| 1. |
- Broberg, Sarah, et al.
(författare)
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Biogas production supported by excess heat - A systems analysis within the food industry
- 2015
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Ingår i: Energy Conversion and Management. - : Elsevier. - 0196-8904 .- 1879-2227. ; 91, s. 249-258
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this paper was to study the effects on greenhouse gases and economics when a change is made in the use of industrial organic waste from external production and use of biogas (A) to internal production and use (B). The two different system solutions are studied through a systems analysis based on an industrial case. The baseline system (A) and a modified system (B) were compared and analysed. Studies show that industrial processes considered as integrated systems, including the exchange of resources between industries, can result in competitive advantages. This study focuses on the integration of internally produced biogas from food industry waste produced by a food company and the use of excess heat. Two alternative scenarios were studied: (1) the use of available excess heat to heat the biogas digester and (2) the use of a part of the biogas produced to heat the biogas digester. This study showed that the system solution, whereby excess heat rather than biogas is used to heat the biogas digester, was both environmentally and economically advantageous. However, the valuation of biomass affects the magnitude of the emissions reduction. Implementing this synergistic concept will contribute to the reaching of European Union climate targets. (C) 2014 Elsevier Ltd. All rights reserved.
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| 2. |
- Feiz Aghaei, Roozbeh, et al.
(författare)
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Key performance indicators for biogas production : methodological insights on the life-cycle analysis of biogas production from source-separated food waste
- 2020
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 200
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Tidskriftsartikel (refereegranskat)abstract
- The anaerobic digestion of food waste can not only enhance the treatment of organic wastes, but also contributes to renewable energy production and the recirculation of nutrients. These multiple benefits are among the main reasons for the expansion of biogas production from food waste in many countries. We present methodological insights and recommendations on assessing the environmental and economic performance of these systems from a life-cycle perspective. We provide a taxonomy of the value chain of biogas from food waste which describes major activities, flows, and parameters across the value chain with a relatively high detail. By considering the multiple functions of biogas production from food waste, we propose a few key performance indicators (KPI) to allow comparison of different biogas production systems from the perspectives of climate impact, primary energy use, nutrients recycling, and cost. We demonstrate the operational use of our method through an example, where alternatives regarding the heat supply of the biogas plant are investigated. We demonstrate how global and local sensitivity analyses can be combined with the suggested taxonomy and KPIs for uncertainty management and additional analyses. The KPIs provide useful input into decision-making processes regarding the future development of biogas solutions from food waste. (C) 2020 Elsevier Ltd. All rights reserved.
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| 3. |
- Feizaghaii, Roozbeh, 1975-, et al.
(författare)
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The biogas yield, climate impact, energy balance, nutrient recovery, and resource cost of biogas production from household food waste — A comparison of multiple cases from Sweden
- 2022
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Ingår i: Journal of Cleaner Production. - : Elsevier Science Ltd. - 0959-6526 .- 1879-1786. ; 378
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Tidskriftsartikel (refereegranskat)abstract
- The depletion of natural resources, climate change and energy security are some of today's societal challenges. One way to address these is through anaerobic digestion of food waste, which provides multiple benefits such as waste treatment, nutrient recycling and renewable energy, such as biogas. Biogas solutions tend to vary, so to gain a holistic understanding of their pros and cons there is a need to use a common analytical approach and simultaneously consider several issues. This study has analysed the climate impact, primary energy use, nutrient recycling potential, and resource cost of producing biogas from food waste in three Swedish biogas plants with different setups. In addition, several scenarios representing changes in the existing systems were analysed. The study aims to provide insights into factors that affect the performance of biogas production from food waste. The method applied is based on life cycle analysis and key performance indicators (KPIs), which were used to compare and analyse the performance of the biogas systems. The analysis synthesises a large amount of information about the performance of these systems and their sub-systems. Despite significant differences between the studied cases, all led to the production of biomethane with a low climate impact (62–80% less climate impact in grCO2eq/MJ compared with the fossil reference), low non-renewable primary energy use (16–31% MJ per MJ delivered biomethane), and significant nutrient recovery (e.g., 52–86% of phosphorus content of food waste was delivered as biofertilizer). In addition to the collection system, the efficiency of pretreatment, the choice of energy system (e.g., for heating the biogas plant), and a suitable digestate treatment were found to be among the main factors that influence the overall performance of these systems.
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| 4. |
- Hofko Lindkvist, Emma, et al.
(författare)
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National survey of physicians in Swedish child health centres finds insecurity and unawareness regarding management of undescended testicles
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Ingår i: Acta Paediatrica, International Journal of Paediatrics. - 0803-5253.
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To investigate underlying factors for previously reported shortcomings in child health centres' (CHC) referral process of boys with undescended testicles. Methods: A total of 386 physicians working at Swedish CHCs were surveyed regarding their knowledge about undescended testicles and their clinical management. Multivariate regression analyses were performed to identify risk factors of non-adherence to guidelines and self-reported lack of clinical skills. Results: The overall knowledge of the health benefits of undescended testicle surgery was high (89%), while two-thirds were unaware of surgery being recommended <1 year of age. One-fifth of respondents had never received guidance on examination techniques. Male gender (adjusted odds ratio [aOR] 0.51, 95% confidence interval [95% CI] 0.31–0.86), education in paediatrics (aOR 0.37, 95% CI 0.18–0.76) and more experience (aOR 0.02, 95% CI 0.01–0.09) significantly decreased the risk of unfamiliarity with examinations. More experience decreased the risk of stating the incorrect indications for undescended testicle surgery (aOR 0.17, 95% CI 0.03–0.95) and finding examinations difficult (aOR 0.22, 95% CI 0.07–0.72). Medical education outside Nordic countries was a risk factor for unawareness of guidelines (aOR 2.06, 95% CI 1.21–3.51). Conclusion: The knowledge and confidence level of the study population varied widely. The results indicate a need for further theoretical and practical education among Swedish CHC physicians.
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| 5. |
- Johansson, Markus, et al.
(författare)
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Effects of the Covid-19 pandemic on the Swedish Biogas Sector
- 2024
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Ingår i: Energy for Sustainable Development. - : ELSEVIER. - 0973-0826 .- 2352-4669. ; 78
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Tidskriftsartikel (refereegranskat)abstract
- With a growing population, the world requires solutions that provide energy, waste management, transportation, and nutrient recovery in a sustainable manner. Biogas is a local system solution that can fill these needs and make society more self-sufficient. In an increasingly uncertain world, forthcoming crises and external economic pressure will affect industries, including biogas, and lead to higher risk. To manage these uncertainties and to create resilience, knowledge needs to be gathered on how industries providing system solution, such as the biogas industry, are affected by crises. The Covid-19 pandemic offers the possibility to analyse the effects of a global crisis in real-time. The aim of this study is to investigate the effects the covid-19 pandemic had on the production, distribution, and demand of biogas in Sweden. Ten semi-structured interviews were carried out with different actors in the biogas value chain. Some key findings in the result include continued availability of substrate for biogas production but with a changed composition, increased demand for biofertilizer and smallscale production of biogas, and disturbances in biogas related policies. The underlying factors contributing to these effects can be attributed to pandemic related restrictions, disturbances in logistical chains, increased energy prices and political factors. The lessons learned are that the biogas industry should try to be decoupled from policies and review the resilience of the supply chains. If this is managed, biogas is a way forward for providing waste management, transportation fuel and nutrient recovery while facilitating the transition towards selfsufficient and sustainable societies with resilience against global crises.
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| 6. |
- Johansson, Maria, 1968-, et al.
(författare)
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Methodology for Analysing Energy Demand in Biogas Production Plants : A Comparative Study of Two Biogas Plants
- 2017
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Ingår i: Energies. - : MDPIAG. - 1996-1073. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- Biogas production through anaerobic digestion may play an important role in a circular economy because of the opportunity to produce a renewable fuel from organic waste. However, the production of biogas may require energy in the form of heat and electricity. Therefore, resource-effective biogas production must consider both biological and energy performance. For the individual biogas plant to improve its energy performance, a robust methodology to analyse and evaluate the energy demand on a detailed level is needed. Moreover, to compare the energy performance of different biogas plants, a methodology with a consistent terminology, system boundary and procedure is vital. The aim of this study was to develop a methodology for analysing the energy demand in biogas plants on a detailed level. In the methodology, the energy carriers are allocated to: (1) sub-processes (e.g., pretreatment, anaerobic digestion, gas cleaning), (2) unit processes (e.g., heating, mixing, pumping, lighting) and (3) a combination of these. For a thorough energy analysis, a combination of allocations is recommended. The methodology was validated by applying it to two different biogas plants. The results show that the methodology is applicable to biogas plants with different configurations of their production system.
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| 7. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Kjær, Christina, et al.
(författare)
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A new setup for low-temperature gas-phase ion fluorescence spectroscopy
- 2021
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 92:3
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Tidskriftsartikel (refereegranskat)abstract
- Here, we present a new instrument named LUNA2 (LUminescence iNstrument in Aarhus 2), which is purpose-built to measure dispersed fluorescence spectra of gaseous ions produced by electrospray ionization and cooled to low temperatures (<100 K). LUNA2 is, as an earlier room-temperature setup (LUNA), optimized for a high collection efficiency of photons and includes improvements based on our operational experience with LUNA. The fluorescence cell is a cylindrical Paul trap made of copper with a hole in the ring electrode to permit laser light to interact with the trapped ions, and one end-cap electrode is a mesh grid combined with an aspheric condenser lens. The entrance and exit electrodes are both in physical contact with the liquid-nitrogen cooling unit to reduce cooling times. Mass selection is done in a two-step scheme where, first, high-mass ions are ejected followed by low-mass ions according to the Mathieu stability region. This scheme may provide a higher mass resolution than when only one DC voltage is used. Ions are irradiated by visible light delivered from a nanosecond 20-Hz pulsed laser, and dispersed fluorescence is measured with a spectrometer combined with an iCCD camera that allows intensification of the signal for a short time interval. LUNA2 contains an additional Paul trap that can be used for mass selection before ions enter the fluorescence cell, which potentially is relevant to diminishing RF heating in the cold trap. Successful operation of the setup is demonstrated from experiments with rhodamine dyes and oxazine-4, and spectral changes with temperature are identified.
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| 9. |
- Kreuger, Emma, et al.
(författare)
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Biogas från Skånsk betblast - potential, teknik och ekonomi
- 2014
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Rapport (populärvet., debatt m.m.)abstract
- Sammanfattning I Skåne odlas 34 500 ha sockerbetor för sockerutvinning och i Sverige 36 000 ha (Jordbruksstatistik årsbok 2014). Vid insamling och rötning av blasten från betorna i Skåne skulle drygt 200 GWh biogas kunna produceras per år och driva minst 19 000 bilar eller 1000 bussar. Men idag lämnas den i fält. Tidigare studier har visat att betblast från sockerproduktion är på gränsen till lönsamt att skörda och använda för biogasproduktion (Lantz, 2013b). I det här projektet har flera forskare, en biogasproducent och en representant för betodlarna gemensamt tagit fram och undersökt ett par förslag för hur skörd, lagring och rötning av betblast kan genomföras och hur olika tillvägagångssätt påverkar kostnader och klimatpåverkan. Dessa innefattar en jämförelse av två olika skördekedjor och undersökning av effekterna av att fraktionera betblast före lagring och rötning på; biogasproduktion, ekonomi och klimatpåverkan. För dessa beräkningar antogs att endast betblast rötades i en biogasanläggning med en årlig produktion om 172 TJ (48 GWh) metan. Effekterna av att introducera icke fraktionerad och fraktionerad betblast i en samrötningsanläggning analyserades också. Dessutom arrangerades en skördedemonstration i oktober 2013 i samarbete med Skånska Biobränslebolaget (länk till video). Analysen av skördeteknik har begränsats till skörd av blast från betor odlade för sockerproduktion, vilket är det som görs i Sverige idag. Om sockerbetor odlas endast för biogasproduktion kan andra skördetekniker för betor och blast vara aktuella. Studien har visat att när biogas från betblast ersatte fossil energi som drivmedel så sänktes utsläppen av klimatgaser kraftigt, med 80 %. Därmed uppfylldes EUs hållbarhetskriterier för biodrivmedel, både enligt dagens direktiv (35 % reduktion) och föreslagna framtida (60 % reduktion). Viktigt i detta sammanhang är att blasten är en restprodukt och den konkurrerar inte om åkermark för livsmedelsproduktion. I Skåne skulle ca 200 GWh biogas kunna produceras från betblast vid dagens sockerbetsproduktion. Men, även för den andel av blasten som skördas under september (motsvarande ca 40 GWh), då det är mer gynnsamt än vid senare skörd, är det svårt att hitta ekonomisk hållbarhet. Studien tyder på att kostnader och klimatpåverkan är de samma om betblast fraktioneras eller ej. I fallstudien framkom att fraktionering av betblasten gav praktisk möjlighet att ta emot mer material i den studerade samrötningsanläggningen. Vätskefraktionen kunde då ersätta vatten i förbehandlingen och mera torrsubstans (TS) kunde tas emot med den fasta fraktionen innan uppehållstiden begränsade mängden i rötningsprocessen. Att ersätta vatten i förbehandlingsanläggningen ger mindre kapitalkostnader per producerad MWh jämfört med om man skulle röta denna fraktion i en dedikerad anläggning. Men, inte heller i fallstudien medförde fraktionering lägre kostnader per producerad mängd metan. Blastskörden visade sig vara högre i september, 3,6 ton torrsubstans per hektar (t TS/ha), än i oktober, 3,2 t TS/ha, vilket gör det fördelaktigare att samla in blast i september än oktober. Av de skörde- och transportkedjor som teoretiskt utvärderades i projektet var det ekonomiskt mest fördelaktigt med en skördekedja där en mindre mängd blast samlades in (55 % av tillgänglig mängd) för att minimera maskinernas väntetider. Alternativet har dock nackdelen att en större andel kvarlämnad blast gör att en större andel av fältets ytafår ojämn förfruktseffekt i efterföljande gröda jämfört med ett scenario då större andel av blasten samlas in. Priset för skörd (i september) och lagring beräknades till 1,7–2,1 kr/kg TS både med och utan fraktionering. Detta är högre än det pris som tidigare beräknats (Gissén et al. 2014), vilket bedöms som underskattat. Tester av fraktionering av betblast gjordes i liten skala med en äppeljuicepress. Metanpotentialtester gjordes på de olika fraktionerna. Pressning av strimlad blast (13 % TS) gav en vätskefraktion (7 % TS) motsvarande en fjärdedel av våtvikten och 3 fjärdedelar återstod som fast fraktion (15 % TS). Den fasta fraktionen gav dubbelt så högt metanutbyte per kg våtvikt som vätskefraktionen, men ingen signifikant skillnad i metanutbyte per kg organiskt material. Ingen inverkan av sortval på betblastskörden eller metanutbyte per kg organiskt material kunde hittas vid test av fem sockerbetssorter som förädlats fram för sockerproduktion. När fraktionerad blast används kan möjlighet finnas att dubbelanvända lager för den våta fraktionen och rötrest. Det gäller även för andra flytande substrat som behöver lagras. Studien visar att dubbelanvändning kan påverka investeringskostnaderna för rötrestlagret signifikant och en närmare undersökning av om det är praktiskt möjligt vore intressant. När flera positiva faktorer samspelar kan det finnas möjlighet att med dagens förhållanden producera biogas som biodrivmedel från betblast på ett ekonomiskt hållbart sätt. Exempel på identifierade positiva faktorer är: högt blastutbyte, användning av underutnyttjade jordbruksredskap, rötning i befintliga anläggningar för att fylla ut substratluckor, korta transportsträckor och direktanvändning av färsk betblast utan lagring. Det är troligtvis endast för en liten del av den totala mängden blast som tillräckligt många positiva faktorer samspelar för att den idag ska kunna vara ekonomiskt intressant att använda för biogasproduktion.
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| 10. |
- Lindkvist, Emma, et al.
(författare)
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Biogas production feasibility in food industry clusters
- 2016
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Ingår i: eceee Industrial Summer Study proceedings – Industrial Efficiency 2016. - 9789198048285 - 9789198048292
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Konferensbidrag (refereegranskat)abstract
- This paper investigates if biogas production is a good alternative to treat food industry by-products and if so, under which circumstances. All food industries in Sweden, with more than 49 employees were mapped. Geographical clusters of industries were identified, and from these five clusters with no or minor biogas production were selected and further analyzed. Three different perspectives were analyzed for each cluster: economic, energy and environmental performance (Global Warming Potential (GWP), Acidification Potential (AP) and Eutrophication Potential (EP). The analysis was based on a comparison of three systems: BAU (Business as Usual) and two biogas production systems: “CHP” and “Vehicle”. In system CHP (Combined Heat and Power) the produced biogas is used to produce heat and electricity and in system Vehicle, the produced biogas is used as vehicle fuel. Interviews were carried out with the food companies in the selected clusters to determine the amounts of organic waste and the present treatment of the waste, as basis for System BAU. The results show that biogas should be produced in one of the clusters, whilst System BAU has an advantage over the biogas systems in all other clusters. The results for the biogas systems (CHP and Vehicle) are varying depending on the origin of the electricity production, whilst the results for System BAU is robust regarding electricity. The conclusion of this paper is that both the perspective in focus and the system at hand are vital for deciding whether or not biogas production is the best option to treat industrial food waste. Different alternatives can also be “best” from different perspectives. System CHP is a bad economical choice, but the almost always the best choice from an energy perspective for all clusters. This means that invest decisions on biogas production plants have to be made with a broad systems perspective taking existing and potential local value-chains into account.
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