| 1. |
- Aboelazayem, Omar, et al.
(författare)
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Biodiesel Production from High Acid Value Waste Cooking Oil Using Supercritical Methanol: Esterification Kinetics of Free Fatty Acids
- 2017
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Ingår i: European Biomass Conference and Exhibition Proceedings, 25thEUBCE, June 2017. - 2282-5819. - 9788889407172 ; , s. 1381-1387
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Konferensbidrag (refereegranskat)abstract
- In this study, low quality waste cooking oil (WCO) with high total acid value has been used for biodiesel production. The main factors affecting the reaction have been analysed using Response Surface Methodology (RSM). A quadratic model representing the interrelationships between reaction variables and free fatty acids (FFA) conversion has been developed. Analysis of variance (ANOVA) has been used to evaluate the significance of the predicted model. Numerical optimisation predicted the optimum conditions for maximum conversion of FFA at methanol to oil (M:O) molar ratio, temperature, pressure and time of 35:1, 260 °C, 110 bar and 16 min, respectively for 98 % conversion. The predicted optimum conditions have been validated experimentally resulting in 97.7 % conversion of FFA with 0.3 % relative error. Kinetic and thermodynamic data of the esterification reaction has been studied resulting in pseudo first-order reaction with reaction rate constant of 0.00103 s-1, activation energy of 34.5 kJ/mol and Arrhenius constant of 1.26 s-1. Finally, a kinetic reactor has been simulated resulting in 97 % conversion of FFA with 0.716 % relative error from the experimental results.
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| 2. |
- Björnsson, Lovisa, et al.
(författare)
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Grass biomass as biofuel feedstock –sustainable or not?
- 2017
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Ingår i: European Biomass Conference and Exhibition Proceedings, 25thEUBCE, June 2017. - 2282-5819. - 9788889407172 ; 2017, s. 39-40
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Konferensbidrag (refereegranskat)abstract
- Low carbon input due to increasing specialization, intensification and reduced use of bio-fertilizer, leads to soil organic carbon (SOC) decreases in arable land. This is an emerging problem in Europe in general, where 45% of the EU soils have low and declining SOC content. SOC losses from agricultural soils influence soil fertility, putting food security at risk, and contributes to greenhouse gas (GHG) emissions. An agricultural practice rendering loss of SOC is thus not sustainable in the long term, and measures must be taken to reverse this trend. However, existing policies for agriculture and biofuels address these issues in isolation, SOC impact is not considered when sustainability criteria for biofuels are defined in the EU renewable energy directive (RED). The aim of this study was to illustrate the relevance of SOC impact on integrated production of food and grass as energy crop for biofuel production. This diversification of current cereal dominated crop rotations proved an efficient tool to reverse SOC losses, simultaneously producing a grass-based biofuel with low climate impact. Since SOC-related aspects are excluded in EU RED, the GHG reduction calculated according to the directive does, however, not meet the 60% GHG reduction demand. This narrow perspective causes potentially interesting double benefits to be missed.
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| 3. |
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| 4. |
- Dimitriou, Ioannis
(författare)
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Short Rotation Coppice Moving Forward in a Bio-Based Economy
- 2016
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Ingår i: European Biomass Conference and Exhibition Proceedings. - 2282-5819. ; , s. 264-269
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Konferensbidrag (refereegranskat)abstract
- Perennial Short Rotation Woody Crops ("SRC" or "Short Rotation Coppice") are woody species such as willow, poplar, robinia and others. Their cultivation is a good alternative to annual energy crops and can be complementary to existing agricultural systems. Aside from being harvested for energy production, the cultivation of SRCs has many potential benefits compared to annual crops. For instance, they may help to improve water quality, enhance biodiversity, provide ecosystem services (hunting, beekeeping, water supply, fire protection), mitigate animal diseases between farms, prevent erosion, reduce artificial input materials (fertilizers, pesticides) and mitigate climate change due to carbon storage. These advantages have to be promoted to produce sustainable woodchips from SRC, enhancing the positive impacts of SRC to the environment. Thereby, the following sustainability aspects must be considered: SRC has most positive impacts on marginal land and especially as structural elements in the landscape, bordering for instance fields, roads, and electricity lines. The sustainability of the supply chains is specifically addressed in the project SRCplus. The SRCplus project contributes to remove the non-technological barriers of SRC development in Europe through the support of implementing local SRC supply chains. Thereby, synergies with other agricultural uses, ecosystem services and nature conservation measures are exploited. This paper presents first results of the SRCplus project, and discusses sustainability aspects of SRC.
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| 5. |
- Dimitriou, Ioannis
(författare)
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Short Rotation Woody Crops: Experiences from the EU Project SRCplus
- 2017
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Ingår i: European Biomass Conference and Exhibition Proceedings. - 2282-5819. ; , s. 143-149
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Konferensbidrag (refereegranskat)abstract
- Perennial Short Rotation Woody Crops ("SRC" or "Short Rotation Coppice") are woody species such as willow, poplar, robinia and others. Their cultivation is a good alternative to annual energy crops and can be complementary to existing agricultural systems. Aside from being harvested for energy production, the cultivation of SRCs has many potential benefits compared to annual crops. For instance, they may help to improve water quality, enhance biodiversity, provide ecosystem services (hunting, beekeeping, water supply, fire protection), mitigate animal diseases between farms, prevent erosion, reduce artificial input materials (fertilizers, pesticides) and mitigate climate change due to carbon storage. These advantages have to be promoted to produce sustainable woodchips from SRC, enhancing the positive impacts of SRC to the environment. Thereby, the following sustainability aspects must be considered: SRC has most positive impacts on marginal land and especially as structural elements in the landscape, bordering for instance fields, roads, and electricity lines. The sustainability of the supply chains is specifically addressed in the project SRCplus. The SRCplus project contributes to remove the non-technological barriers of SRC development in Europe through the support of implementing local SRC supply chains. Thereby, synergies with other agricultural uses, ecosystem services and nature conservation measures are exploited. This paper presents the final results of the SRCplus project.
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| 6. |
- Egnell, Gustaf
(författare)
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Lessons learned from compliance and verification processes in certification of forestry biomass
- 2023
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Ingår i: European Biomass Conference and Exhibition Proceedings. - 2282-5819. ; , s. 308-310
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Konferensbidrag (refereegranskat)abstract
- The concept of the bioeconomy and the growing demand for biomass have raised concerns about the sustainability of an increased biomass use. To address this issue, various certification systems and labels have been developed to verify compliance with sustainability requirements in bioenergy and bio-based value chains. However, various market requirements and political frameworks make certification complex and difficult to understand. An IEA Bioenergy Task 45 project has analyzed existing certification schemes to better understand methodological differences and compliance factors. This article summarises the main project outcomes regarding relevant compliance and verification parameters such as risk assessments, transparency, auditor competencies and others. Sustainability certification supports sustainable biomass production, but it alone cannot guarantee sustainability. Certification should be part of a broader sustainability governance framework, including national policies and legislation. The complexity and competition of markets and political frameworks can lead to a race to the bottom that jeopardizes trust and reputation. Policy makers and industry need to streamline certification as a driver of change within a functional governance framework.
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| 7. |
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| 8. |
- Ericsson, Niclas, et al.
(författare)
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The effect of Soil Organic Carbon and the Time Frame on the GWP in a Short Rotation Coppice LCA
- 2012
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Ingår i: European Biomass Conference and Exhibition Proceedings. - 2282-5819. ; , s. 2235-2237
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The energy delivered from short rotation coppice willow is expected to increase in Sweden. Expanding the area of willow will lead to land use changes which may affect soil organic carbon stocks. Many previous life cycle assessments on climate impact of willow exclude soil organic stock changes. These studies also use different system time frames, depending on how long the plantation is expected to prevail. In the present work the global warming potential was assessed for a short rotation coppice willow system established on a 20-year old fallow, including and excluding soil organic carbon, using different time frames and functional units. The global warming potential using a time frame of 24 years was -16.3 kg CO2-eq • GJ-1 including soil organic carbon compared to 6.7 kg CO2-eq • GJ-1 when excluded, showing the importance to consider soil organic carbon changes in life cycle assessments of short rotation coppice when a land use change take place. The time frame and the functional unit chosen were also shown to have an influence on the climate impact.
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| 9. |
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| 10. |
- Gebresenbet, Girma
(författare)
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Comparison of Environmental, Social and Economic Approach to the Pruning Utilization within the Europruning Project
- 2016
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Ingår i: European Biomass Conference and Exhibition Proceedings. - 2282-5819. ; , s. 1513-1515
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Konferensbidrag (refereegranskat)abstract
- In the paper an outline of the assessment methodology and the determined results for three types of analysis (environmental, social and economic) are compared. The overall conclusion is, that there is a negative correlation between economic and social analysis results. The social analysis for scenarios, when a farmer collects the branches as a hobby (unpaid labor) gave the highest values of social indicator (SROI). Scenarios with market wages for a handmade collection gave also positive, but not so high SROI results. They also generated high incomes for local energy producer. In this case subsidizing should be considered. For standard business models (with the machinery specialized for pruning) all three analyses - economic, environmental, and social - gave positive results. For social analysis the result (SROI) varied in the range from 2 to 8.
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