| 1. |
- Gunnarsson, Carina, et al.
(författare)
-
Utvinning av högvärdiga komponenter för förbättrad värdekedja för vall till etanol och bioolja
- 2022
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Grass-clover ley holds an importance role for a sustainable crop production and is mainly used as feed for ruminants. But ley also contains proteins, if extracted, suitable for monogastric animals such as pigs and poultry. If these proteins are extracted, the degree of self-sufficiency of proteins in Sweden can increase and better resource utilization is achieved. In this study we evaluated the utilization of fresh and ensiled grass-clover ley in a straw-based agricultural biorefinery for producing protein concentrate, ethanol, bio-oil and biogas.Practical lab scale tests of extraction of high value components for food and feed applications from the liquid fraction after ley pressing were carried out. Pretreatments of the solid fraction prior to ethanol fermentation, bio-oil production using HTL (hydrothermal liquefaction) and biogas production were tested. The system for production and supply of the ley was described and the potential for increased ley production in Sweden was quantified. The environmental and economic efficiency of the proposed biorefinery system was evaluated using environmental systems analysis and technoeconomic assessment.In terms of system profitability, a high protein yield in the extracted protein concentrate it is important. To achieve that, a thorough pre-treatment using mechanical biomass disintegration before fractioning is crucial. This may need to be done in several steps. Screw pressing is a common technique for fractionating ley into a liquid and solid fraction. Double pressing combined with enzymatic treatments or only water addition during the second pressing stage were found to increase the protein yield compared to single pressing. Second pressing had no effect on the amino acid profile of the protein concentrate.After pressing fresh ley, heat coagulation or isoelectric precipitation can be used to precipitate protein concentrates in one- or two-step processes to produce protein fractions with different functional properties. Tests showed that it is possible to recover chlorophyll and carotenoids from the ley using supercritical carbon dioxide extraction. which is a suitable method for food applications as toxic organic solvents can be avoided. The ensiling process degrades the protein into smaller peptides or free amino acids which makes ensiled grass less suitable for protein recovery by heat coagulation or isoelectric precipitation. Fresh and ensiled timothy and meadow fescue showed a similar amino acid profile as soybeans.The initial hypothesis that mechanical pressing may disintegrate the lignocellulosic structure of ley sufficiently to produce a sugar stream with a high concentration of sugar for further fermentation by enzymatic hydrolysis was not confirmed. The content of sugars released after the enzymatic hydrolysis was relatively low. The fibre fraction after the mechanical pressing can be suitable for ethanol production if an additional pretreatment method will be incorporated. Fermentation of pressed and steam-exploded ensiled mixed ley showed promising results. The bio-oils produced with the HTL-process were described of high quality, i.e., high carbon content and low ash content. Although, the obtained materials are not directly integrable in today's refineries, the ensiling did not seem to affect the material's potential for biofuel production. The methane potential tests that were carried out in the project of the liquid residual fraction after protein extraction and after the HTL process showed that both can be suitable for methane production, but they showed great behavior differences.The results from the environmental system analysis showed that extraction of high-quality products from ley, straw and sawdust according to the studied system reduces climate impact (CO2 eq) when the use of ethanol, bio-oil and biogas replaces fossil fuels, protein concentrate replaces soy as feed and carbon dioxide replaces fossil carbon dioxide. At present, the climate impact from extracted protein concentrate is higher than for soybean meal. Grass source for protein extraction followed by ethanol and bio-oil production as an alternative to straw-based ethanol and bio-oil production did not seem to improve the profitability of the studied biorefinery system. Profitability may be improved if protein extraction is performed the whole all year and not seasonal. Higher prices of the extracted protein concentrate may also improve profitability.The potential for increased grassland cultivation in Sweden for biorefining was estimated at approximately 3.4 million tonnes grass per year. This included incorporating grassland in the crop rotation in grain-dominated areas, intensification of existing grassland cultivation, utilization of fallow and abandoned arable land for grassland cultivation.Based on the results and the experience acquired from this project, we suggest an extraction plant for grass-clover ley that operates for both fresh and ensiled grassland all year. The plant needs to be supplemented with more advanced technologies such as membrane filtration for the extraction of amino acids from the ensiled ley during the winter season. The protein extraction plants should be located near farms. The extraction plant is also suggested to be located together with a biogas plant to enable co-digesting residual fractions with manure. Thereby, enabling plant nutrients and minerals in digestate to be returned to arable land. Utilizing the solid fiber fraction for biofuel production with fermentation and HTL in large-scale processes remains promising.
|
|
| 2. |
- de Toro, Alfredo, et al.
(författare)
-
Effects of variable weather conditions on baled proportion of varied amounts of harvestable cereal straw, based on simulations
- 2021
-
Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 13:16
-
Tidskriftsartikel (refereegranskat)abstract
- All harvestable cereal straw cannot be collected every year in regions where wet periods are probable during the baling season, so some Swedish studies have used 'recovery coefficients’ to estimate potential harvestable amounts. Current Swedish recovery coefficients were first formu-lated by researchers in the early 1990s, after discussions with crop advisors, but there are no recent Swedish publications on available baling times and recovery proportions. Therefore, this study evaluated baling operations over a series of years for representative virtual farms and machine systems in four Swedish regions, to determine the available time for baling, baled straw ratio and annual variation in both. The hourly grain moisture content of pre-harvested cereals and swathed straw was estimated using moisture models and real weather data for 22/23 years, and the results were used as input to a model for simulating harvesting and baling operations. Expected available baling time during August and September was estimated to be 39–49%, depending on region, with large annual variation (standard deviation 22%). The average baling coefficient was estimated to be 80– 86%, with 1400 t·year−1 harvestable straw and 15 t·h−1 baling capacity, and the annual variation was also considerable (s.d. 20%). © 2021 by the authors.
|
|
| 3. |
- de Toro, Alfredo, et al.
(författare)
-
Väderlekens inverkan på pressning av halm : Bedömning av leveranssäkerhet baserat på simulering
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det övergripande syftet med denna studie var att undersöka leveranssäkerheten för halm kopplat till risker på grund av dåliga väderförhållanden vid skörd samt utvärdera regionala skillnader i fyra viktiga odlingsområden i landet. Väderlekens inverkan på halmens vattenhalt i sträng och halmmängd som kunde pressas vid varierande gårdsstorlek, bärgningsperiod och halmmängd undersöktes. Med hjälp av simuleringsmodeller och historiska väderleksdata från 22-23 år beräknades vattenhalten på timbasis för spannmålskärna i den stående grödan och för halm i sträng. Skördetröskning och halmpressning simulerades med en annan modell under samma period, där en kort pressningsperiod till sluten av augusti och en längre period till mitten av september utvärderades. Väderlekens inverkan på pressningsförloppet uppskattades, samtidigt som begränsande och känsliga faktorer identifierades. De årliga pressade halmmängderna beräknades för typgårdar med 100, 300 och 600 ha spannmålsareal, belägna i Västmanland, Östergötland, Västra Götaland och Skåne.
|
|
| 4. |
- Pari, L., et al.
(författare)
-
Performance and work quality of the chaff collection in Sweden : A case study
- 2021
-
Ingår i: European Biomass Conference and Exhibition Proceedings. - : ETA-Florence Renewable Energies. ; , s. 207-210
-
Konferensbidrag (refereegranskat)abstract
- Grain chaff could provide 54.8 Mt of additional annual potential biomass in Europe. In the framework of the AGROinLOG H2020 Project, the chaff collection system developed by Thierart company was tested in Sweden to evaluate the amount of biomass collectible, the harvesting losses and performance, and the economic feasibility of the system. Such system allows to collect the chaff separately onto a trailer. The total residual biomass increased by 0.84 t ha−1 without negatively affecting the performance of the combine.
|
|
| 5. |
- Casimir, Justin, et al.
(författare)
-
Farmers current practices, and their opinion on supplying straw for production of second-generation biofuels in Sweden
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents results from the EU project AGROinLOG (Grant Agreement 727921) and especially focuses on the results from a survey looking at the current practices with straw use in Sweden as well as the farmer’s opinion on supplying straw for the production of second-generation biofuel. The survey was developed as a collaboration between LRF (Federation of Swedish farmers) RISE and Lantmännen.The reader can first read about the context within which the survey was developed and analysed. The questions and the methodology are then presented. The main part of the report presents the questionnaire results before drawing conclusions in line with the project’s objectives.The survey shows that about 60% of the straw from farmers participating in the survey, remains in the field while 40% is harvested mostly for animal production. The county of Skåne, the “ÖSÖ” region (Östergötland, Södermanland, and Örebro counties), the region including Uppsala, Stockholm and Västmanland counties, and the county of Västra Götaland have the largest potential for collection of straw for industrial processes in Sweden. However, farmers from these regions are the most concerned about the decrease of soil quality due to straw removal. The current common practices for straw handling in Sweden, including baling, collection, transport, storage and sale, are highlighted.Some interesting conclusions are drawn concerning the logistics needed for the handling of straw for the biobased industry. Moreover, the answers from the survey give some insights concerning a potential “straw contract” between Lantmännen and the farmers. The report also highlights the aspects to be further researched.More information concerning the Swedish contribution to the AGROinLOG project can be found in the public report AGROinLOG (2020a).
|
|
