| 1. |
- Ebrahimian, Farinaz, et al.
(författare)
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A biorefinery platform to valorize organic fraction of municipal solid waste to biofuels : An early environmental sustainability guidance based on life cycle assessment
- 2023
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Ingår i: Energy Conversion and Management. - : Elsevier. - 0196-8904 .- 1879-2227. ; 283
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Tidskriftsartikel (refereegranskat)abstract
- The biorefining of biowastes, specifically the organic fraction of municipal solid waste (OFMSW), into biofuels and high-value products is an energy-demanding process, still immature, and largely dependent on the process configuration and efficiency of employed microorganisms. Such issues might undermine the environmental sustainability of the biorefinery by inducing adverse impacts on human health, ecosystem quality, climate change, and resources, which need to be explored before the process scale-up. Hence, this study was performed as early sustainability guidance to investigate the environmental impacts of different biorefinery platforms for biofuels production from OFMSW. More specifically, three pretreatment methods (i.e., acetone organosolv, acid, and hot water), two hydrolysis treatments (i.e., acidic and enzymatic), and two fermentation alternatives (i.e., ethanolic fermentation and acetone-butanol-ethanol (ABE) fermentation) were investigated. Based on European Commission's Joint Research Center instruction, the environmental impacts were studied using consequential life cycle assessment for the macro-level decision context. The results demonstrated that ABE fermentation scenarios were not environmentally favorable because the avoided impacts from final products were not sig-nificant enough to compensate for the induced environmental burdens from acetone pretreatment. On the contrary, the ethanolic fermentation scenarios with either acid or hot water pretreatment outperformed both ABE fermentation and ethanolic fermentation with acetone pretreatment. Based on the results, the scenario including simultaneous dilute acid pretreatment and hydrolysis of OFMSW followed by ethanolic fermentation manifested the best performance in all damage categories, as compared to those including acetone pretreatment or higher consumption of enzymes. Such improvements in this scenario led to the highest net saving of-842 potentially disappeared fraction (PDF)/m2/yr,-249.95 kg CO2 eq, and-3275.22 MJ primary per ton of OFMSW on ecosystem quality, climate change, and resources, respectively, and the lowest net burden of 1.54 x 10-5 disability-adjusted life years (DALY) per ton of OFMSW on human health. The results of sensitivity analysis on this scenario demonstrated that the substitution of excess heat for marginal heat with fossil origin can consid-erably decrease impacts on human health.
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| 2. |
- Ebrahimian, Farinaz, et al.
(författare)
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A critical review on pretreatment and detoxification techniques required for biofuel production from the organic fraction of municipal solid waste
- 2023
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 368
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Tidskriftsartikel (refereegranskat)abstract
- The organic fraction of municipal solid waste (OFMSW) is a widely-available promising feedstock for biofuel production. However, the presence of different inhibitors originating from fruit and food/beverage wastes as well as recalcitrant lignocellulosic fractions hampers its bioconversion. This necessitates a pretreatment to augment the biodigestibility and fermentability of OFMSW. Hence, this review aims to provide the in-vogue inhibitory compound removal and pretreatment techniques that have been employed for efficient OFMSW conversion into biofuels, i.e., hydrogen, biogas, ethanol, and butanol. The techniques are compared concerning their mode of action, chemical and energy consumption, inhibitor formation and removal, economic feasibility, and environmental sustainability. This critique also reviews the existing knowledge gap and future perspectives for efficient OFMSW valorization. The insights provided pave the way toward developing energy-resilient cities while addressing environmental crises related to generating OFMSW.
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| 3. |
- Khoshnevisan, Benyamin, et al.
(författare)
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A critical review on livestock manure biorefinery technologies : Sustainability, challenges, and future perspectives
- 2021
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 135
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Tidskriftsartikel (refereegranskat)abstract
- An ever increasing demand for animal protein products has posed serious challenges for managing the increasingquantities of livestock manure. The choice of treatment technologies is still a complicated task and considerabledebates over this issue still continue. To build a clearer picture of manure treatment framework, this study wasconducted to review the most frequently employed manure management technologies from their state of the art,challenges, sustainability, environmental regulations and incentives, and improvement strategies perspectives.The results showed that most treatment technologies have focused on the solid fraction of manure while theliquid fraction still remains a potential environmental threat. Compared to other waste to energy solutions,anaerobic digestion is the most mature technology to upgrade manure’s organic matter into renewable energy,however the problems associated with high investment costs, operating parameters, manure collection, anddigestate management have hindered its developments in rural areas in developing countries. Bio-oil productionthrough hydrothermal liquification is also a promising solution, as it can directly convert the wet manure intobiofuel. However, lipid-poor nature of manure, operational difficulties, and the need for downstream process toremove nitrogenous compounds from the final product necessitate further research. Livestock manure management(both solid and liquid fractions) under biorefinery approach seems an inevitable solution for futuresustainable development to meet circular bioeconomy requirements. Much research is still required to establish asystematic framework based on regional requirements to develop an integrated manure nutrient recycling andmanure management planning with minimum environmental risks and maximum profit.
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| 4. |
- Mohammadi, Ali, 1983-, et al.
(författare)
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A Critical Review on Advancement and Challengesof Biochar Application in Paddy Fields: Environmental and Life Cycle Cost Analysis
- 2020
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Ingår i: processes. - : MDPI. - 2227-9717. ; 8:10
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Tidskriftsartikel (refereegranskat)abstract
- Paddy fields emit considerable amounts of methane (CH4), which is a potent greenhousegas (GHG) and, thereby, causes significant environmental impacts, even as they generate wealth andjobs directly in the agricultural sector, and indirectly in the food-processing sector. Application ofbiochar in rice production systems will not just help to truncate their carbon footprints, but alsoadd to the bottom-line. In this work, the authors have reviewed the literature on climate change,human health, and economic impacts of using organic residues to make biochar for the additionto croplands especially to rice paddy fields. Biochar-bioenergy systems range in scale from smallhousehold cook-stoves to large industrial pyrolysis plants. Biochar can be purveyed in dierentforms—raw, mineral-enriched, or blended with compost. The review of published environmental lifecycle assessment (E-LCA) studies showed biochar has the potential to mitigate the carbon footprint offarming systems through a range of mechanisms. The most important factors are the stabilization ofthe carbon in the biochar and the generation of recoverable energy from pyrolysis gases produced asco-products with biochar as well as decreased fertiliser requirement and enhanced crop productivity.The quantitative review of E-LCA studies concluded that the carbon footprint of rice produced inbiochar-treated soil was estimated to range from -1.43 to 2.79 kg CO2-eq per kg rice grain, implying asignificant reduction relative to rice produced without a biochar soil amendment. The suppressionof soil-methane emission due to the biochar addition is the dominant process with a negativecontribution of 40–70% in the climate change mitigation of rice production. The review of the lifecycle cost studies on biochar use as an additive in farmlands demonstrated that biochar applicationcan be an economically-feasible approach in some conditions. Strategies like the subsidization ofthe initial biochar capital cost and assignment of a non-trivial price for carbon abatement in futurepricing mechanisms will enhance the economic benefits for the rice farmers.
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