| 1. |
- Björnsson, Lovisa, et al.
(författare)
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Bioolja från befintliga kraftvärmeverk-en systemstudie : Sammanfattning av ett forskningssamarbete mellan Lunds Tekniska Högskola, Karlstad universitet och Kraftringen Energi
- 2021. - Rapport 123
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Rapport (populärvet., debatt m.m.)abstract
- Samhällets pågående omställning mot minskade utsläpp av växthusgaser kräver bland annat stora mängder fasta biobränslen och flytande biodrivmedel. Den svenska biobränslepotentialen domineras av bi- och restprodukter från skogen, som sågspån från sågverken och grenar och toppar (sk grot) från avverkning av skog. Att omvandla trä till flytande bränslen med hög omvandlingseffektivitet är utmanande, och kräver kommersialisering av ny och innovativ teknik. Behovet av flytande biodrivmedel i transportsektorn har därför hittills framför allt tillgodosetts genom import. Ett utökat och resurseffektivt utnyttjande av den inhemska potentialen av biomassa från skogen skulle kunna vara en viktig komponent i att nå både målet om ett fossilfritt samhälle och mål om miljömässig hållbarhet och spårbarhet för råvaran. Kraftvärmesektorn är i stora delar redan fossilfri och hanterar redan idag inhemska fasta bio-bränslen från skogen. I befintliga kraftvärmeverk finns potential för ökad nyttjandegrad av anläggningen, en befintlig infrastruktur för bränslehantering och möjlighet till värmeavsättning i fjärrvärmenät. Detta skapar förutsättningar för att i tillägg till el och värme komplettera med processer för produktion av flytande energibärare från inhemska, spårbara och hållbara biobränslen från skogen.I denna skrift sammanfattas ett forskningsprojekt där möjligheten att vidareutveckla en befintlig kraftvärmeanläggning genom integrerad produktion av pyrolysolja undersökts. Vi har ställt oss frågor som: Kan vi åstadkomma inhemsk produktion av flytande bränsle från skogsbaserade fasta biobränslen genom att kraftvärmeproduktion kombineras med pyrolysoljeproduktion? Kan detta förbättra konkurrenskraften för kraftvärmeverket vid ett framtida vikande behov av fjärrvärme inom bostadssektorn? Vad innebär möjligheten att bli producent av pyrolysolja både för egen förbrukning och för andra marknader som transportsektorn, för kraftvärmeverket och för klimatet?
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| 2. |
- Björnsson, Lovisa, et al.
(författare)
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Integrating bio-oil production from wood fuels to an existing heat and power plant - evaluation of energy and greenhouse gas performance in a Swedish case study
- 2021
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Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 48
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Tidskriftsartikel (refereegranskat)abstract
- Combined heat and power (CHP) production in combination with a district heating (DH) grid gives an energy efficient use of wood fuels. The heat demand in the DH grid will, however, decline in the coming decades, and operators are seeking additional heat sinks. In this case study, the integration of a pyrolysis unit into an existing CHP plant was investigated as a possible solution. The retrofitted pyrolysis unit makes use of excess heat and yields a liquid bio-oil. Pyrolysis integrated with CHP production was shown to give a net energy yield of at least 80%, and to decrease the net heat output to the DH grid. The carbon footprint of the delivered heat was very low at maximum 1.6 g CO(2)eq/MJ. Prolonging the operation of the pyrolysis unit to periods without heat delivery to the DH grid would increase the use of existing installations, but at the cost of energy yields decreasing to 63-70%. Up to 2.8 PJ(LHV)/yr crude bio-oil could be produced at the investigated CHP plant. The bio-oil was shown to have a low carbon footprint, 1.7-4.0 g CO(2)eq/MJ(LHV), which makes it attractive for the rapidly expanding transport biofuel market.
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| 3. |
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| 4. |
- Pettersson, Malin, et al.
(författare)
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Recycling of ash from co-incineration of waste wood and forest fuels: An overlooked challenge in a circular bioenergy system
- 2020
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Ingår i: Biomass & Bioenergy. - : Elsevier BV. - 0961-9534. ; 142C
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Tidskriftsartikel (refereegranskat)abstract
- Wood ash recycling to forests after logging residues harvest is important to ensure long-term sustainable forest management, however, it is not recycled in Sweden at the level required to compensate for current logging residue out-take. A problem in this context is wood ash contamination through co-incineration of waste wood with forest fuels, a practice driven by the political goal of a circular bioenergy system. We performed a case study of co-incineration at a typical Swedish district heating (DH) plant, which showed that the forest fuel ash alone could be recycled to forests due to high nutrient levels. Co-incineration with waste wood resulted however in such high levels of contaminants that the ash was landfilled as hazardous waste. Our assessment of the Swedish DH sector showed that wood ash contamination through co-incineration is common, and that only a minor proportion of the ash from forest fuels is recycled to the forest. It also revealed a lack of reliable data regarding ash production and management, making implementation and evaluation of effective countermeasures difficult. Practical measures to enable wood ash recycling, such as removal of waste wood from the fuel mix, incineration of separate fuels, and ash after-treatment, are hampered by technical and economic barriers. Furthermore, no comprehensive policy tools currently exist on either a national or EU level that facilitate wood ash recycling. Thus, we conclude that comprehensive and efficient policy tools are urgently needed to overcome current barriers, and stimulate large-scale recycling of wood ash for long-term sustainable forest fuel utilisation.
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| 5. |
- Pettersson, Malin, et al.
(författare)
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Reductions in greenhouse gas emissions through innovative co-production of bio-oil in combined heat and power plants
- 2022
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619. ; 324
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Tidskriftsartikel (refereegranskat)abstract
- Integrating fast pyrolysis into existing biomass-based combined heat and power (CHP) plants offers an innovative opportunity for plant operators to acquire an additional heat sink and produce a renewable transport fuels feedstock. This technology is particularly interesting in Sweden, where biobased heat and power constitute an important part of the energy system. It is important to establish the GHG emissions reduction of the production, through e.g. substitution effects in the transport sector, to ensure coherence with climate ambitions. In this study, the GHG emission avoidance methodology in the newly introduced EU Innovation Fund (IF) was adapted to determine whether integrating bio-oil production into an existing wood-fuelled CHP plant through fast pyrolysis would lead to a significant reduction in GHG emissions compared to the status quo. The results showed a reduction in GHG emissions of up to 0.24 MtCO2-eq per year, due mainly to the replacement of fossil fuels in the transport sector. A potential production volume in existing Swedish CHP plants was estimated to be 6.8–8.1 Mt of bio-oil annually, leading to a GHG emission avoidance of 8.6–10.3 MtCO2-eq/y, requiring a wood fuel input of 181–185 PJ/y. Sensitivity analysis indicated a significant potential for the reduction using input parameters for heating, electricity and hydrogen production whether pre-defined in the IF methodology or determined from case-specific conditions. However, the detailed results indicate that case-specific conditions should be used to reflect the fact that different European countries are at different stages in the transition to a fossil-free energy system. In conclusion, according to IF-based calculations, commercialisation of combined heat, power and bio-oil technology could lead to significant GHG emission avoidance across multiple sectors.
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