| 1. |
- Anerud, Erik, et al.
(författare)
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Kostnadseffektiv och hållbar lagring av flisad skogsråvara och fasta biprodukter
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet syfte var att utvärdera metoder för kostnadseffektiv, hållbar och brandsäker hantering av skogsrester från skogsindustrin. Inom projektet har omfattande lagringsförsök i industriell skala genomförts från Småland till Norrbotten och försöken speglar såväl ett kust- som inlandsklimat som säsongsvariationer. Två huvudsakliga metoder för att öka lagringsbarheten har studerats; täckning, med olika typer av täckningsmaterial, samt sållning av sönderdelad biomassa. Det senare syftar till att dels höja bränslets kvalité, dels reducera mängden finfraktion i materialet. Studien har genomförts inom 7 olika arbetspaket, vilket innefattar lagringsstudier, produktions- och kostnadsstudier av sållning, kostnadsstudier av terminalhantering, materials självuppvärmningspotential, avgasning under lagring, modellering av temperaturutveckling och substansförluster samt hållbarhetsaspekter vid implementering av de olika metoderna. Sammantaget visar studierna att täckning och sållning resulterar i en avsevärt bättre lagringsbarhet. Sållning är den metod som har lett till bäst lagringsbarhet och resultaten från studierna har visat att det ekonomiska värdet på biomassan är ca 20 % högre i sållat material efter lagring jämfört med i osållat. Samtidigt visar studierna att såväl täckning som sållning leder till lägre stacktemperaturer, dvs. minskar risken för brand, och att avgasningen från stackarna minskar. Sållningen medför en kostnad motsvarande ca 10 % av det ekonomiska värdet, men siffran baseras på dieseldrivna mobila enheter. Det är högst troligt att denna kostnad är lägre för stationära sållverk som installeras i serie med befintlig sönderdelningsutrustning. I dessa fall kan el-driven utrustning nyttjas. Ökad lagringsbarhet genom sållning innebär inte enbart erhållande av ett homogenare bränsle av högre kvalitet, lägre avgasning och en energibesparing under själva lagringen. Det ger även förutsättningar för en mer kostnadseffektiv och hållbar hantering av bränslet genom hela kedjan från skog till förbränning. Implementering av en lagringsstrategi i syfte att öka lagrinsbarheten för sönderdelade bränslen kan påverka samtliga steg inom tillförselkedjan, och exempelvis ge ett jämnare maskinutnyttjande över året, lägre produktionskostnader, effektivare transporter, ökad lönsamhet för bränsleproducenterna, ökad möjlighet för anläggande av bränsleproduktionsanläggningar med stationär eldriven utrustning. Implementering av bränsleproduktionsanläggningar skulle i sin tur kunna leda till en säkrare och billigare lagring med mindre risk för självantändning, säkrare bränsleleveranser, bättre kvalitetsövervakning och ökad bränsleanpassning utifrån kundens önskemål. Därtill skulle dessa anläggningar kunna hantera flera olika typer av materialströmmar för olika ändamål och således utgöra noder/biohubbar som fördelar material mellan olika hanteringskedjor.
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| 2. |
- Antti, Lena, et al.
(författare)
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Effects of microwave drying on biomass fatty acid composition and fuel pellet quality
- 2011
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Ingår i: Wood Material Science & Engineering. - : Informa UK Limited. - 1748-0272 .- 1748-0280. ; 6:1-2, s. 34-40
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Tidskriftsartikel (refereegranskat)abstract
- Drying of biomass for fuel pellet production is a time- and energy-consuming process. The objective of this study was to investigate not only whether microwave drying could be an alternative drying method but also whether the microwave treatment brings beneficial chemical properties into the biomass feedstock in terms of, for example, fatty acid composition and, further, whether this could be advantageous in the production of wood pellets. Microwave drying tests were conducted using fresh sawdust from pinewood as a biomass model. In these tests sawdust was dried from weight-based moisture content 0.47 to final moisture contents in the interval 0.08-0.14. The chemical composition, pellet-making and mechanical properties of the pellets were then investigated. It was shown that 0.5 kg sawdust could be dried within 40 min of microwave exposure. The effects of microwave treatment on the fatty and resin acid composition indicated that some changes occurred, but the total amounts were not significantly different from those in oven-dried samples. However, the microwave treatment of sawdust significantly improved pellet density and pellet strength. These results indicate new possibilities to alter fatty and resin acid composition and to improve particle bonding within fuel pellets.
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| 3. |
- Arshadi, Mehrdad, et al.
(författare)
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Antioxidants as additives in wood pellets as a mean to reduce off-gassing and risk for self-heating during storage
- 2018
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Ingår i: Fuel Processing Technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 179, s. 351-358
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Tidskriftsartikel (refereegranskat)abstract
- Spontaneous self-heating and off-gassing of wood pellets during storage is well-recognized problem. The reason for the phenomena is be autoxidation of fatty/resin acids in the pellets material. Two antioxidants, TBHQ (tert-Butylhydroquinone) and PG (propyl gallate), have been used as additives during pellets production in order to investigate how effective these antioxidants are in blocking autoxidation. Off-gassing of volatile aldehydes, CO and CO2 from wood-pellets and depletion of O-2 during storage at room temperature in two different scales of closed storage systems were investigated and antioxidant fortified pellet batches and a reference batch without additive were compared. The results show that TBHQ is an efficient antioxidant at a low concentration (0.5%) in blocking autoxidation of fatty/resin acids in wood pellets. The CO emissions are reduced between 72 and 90% depending on the pellets temperature. Some of the fatty acids are almost intact in the samples with TBHQ compared to reference sample; showing that TBHQ blocking degradation by autoxidation of those fatty acids. For PG, autoxidation has not been blocked. The total amount of emitted aldehydes are 77% less than in pellets made with antioxidants as compared to the reference pellets, showing that TBHQ is acting as inhibitor in the autoxidation processes.
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| 4. |
- Arshadi, Mehrdad, et al.
(författare)
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Bark Assortments of Scots Pine and Norway Spruce as Industrial Feedstock for Tall Oil Production
- 2018
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Ingår i: Forests. - : MDPI AG. - 1999-4907. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Fatty and resin acids in bark residues generated by forest industries can be used to produce high-value green chemicals, but more information about their concentrations in potential sources is required. We examined variations in the content of lipophilic extractives from both pulpwood bark and timber bark of Norway spruce and Scots pine trees growing in homogenous stands in mid-Sweden. We found that spruce pulpwood bark had the highest total amounts of fatty and resin acids (average yield, 0.9 kg/m(3) wood). The regression functions, based on readily available tree parameters (age, stem diameter, height, growth rate and inner bark proportions), can be used to predict the concentrations of fatty and resin acids, triglycerides, sterols and steryl esters in bark materials before harvesting stands that supply industrial plants.
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| 5. |
- Arshadi, Mehrdad
(författare)
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Biochemical production of bioethanol
- 2011
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Ingår i: Handbook of biofuels production: Processes and technologies. - 9781845696795 ; :15, s. 199-220
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Arshadi, Mehrdad
(författare)
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Biomass-Based Energy Production
- 2015
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Ingår i: Introduction to chemicals from biomass. - : Wiley. - 9781118714485 ; , s. 249-284
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Bokkapitel (refereegranskat)
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| 7. |
- Arshadi, Mehrdad, et al.
(författare)
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Biomass-based energy production
- 2015. - 2
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Ingår i: Introduction to chemicals from biomass. - : John Wiley & Sons. - 9781118714485 - 9781118714478 ; , s. 249-284
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Bokkapitel (refereegranskat)abstract
- Today, bioenergy is a practical and increasingly widely available option for heating that is being adopted by many industries and households that are looking to use more sustainable energy sources. Biomass‐derived fuels may be solids, liquids, or gases. They can be classified based on the processes used in their production, which include physical upgrading, microbiological processes, thermochemical processes, and chemical processes. The production of solid fuels from renewable resources has become more important due to the growing global demand for energy and environmental concerns. Various microbial processes can be exploited to utilize energy that has been stored in biomass by photosynthesis. Methanol, ethanol, and butanol are liquid biofuels that can be synthesized from biomass and used in both four‐stroke gasoline and diesel engines. These alcohols can be prepared from sugarcane, sugar beet, wheat, barley, corn, switch grass, agricultural residues, wood, and many other industrial wastes.
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| 8. |
- Arshadi, Mehrdad, et al.
(författare)
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Comparison of fatty and resin acid composition in boreal lodgepole pine and Scots pine for biorefinery applications
- 2013
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Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 49, s. 535-541
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the potential for Scots- and lodgepole pine for biorefinery applications such as e.g., biodiesel and glue production, wood samples from five different sites in northern Sweden were compared. 21 fatty and 10 resin acids were detected by extraction and GC MS analysis. Total fatty- and resin acid contents of Scots pine varied between 2.4 and 41.4 mg/g. Corresponding concentrations for lodgepole pine were 23 and 26.0 mg/g of dry material. Multivariate models were made with principal component analysis to take advantage of the multivariate correlations between the individual acids. Wood tissue type explained most of the variation in fatty and resin acid content, with heartwood having up to five times the extractive concentration of sapwood. Resin acids were mainly associated with heartwood, while fatty acids were more associated with sapwood. A five-component PLSDA-model distinguished between the two species, mainly due to differences in their hexadecanoic and heptadecanoic acid contents. Heartwood from Scots pine is more suitable for resin extraction while lodgepole pine is a better option for fatty- and resin acid extraction because of the extractives' evenly distribution between wood types. Around 150 kg of fatty acids and 1 ton of resins can be harvested per hectare from a typical mature boreal lodgepole pine stand, for biorefinery use. Systematic fractionation and selection of heartwood and sapwood will likely optimize industrial applications (e.g. biodiesel production) of each fraction. (C) 2013 Elsevier B.V. All rights reserved.
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| 9. |
- Arshadi, Mehrdad, et al.
(författare)
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Emission of Volatile Aldehydes and Ketones from Wood Pellets under Controlled Conditions
- 2009
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Ingår i: Annals of Occupational Hygiene. - : Oxford University Press (OUP). - 0003-4878 .- 1475-3162. ; 53, s. 797-805
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Tidskriftsartikel (refereegranskat)abstract
- Different qualities of biofuel pellets were made from pine and spruce sawdust according to an industrial experimental design. The fatty/resin acid compositions were determined by gas chromatography-mass spectrometry for both newly produced pellets and those after 2 and 4 weeks of storage. The aldehydes/ketones compositions were determined by high performance liquid chromatography at 0, 2, and 4 weeks. The designs were analyzed for the response variables: total fatty/resin acids and total aldehydes/ketones. The design showed a strong correlation between the pine fraction in the pellets and the fatty/resin acid content but the influence decreased over storage time. The amount of fatty/resin acids decreased similar to 40% during 4 weeks. The influence of drying temperature on the aldehyde/ketone emission of fresh pellets was also shown. The amounts of emitted aldehydes/ketones generally decreased by 45% during storage as a consequence of fatty/resin acid oxidation. The matrices of individual concentrations were subjected to multivariate data analysis. This showed clustering of the different experimental runs and demonstrated the important mechanism of fatty/resin acid conversion.
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| 10. |
- Arshadi, Mehrdad
(författare)
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Food Supply Chain Waste: Emerging Opportunities
- 2016
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Ingår i: Chemicals and Fuels from Bio-Based Building Blocks. - Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA. - 9783527338979 ; , s. 667-680
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Bokkapitel (refereegranskat)
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