| 1. |
- Alvfors, Per, 1954-, et al.
(författare)
-
Research and development challenges for Swedish biofuel actors – three illustrative examples : Improvement potential discussed in the context of Well-to-Tank analyses
- 2010
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Currently biofuels have strong political support, both in the EU and Sweden. The EU has, for example, set a target for the use of renewable fuels in the transportation sector stating that all EU member states should use 10% renewable fuels for transport by 2020. Fulfilling this ambition will lead to an enormous market for biofuels during the coming decade. To avoid increasing production of biofuels based on agriculture crops that require considerable use of arable area, focus is now to move towards more advanced second generation (2G) biofuels that can be produced from biomass feedstocks associated with a more efficient land use. Climate benefits and greenhouse gas (GHG) balances are aspects often discussed in conjunction with sustainability and biofuels. The total GHG emissions associated with production and usage of biofuels depend on the entire fuel production chain, mainly the agriculture or forestry feedstock systems and the manufacturing process. To compare different biofuel production pathways it is essential to conduct an environmental assessment using the well-to-tank (WTT) analysis methodology. In Sweden the conditions for biomass production are favourable and we have promising second generation biofuels technologies that are currently in the demonstration phase. In this study we have chosen to focus on cellulose based ethanol, methane from gasification of solid wood as well as DME from gasification of black liquor, with the purpose of identifying research and development potentials that may result in improvements in the WTT emission values. The main objective of this study is thus to identify research and development challenges for Swedish biofuel actors based on literature studies as well as discussions with the the researchers themselves. We have also discussed improvement potentials for the agriculture and forestry part of the WTT chain. The aim of this study is to, in the context of WTT analyses, (i) increase knowledge about the complexity of biofuel production, (ii) identify and discuss improvement potentials, regarding energy efficiency and GHG emissions, for three biofuel production cases, as well as (iii) identify and discuss improvement potentials regarding biomass supply, including agriculture/forestry. The scope of the study is limited to discussing the technologies, system aspects and climate impacts associated with the production stage. Aspects such as the influence on biodiversity and other environmental and social parameters fall beyond the scope of this study. We find that improvement potentials for emissions reductions within the agriculture/forestry part of the WTT chain include changing the use of diesel to low-CO2-emitting fuels, changing to more fuel-efficient tractors, more efficient cultivation and manufacture of fertilizers (commercial nitrogen fertilizer can be produced in plants which have nitrous oxide gas cleaning) as well as improved fertilization strategies (more precise nitrogen application during the cropping season). Furthermore, the cultivation of annual feedstock crops could be avoided on land rich in carbon, such as peat soils and new agriculture systems could be introduced that lower the demand for ploughing and harrowing. Other options for improving the WTT emission values includes introducing new types of crops, such as wheat with higher content of starch or willow with a higher content of cellulose. From the case study on lignocellulosic ethanol we find that 2G ethanol, with co-production of biogas, electricity, heat and/or wood pellet, has a promising role to play in the development of sustainable biofuel production systems. Depending on available raw materials, heat sinks, demand for biogas as vehicle fuel and existing 1G ethanol plants suitable for integration, 2G ethanol production systems may be designed differently to optimize the economic conditions and maximize profitability. However, the complexity connected to the development of the most optimal production systems require improved knowledge and involvement of several actors from different competence areas, such as chemical and biochemical engineering, process design and integration and energy and environmental systems analysis, which may be a potential barrier.
|
|
| 2. |
- Alvors, Per, et al.
(författare)
-
Research and development challenges for Swedish biofuel actors – three illustrative examples : Improvement potential discussed in the context of Well-to-Tank analyses
- 2010
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Currently biofuels have strong political support, both in the EU and Sweden. The EU has, for example, set a target for the use of renewable fuels in the transportation sector stating that all EU member states should use 10% renewable fuels for transport by 2020. Fulfilling this ambition will lead to an enormous market for biofuels during the coming decade. To avoid increasing production of biofuels based on agriculture crops that require considerable use of arable area, focus is now to move towards more advanced second generation (2G) biofuels that can be produced from biomass feedstocks associated with a more efficient land use.Climate benefits and greenhouse gas (GHG) balances are aspects often discussed in conjunction with sustainability and biofuels. The total GHG emissions associated with production and usage of biofuels depend on the entire fuel production chain, mainly the agriculture or forestry feedstock systems and the manufacturing process. To compare different biofuel production pathways it is essential to conduct an environmental assessment using the well-to-tank (WTT) analysis methodology.In Sweden the conditions for biomass production are favourable and we have promising second generation biofuels technologies that are currently in the demonstration phase. In this study we have chosen to focus on cellulose based ethanol, methane from gasification of solid wood as well as DME from gasification of black liquor, with the purpose of identifying research and development potentials that may result in improvements in the WTT emission values. The main objective of this study is thus to identify research and development challenges for Swedish biofuel actors based on literature studies as well as discussions with the the researchers themselves. We have also discussed improvement potentials for the agriculture and forestry part of the WTT chain. The aim of this study is to, in the context of WTT analyses, (i) increase knowledge about the complexity of biofuel production, (ii) identify and discuss improvement potentials, regarding energy efficiency and GHG emissions, for three biofuel production cases, as well as (iii) identify and discuss improvement potentials regarding biomass supply, including agriculture/forestry. The scope of the study is limited to discussing the technologies, system aspects and climate impacts associated with the production stage. Aspects such as the influence on biodiversity and other environmental and social parameters fall beyond the scope of this study.We find that improvement potentials for emissions reductions within the agriculture/forestry part of the WTT chain include changing the use of diesel to low-CO2-emitting fuels, changing to more fuel-efficient tractors, more efficient cultivation and manufacture of fertilizers (commercial nitrogen fertilizer can be produced in plants which have nitrous oxide gas cleaning) as well as improved fertilization strategies (more precise nitrogen application during the cropping season). Furthermore, the cultivation of annual feedstock crops could be avoided on land rich in carbon, such as peat soils and new agriculture systems could be introduced that lower the demand for ploughing and harrowing. Other options for improving the WTT emission values includes introducing new types of crops, such as wheat with higher content of starch or willow with a higher content of cellulose.From the case study on lignocellulosic ethanol we find that 2G ethanol, with co-production of biogas, electricity, heat and/or wood pellet, has a promising role to play in the development of sustainable biofuel production systems. Depending on available raw materials, heat sinks, demand for biogas as vehicle fuel and existing 1G ethanol plants suitable for integration, 2G ethanol production systems may be designed differently to optimize the economic conditions and maximize profitability. However, the complexity connected to the development of the most optimal production systems require improved knowledge and involvement of several actors from different competence areas, such as chemical and biochemical engineering, process design and integration and energy and environmental systems analysis, which may be a potential barrier.Three important results from the lignocellulosic ethanol study are: (i) the production systems could be far more complex and intelligently designed than previous studies show, (ii) the potential improvements consist of a large number of combinations of process integration options wich partly depends on specific local conditions, (iii) the environmental performance of individual systems may vary significantly due to systems design and local conditons.From the case study on gasification of solid biomass for the production of biomethane we find that one of the main advantages of this technology is its high efficiency in respect to converting biomass into fuels for transport. For future research we see a need for improvements within the gas up-grading section, including gas cleaning and gas conditioning, to obtain a more efficient process. A major challenge is to remove the tar before the methanation reaction.Three important results from the biomethane study are: (i) it is important not to crack the methane already produced in the syngas, which indicates a need for improved catalysts for selective tar cracking, (ii) there is a need for new gas separation techniques to facilitate the use of air oxidation agent instead of oxygen in the gasifier, and (iii) there is a need for testing the integrated process under realistic conditions, both at atmospheric and pressurized conditions.From the case study on black liquor gasification for the production of DME we find that the process has many advantages compared to other biofuel production options, such as the fact that black liquor is already partially processed and exists in a pumpable, liquid form, and that the process is pressurised and tightly integrated with the pulp mill, which enhances fuel production efficiency. However, to achieve commercial status, some challenges still remain, such as demonstrating that materials and plant equipment meet the high availability required when scaling up to industrial size in the pulp mill, and also proving that the plant can operate according to calculated heat and material balances. Three important results from the DME study are: (i) that modern chemical pulp mills, having a potential surplus of energy, could become important suppliers of renewable fuels for transport, (ii) there is a need to demonstrate that renewable DME/methanol will be proven to function in large scale, and (iii) there is still potential for technology improvements and enhanced energy integration.Although quantitative improvement potentials are given in the three biofuel production cases, it is not obvious how these potentials would affect WTT values, since the biofuel production processes are complex and changing one parameter impacts other parameters. The improvement potentials are therefore discussed qualitatively. From the entire study we have come to agree on the following common conclusions: (i) research and development in Sweden within the three studied 2G biofuel production technologies is extensive, (ii) in general, the processes, within the three cases, work well at pilot and demonstration scale and are now in a phase to be proven in large scale, (iii) there is still room for improvement although some processes have been known for decades, (iv) the biofuel production processes are complex and site specific and process improvements need to be seen and judged from a broad systems perspective (both within the production plant as well as in the entire well-to-tank perspective), and (v) the three studied biofuel production systems are complementary technologies. Futher, the process of conducting this study is worth mentioning as a result itself, i.e. that many different actors within the field have proven their ability and willingness to contribute to a common report, and that the cooperation climate was very positive and bodes well for possible future collaboration within the framework of the f3 center.Finally, judging from the political ambitions it is clear that the demand for renewable fuels will significantly increase during the coming decade. This will most likely result in opportunities for a range of biofuel options. The studied biofuel options all represent 2G biofuels and they can all be part of the solution to meet the increased renewable fuel demand.
|
|
| 3. |
- Albrekt, Ann-Sofie, et al.
(författare)
-
Skin sensitizers differentially regulate signaling pathways in MUTZ-3 cells in relation to their individual potency
- 2014
-
Ingår i: Bmc Pharmacology & Toxicology. - : Springer Science and Business Media LLC. - 1471-2210 .- 2050-6511. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Due to the recent European legislations posing a ban of animal tests for safety assessment within the cosmetic industry, development of in vitro alternatives for assessment of skin sensitization is highly prioritized. To date, proposed in vitro assays are mainly based on single biomarkers, which so far have not been able to classify and stratify chemicals into subgroups, related to risk or potency. Methods: Recently, we presented the Genomic Allergen Rapid Detection (GARD) assay for assessment of chemical sensitizers. In this paper, we show how the genome wide readout of GARD can be expanded and used to identify differentially regulated pathways relating to individual chemical sensitizers. In this study, we investigated the mechanisms of action of a range of skin sensitizers through pathway identification, pathway classification and transcription factor analysis and related this to the reactive mechanisms and potency of the sensitizing agents. Results: By transcriptional profiling of chemically stimulated MUTZ-3 cells, 33 canonical pathways intimately involved in sensitization to chemical substances were identified. The results showed that metabolic processes, cell cycling and oxidative stress responses are the key events activated during skin sensitization, and that these functions are engaged differently depending on the reactivity mechanisms of the sensitizing agent. Furthermore, the results indicate that the chemical reactivity groups seem to gradually engage more pathways and more molecules in each pathway with increasing sensitizing potency of the chemical used for stimulation. Also, a switch in gene regulation from up to down regulation, with increasing potency, was seen both in genes involved in metabolic functions and cell cycling. These observed pathway patterns were clearly reflected in the regulatory elements identified to drive these processes, where 33 regulatory elements have been proposed for further analysis. Conclusions: This study demonstrates that functional analysis of biomarkers identified from our genomics study of human MUTZ-3 cells can be used to assess sensitizing potency of chemicals in vitro, by the identification of key cellular events, such as metabolic and cell cycling pathways.
|
|
| 4. |
- Bengtsson, Björn, et al.
(författare)
-
High occurrence of mecC-MRSA in wild hedgehogs (Erinaceus europaeus) in Sweden
- 2017
-
Ingår i: Veterinary Microbiology. - : Elsevier. - 0378-1135 .- 1873-2542. ; 207, s. 103-107
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the occurrence of mecC-MRSA in wild hedgehogs (Erinaceus europaeus) in Sweden and characterized the obtained isolates. Samples from 55 hedgehogs from five counties of Sweden were cultivated selectively for MRSA and putative isolates were confirmed by real-time PCR detecting mecA, mecC, nuc and PVL genes. mecC-MRSA was confirmed in 35 (64%) animals from three geographically separated counties. Confirmed isolates were spa-typed and tested for antimicrobial susceptibility by broth microdilution. Eight different spa-types were identified (t843, t978, t3391, t9111, t10751, t10893, t11015, t15312) of which t843 (49%) was the most common. The spa-types t843, t3391 and t978 were found in isolates from two counties. The study shows that mecC-MRSA is common in wild hedgehogs in two counties of Sweden but occurs in hedgehogs also in other parts of the country. Our findings suggest that hedgehogs could be a reservoir for mecC-MRSA. In addition, similar spa-types of isolates from hedgehogs and isolates previously described in domesticated animals and in humans indicates transfer between these populations.
|
|
| 5. |
- Berglund, Henrik, 1973, et al.
(författare)
-
CBIs studie om innovationsledning
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- CBI har under andra halvåret 2010 och första halvåret 2011 genomfört en studie av innovationsledning hos 38 utvalda svenska företag inom tillverkning, IT och Telekom. Syftet var att undersöka hur företagen leder och organiserar innovation samt vilka utmaningar de står inför. Frågorna har besvarats av antingen VD eller en medlem i ledningsgruppen med insyn i företagets hantering av innovation.Resultatet visar att -de flesta företagen inte skiljer på radikal och inkrementell innovation-i många företag används ordet innovation för all produkt- och tjänsteutveckling-de flesta företag ser en ökning av innovationstakten inom sin respektive bransch-de flesta företag uttrycker att innovation är viktigt, samtidigt som få företag har innovationsfrågor bland sina tre största utmaningar-hälften av företagen använder någon form av rutin för att stärka sin förmåga att skapa nya produkter och tjänster, men endast ett fåtal använder flera olika rutiner-förstainnovationsföretagen (mindre, relativt nystartade företag) skiljer sig från de övriga i det att de är starkt innovationscentrerade-många företag välkomnar stöd från akademin, men endast ett fåtal önskar stöd att öka sin innovationsförmågaCBIs samtliga seniora forskare har genomfört intervjuerna.
|
|
| 6. |
|
|
| 7. |
- Bjerke, Maria, 1977, et al.
(författare)
-
Cerebrospinal Fluid Fatty Acid-Binding Protein 3 is Related to Dementia Development in a Population-Based Sample of Older Adult Women Followed for 8 Years.
- 2016
-
Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908. ; 49:3, s. 733-741
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Increased fatty acid-binding protein 3 (FABP-3) levels have been reported in neurodegenerative diseases, including Alzheimer's disease (AD). Cerebrospinal fluid (CSF) FABP-3 has therefore been proposed as a putative marker for dementia. Population-based studies examining whether CSF FABP-3 predicts later development of dementia are lacking. OBJECTIVE: The aim of this study was to examine CSF levels of FABP-3 in relation to later development of dementia in elderly women and in relation to Aβ42, T-tau, P-tau181, and CSF: serum albumin ratio. METHODS: 86 non-demented women aged 70-84 years who participated in the Prospective Population Study of Women in Gothenburg, Sweden took part in a lumbar puncture in 1992-93. CSF-FABP-3, Aβ42, T-tau, P-tau181, and the CSF: serum albumin ratio were measured at baseline. Participants were examined with a neuropsychiatric exam at baseline and at follow-up in 2000. Dementia was diagnosed in accordance with DSM-III-R criteria. RESULTS: Between 1992 and 2000, 8 women developed dementia (4 AD, 3 vascular dementia, 1 mixed vascular dementia and AD). Higher levels of CSF-FABP-3 at baseline were related to development of dementia (OR 1.36 CI [1.05-1.76] p=0.022) and the subtype AD (OR 1.38 CI [1.06-1.82), p=0.019) during follow-up. FABP-3 correlated with CSF T-tau (r=0.88, p< 0.001), P-tau181 (r=0.619, p< 0.001), and CSF:serum albumin ratio (r=0.233, p=0.031), but not with Aβ42 (r=-0.08, p=0.444)Conclusion: CSF FABP-3 may be an early marker for later development of dementia, probably related to neuronal degeneration, but independent of Aβ metabolism.
|
|
| 8. |
- Börjesson Axén, Jenny, 1986-, et al.
(författare)
-
A dynamic gas pressure model for management of nickel metal hydride batteries
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The Nickel Metal Hydride (NiMH) battery has an active gas phase during operation. This is due in part to the aqueous electrolyte causing oxygen evolution on the positive nickel electrode, and in part due to the hydrogen stored in the negative metal hydride (MH) electrode being in equilibrium with gaseous hydrogen. The gas phase reactions are closely connected to the battery function and must therefore be accounted for when creating a successful battery management system (BMS).This study explores a pressure model for management of the NiMH battery. By using measured current, voltage, and temperature as input, the total pressure and gas composition can be modeled. Model parameters are fitted by comparing the modeled total pressure to the measured pressure. By using the system voltage signal, the difficulty of simultaneously modeling the voltage based on the current is circumvented. A model like this opens the way to new ways of battery system management through use of calculated partial pressures and deviations from the modeled total pressure. This can help increasing safety and longevity of battery systems.
|
|
| 9. |
- Börjesson Axén, Jenny, 1986-, et al.
(författare)
-
Creating a dynamic P2D model for the nickel metal hydride battery
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this study, a predictive voltage and pressure nickel metal hydride (NiMH) battery model is presented. The model was validated under conditions that would be seen in applications, with mixed charge and discharge usage patterns. The model is based on an extended P2D model using concentrated electrolyte and porous electrode theory. On top of the charging and discharging processes, the NiMH battery has additional side reactions that affects the battery behavior. These processes are important to include for a model to accurately reproduce the voltage and pressure behavior under usage like conditions. Two processes were identified as necessary for the model to be predictive: Open circuit voltage hysteresis and the gas phase reactions involving oxygen and hydrogen. To take these into account, results from two previous studies that modeled these phenomena separately was introduced into the model. Hysteresis was described using empirical mathematical expressions and the gas phase reactions were described using electrochemical rate equations.The results show that the resulting model is capable of qualitatively reproducing NiMH battery voltage and pressure behavior, both for a continuous charge/discharge cycle and a varied usage pattern with mixed charge and discharge pulses using different currents. The model was used to study the effect of changes in electrode thickness on the energy and power density during discharge. The mechanism behind the drop in cell voltage at the end of charge was also investigated and found to be connected to the temperature dependence of the oxygen evolution equilibrium potential. Although the model can be fine-tuned further to improve quantitative reproducibility, this study shows that taking the OCV hysteresis and gas phase reactions into account creates a basis for a NiMH battery model that can function for different usage patterns. Such a model has potential to improve the development and use of NiMH batteries, providing a tool to improve battery design and battery management algorithms.
|
|
| 10. |
- Börjesson Axén, Jenny, et al.
(författare)
-
Evaluation of hysteresis expressions in a lumped voltage prediction model of a NiMH battery system in stationary storage applications
- 2022
-
Ingår i: Journal of Energy Storage. - : Elsevier BV. - 2352-152X .- 2352-1538. ; 48, s. 103985-
-
Tidskriftsartikel (refereegranskat)abstract
- As a part of battery system operation, battery models are often used to determine battery characteristics such as the state of charge (SOC) and the state of health (SOH). A phenomenon that has a large impact on battery model accuracy for NiMH batteries is open circuit voltage (OCV) hysteresis, which causes the OCV to differ not only with the SOC of the battery but also with the charge-discharge history. This characteristic is especially influential when running the system in applications with dynamic current patterns. A model including a way to emulate battery hysteresis behavior would improve the battery management system function. In this study a lumped battery model for cell voltage prediction was expanded to include an OCV hysteresis model. Different expressions to describe the hysteresis behavior were explored. The different models were then evaluated using both synthetic and real-life application experimental data. In all cases the error was reduced by adding a hysteresis component to the model. Using this type of model in the battery management system of stationary energy storage systems based on NiMH batteries could help make the state prediction more accurate. This, in turn, would allow for better optimization of the system operation, something that could help increase system efficiency and lifetime.
|
|
