, some important biophilic strategies on outdoor human sensorial experience are missed out in GBRTs. Methodologically, green building design should shift from the building centric engineering approach towards a human centric biophilic approach for promoting health and wellbeing. The proposed biophilic framework and strategies provide guidelines for such shifting.
Article
To counter the negative environmental impact, particularly greenhouse gas emission generated by the construction industry, many low-impact materials are being produced and researched having neutral CO2 emissions and low thermal conductivity. One of these materials is lime-hemp concrete, a self-bearing bio-based insulation material with low thermal conductivity and good CO2 uptake but with weak mechanical properties. In this study alternative magnesium binders are proposed to substitute the traditionally used lime binder in hemp concrete, comparing the environmental impact of these binder composites. To make the comparison, experimental mixtures with both traditionally used and alternative binder composites were produced and their mechanical and thermal properties tested. The magnesium binders showed promising results as these composites were approximately two times stronger, having similar density and thermal conductivity. Afterwards the Life Cycle Assessment (LCA) was carried out to evaluate and compare the environmental impact of all tested composites. Lime based binder composites achieved negative CO2 emissions, varying from -46.5 to -68.6 kg CO2/m(3). Alternative binder, magnesium phosphate cement, demonstrated significantly greater environmental impact than all other binders due to its hardener, potassium phosphate, which is highly energy and resource intensive. Magnesium oxychloride cement showed promising results with bio-based filler, as their combined environmental impact was lower in most categories compared to lime-hemp concrete, and negative CO2 emissions of -37.38 kg CO2/m(3) were achieved. These negative CO2 emissions were achieved with biogenic CO2 uptake from hemp growth and low binder content, thus achieving low thermal conductivity of 0.062 W/m(2)*K at 214 kg/m(3) density.
Article
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Article
Currently, wood and wood construction materials have limitations in how carbon fluxes are accounted for in life cycle assessments. The biogenic carbon balance of wood is often considered to be neutral, meaning that the carbon sequestered by biomass through photosynthesis is considered equal to the carbon feedstock in wood that is eventually released throughout its life cycle. Several publications have recently shown that this assumption could lead to accounting errors. This research work aims to improve the biogenic carbon accounting of the forestry phase of the life cycle of softwood products. This involved specifically modelling carbon fluxes as a function of tree species, growing conditions and forest management practices, from Canadian managed forests. A baseline natural forest scenario was run for 1000 years until the carbon stocks were assumed to reach an approximate steady-state, followed immediately by a harvest scenario that was simulated for another 100 years. The ecosystem carbon costs of the harvest activity were calculated for 117 species and region forest landscapes across Canada and expressed per cubic meter of harvested wood. Most landscapes showed net sequestration after 100 years of harvest history. Exceptions to this included outlier landscapes characterized by low average annual temperatures and precipitation where slightly positive values (net emissions) were found. The mean time to ecosystem cost neutrality for each species ranged from 16 to 60 years. Knowing the time since forest management has started on a particular forest landscape now enables managers to obtain an estimate of ecosystem carbon cost per cubic meter of wood harvested for most of Canada's forests and commercial tree species. These ecosystem carbon costs can be used to generate regionalized cradle-to-gate life cycle inventories for harvested wood products across Canada.
Article
Storing carbon in construction products and building components seems a particularly attractive strategy for compensating the initial greenhouse gas (GHG) emissions from production and construction. Typically, in LCA methods, when a sustainable forestry management is assumed, biogenic carbon is not included in the calculation since forest products are considered as carbon neutral due to the full regeneration of biomass in forest at the end of a rotation period. The purpose of this article is to investigate the effect of storing carbon in biogenic materials and lime-based products when they are used as construction materials and left long in a building. Five different alternative exterior walls with different construction technologies are compared. In the first two alternatives (STR and HEM), a significant amount of fast-growing biogenic material is used as thermal insulation, while the third (TIM) represents a typical timber frame structure with mineral insulation. The last two are traditional wall alternatives based on bricks (BRI) and cast concrete (CON) with an additional external thermal insulation composite system (ETICS) in EPS. A model based on a dynamic LCA is adopted to include timing in the calculation. The results, expressed in terms of radiative forcing in the atmosphere, show that storing carbon in fast-growing biogenic materials is much more efficient than in timber elements. The carbon stored in fast-growing biogenic materials is fully captured by crop regrowth only one year after construction, while a longer time is expected for forest products due to the long rotation period required for forest regrowth.
Article
Life cycle assessment is a useful tool that helps to quantify the ecological impact of a product. It also enables us to compare two products. Regardless of its weaknesses, this tool is by far one of the best methods introduced and is one of the most complicated techniques available for environmental assessment. While the benefit of using bio-based materials instead of synthetic materials is well known, to date very few studies are available comparing the two products. The aim of this paper is to compare a currently available car engine beauty cover with a hybrid bio-based cover. This study's results show that the new hybrid materials not only perform better in terms of emissions during car operation (because of the fuel savings resulting from lightweighting), but that their production and end of life is also environmentally benign. A cost analysis of the two types of engine covers shows that the new hybrid materials are a good substitute for current materials because their manufacture costs half that of current materials.
Article
Natural and bio-based construction materials represent a promising solution for optimizing buildings' environmental sustainability. In this view, the paper presents the multipurpose experimental thermo-acoustic characterization of common reed-based building panels. Different geometries, densities, humidity rates and stalk shapes were considered and tested by means of hot-plate, hot-box and impedance tube in-lab experimental benches. The thermal analysis showed that the geometry scarcely affects the thermal conductivity, which is around 0.05 W/mK and, therefore, comparable to other materials already commercialized for the same scope. On the other hand, the acoustic behavior is strongly affected by the stalk configuration, e.g. perpendicular, parallel or combined orientation with respect to the incident wave. In particular, the longitudinal stalk layout showed a significant sound absorption performance. The exhaustive experimental original characterization of such by-product, therefore, showed a very promising overall thermo-acoustic behavior. At the same time, for optimizing the panel field performance, the acoustic requirements should represent the panel design drivers, given the high sensitivity of the panel layout characteristics affecting the acoustic performance.
Article
Application of Life Cycle Assessment (LCA) in buildings is usually performed at the envelope scale, mainly for comparison of several sample-solutions, and provides in-depth analyses of the related energy and environmental performances. In this way, it is possible to identify those solutions that perform best in energy and environmental terms, and that so are suitable for construction of sustainable buildings. In this context, the study was aimed at carrying out energy and environmental assessments to compare four external-wall samples characterised by different rates of sophistication in terms of assembly technologies and component materials. The samples considered were properly designed for development of the subsequent energyenvironmental analysis. In particular, two “standard” wall compositions and two ventilated façades were considered, using rock-wool and recycled Polyethylene Terephthalate (R-PET) as insulating materials. Cover Letter_for review The study documented that, as regards both energy and environmental impacts, ventilated façades perform quite well compared to the "standard" wall compositions, especially when equipped with R-PET. It also confirmed that both solutions easy to be disassembled and recycled materials are key design choices for environmental sustainable and low energy demanding buildings along their whole life cycles. Finally, the authors believe that the study provides helpful insights on the environmental sustainability of eco-friendly materials and technologies, and can contribute to less time and resources consuming LCAs at the building scale.
Chapter
In agri-food sector there has been the springing up of voluntary environmental labelling systems used as instruments for environmental communication and useful to obtain a commercial feed-back of eco sustainable management. The result is a varied survey and it becomes extremely difficult and complex for the operators to choose the most effective label which explains the values of their environmental involvement and the application of the operating modes of the chosen labelling system. The aim of this chapter is to draw up some guidelines which take into account the peculiarities of the soil, the specific quality of the products, the characteristics of the supply chain and of the company operative context and the final reference markets; by doing so, these guidelines provide the firms with the right criteria whereby they can choose the most adequate environmental label for their agricultural and food products thus helping them to enhance their communication strategies and their visibility on the market. These guidelines will assist the firms which want to apply an environmental label to their own outputs, choosing a communication system close to their realities through the evaluation of objective, comparable and believable information.
Article
Over half of the global raw materials are consumed in the construction of buildings and roads, their associated greenhouse gas emissions from excavation to final disposal are pivotal to the change in global climate. Hemp is a natural resource that has recently been used as a low environmental impact material in a number of composite products. In buildings, it is increasingly used with a lime base binder in wall constructions. There are limited data available to evaluate the environmental impact of this type of construction in the UK. This research aims to identify the processes and materials involved in the construction of hemp-lime walls and to establish their life cycle impact on climate change. The study follows assessment procedures and guidelines of international (ISO14040) and UK (PAS2050) standards. The functional unit defined for the hemp-lime wall construction is 1 m square in area, 300 mm thick with timber frame support inside. Primary data were collected for processes and materials that have no existing information. Other processes with impact data available from credible database were adapted in the assessment by taking into account the conditions and practice in the UK. Assessment was carried out using the SimaPro LCA tool over a lifetime of 100 years. Within the boundary and assumptions made, results showed the functional unit could sequestrate 82.7 kg of carbon dioxide with a net life cycle reduction of greenhouse gas emission of 36.08 kg CO2e. Crown Copyright
Article
The need to reduce greenhouse gases emission produced by the building sector leads to the research of renewable and less impacting materials that can replace traditional ones. This subject has encouraged new researches on biocomposite concretes with the aim to exploit renewable resources like vegetal fibres intended as materials whose production processes are generally characterized by low costs and energy demand. This biocomposite is obviously much lighter than concrete and, therefore, can be suitably used in such cases where a structure cannot be overloaded, for instance in the realization of a green covering on top of a preexistent building. In this work, a first analysis of the thermal and structural behaviour of a biocomposite concrete, constituted by a mineral matrix (lime) with the addition of vegetal fibres (hemp), has been carried out, with particular attention to the amount of fibres and its granulometry in the mixture. The drying process contemplate a permanence of the material in a thermostatic chamber. The analysis carried out shows that hemp can be used both for the realization of insulation panel (hemp fibres alone) and as a construction material (hemp bast and concrete mix). This biocomposite has shown good insulation properties and some mechanical resistance. However, the results show that further analyses should be carried out on the drying process of the material, as it can greatly influences thermal and mechanical properties.
Article
In life cycle assessment (LCA), the same characterization factors are conventionally applied irrespective of when the emissions occur (the same importance is given to emissions in the past, present, and future). When the assessment is constrained by fixed timeframes, the appropriateness of this paradigm is questioned and the temporal distribution of emissions becomes of relevance. One typical example is the accounting for biogenic CO2 emissions and removals. This article proposes a methodology for assessing the climate impact of time‐distributed CO2 fluxes using probability distributions. Three selected wood applications, such as fuel, nonstructural panels, and housing construction materials are assessed. In all the cases, CO2 sequestration in growing trees is modeled with an appropriate forest growth function, whereas CO2 emissions from wood oxidation are modeled with different probability distributions, such as the delta function, the uniform distribution, the exponential distribution, and the chi‐square distribution. The combination of these CO2 fluxes with the global carbon cycle provides the respective changes caused in CO2 atmospheric concentration and hence in the radiative forcing. The latter is then used as basis for climate impact metrics. Results demonstrate the utility of using emission and removal functions rather than single pulses, which generally overestimate the climate impact of CO2 emissions, especially in presence of short time horizons. Characterization factors for biogenic CO2 are provided for selected combinations of biomass species, rotation periods, and probability distributions. The time discrepancy between biogenic CO2 emissions and capture through regrowth results in a certain climate impact, even for a system that is carbon neutral over time. For the oxidation rate of wooden products, the use of a chi‐square distribution appears the most reliable and appropriate option under a methodological perspective. The feasibility of its adoption in LCA and emission accounting from harvested wood products deserves further scientific considerations.
Article
Green building is one of measures been put forward to mitigate significant impacts of the building stock on the environment, society and economy. However, there is lack of a systematic review of this large number of studies that is critical for the future endeavor. The last decades have witnessed rapid growing number of studies on green building. This paper reports a critical review of the existing body of knowledge of researches related to green building. The common research themes and methodology were identified. These common themes are the definition and scope of green building; quantification of benefits of green buildings compared to conventional buildings; and various approaches to achieve green buildings. It is found that the existing studies played predominately focus on the environmental aspect of green building. Other dimensions of sustainability of green building, especially the social sustainability is largely overlooked. Future research opportunities were identified such as effects of climatic conditions on the effectiveness of green building assessment tools, validation of real performance of green buildings, unique demands of specific population, and future proofing.
Article
There is growing interest in understanding how storage or delayed emission of carbon in products based on bioresources might mitigate climate change, and how such activities could be credited. In this research we extend the recently introduced approach that integrates biogenic carbon dioxide (CO) fluxes with the global carbon cycle (using biogenic global warming potential [GWP]) to consider the storage period of harvested biomass in the anthroposphere, with subsequent oxidation. We then examine how this affects the climate impact from a bioenergy resource. This approach is compared to several recent methods designed to address the same problem. Using both a 100‐ and a 500‐year fixed time horizon we calculate the GWP factor for every combination of rotational and anthropogenic storage periods between 0 and 100 years. The resulting GWP factors range from −0.99 (1‐year rotation and 100‐year storage) to +0.44 (100‐year rotation and 0‐year storage). The approach proposed in this study includes the interface between biomass growth and emissions and the global carbon cycle, whereas other methods do not model this. These results and the characterization factors produced can determine the climate change benefits or impacts associated with the storage of biomass in the anthroposphere, and the subsequent release of biogenic CO with the radiative forcing integrated in a fixed time window.
Article
The environmental performance of hemp based natural fiber mat thermoplastic (NMT) has been evaluated in this study by quantifying carbon storage potential and CO2 emissions and comparing the results with commercially available glass fiber composites. Non-woven mats of hemp fiber and polypropylene matrix were used to make NMT samples by film-stacking method without using any binder aid. The results showed that hemp based NMT have compatible or even better strength properties as compared to conventional flax based thermoplastics. A value of 63 MPa for flexural strength is achieved at 64% fiber content by weight. Similarly, impact energy values (84–154 J/m) are also promising. The carbon sequestration and storage by hemp crop through photosynthesis is estimated by quantifying dry biomass of fibers based on one metric ton of NMT. A value of 325 kg carbon per metric ton of hemp based composite is estimated which can be stored by the product during its useful life. An extra 22% carbon storage can be achieved by increasing the compression ratio by 13% while maintaining same flexural strength. Further, net carbon sequestration by industrial hemp crop is estimated as 0.67 ton/h/year, which is compatible to all USA urban trees and very close to naturally, regenerated forests. A comparative life cycle analysis focused on non-renewable energy consumption of natural and glass fiber composites shows that a net saving of 50 000 MJ (∼3 ton CO2 emissions) per ton of thermoplastic can be achieved by replacing 30% glass fiber reinforcement with 65% hemp fiber. It is further estimated that 3.07 million ton CO2 emissions (4.3% of total USA industrial emissions) and 1.19 million m3 crude oil (1.0% of total Canadian oil consumption) can be saved by substituting 50% fiber glass plastics with natural fiber composites in North American auto applications. However, to compete with glass fiber effectively, further research is needed to improve natural fiber processing, interfacial bonding and control moisture sensitivity in longer run.
Article
The aim of the present paper is to assess the sustainability of a natural fiber, such as hemp (Cannabis sativa), and its use as thermal insulator for building applications. The sustainability of hemp was quantified by Life Cycle Assessment (LCA) and particular attention was given to the amount of CO2eq of the whole process, and the indicator Greenhouse Gas Protocol (GGP) was selected to quantify CO2eq emissions. In this study also CO2 uptake of hemp was considered. Two different allocation procedures (i.e. mass and economic) were adopted. Other indicators, such as Cumulative Energy Demand (CED) and EcoIndicator99 H were calculated. The production of 1 ha yielded 15 ton of hemp, whose global warming potential (GWP100) was equal to about -26.01 ton CO2eq: the amount allocated to the technical fiber (20% of the total amount of hemp biomass) was -5.52 ton CO2eq when mass allocation was used, and -5.54 ton CO2eq when economic allocation was applied. The sustainability for building applications was quantified by considering an insulation panel made by hemp fiber (85%) and polyester fiber (15%) in 1 m2 of wall having a thermal transmittance (U) equal to 0.2 W/m2_K. The environmental performances of the hemp-based panel were compared to those of a rockowool-based one.
Article
The paper presents a life cycle assessment of a kenaf-fibre insulation board following the international standards of the ISO 14040 series. Each life-cycle step has been checked, from kenaf production and board manufacture by an Italian firm, to use and disposal. The aim is to assess the board eco-profile and to compare, on the basis of a life-cycle approach, the energy and environmental benefits and drawbacks related to its employment into a typical residential dwelling. A comparison among various insulating materials has been carried out. The study focuses also on processes and input materials which cause the main environmental impacts of the product, and points out critical issues and the life-cycle steps with the highest improvement potentials
Article
An alternative expedite experimental set-up is proposed to evaluate the thermal insulation performance of corn cob particleboards. Testing in situ thermal insulation performance under real thermal and hygrometric conditions, using more realistic sample dimensions, testing simultaneously several samples and monitoring continuously for several days the thermal behavior of a product are some advantages of this proposed technique. Therefore, it has shown to be accurate and versatile. Through this experimental methodology, a parametric thermal insulation study of the corn cob particleboard in which the impact of its thickness on its thermal insulation performance was also possible to perform.
Article
Calculation of Cumulative Energy Demand (CED) of various energy systems and the computation of their Energy Yield Ratio (EYR) suggests that one single renewable energy technology cannot be said to be the best. Due to the difference in availability of renewable energy sources, their suitability varies from place to place. Wind energy converters, solar water heating systems and photovoltaic systems have been analysed for different types of locations. Comparing the general bandwidth of performance of these technologies, however, the wind energy converters tend to be better, followed by solar water heating systems and photovoltaic systems. Since a major part of the methodology of findingCED is very close to that of life cycle assessment and also because of the dominance of environmental impacts caused by the energy demand in the entire life cycle of any product or system, it is suggested that theCED can be used as an indicator of environmental impacts, especially in the case of power producing systems. Keywords: Cumulative energy demand; life cycle assessment; energy yield ratio; photovoltaics; solar water heating; wind energy Abbreviations: CED — Cumulative Energy Demand; EYR — Energy Yield Ratio; LCA — Life Cycle Assessment; Photovoltaics — PV; WEC — Wind Energy Converters
Article
Nitrogen compounds emitted from the field are usually considered in Life Cycle Assessments (LCA) of agricultural products or processes. The environmentally most important of these N emissions are ammonia (NH3), nitrous oxide (N20) and nitrate (N03). The emission rates are variable due to the influence of soil type, climatic conditions and agricultural management practices. Due to considerable financial and time efforts, and great variations in the results, actual measurements of emissions are neither practical nor appropriate for LCA purposes. Instead of measurements, structured methods can be used to estimate average emission rates. Another possibility is the use of values derived from the literature which would, however, require considerable effort compared to estimation methods, especially because the values might only be valid for the particular system under investigation. In this paper methods to determine estimates for NH3, N20 and NO3 emissions were selected from a literature review. Different procedures were chosen to estimate NH3 emissions from organic (Horlacher &Marschner, 1990) and mineral fertilizers (ECETOC, 1994). To calculate the N2O emissions, a function derived by Bouwman (1995) was selected. A method developed by the German Soil Science Association (DBG, 1992) was adopted to determine potential NO3 emissions. None of the methods are computer-based and consequently require only a minimum set of input data. This makes them, on the one hand, transparent and easy to perform, while, on the other hand, they certainly simplify the complex processes.
Article
Bast fibres of, for example, flax and hemp are used as raw materials of thermal insulations. However, they have only a minor share in the market. The aim of this paper was to evaluate the suitability of bast fibres of flax and hemp for thermal insulations. The functions and requirements of the bast fibrous insulations and their combustion resistance are discussed. Thermal conductivity and the effects of several parameters on thermal performance are reviewed. The potential and costs of the raw material and quality and ecological aspects are also discussed. Finally, needs for future research is proposed.
Les filières lin et chanvre au coeur des enjeux des matériaux biosourcés émergents
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Agribalyse: Rapport Methodologique
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Etude sur le secteur et les filières de production des matériaux et produits bio-sourcés utilisés dans la construction (à l'exception du bois)
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