| 1. |
- Albers, Eva, 1966, et al.
(författare)
-
Influence of preservation methods on biochemical composition and downstream processing of cultivated Saccharina latissima biomass
- 2021
-
Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 55
-
Tidskriftsartikel (refereegranskat)abstract
- Saccharina latissima biomass cultivated along the Swedish west coast was subjected to four different scalable preservation methods after harvest; freezing, sun-drying, oven-drying and ensiling. Freeze-drying and freezing at -80 ?C were also included to provide dry and wet references. The effects of the different preservation methods on the composition of Saccharina biomass (on dry weight, DW, basis), and the recovery as well as properties of high-quality protein, alginate and biogas were evaluated. Sun-drying significantly reduced protein, alginate and fatty acid content of the seaweeds and thereby concentrated ash in the biomass compared to the other methods. Protein/amino acids and fatty acids were significantly concentrated in ensiled biomass, while mannitol and laminarin were reduced compared to the other biomasses. Oven-drying and -20 ?C freezing affected the composition the least, with lower ash content and alterations in some specific amino and fatty acids. Sun-drying and ensiling resulted in significantly lower protein solubility at high pH compared to the other biomasses which translated into the lowest total seaweed protein recovery using the pH-shift process. Highest protein yield was obtained with the freeze-dried reference. Ensiling lead to a significant decrease in the molecular weight of alginate, while sun-drying caused a negative effect on alginate by inducing a shift in the guluronic and mannuronic acids composition of alginate. Sun-drying gave the lowest methane yield in the anaerobic digestion experiments while freezing at -80 ?C gave the highest yield, closely followed by freezing at -20 ?C and ensiling. To conclude, preservation methods must be carefully chosen to protect the valuable component in Saccharina latissima, and to achieve an efficient downstream processing ultimately yielding high quality products as part of a seaweed biorefinery.
|
|
| 2. |
|
|
| 3. |
- Blomqvist, Per, et al.
(författare)
-
An experimental study of spontaneous ignition in storages of wood pellets
- 2007
-
Ingår i: 10th International Conference - Fire and Materials 2007.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This article focuses on experimental studies of self-heating characteristics of wood pellets. Controlled experiments have been conducted in physical scales from 1 dm3 to 4 m3 with wood pellets. Basket tests have been conducted according to the "crossing-point method" to derive kinetic data on the exothermic reactions responsible for self-heating and eventually spontaneous ignition. The kinetic data was used in the planning of the large-scale experiments for predictions of approximate critical temperatures. The experiments in the 1 m3 scale were set-up basically as an enlargement of the basket tests to obtain validation experiments with controlled boundary conditions in a reasonable large scale. Several experiments were conducted and spontaneous ignition was seen in the centre of the pellet bulk at an ambient temperature of 115C. The close to real-scale experiments with 4 m3 wood pellets filled in a 6 m high silo were not strictly self heating experiments, instead a core shaped heating element was allowed to initiate the pyrolysis in the pellets. Heat and gas production and transportation from the growing pyrolysis zone were mapped with a large number of measurement points in the pellets bulk and in the top of the silo. The experimental work conducted gave kinetic data on the exothermic reactions in wood pellets, insight in self heating processes, a link between different experimental scales and knowledge regarding possibilities for detection of fires in storages of wood pellets.
|
|
| 4. |
- Blomqvist, Per, et al.
(författare)
-
Fires in storages of biofuels
- 2007
-
Ingår i: Fire and Materials 2007 Proceedings.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 5. |
- Boussaa, Youcef, 1993-, et al.
(författare)
-
Analysis of cost-effective energy efficiency measures for thermal envelope of a multi-apartment building in Sweden
- 2020
-
Ingår i: Proceedings of 12th International Conference on Applied Energy, Part 3, Sweden, 2020. - : ICAE. - 9789198673821
-
Konferensbidrag (refereegranskat)abstract
- A large potential for energy savings can be found in building envelopes of the existing Swedish dwelling stock. This study analyzes the final energy savings and cost implications of energy efficiency measures for an existing multi-apartment building in Sweden. Energy efficiency improvements consisting of high-performance windows as well as doors, and additional insulation to attic floor and exterior walls were modelled to the building’s thermal envelope. Dynamic energy balance simulations were performed to determine the final energy savings of the improvements. The cost-effectiveness of the improvements were then analyzed considering the net present value of the energy cost savings and the investment costs of the improvement measures. The results showed that additional insulation to the attic floor is the only cost-effective measure for the building under the existing operating conditions. The other improvement measures give high final energy savings but are not cost effective due to their high investment costs.
|
|
| 6. |
- Boussaa, Youcef, 1993-, et al.
(författare)
-
Comprehensive renovation of a multi-apartment building in Sweden : techno-economic analysis with respect to different economic scenarios
- 2024
-
Ingår i: Building Research & Information. - : Taylor & Francis Group. - 0961-3218 .- 1466-4321. ; 52:4, s. 463-478
-
Tidskriftsartikel (refereegranskat)abstract
- A wider deployment of nearly zero energy buildings (NZEBs) is expected to contribute to the transition to a decarbonized and energy-efficient building sector in Europe. This study proposed an integrated energy-economic analysis to exemplify the feasibility of NZEB renovation in temperate climate. A parametric analysis was performed to identify technical building system configurations that give minimum share of renewable energy systems contributing to NZEB level. Final energy savings, global costs and cost-effectiveness of renovating a building to NZEB level are analysed, considering active and passive energy efficiency measures (EEMs). The active EEMs included efficient water taps and heat recovery ventilation, and the passive EEMs encompassed insulations to roof, exterior walls and ground floor, and improvements of windows and doors. The building had initial final energy use of 133 kWh/m2 year for space heating, domestic hot water production (DHW) and facility electricity. The results show that NZEB level is achieved with active and passive EEMs, without renewable energy systems for scenarios with low discount rates and high future energy price escalations. The annual final energy use for space heating, DHW and facility electricity is reduced cost-effectively by 37-54%. Furthermore, increasing size of PV-system enhanced cost-effectiveness by lowering total global costs.
|
|
| 7. |
- Boussaa, Youcef, 1993-, et al.
(författare)
-
Energy efficient measures for thermal envelope of a multi-apartment building in Sweden : Analysis of cost effectiveness with respect to carbon abatement costs implementation
- 2021
-
Ingår i: eceee 2021 Summer Study on energy efficiency: a new reality?. - : European Council for an Energy Efficient Economy (ECEEE). - 9789198387889 ; , s. 1015-1024
-
Konferensbidrag (refereegranskat)abstract
- A considerable share of the existing buildings in Europe has low energy performance and are expected to last at least for the next 50 years. The operation of these buildings causes high atmospheric greenhouse gases emissions, besides low thermal comfort for occupants. In Sweden, most of the existing buildings are residential, consisting of multi- and single-family houses. Large final energy savings can be achieved by integrating energy efficient measures (EEMs) to the thermal envelopes of these buildings. However, it is often a challenge to achieve a considerable energy savings and realize cost effectiveness simultaneously. This study investigates the effect of carbon taxes implementation on the cost effectiveness of EEMs applied to an existing multi-apartment building in southern Sweden. It explores the implications of different additional insulation thicknesses for exterior walls and roof, and high-performance windows and doors, for the final energy use and carbon dioxide (CO2) emissions of the building. The final energy savings of the EEMs are estimated through dynamic energy balance simulations and the CO2 emissions are calculated considering the full energy chains. The cost effectiveness of the EEMs are analyzed with and without carbon abatement costs considering the investment costs and associated net present value of costs savings of the EEMs. The results show that replacing the existing windows give the highest final energy savings, reducing the building’s space heating demand by 23 %. The cost optimal analysis without carbon abatement costs shows that all the analyzed thicknesses of roof insulation and high-performance windows are cost effective. Considering the carbon abatement costs altered the cost effectiveness of the EEMs, with exterior walls as well as ground floor insulations and door replacement becoming cost effective for certain thicknesses and U-values, respectively.
|
|
| 8. |
- Boussaa, Youcef, 1993-, et al.
(författare)
-
Integrating Passive Energy Efficient Measures to the Building Envelope of a Multi-Apartment Building in Sweden : Analysis of Final Energy Savings and Cost Effectiveness
- 2023
-
Ingår i: Buildings. - : MDPI. - 2075-5309. ; 13:10
-
Tidskriftsartikel (refereegranskat)abstract
- A major challenge in building energy renovation is to cost effectively achieve notable energy savings. This paper investigates cost-effective passive energy-efficiency measures for thermal envelope retrofit of a typical Swedish multi-apartment building from the 1970s. Here, the use of different types of insulation materials for the retrofits of roof, exterior walls, and ground floor are analyzed along with changing windows and doors with varying thermal transmittance values. The cost-effectiveness analysis is based on the net present value of the investment costs of the energy-efficiently measures and the achieved energy cost saving. Different economic scenarios and renovation cases are considered in techno-economic analyses to determine the cost-effective energy-efficiency retrofit measures. The results indicate that improved windows reduce energy demand for space heating by up to 23% and yield the highest final energy savings. However, additional mineral wool roof insulation is the most cost-effective measure under all economic scenarios. This measure gave the lowest ratio of cost effectiveness of about 0.1, which was obtained under the stable scenario. The final energy savings that can be achieved in a cost-effective manner vary between 28% and 61%, depending on the economic scenario and renovation case. This analysis emphasizes the influence of different renovation cases and economic parameters on the cost effectiveness of passive energy-efficiency measures.
|
|
| 9. |
- Edström, Mats, et al.
(författare)
-
Rötning av fjäderfägödsel med gödselförädling i tillämpad skala
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Ett tjugotal lantbrukare i Mönsterås kommun planerar för att bygga en stor biogasanläggning som kommer att ha fastgödsel från höns som huvudsubstrat. Den gemensamma biogasanläggning kan bli den största i sitt slag i Sverige, med en biogasproduktion på ca 70 GWh biogas/år för produktion av drivmedel. Den genererade rötresten kan kväveförsörja ca 12 000 ha/år växtodling och fosforförsörja ca 20 000 ha/år. Den rötade gödseln bidrar i princip till all växtnäring i rötresten, där fjäderfägödseln kommer att bidra med ca 80 % av rötrestens innehåll av kväve och fosfor. Ett hinder för att realisera denna anläggning är att det idag saknas erfarenhet från praktisk drift av rötningsanläggningar med betydande inblandning av fjäderfägödsel. Fjäderfägödsel är både ett fosfor- och kväverikt substrat, och innehåller dessutom både tunga och lätta partiklar som riskerar att bilda sediment och svämtäcken i rötkammaren. Idag betraktas fjäderfägödsel framför allt som ett fosforgödselmedel eftersom huvuddelen av kvävet inte är direkt upptagbart av växter, men rötning av fjäderfägödsel ökar andelen direktverkanande kväve. För att optimera hantering, spridning och utnyttjande av kväve och fosfor i fjäderfägödsel är det önskvärt att processa denna gödsel för att generera fyra stycken gödselmedel med olika kväve- och fosforkvot. För att kunna studera dessa frågeställningar och bredda gödselbasen för rötning har Vinnova, under 2016-2018, finansierat denna tillämpade studie.Under ett tillämpat försök genomfördes rötning i pilotskala av kväverik hönsgödsel som huvudsubstrat. Rötningsprocessen gick att driva stabilt vid en ammoniumkvävehalt på närmare 6 g/l inom det mesofila temperaturområdet i en totalomblandad rötkammare med volymetrisk metanproduktion som uppgick till 1,1 m3 CH4/m3 slamvolym & dag. Järnklorid tillfördes rötkammaren för att hålla biogasens innehåll av svavelväte vid ca 100 ppm. För att hålla ammoniumhalten vid angiven nivå tillfördes vatten motsvarande halva inflödet in i rötkammaren, för att späda ner kvävet till denna nivå. Efter rötningen av substratblandningen ökade dess ammoniuminnehåll med 3,7 gånger.Under pilotförsöket producerades ca 13 m3 rötrest som sparades och lagrades 4–8 månader innan den förädlades i två steg till två olika gödselmedel. I första steget genomfördes fasseparation med en dekantercentrifug följt av indunstning av surgjord tunnfas. Baserat på dessa försök beräknas fassepareringen kunna generera ett fast gödselmedel vars vikt motsvarar 23 % av i rötningsprocessen producerad rötrest. Det fasta gödselmedlets innehåll av fosfor utgör dryga 70 % av rötrestens fosforinnehåll. Vidare beräknas indunstningen kunna generera ett uppkoncentrerat flytande gödselmedel vars vikt motsvarar 2o % av i rötningsprocessen producerad rötrest. Det flytande gödselmedlets innehåll av ammoniumkvävet utgör dryga 70 % av rötrestens ammoniuminnehåll. Det producerade koncentratgödselmedlet liksom tunnfasgödselmedlet hade en hög andel lättillgängligt kväve, vilket är en viktig delförutsättning för att uppnå höga skördar vid växtodling. Gödselmedel från Mönsterås Biogas planerade biogasanläggning kan i framtiden bidra till att jordbruket i Kalmar län med omnejd kan gå mot en hållbar intensifiering av livsmedelsproduktionen.
|
|
| 10. |
- Ibrahim, Muhammad Asim, 1980-, et al.
(författare)
-
Mitigating the emissions released from spontaneous fires at biomass storages : A footstep towards sustainability
- 2015
-
Ingår i: 23rd European Biomass Conference and Exhibition, Vienna, Austria, 1-4 June 2015. - 9788889407516 ; , s. 1550-1557
-
Konferensbidrag (refereegranskat)abstract
- Fires at the material storages sites of manucipal and industrial sectors are a major environmental risk and have increased significantly. Toxic emissions released from such open fires have severe environmental and health consequences. Considering that it is not possible to install any unit operation to control the emissions released from such open fires, the possibilities to employ natural vegetation to act as a sink for aerosol particles released from open fires was investigated. A series of tests was conducted in a controlled wind tunnel environment. Smoke was generated in a smoke-aerosol generator and measurements of smoke concentrations upwind and downwind of “green filter packs” (vegetation filters) were made. Measurements involved laser-based particle counters, two-stage Nuclepore filter systems, and Solid Phase Microextraction (SPME) techniques followed by Gas Chromatography-Mass Spectrometry (GC-MS). The main objective of the work was to illustrate ways to design experiments that can assist in the study of vegetation as “pollution screens”. Our observations and findings imply that several refinements to the experimental design will be needed, including with respect to methods for assessing the distribution of particle number and mass as a function of particle size.
|
|
| 11. |
- Jansson, Anette, et al.
(författare)
-
Pilot-Scale Experiments Using Cultivated Macro Algae for Biogas Production, Part of a Future Seafarm Biorefinery
- 2016
-
Ingår i: 24th EUBCE Online Proceedings 2016. - : ETA-Florence Renewable Energies. - 9788889407165 ; , s. 627-629
-
Konferensbidrag (refereegranskat)abstract
- The research is focused on evaluation of substrates not commonly used for biogas production and the development and optimization of processes adjusted to these substrates. This study deals with evaluation of sea weeds (Saccharina Lattisima and Laminaria digitata). Biomethane potential tests (BMP) have shown the methane potential of the algae to be 180-440 l CH4/kg organic material. These potentials are in the same range as potentials found for commonly used substrates such as sewage sludge and slaughterhouse waste. Sampling of produced biogas, substrate and digest were performed by using Solid Phase Microextraction (SPME) followed by analysis by a Gas Chromatograph with a Mass Spectrometrer (GC-MS) in order to develop a method to be able to characterize, monitor and possibly control the process.
|
|
| 12. |
- Kans, Mirka, et al.
(författare)
-
School-wide approach for the degree project courses
- 2013
-
Ingår i: Proceedings of the 9th International CDIO Conference, Massachusetts Institute of Technology and Harvard UniversitySchool of Engineering and Applied Sciences, Cambridge, Massachusetts, June 9 – 13, 2013..
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The poster contains a practical example of how the CDIO concept can be used for developing common course contents with the aim to improve the students’ generic and professional competences. The overall purpose is to create a school-wide spirit of community for the students and introduce CDIO for faculty.OBJECTIVES1. Ideas for how to coordinate school-wide activities aiming at increasing students’ generic skills and professional identity2. Strategies for introducing the CDIO concept for the school faculty membersDESCRIPTIONFor reaching high employability, students require knowledge and skills connected to the future working area, as well as generic skills and a professional attitude [1]. Ensuring these abilities is a major challenge of higher education today [2-4]. All these abilities are trained in the final independent work, where students, normally in collaboration with industry, acts as professionals while fulfilling the goals of academy. In the past, every subject had their own way of running the degree courses, but a need to coordinate the efforts for assuring the required outcome has gradually evolved. This emerging need was used as an opportunity to introduce CDIO thinking on school level, because most staff is involved in the degree project courses. Activities open for all students, such as joint introduction and lectures, workshops in literature search and a final dinner together with industry collaborators, are offered during the final semester, and general tools supporting the process have been developed, covering templates for report writing, a common web portal and a web based tool for registering of degree theses. The approach is extended with faculty pedagogic development activities, such as discussion meetings regarding generic skills training and the tutors’ role in the learning process.
|
|
| 13. |
- Lillieblad, Lena, et al.
(författare)
-
Boiler operation influence on the emissions of submicrometer-sized particles and polycyclic aromatic hydrocarbons from biomass-fired grate boilers
- 2004
-
Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 18:2, s. 410-417
-
Tidskriftsartikel (refereegranskat)abstract
- The emissions of particles, and gaseous compounds, into the ambient air from biomass-fired moving grate boilers were characterized under different boiler operation conditions. The boilers had a thermal capacity of similar to1 MW. The flue gas cleaning systems consisted of multicyclones for the removal of coarse particles. Dry wood fuel that consisted of shavings, wood chips, and sawdust from a local wood industry and wood pellets were fired at two plants. The influence of boiler load on the emissions was characterized. An electrical low-pressure impactor (ELPI) was used to determine the particle number concentration with high time resolution. A low-pressure cascade impactor (LPI) was utilized for the mass size distribution and the size-differentiated chemical composition. Elemental analysis of the fly ash collected on impactor substrates was made by particle-induced X-ray emission (PIXE) analysis. The concentration of elemental carbon under different load conditions was also measured. In addition, emissions of polycyclic aromatic hydrocarbons (PAHs) from the boiler that was operating on dry wood fuel were compared with PAH emissions from two different biomass-fired boilers (one was operating on forest residues and the other on pellets). The boiler load had little influence on the particle mass concentration of submicrometer-sized particles, which was in the range of 50-75 mg/m(3) (0 degreesC, 101.3 kPa, dry gas, 13% CO2). The total particle number concentration increased and the particle size decreased as the boiler load increased. The elemental analysis revealed that potassium and sulfur were the dominating components in the submicrometer size range, whereas potassium and calcium were major components in the coarse fraction. The PAH emissions between the three boilers varied by almost 3 orders of magnitude.
|
|
| 14. |
- Ohlsson, Lars-Ola, et al.
(författare)
-
Evaluation of Laminaria digitata and Phragmites australis for biogas production and nutrient recycling
- 2020
-
Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 140
-
Tidskriftsartikel (refereegranskat)abstract
- Eutrophication and climate change are major global problems. The sea weed Laminaria digitata and the reed Phragmites australis have the potential to absorb nutrients and CO2 during growth, as well as being a source of renewable energy in the form of biogas. The aim of this study was to evaluate Laminaria digitata and Phragmites australis concerning biogas production and nutrient recycling using a two-stage pilot scale process. The plant has a total volume of 430 L and consists of a hydrolysis bed and an up-flow anaerobic sludge blanket reactor (UASB). Two experiments were performed; one with Laminaria digitata as the sole substrate and one with a mixture of Laminaria digitata and Phragmites australis. Frozen substrates were placed in the hydrolysis bed and digestion was performed at 305 K during 70 days for Laminaria digitata and 100 days for the mixture of Laminaria digitata and Phragmites australis. The methane yield achieved was approximately 170 L kg−1 volatile substances (273.15 K, 101.3 kPa) in both experiments. These results suggest that Laminaria digitata can be efficiently digested in larger scale and has the potential to contribute to a future sustainable energy mix, considering its relatively high methane yield when anaerobically digested as the sole substrate. Digestion of Phragmites australis needs further development to make use of its full potential.
|
|
| 15. |
- Pardalis, Georgios, 1983-, et al.
(författare)
-
Kundresa för One-Stop-Shop
- 2022
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den här guiden är en av tre guider som publiceras inom detta projektoch bygger på tidigare forskning, med syftet att utveckla kunskap och metoder för aktörer på efterfråge- och utbudssidan på marknaden för energieffektiv renovering av villor. Guiden ger en översikt över den kundresa som villaägare följer i sitt beslut att genomföra eller inte att energirenovera sin villa, och hur One-stop-shop (OSS) konceptet kan bidra med renoveringsresan.
|
|
| 16. |
- Rupar-Gadd, Katarina, 1974-, et al.
(författare)
-
A theoretical and experimental framework for the study of vegetation as a screen against aerosol pollution
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- It is well known that vegetation acts a sink for aerosol particles, with the particle-capture efficiency strongly related to vegetation characteristics (such as dimensions of needles and leaves) and to particle size and aerodynamic conditions. However, there is a need for studies of ways to harness this sink capacity for constructing “green screens” to help reduce aerosol-particle concentrations, and thus health effects, in downwind residential areas. In this report we present a simplified mathematical model for the particle-capture processes involved and use results of model simulations to explore ways to address the problem through experiments with vegetation-filter components (“green filter packs”) placed in a windtunnel. Because of the exploratory nature of our work, the very limited logistics available, and the severe time constraints for the work (a few weeks only were available) the report is shaped as a kind of “scientific narrative” (rather than as a traditional technical paper). A series of tests is described wherein steps are taken towards practical implementation of experimental designs and procedures based on a simple smoke-aerosol generator and measurements of smoke concentrations upwind and downwind of “green filter packs”. Measurements involve laser-based particle counters, two-stage Nuclepore filter systems, and Solid Phase Microextraction (SPME) techniques followed by Gas Chromatography-Mass Spectrometry. The main objective of the work was thus to illustrate ways to design experiments – rather than perform full-fledged experimental work – and to show how experimental data can be processed and used to assist in the study of vegetation as “pollution screens”. Despite the very limited time available for the work, the results show that our experimental approach is able to generate relevant information; for instance, a study of the particle-filtration capacity of a “green filter pack” consisting of an arrangement with Scots pine needles yielded interesting data. Also, the study suggests opportunities for more systematic comparisons between theory and practice, inasmuch it showed how, in principle, parameters involved in the mathematical model can be quantified. The SPME tests also provided interesting information with respect to chemical characteristics of the smoke-aerosol that was generated for the experiments. However, the tests with Nuclepore-filter sampling as well as the SPME applications showed needs for improving the smoke-generation method so that high and stable smoke-aerosol concentrations can be maintained over long periods (several hours). Our observations and findings imply that several refinements to the experimental design will be needed, including with respect to methods for assessing the distribution of particle number and mass as a function of particle size (in the present study, the distribution is indicated by two particle-size classes only, 0.5 to 5 μm and >5 μm). Several other needs for improving the modelling as well experimental approach are also discussed in the report. Finally, a few observations on the needs for field-based studies are made together with remarks on the implications of the multi-disciplinary nature of this kind of work, with is linkages to the broader air-pollution context.
|
|
| 17. |
|
|
| 18. |
- Rupar-Gadd, Katarina, et al.
(författare)
-
Biological treatment of air polluted with alpha-pinene
- 2008
-
Ingår i: 16 th European Biomass Conference&Exhibition. - : Eta-Florence Renewable Energies.
-
Konferensbidrag (refereegranskat)abstract
- A study was performed in order to evaluate if a more hydrophobic biofilter surface could facilitate the removal of hydrophobic pollutants from air. Alpha-pinene was used as a model compound since it is released from wood handling industries e.g. sawmills. Two biofilters were used during the study. One of the filter was filled with perlite soaked with silicone oil while the other was filled with untreated perlite. The removal efficiency was approximately the same for both filters except for the start up period when the oil soaked filter was more efficient.
|
|
| 19. |
- Rupar-Gadd, Katarina, 1974-
(författare)
-
Biomass Pre-treatment for the Production of Sustainable Energy : Emissions and Self-ignition
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Organic emissions with focus on terpenes, from biomass drying and storage were investigated by Solid Phase Microextraction (SPME) and GC-FID and GC-MS. The remaining terpenes in the biomass (Spruce and pine wood chips) after drying were dependant on the drying temperature and drying medium used. The drying medium used was steam or hot air; the drying temperatures used were 140degreeC, 170degreeC and 200degreeC. Steam drying at 170degreeC left more of the terpenes remaining in the wood chips, not emitting them into the drying medium. The terpenes emitted from storage of forest residues and bark and wood chips increased up to three-four or four-five months of storage, and then dropped down to approximately the same low level as the first month. The leachate taken from the forest residue pile contained 27µg PAH per liter. The SPME response for a monoterpene (a-terpene) at different temperatures, amounts and humidities was quantified. The highest concentration calibrated was 250 ppm and the lowest 9.4 ppm. There is a better linear agreement at higher temperatures (70degreeC and 100degreeC) than lower temperatures (below 40degreeC). Organic emissions from biofuel combustion were measured at three medium sized (~ 1MW) biomass fired moving grate boilers fired with different fuels: dry wood fuel, forest residues and pellets. The PAH emissions varied by almost three orders of magnitude between the three boilers tested, 2.8-2500 microgram/m3. It was difficult to identify any general parameters correlating to the PAH emissions. The variation in PAH emission is most probably a result of boiler design and tuning of the combustion conditions. When comparing the contribution to self-heating from different wood materials by means of isothermal calorimetry with different metals added and stored at different temperatures, the differences were quite large. Some of the samples released as much as 600mW/kg, whereas others did not contribute at all to the self-heating. The storage temperature, at which the samples released the most heat, was 50C. There was a peak in heat release for most of the samples after 10-30 days. Stepwise increase in temperature did not favour the heat release in the sample Dry Mix; the heat released was even lower than when it was directly put in the different storage temperatures. When metal is added, there is an increase in heat release, the reference sample without metal released 200mW/kg compared to 600mW when copper was added.
|
|
| 20. |
|
|
| 21. |
- Rupar-Gadd, Katarina, et al.
(författare)
-
Emissions from stored biofuels for house-hold use, risks and health effects
- 2008
-
Ingår i: 16th European Biomass Conference&Exhibition, 2-6 June 2008, Valencia, Spain. - : ETA-Florence Renewable Energies.
-
Konferensbidrag (refereegranskat)abstract
- By varying the storage conditions for lab-scale samples of different biomasses, the mircrobial growth in the samples varied. The microbial acitvity caused heat release and organic emissions were sampled. By measuring the heat release with isothermal calorimetry and organic emissions with solid phase microextraction (SPME) and gas chromatorgraphy with mass spectrometry (GC-MS), it may be posssible to predict the deterioriation in fuel quality, substance losses and health effects for a special fuel storage. The biofuels investigated were pellets made from peat/wood, bark/wood and wood pellets.
|
|
| 22. |
- Rupar-Gadd, Katarina, 1974-, et al.
(författare)
-
Evaluation of increased electricity production when cooling solar panels
- 2022
-
Ingår i: SBE22Delft - Innovations for the Urban Energy Transition. - Bristol, United Kingdom : Institute of Physics (IOP).
-
Konferensbidrag (refereegranskat)abstract
- A municipal housing company located in the south of Sweden has energy renovatedseveral buildings with a total of 380 apartments to meet today’s energy standards. Several energyefficient technologies and solutions were implemented and the energy consumption for thesebuildings were lowered by 50%. One of the buildings functions as a demonstration building forinnovative solutions such as low temperature district heating, waste water heat recovery, andsolar photovoltaic and thermal (PVT) panels. The solar PVT panels are cooled down with themain purpose to increase the electricity production. The cooling medium for these panels iscirculated through two bedrock boreholes to dissipate the collected heat. The heat from theboreholes is then used for an electric heat pump to produce heat to send to the local districtheating company. The electricity produced is primarily used in the building. The objective ofthis paper is to assess the electricity production from real-life outdoor Photovoltaic-thermal(PVT) plant. The plant was installed on the roof top of an energy renovated multi-familyapartment building located in the south of Sweden. The cooling of the panels were turned on andoff to assess if the electricity production would increase or not. The electricity production didnot increase when the cooling was applied. The temperature measuring equipment which wasinstalled at the wrong position and was supposed to measure the temperature at the back of thePVT is needed to compare the efficiency of the PVT plant and draw further conclusions.
|
|
| 23. |
- Rupar-Gadd, Katarina, 1974-, et al.
(författare)
-
Evaluation of smart energy solutions in a multifamily apartment building in Småland, Sweden
- 2021
-
Ingår i: eceee Summer Study on Energy Efficiency. - : European Council for an Energy Efficient Economy (ECEEE). - 9789198387889 ; , s. 999-104
-
Konferensbidrag (refereegranskat)abstract
- A municipal housing company in the south of Sweden constructed three energy efficient multi-family apartment buildings in 2020 in which smart technologies were implemented. One of the buildings with a total heated area of 976 m2 is designed to have a primary energy number of 19.3 kWh/ m2 /year compared to the 85 kWh/m2/year as required by the Swedish Building Regulations. Apart from building envelope energy efficiency measures solar panels were installed and the excess electricity produced is stored to a battery. The excess heat from the solar panels is used in the bedrock heating system with cooling possibilities. The aim of this energy solution is to make the buildings partially off-grid. The actual electricity produced from the solar hybrid panels is so far lower than the simulated self-consumption and the battery is not used to its full potential. The rainwater collected was enough to save 75 percent of drinking water volume normally used for toilet flushing according to calculations made from incomplete data. A faulty installed meter, a fire incident, the use of several different systems and companies for collecting and logging data, and many other contributing factors affecting the possibility to evaluate the installed smart energy systems needs to be remediated. A recommendation is to assign someone the role of energy coordinator with the purpose of making evaluation possible within one year.
|
|
| 24. |
- Rupar-Gadd, Katarina, et al.
(författare)
-
Evaluation of the role of microbail activity in self-jheating of stored wood based biofuels
- 2005
-
Ingår i: Swedish-Finnish Flame Days. - : International Flame Research Foundation. - 9171781854 ; , s. 262-267
-
Konferensbidrag (refereegranskat)abstract
- Self-ignition in storde wood based biofuels is an environmental as well as an economical problem. The amount of biofuels, which is going to be stored, might increase due to the decision taken by the European Union that the emissions of greenhouse gases should decrease. Storage of oragnic material leads to chemical as well as microbial activities. The heat released from aged sawdust (stored outside for three months), dried mixture before it was pressed to pellets and three different kinds of pellets due to microbial activity was measurede with an isothermal calorimeter (TAM Air) under various conditions.- Experiments with and without addition of Cu,Fe and Mn were performed in order to investigate if a catalytical effect could be observed. The results showed that the addition of copper had different efffects depending on which wood material that was studied and the temperature at which the samples had been stored. The addition of Fe or Mn generally did not give any measurable increase in the heat released.
|
|
| 25. |
|
|
