Forskningsrapporter

Energi

Anslag ges till projekt inom många olika energiforskningsområden. Rapporter kan omfatta ämnen, såsom

• Förbränning
• Vindkraft
• Solenergi
• Användning av biobränslen
• Solceller
• Vattenkraft
• Bränsleceller
• Energilagring
• Vätgas som energibärare
• El- och hybridfordon

Evaluations of a High power, Medium frequency and High voltage transformer prototypes as main part of a Solid State Transformer for Flexible, Efficient and Sustainable Integration of Renewable Energies to Smart Grid as well as future power distribution

The main purpose of this project which is commonly financed by ÅForsk, Chalmers and SP was to experimentally evaluate the electrical characteristics of the manufactured prototypes and examine their design and manufacturing processes and methodologies.

The follow objectives were achieved in this project:

  • Identifying sets of proper masurement methods of loss components of manufactured MFHVPT prototypes and performing the measurements
  • Identifying proper methods for heat-run tests on existing MFHVPT prototypes and performing thermal characterisation tests on the important transformer parts
  • High voltage withstand tests on transformer's components and insulation configurations
  • Releasing the required considerations for manufacturing an updated version of the transformer.

Moreover, worth mentioning is that, based on the results presented in details in the report and summarized at the final section of it, it is now possible, using the gained knowledge, to manufacture the next generation of the MFHVPT transformers.

Datum
2016-08
Författare

SP Technical Research Institute of Sweden; Mohammad Kharezy

Design and Assembly of Novel Pathways for Advanced Biofuel Synthesis

Microbial production of fuels and chemicals from renewable resources offers sustainable alternatives to the current petroleum-based production. However, many challenges still remain in realizing the commercialization and to compete with more conventional processes. The key factor to commercialization is engineering of the microorganism's  metabolism, to reach the titaters, yields and productivities (rates) required to meet economic targets. This yeast Saccharomyces cerevisiae is an attractive cell factory for production of many industrially relevant products. Especially in the field of biofuel production, much interest has centered on this organism for advanced biofuel production, as it is well adapted to industrial condictions and thus allows flexibilities of production facilities, which  are very capital intensive. The objective of this project is to develop yeast platform cell factories for efficient production of advanced biofuels, e.g. fatty acid derived esters (fatty acid ethyl esters, FAEEs) and alkanes. More specifically, the primary aim of this project is to design and assemble  a synthetic pathway in yeast, providing an alternative route for efficient provision of acetyl-CoA and malonyl-CoA as precursor metabolites for advanced biofuels production, and combining this feature with elimination of pyruvate decarboxylase activity and thus avoiding by-product ethanol formation. Through the investigations in this project we have firstly delimited the rate limiting step in conversion of acetyl-CoA to malonyl-CoA, via removing the reversible phosphorylation sites in acetyl-CoA carboxylase Acc1. By doing so the enzyme activity of Acc1 increased by three fold, and in turn the production of FAEEs enhanced by three fold, which indicates the increased supply of malonyl-CoA. Secondly we have constructed a Pdc minus yeast strain in order to abolish ethanol formation, via knocking out the main enzymes responsible for pyruvate decarboxylase activity - PDEC1, PDC5 and PDC6. The resulted strain cannot grow on glucose as the sole carbon source due to the lack of cytosolic acetyl-CoA. Therefore, adaptive evolution has been performed to get better growth of Pdc minus strains. In parallel, we have identified a mechanism, in which Ach1 is involved in shuttling mitochondrial acetyl unis to cytosolic C2 provision in Saccharomyces cerevisiae lacking pyruvate decarboxylase. This new finding signifcantly contribute to our knowledge on yeast carbon metabolism and further to better strain design. Thirdly, in order to reconstruct the phosphoketolase  pathway in yeast that allows the shunt of carbon from the glycolysis/pentose phoshate pathway intermediates frucose-6-phosphate (F6P)/xylulose-5-phosphate (X5p) to acetyl-Coa, offering an alternative route for acetyl-coA synthesis. We have screened nina phosphoketolase enzymes from Bifidobacterium genus and, the Firmucute phyla (includes lactic acid bacteria and Clostridia). Characterizing the strains with phosphoketolase expression reveals addiitional C2 compounds (acetate) formation, a potential direct substrate for acetyl-CoA biosynthesis.

Datum
2016-06
Författare

Chalmers; Yun Chhen

Chemical cyclist combustion (CLC ) of biomass to remove carbon dioxide from the atmosphere

Chemical-looping combustion (CLC) is a low-cost CO2 capture technology that uses oxygen carriers - metal oxides - for oxygen transfer from air till fuel, which enables fuel oxidation without mixing fuel and combustion air. Thus, CO2 can be recovered in a separate gas stream without active gas separation. The capture and storage of CO2 from biogenic emission sources make it possible to obtain so-called negative emissions - the atmosphere is cleansed from carbon dioxide. This concept of storing biogenic CO2 could prove to be highly instrumental for a country such as Sweden, which has substantial point emissions of biogenic CO2.

The purpose of the present study was to investigate the suitability of different manganese ores as oxygen carriers in the chemical-looping combustion of biomass fuels. Since this was a pioneering screening study, a compact, 30 cm high CLC system that is easy to operate was chosen, in order to enable screening of many materials within a limited time period. The primary focus was to investigate the reacitivty of these oxygen carriers towards biomass fuels, and find a reactive oxygen carrier with sufficient mechanical stability that could be suitable for large-scale chemical-looping combustion of biomass. Biomass fuels consist largely of volatile components, which are released as an energy-rich gas when the fuels is heated. A synthetic "biomass volatiles" gas - representing the gas generated during devolatilization of a wood-based fuel - was produced for use as fuel in this study. Hence, it was possible to study how the different gas components reacted with the oxygen-carrier particles.

The study shows that chemical-looping combustion of biomass is technically feasible using low-cost manganese minerals as oxygen carrier. This is a significant finding, as it is likely that natural materials would likely be needed for a cost-effective process. Parameter studies concerning temperature and specific fuel-reactor bed mass (bed mass per fuel thermal power in kg/MVth) were carried out in the 300 W CLKS system. Conversion of fuel carbon to CO2 as high as 97.6% was achieved, which is very high. For a majority of the investigated ores, essentially all C2 and C3 hydrocarbons were converted, as well as a very high fraction of the CO. Reactivity towards CH4, on the other hand, was generally lower, but improved at higher temperatures. The resistance of the oxygen carriers towards mechanical degradation was measured in a jet-cup attrition test rig. The measured attrition was estimated as "intermediate" for four of the five tested materials, while one of the ores showed low resistance. Furthermore, a batch reactor was used to investigate the kinetics data for CO, CH4 and wood char for one of the manganese ore oxygen carriers. In conclusion, this study shows that it is possible to remove CO2 efficiently from the atmosphere through a chemical-looping combustion process with biomass as fuel. The use of manganese ores has the potential to keep the costs of the CLC process low, and deserves more investigation at larget scale.

 

Datum
2016-04
Författare

Chalmers; Carl Linderholm, Patrick Moldenhauer, Martin Keller och Tobias Mattisson

Conditioner importance to energy and quality in the production of pellets

Water has been found to have an important role in production of pellets and the durability of pellets. To improve the pellet durability many manufacturers ads water or steam to the raw material before it is pelletized. This work has investigaged how the energy consumption of the pellet press and the durability of pellets are affected by the production of pellets from sawdust treated with steam. Further, it is examined how the residence time in the mixer, where water and steam is supplied, affects the energy consumption and pellet durability.

The sawdust was moistened up to reference levels of 11,13 and 15% moisture before pelletizing in pilot scale at Karlstad University. During the test series the residence time in the mixer varies between 25 to 300 seconds.

The results show that the amount of moisture in the pellets, in the range of 6-9%, and the residence time in the mixer is important for the pellets durability. The durability and the energy consumption increased with increased amount of moisture in the sawdust.

Datum
2016-04
Författare

Magnus Ståhl, Jonas Berghel; Karlstads Universitet

Behavioral change towards a sustainable lifestyle - effects of intervention and psychological factors on residential energy conservation

Adopting a more sustainable lifestyle is highly necessary given the threat of global climat change. The project examend how an intervention with motivation-increasing design and behaviour focused techniques affect individual's capacity to behavior change towards a reduction of residential energy use. Differentiated energy use for daily domestic behaviors was monitored in real time via an internet-based system for a period of eight weeks by 25 residents. Psychological factors including soclal value orientation, awareness of consequences, environmental concern, locus of control, moral judgment and sense of coherence were assesssed by web survey. Modern feedback- and reinforcement strategies, based on learning psychology, were carried out in order to enhance motivation for change and follow-up studies analysed the maintenance of change for another 3 months. International failure of pacticipants reached 68% with only 8 participants comopleteing the intervention. The results could not point out any sign9ficant energy conservation effects of the motivation-increasing strategies in the experimental group. The small sample size and the loss of monitoring warm water energy use were discussed as explanatory factors.

Datum
2016-01
Författare

Richard Ahlström, Mittuniversitetet

Hetero-doped Carbon Nanomaterials as Bi-functional Catalysts for Fuel Cell Applications

Fuel cells offer a great opportunity to obtain clean and sustainable energy; however, the use of expensive catalyst (Pt-based materials) for oxygen reduction reaction (ORR) hinders their developments, but opens a market for metal-free catalysts. As a result, the exploration of metal-free catalysts with low cost, but still high catalytic activity and durability is needed. Therefore, in the present project, we carried out the production of nitrogen and phosphorous co-doped graphene as an efficient metal-free catalysts for ORR. The experimental observations were complementen by a computer-based design, whre ab initio theoretical simulations were used to optimized the catalytic activity of doped graphene, and thus guiding the experimental development of the electrocatalysts.

Datum
2016-01
Författare

Eduardo Gracia-Espino, Physics Department, Umeå University

Pilot Cultivation of Spirulina for fish feed

This study has investigated micro-cultivation of Spirulina in a prototype home photobioreactor with the aim of measuring biomass productivie.

Culvtivation in the home bioreactor achieved a maximum biomass productive of 4.34 gm-2  day1 with supplementary red LED lighting and gm 0,9-2day1 without. These values are lower than expected and attributed to a number of factors suc as strain selection, light limitation, foaming and flocculation.

The biomass produiced was deemed microbiologically safe when cultered under sanitary condittions equating to a home/coffee-room environment. The nutrient content was comparable to commercially available Spirulina. Lead levels in the biomass were however marginally over the legal requirements set by the EU. This was considered to be due to corrosion of a portion of the sparging system. Appropriate changes to the reactor design and sparger system are recommended for future product development work.

With the aim of improving the sustainability of the Spirulina nutrient media, cultivation experiments have been performed using separated human urine that has been treated with ozone in order to break down medicinal residues. Previous studies have indicated that such a treatment step located upstream of municipal wastewater treatment plants allows for more energy efficient treatment of such substances and renders a hygienic nutrient solution that can be used as fertilizer.

Cultures fed with the urine based medium grew faster than those on the standard minsteral based nutrient. Potential harmful substances from the ozone treatment of medicianl residues were hence deemed not to affect growth. Further analysis of these substances was left outside the scope of this project.

Cultivation experiments were also performed at an ecological farm in Hemy, 2 hrs, north of Stockholm, using column photobioreactors utilizing flue gas from a 200 kW woodchip fired boiler as an additional carbon source. Maximum productivity in this cultivation system with only natural sunlight amonted to 0.1 gl-1day-1. The low-cost control system chosen proved sufficient for the purpose when the pH electrode was changes to a higher quality unit.

Further product development work is recommended regarding design of a user friendly harvesting unit and a low cost quality control and analysis system for continuous monitoring of the culture. Longer term cultivation on the urine based medium is of interest to determine how the macro and micronutrients can be kept in balance,. The first recommendation regarding future work is however to test cultivating more robust and productive stains of Spirulina.

Datum
2015-12-14
Författare

ÅF-Industry AB; Max Larsson

Oxygen carriers in Combustion

Bed material in Circulating Fluidized Bed (CFB) combustion plays an important role on heat and mass transfer, and also it determines the heat capability of the boiler. By replacing part of the conventional inert bed material sand with ozygen carrier Ilmenite, a lower emission of CO and NO, and a higher combution efficiency has been achieved (Thunman et al, 2013). This is because oxygen carriers participated the combution, and were continuously oxidized and reduced in different part of the combustion system, where there was a reducing or oxidizing athmosphere during circulation. When Oxygen carrier doing so, a better oxygen-fuel contact is achieved, and the poor gas solid mixing is compensated, and a more even smooth combustion is achieved. This is a new concept referred to as Oxygen Carrier Aided Combustion (OCAC). In this work, Ilmenite and manganese ore-the most common oxygen carries studied in Chemical Looping Combustion, and two oxide scales-production wastes from ESAB denoted as AQS and LDst, were used as bed material, and the results are compared to sand. Wood char was used as solid fuel for the tests, and the contents of CO2, CO, CH4, O2 and NO were monitored during combustion. The combustion tests were conducted in a laboratory fluidized bed combustor using different air to fuel rations. The results show that utilization of oxygen carrier lowered CO emission thus increased the combustion efficiency. It is also shown that the increased combusition efficiency is mainly due to the reactitivity of oxygen carriers with CO. Manganese ore gives the best performance. The behaviour of NO formation varies with the utilization of varied oxygen carriers. The Ilmenite and oxide scales do not increase NO-emission in two oxygen lean and most of the oxygen rich cases, a lower NO emission was also observed in stoichiometric case. However, a higher NO emission was detected when manganese ore and fresh LDst were used in oxygen rich condictions. However, by reducing the excess air, a lower NO emission can be achieved with the same level of CO emission through OCAC for all the tested cases. Manganese ore tends to agglomerate in reducing athmosphere, which may be caused by the potassium content in itself, and showed ion SEM-DEX resuilts. Detailed understanding is important and the furterher investigation is needed.

Datum
2015-12-14
Författare

Chalmers; Dongmei Zhao

Guiding Device with a lateral force damper for a Submerged Wave Energy Converter

The purpose of this project is to devewlop a new typ of guiding system for a linear direct driven permanent magnet generator where friction will be minimized by rolling friction.

The lateral force form the waves is to be absorbed by the powerful spring with minimum wear at the contact surface.

In a previous wave power experiments at the Swedish west coast, a funnel with a smooth shape hade been used.

The connection line for such a funnel is housed in 2 layers of jacketing compounds. Firstly, the steel wire is housed in a PEX jacketing compound. Secondly, the wire is covered with a braided Dyneema compound.

The new guiding system allows using a connection line without any jacketing compund. Parameters of importance in this case are flexibility and high breaking strength of the connection line.

The main emphases in this project is an innovation proposal for the guiding device in terms if minimizing of wear of the connection line and especially for increasing the service life of the wave energy converter.

The research in this area is of importance because a search for new solutions for generation of energy is becomin more and more important for our future.

 

Datum
2015-12-11
Författare

Uppsala Universitet; Andrej Savin

Visualization and Measurement of Two-phase Flow Fields at an Aerator Using PIV and BIV Techniques

Hydraulic structures subjected to a flow velocity exceeding 20-25 m/s are usually phone to cavitation damages. The use of aeroators is a common way to prevent the formation of cavitation. The entrainment and detrainment process of a aerator is still not well understood, which is mainly due to laboratory instrumentation limitations. The difficulty rests with capture of instantaneous images of the water-air mixture with high air concentation. The Buggle Image Velocimetry (BIV) is a recently developed technique that makes it feasible to instantaneously capture the two-phase flow texture and its evolution with time. No artificial tracer is added and ir bubbles act as tracer for flow visualization. The aim of the project is, with the use of the BIV technique, to investigate the entrainment at an aerator and examen the streamwise development of the detrainment process. The results of the project provide insight into both the local and overall physical flow features of an aerator, an essential safety structure in almost each medium- and high-head spillway.

Datum
2015-12-11
Författare

National Chung Hsing University, Taiwan; Chang Lin
Kungliga Tekniska Högskolan; James Yang
Sweco; Hans Ericsson
ÅF-Industry; Anders Frisk

New Detection Techniques for Fault Tolerant Control - Individual Pitch Control of Wind Turbines

Detection of the blade root moment sensor failures is an important problem for fault tolerant individual pitch control, which plays a key role in reduction of uneven blade loads of large wind turbines. A new method for detection of the blade root moment sensor failures which is based on variations induced by a vertical wind shear is described in this report. The detection is associated with monitoring of statistical properties of the difference between amplitudes of the first harmonic of the blade load, which is calculated in two different ways. The first method is based on processing of the load sensor signal, which contains a number of harmonics. The first harmonic is recovered via least squares estimation of the blade load signal with harmonic regressor and SDD (Strictly Diagonally Dominant) information matrix. The second method is a model based method of estimation of the first harmonic, which relies on the blade load model and upwind speed measurements provided by multibeam LIDAR. This is a new application for future LIDAR-enabled wind turbine technologies. Moreover, adaptation of the load model in a uniform wind field is proposed. This adaptation improves accuracy of the load estimation and hence the performance of the blade load sensor failure detection method.

Datum
2015-12-11
Författare

Chalmers; Alexander Stotsky

Application of Waste heat recovery techniques to inland ferrie

In a siutation where shipping is subject to strong external pressure in relation to fluctuating fuel prices and stricter environmental regulation, inland shipping has been indicated as on of the future solution for European local transport.

Waste heat recovery systems can be a solution to improve the efficiency of existing ship propulsion systems. However, the specifics of inland shipping, and in particular inland ferries, makes this application a particularly challenging one.

In this study, we analyzed two main challenges of the application of waste heat recovery to inland ferries. The highly dynamic, cyclic operational profile initially suggested that the application of thermal storage could be an option for improving the performance of the system; the results of our simualtions, however, suggests that the utilization of thermal storage would not significantly improve the power output of the WHR system.

On the other hand, the large time spent by the system at part-load operational conditions suggested that these operational points should be included in the optimization of the system's design. The results of the application of different optimization criteria led to the conclusion that for such systems the inclusion of the part-load efficiency in the optimiization procedure is crucial for getting the full benefits from the installation of a WHR system onboard.

Datum
2015-12-10
Författare

Chalmers; Francesco Baldi

Quantum Confined Stark Effects in ZnO Quantum Dots Investigated with Photoelectrochemical Methods

The optical absorption behaviour of ZnO quantum dots has been investigated as a function of particle size in the quantum confined regime, between 4 and 9 nm in diameter, by using photoelectrochemical methods. Thin films of quantum dots, with 18 different sizes, were prepared on conducting substrates where the Fermi level could be controlled potentiostatically simultaneously as absorption measurements were perfomed. While raising the Fermi level into the conduction band, the dominant effect is a decrease in absorption as a consequence of increased electron population in the conduction band. This is a potentiostatic analogue to the Burstein-Moss shift for degenerate semiconductors. For applied potentials in an interval of 0,2 eV below the conduction bad edge, the absorption does, however, increases instead of decreases. The absorption incresae was found to be caused by a transition into states located within the bad gap, which are introduced as a consequence of the applied potential. The magnitude of this effect is for the smallest particles (4 nm) approximately 9% compared to the magnitude of the Burstein-Moss bleaching. The effect decreases with increased particle size and essentially disapaears for particles approaching 9 nm. The phenomenon is analyzed in terms of the Stark effect where the conseqeunce of the applied potential is a buildup of an electric field within the particles, breaking the symmetry and splitting the energy levels in the conduction band. The gradual disapperance of the effect for the growing particles gives the extent of the quantum confinement effects of this phenomenon. The size-dependent absorption probability is analyzed and gives important information concerning the nature of both the perturbed states above the conduction band edge and the formation of the sub-band edge states.

Datum
2015-12
Författare

Uppsala Universitet, Ångströmslaboratoriet; Jesper Jacobbson och Tomas Edvinsson

Optimized use of district cooling through reduced power requirements and increased ΔT

The aim is to highlight current issues around how the heat flow through windows calculated and simulated. The focus has been on how convection can affect the U-value (heat transfer coefficient). Because energy transport are related dealt also g-value (solar factor).

The text present and discuss a number of calculation programs, they handle energy transport in various ways, mainly because the programs have different uses.

Datum
2013-12
Författare

ÅF-Infrastructure; Johan Svahn

Carbon dioxide capture using chemical-looping combustion of fossil fuels - development of a reactor system

In the last years, reports about climate change have made both the public and researchers aware of the Earth's global warming. Effects like increased sea levels and melting polar caps indicate a strong connection to the greenhouse effect, as the release of green house gases have increased at the same rate as the increase in temperature. This has led to an increased interest in technologies and storage of carbon dioxonde emissions. In energy production, there are today multiple techniques from which the carbon dioxide can be captured, albeit to the cost of a large efficiency drop. The energy demanding step is the separation av gases, which also has high costs. Chemical-looping combustion is a carbon dioxide  capture technology, which without this efficiency drop can be applied to e.g. a power plant fed with fossil fuels or biomass in a CFB-boiler. The technology is based on the circulation of oxygen carrying particles, led to react with gasified fuel, precluding a mixture of the air's nitrogen with carbon dioxide. The report centres on the design, modelling and operation of a 100 kW chemical-looping combustor for solid fuels. Operation of the unit is flexible, which means that operational parameters can be varied on a wide range to evalate stability and performance. So far, around 30 h of operation with three different fuels has been accomplished. As a part of the modelling in this project, a cold-flow model was design, built and tested. Results from the cold-flow model as well as the 100 kW unit have shown that the operation is stable and that the bed material circulates smoothly. The flexibility of the two systems helped determine that the most important factor for increased gas conversion was the fuel reactor bed inventory. By a close analysis of the relation between the bed inventories, the global solids circulation and the temperature, conditions were found that enabled a gas conversion of over 84% and a Co2 capture of 99% at steady state conditions.

Datum
2012-12
Författare

Chalmers; Anders Lyngfelt

Energicentral med borrhålslager, värmepump och lågtemperatursolfångare - utvärdering och komponentmodellering

Solfångare kan ge ett intressant energibidrag i värmesystem med värmepump och borrhålslager, där de kan ge ett nyttigt tillskott även vid mycket låga temperaturer. Vid simulering av kombinerade solvärme-/värmepumpsystem krävs en dynamisk solfångarmodell som kan hantera drift vid temperaturer under luftens daggpunkt.

En modell över lågtemperatursolfångare, eller oglasade solfångare, som även kan hantera kondensationsförhållanden har validerats genom detta arbete. Valideringen har visat att modellen kan förtusäga värmeutbytet av en oglasad solfångare mycket väl.

Modellen är en utvidgning av den dynamiska kollektormodell som används i teststandarden EN12975 för solfångare, och som finns tillgänglig som Type 136 i simuleringsverktyget TRNSYS.

Valideringen har genomförts med testdata från Sveriges Tekniska Forskningsinstitut, SP, som tillhandahållit testrigg och genomfört testet under perioden september till och med oktober 2010.

Solfångarmodellen har implementerats i den systemmodell som ÅF utvecklat i simuleringsverktyget IDA ICE, för simulering och dimensionering av energicentraler baserade på borrhålslager och värmepump för lokal energiförsörjning av byggnader,

Datum
2012-10
Författare

ÅF-Infrastructure; Carina Martinsson

Motor fuels from lignin by catalytic hydro-cracking at near supercritical water conditions

Catalytic hydrocracking at near supercritical water conditions has the potential for a very efficient conversion of black liquor or lignin to bio-oil and bio-fas of high value.

Such research activities have been started within a cooperation agreement between Chalmers and Metso and a high pressure reactor plant has been acquired for catalytic hydrocracking at near supercritical water conditions of Lignoboost ligning to motor fuels and/or aromatic chemicals. 

The high pressure reactor plant has during this period been further developed an operational standard with instant heating up of th e lignin feed an stable operation at steady state conditions for many hours for reliable results. The plan has also been developed for easy and safe inline cleaning which has given an increased research capacity.

Through this improvements and increased reserach capacity the high pressure reactor plant has been made available to one Post Doc and on PhD project, financed by Chalmers Energy Inititaitive (CEI) and a Licentiate project financed, by the LignoFuel project and Metso. The firstr results from these joint projects aiming at depolymerization of LignoBoost lignin have been presented at international bio-refinery conferences and journals, Nguyen (2013), Maschietti (2013).

The results of this first rest series show an almost quantitative conversion of lignin into 80% aromatic mono-, di- and trimeres with reduced oxygen and low sulfur content together with a 20% char residue. Fuirther developments are aiming at reducing this char residue withour addition of external hydrogen or other non-pulp mill chemicals.

Datum
2011-12
Författare

Chalmers; Lars Olausson

Local Energy Supply based on Borehole Storage, Heat Pumps and Unglazed Solar Colletors

Solar collectors can give an attractive energy contribution as part of a heating system with heat pump and borehole storage, where they can provide a useful contribution even at very low temperatures. The simulation of combined solar/heat pump systems requires a dynamic collector model that can handle operation at temperatures below the dew point of the ambient air.
A model of unglazed solar collectors which also supports operation under condensation conditions has been validated by this work. The validation has shown that the model can predict the heat exchange of an unglazed solar collector very well.
The model is an extension of the dynamic collector model used in the test standard EN12975 for solar collectors, which is also available as Type 136 in the simulation tool TRNSYS.
The validation has been carried out with test data from the Swedish National Testing and Research Institute, SP, who supplied the test rig and performed the test during the period September to October 2010.
The collector model has been implemented in the system model developed by ÅF in the simulationm tool IDA ICE, for the purpose of simulation and design of local energy supply centrals based on borehole storage and heat pumps.

Datum
2011-01-21
Författare

Carina Martinsson
Bengt Peters
Jörgen Eriksson

Hydrogen MacroSpheres

Hydrogen MacroSpheres is a novel higly efficient concept for storage and transport of Hydrogen gas. The idea is to store the gas under very high pressure (1000 bar) in many small spherical tanks, the MacroSpheres. Each tank is completely autonomus with an internal  micromechnical device a chip which is handling the gas flow to and from the tank. The gas flow is pressure controlled, at atmospeheric pressure the tanks are leak tight. At at slightly elevated pressure the tanks start to leak gas. An integrated pressure regulator stops the gas flow at a for the consumer preset working pressure.

The system combines the best storage performance availalbe (11-18 wt%) with focus on a conventient and non-dramatic handling for the user. The project has focused on some important development areas.

A bond burst equipment used for development of the microchip. The chip consists of five silicon wafers bonded together to a stack. Multiple wafer bonding is a well known problem area and a testing tool has been missing up to now. The other activity in the project was to investigate different design concepts for the small high pressure composite tanks, which has been done. The conclusion is to start with aluminum tanks for the biogas track and later shift to a high performance termo plastic LCP (liquid crystal polymer) reinforced with Kevlar for safe failure modes and a low manufacturing cost.

Datum
2010-12-30
Författare

Lars Stenmark

Effekt och energilager

The project has achieved the stated main objectives and all milestones except the last part of the fourth milestone: demonstration of 100kW machine with high efficiency. With this goal we are working further on with the extension project, "Flywheel as power handling system and energy storage'".

Datum
2010-12-27
Författare

Hans Bernhoff

Construction of a compact laser detection system for in-situ toxic gas sensing in harsh environments

The ability of remote sensing at molecular level of a reacting gas plume with non-intrusive optical techniques is of pivotal important in understanding the detail chemical processes and consequently improving the practical tehnologies crucial for energy utilization and environmental protection. The focus of this project has been the development and construction of a compact laser gas sensing system for in situ detection of toxic gases and some small hydrocarbon molecules in harsh environments of strong relevant to energy utilization and environmental protection.

The projet has been performed through a close collaboration with a laser company, GWU-Lasertechnik. We work together in developing and spectroscopic characterizing a prototype infrared OPO system designed by GWU, namely versaScan-L 1064/200, partly by the visiting of Mr Guido Göritz, a senior production specialist form GWU to our laboratory. The results indicated that this compact OPO system can be efficiently pumped by a laser system available in our lab with relatively low pulse energy lasing at 1064 nm, which provides the possibility of building a compact system with sufficiently  laser output at mid-infrared spectral range. A preliminary degenerated 4-wave mixing measurement has been performed. A single-shot based spectral characterization system measurement has been performed. A single-.shot based spectral characterization system was build in our lab, which provides for the first time the possibility to analysis the longitudinal mode structure of the mid-infrared laser pulse, based on which a collaborative efforts with GWU has been putting on injection seeding the infrared OPO with DFB diode laser to narrow the linewidth of the compact infrared laser system.

Datum
2010-12
Författare

Lunds Universitet; Li, Zhongshan

Macroporous Cryostructured Materials for Biobutanol Production

Butanol is regarded as a potential biofuel of great interest. This is due to its high energy content and good miscibility with e.g. diesel. That bio-butanol is not commonly used is due to limitations in the production technology. This project has addressed some of the limitations: the fact that microbial cells are intoxicated by the butanol produced and the problem that product will be present in an aqeuous solution at very low concentrations leading to high distillation costs to recover the butanol formed.

To circumvent these limitations; two steps were studied:

a) ability to produce preparations of high-density packed microbial cells in a format such that access for new substrate and possibility for removal of formed products is facilitated. This was done via cryo-structuring the cells such that a cell suspension was frozen, the cells gathered in the space between the ice crystals and were cross-linked in that position. When feeling substrate (sugar), butanol is formed an removed as soon as it leaves the cell. This becomes an efficient way to reduce the hampering effect that inhibition has on productivity of the cells.

b) the next step was to develop adsorbents capable to enrich butanol from a dilute aqueous solution and later on release the butanol in a more concentrated form. For that matter gel particles of stimuli responsive polymers were produced and later on attached/incorporated in cryostructured gels.

The results are encouraging - butanol producitivity increased substantially. The work on adsorption of butanol for centration is on-going and will need more time.

Datum
2010-12
Författare

Lunds Universitet; Harald Kirsebom

Flywheel as power management and energy storage , continuation of the project " Power and Energy Storage "

In practice, the project continues with design and evaluation of the power conversion system (PCS) for both low and high voltage, the charging and discharging of the batteries is handled, optimization of the electrical machine and analysis of the system.

Datum
2010-12
Författare

Uppsala Universitet; Hans Bernhoff

Systemmodell för dimensionering och optimering av energicentral med borrhålslager

This report describes three different simulation models of plants using a ground source heat pump adapted for the IDA simulation environment (developed by Equa). The first plant is a simple baseline model using a heat pump and a grid of boreholes as main components. The second plant is based on the first one using additional dry coolers to allow the heat pump to function as a chiller when the available cooling power from the boreholes isn't sufficient. When needed, the surplus heat can be returned to the bore hole grid. The third plant studied, is based on the first one using an additional pool-type solar collector.
To better account for the differences of the systems, they are used in a case study using a borehole grid of 600 holes. Hence, the plants are quite big and are assumed to supply a total amount of 30 GWh heating and cooling. The plants are studied using two different load profiles, one where the need for cooling is 80 % of the heating demand and one where the need for cooling is only 20% of the heating demand.
One important issue when using ground source heat pump systems is the supply temperature to the secondary cooling units. Two different temperatures are used in the case study, supply temperatures of 12o C and 18o C respectively. For both cases, the tempeterature rise is 4o C.

It might be dangerous to make generalizations based on the results from the case study. However, the need for electricity to powering the pumps is about 30 % of the electricity to the compressors and for every GWh put into the system four to six times of it could be utilized.
The most urgent task is to increase the speed of calculation. To accomplish this, amore time efficient model of the borehole grid is necessary. In this report, a small study is presented regarding the speed of calculation. In the study, the borehole grid is removed and replaced by a heat exchanger controlled by a sine curve. By doing this, it is possible to account for the part of the simulation speed that is governed by the borehole grid. According to this very preliminary study, the calculation speed might be about 4 minutes per year when using av very efficient model of a borehole grid.
Additionally from this preliminary study, one might draw the conclusion that this simplified model is good enough to use when performing whole year energy simulations required by the government to receive a building permit. To use a more detailed model will probalby not give a more accurate resultat when comparing the calculated energy use to the measured result.

Datum
2010-06-30
Författare

Jörgen Eriksson

Research and development challenges for Swedish biofuel actors - three illustrative examples

Currently biofuels have strong political support, both in 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 transportation by 2020. Fulfilling this amibtion 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.

Datum
2010-06-25
Författare

Maria Grahn m.fl.

The Premises for Swedish production of Fischer-Tropsch diesel

In order to reach the EU-target of 10 % of renewable energy in the transport sector approx. 10 TWh will be needed in Sweden. This report presents one possible renewable fuel which can contribute to reaching this target, the Fischer-Tropsch (FT) diesel, which can be synthesized via a biomass gasification route. The objective of this report has been to investigate the prerequisites for raw material, the technology, the economy and the market concerning production of FT-diesel in Sweden. The FT-process is well-tested and commercial when the feed is coal or natural gas, however the synthesis of FT-fuels via gasification of biomass is not (yet) a commercially proven technology. Possible biomass feeds are all sorts of forest and agricultural based biomass, which are abundant in Sweden but the consumption in competing  sectors is high. Studies of the potential of increased biomass usage show that enough biomass will probably be available to reach the 10 % EU-target. A location close to process industries, such as pulp and paper mills and oil refineries, or a district heating network contributes to enhanced economies. A final upgrade of the FT-product in an oil refinery and use as a blending component in diesel and gasoline will lower production costs. This is also an efficient way to introduce FT-fuels, which can be directly integrated into the existing fuel system and require no change of engines or vechicles. However, three main obstacles have been identified, being: (1) the technology for gasification and gas cleaning needs to be proven in demo-scale, (2) large plants are needed, due to economies of scale, to give profitable production and (3) uncertainties about future policies, due to the fact that renewable will rely on exemptions from energy and COs-tax at current price levels.

Datum
2010-03-31
Författare

Ingrid Nohlgren
Per Lundqvist
Anna Liljeblad
Nippe Hylander

Optimering av biogasproduktion från restprodukter - länkar mellan mikroorganismsamhällets sammansättning och metanbildningskapaciteten

Biogas is one of the greenhouse gas neutral energy sources. Its production has developed from using relatively simple substrates, e.g. manure, towards more complex mixtures such as industry wastes products. However, intensive utilisation of these more energy-rich substrates may result in less stable process conditions with foaming and suboptimal use of the organic material. To run these process conditions at high efficiency (high organic loading with a high volatile solids reduction and at shortest possible retention time while keeping process stability) an active and fast growing microflora is crucial. It is therefore important to increase our understanding regarding microbial composition and interactions within these complex digestion webs. In the present study we map the microbial composition of 22 Swedish full-scale biogas digesters treating different substates (slaughterhouse-, municipal household- and industrial process waste, energy crops and sewage sludge) and process configurations by using the FLX genome sequencing. The obstained microflora patterns are here presented on genus level and discussed in leation to substrate composition.

Datum
2010
Författare

Carina Sundberg
Bo H Svensson
Jörgen Ejlertsson
Anna Karlsson

Lime Kiln Modeling VFD & One-dimensional simulations

The incentives for burning alternative fuels in lime kilns are growing. An increasing demand on thorough investigations of alternative fuel impact on lime kiln performance have been recognized, and the purpose of this project has been to develop a lime kiln CFD model with the possibility to fire fuel oil and ligning. The second part of the project consists of three technical studies. Simulated data from a one-dimensional steady state program has been used to support theories on the impact of biofuels and lime mud dryness.

Datum
2010
Författare

Kristoffer Svedin
Christofer Ivarsson
Rickard Lundborg

Combustion of solid fuels with separation of carbon dioxide

In this project different oxygen carriers for the technology chemical-looping with oxygen uncoupling (CLOU) have been investigated. This process is highly efficient for combustion of solid fuels with inherent CO2 separation. The combustion process can be divided into three steps performed in two reactors. In the air reactor, a reduced metal oxide reacts with the combustion air to an oxidized metal oxide (Step 1). The metal oxide is then transferred to the fuel reactor, where the metal oxide decomposes and releases oxygen in the gas-phase (Step 2). Finally, the oxygen reacts with the fuel through normal combustion to a concentrated stream of CO2 and H2O. Since pure CO2 is obtained after condensation of the steam, the technology is highly applicable for CO2 sequstration. In this project a number of different oxygen carriers based on mixed metal oxides have been investigated with respect to their feasibility for CLOU. More specifically, oxygen carriers of Cu-Zr, Mn-Fe and Mn-Cu were produced through freeze granulation and investigated in a fluidized bed reactor under different conditions. In the first part of the project a screening of the different particles was made with the oxygen release properties and reactivity towards metahne investigated. From this study it was found that all of the materials were able to release oxygen in the gas-phase, albeit the extent was very deptendent on tempature. The most promising system was found to be the Cu-Zr and Cu-Mn. Because no prior investigations of the Cu-Mn materials for CLOU had been performed it was decided to pursue this further. Experiments with materials of different compositions found that even very small amounts of Cu in the Mn-matrix has a pronounced effect on the oxygen carrier behavior, and the material is very promising at temperatures of 750-825o  C.

Datum
2010
Författare

Tobias P Mattiasson

Plasma based total treatment of waste

The project addressed the physical properties of thermal plasmas. It aimed at the synenergy of expertimental and theoretical analysis in order to explain the radiation transport under extreme conditions in modern plasma torches.

By application of a thermal plasma based system to a wide range of possible feedstocks which are CO2 neutral, a clean syngas of high caloric value was produced simultaneously with a non-leachable vitrified lava. The results provided the advanced technology for clean electricity by processing waste and biomass. The driving force behind the project was to give priority to the environmental quality at affordable cost. Thus, the investigation of ways to increase the efficiency of the process turned out to be very important.

The major steps in the project were: the realisation of an efficient system for clean and efficient thermal plasma based waste treatment using a plasma torch and testing the combines system for various feedstocks, including oil shale and wood stocks. The economy of the system depends mostly on a crucial parameter to determine the future of this technology. The optimistic scenario holds the promise to provide 10-15 % of the energy needs for the EU.

Datum
2010
Författare

Professor Michael Tendler

Experimental studies on mobilized thermal energy storage (M-TES) system

Conventional energy sources, oil and electricity, dominate the heat supply market. Due to their rising costs and negative environmental effects on global climate change, it is necessary to develop an alternative heat supply system featuring low cost, high energy efficiency and environment friendliness. At present, it is often challenging to supply heat to detached buildings due to low energy efficiency and high distribution cost. Meanwhile, significant amounts of industrial waste and excess heat are released into the environment without recycling due to the difficulty of matching time and space differences between suppliers and end users. Phase change materials (PCMs), with the advantages of being storable and transportable, offer a solution for delivering that excess heat from industrial plants to detached buildings in sparse, rural areas.

The objective of this project is to develop a mobilized thermal energy storage (M-TES) system using latent thermal energy storage (LTS) technology that can use industrial waste or excess heat for heat recovery and distribution to areas in need.

Different phase change materials have been studied regarding the different structures of the container. And two experiment facilities have been built to study the mechanism of the heat charging/discharing processes. The CFD model was further used for system design. According to the economic assessment result, the cost supplying 1kWh heat with M-TES could be in a range of 0.03-006 USD/kWh, which is primariy determined by the transport distance and heat demand. This price can be competivitve to other heat supply methods, such as pellet/bio-oil/biogas/oil boiler systems and the electrical air-source heat pump, if the end-user has a short transport distance and a large heat demand.

Datum
2009-12-10
Författare

Mälardalens Högskola; Jinyue Yan

Nya mjuka material för bränsleceller

The project main focus has been to study the new soft materials for fuel cells.

Datum
2009-11-25
Författare

Aleksander Matic
Per Jacobsson

Energy balances for biofuel production

The growing interest in biofuels and the urgent need to decrease the import dependence in the transport sector has created a debate about what biofuel to choose and how efficient different biofuels can be produced. There has been a boom in studies calculating the energy efficiency, or energy balances, for different fuels produced by different raw material. The results from these studies are, however, rarely directly comparable, due to differences in assumptions made.

In this project a number of energy balances presented in different reports are presented, discussed and analysed. The reports analysed are: Well-to-wheels (2007), Ahlvik och Brandberg (2001), Blinge et al. (1997), Heyne et al., (unpublished), Vander Meijden et al. (unpublished) and Ekbom et al. (2005).

The results from the reports have been compared as is, and then recalculated with similar assumptions to be able to analyze the differences between the results further. In some cases it was clear that is was the assumptions that differed between the studies. In other cases the differences were even greater after recalculations. Hence the results are hard to interpret.

In any case the discussions and recalculations of the result may service as a basis for anyone trying to analyze the energy efficiency of different biofuels.

Datum
2009-06-30
Författare

Maria Saxe
Ronja Beijer
Anna Liljeblad

Korrosion i våttorr zon i rökgaskondensor

The corrosion resistance for a number of metallic and polymeric materials, in the environment of the inlet part of a flue gas condenser for a combustion plant, has been investigated. The combustion plants have been Igelstaverket and Bristaverket, for which the fuel has been mainly waste wood and biofuels, respectively. The materials were exposed in the dry and the wet zone, and also in the transfer zone in between. The metallic materials where stainless steels of the grades 17-10-2L, 2205, SAF2507 and 254SMO, all with a through weld joint, while the polymeric materials where fibre reinforced plastics (FRP) and glass-flake applied on carbon steel. The FRP materials had been formed partly by a traditional method and partly using new types of reinforcement materials, mainly based on carbon fibre, which where located in the surface layer.
Also laminate with the special reinforcement of 
the type 3D-fabric was investigated. The investigation showed that all the metallic materials came off good under normal operating conditions when using biofuels, while 17-10-2L did not manage when using waste wood. The welds of 2205 showed a somewhat restricted corrosion resistance, otherwise being the best choice for waste wood plants when taking the material cost into consideration. FRP, as it seems, can be used successfully in the environments studied for combustion plants using bio fuels. The results also indicate that the lifetime can be improved and the maintenance reduced by doing the correct choice of laminate structure and material compared to the laminates of the common type. The laminate structure, however, has to be adjusted to fulfil the demands given by the process environment. It should also further be pointed out that the good results for the flake coatings not necessarily would be the case for real use, where the walls are exposed to a temperature gradient.
Finally, a conclusion, outside the initial 
purpose of the project, was that the addition of ammonium sulphate in Bristaverket in accordance with ChlorOut, contributed to the heavy coatings formed in the inlet part of a flue gas condenser of Bristaverket.

Datum
2008-07-15
Författare

Magnus Nordling
Stefanie Römhild
Gunnar Bergman

Förutsättningar för experimentella studier av vätskesidiga panntubsprocesser

Three different types of making realistic examinations of water side corrosion for combustion plants exist - by using a loop, by using an autoclave and by doing in situ measurements. If using a loop, the exposure of the sample can be made very realistic, and the environment can be held under strict control and at the same time be changed towards extreme characteristics. No loops for doing investigations of water side corrosion is however available in Sweden. The focus was therefore on the testloop, by ascertain the different variations of construction possibilities and the cost.

The cost of building a loop capable of doing measurements at extreme pressures e.g. 200 bar, is however very high. A level of 1.3 million SKR is not an understatement and the cost of operating is also not low, e.g. 20 000 SKR per month for a measurement on a tube with an inner diameter of 2.5 cm, a flow rate of the tube water of 0.5 m/s and having a pressure of 200 bar. It is a cost that can be overcome though, if some sort of cooperation is made. Doing measurements by using an autoclave is less expensive but far less realistic due to that no heat gradient occurs through the sample, due to no risk of boiling and therefore increase of water soluble species concentrations and due to no erosive effects from the water flow. Doing in situ measurements by changing the plant tubes are even less expensive, but the exposure environment can not be varied as much as wanted because of the plant safety.

However, all three methods have their own advantages and can be of useful complement to each
other when trying to increase the knowledge of waterside corrosion and how to attain a good
magnetite layer.

Datum
2008-07-15
Författare

Magnus Nordling

Syntesrapport om kunskapsläget gällande löslighet och aktivitetsdata för högkoncentrerade saltlösningar i skogsindustriella tillämpningar

The purge of chloride and potassium from the chemical recovery cycle will be of increased importance in the future since a new generation of high-pressure recovery boilers will be taken into operation in Sweden within the next few years. In order to successfully purge these two salts, the solubility of an aqueous salt mixture containing Na2SO4 – N a2CO3 – NaCl – NaOH – KCl – K2SO4 – K2CO3 – Na2S must be know. The present knowledge in this matter is incomplete. This study aims to summarize the present knowledge on salt solutions and point to areas of further research. A number of conclusions can be made form the material collected for this study. Based on the conclusions in this study, the following future research activities are recommended.

Datum
2007
Författare

Mikael Ahlroth
Ulrica Johansson
Kristoffer Svedin

Ethanol production from wood in Sweden

The study analysis prerequisites for ethanol production from wood in Sweden with concern to market issues, production methods, raw material supply and current usage of requested raw material assortments. From a Swedish perspective, cereals, sugar beet and several cellulosecontaining materials as straw, energy forest and wood are possible raw materials. At an early stage, Swedish research focused on wood, with branches and tops, as the primary resource for ethanol production. The R&D has so far only tested purer materials as wood chips and saw dust. Research progress within fermentation of pentose sugars, minimising water flows, optimising byproduct usage and integration concepts are also needed before large scale plants can be built. The raw material competition is increasingly fierce with several sectors (pulp and paper, energy, saw mill, board producers and biofuel) competing for wood raw material. Our analysis indicates a raw material potential of 5 TWh (branches and tops) could be available for ethanol production under two conditions; an increased take-out of forest residues and usage of new raw material assortments from agriculture and forest. 5 TWh raw material corresponds to approximately 350 000 m3 ethanol. The EU biofuel directive recommends a substitution of fossil vehicle fuels of 5,75% and 10% 2010 respectively 2020. If these figures where to correspond to ethanol, 760 000 respectively 1 400 000 m3 ethanol will be needed. Thus, wood raw material cannot fully substitute fossil fuels without using assortments already used by other sectors. Today, Swedish ethanol production (wheat) is expensive in comparison to production based on other raw materials as sugar cane or molasses. The reasons are lower cost for raw material and labour. Today, the custom duty on ethanol from countries outside is a condition for profitability of Swedish production. The Swedish government are currently working to annull the duty, which if succeded, will cause great difficulties for Swedish ethanol producers as the competition with imported ethanol from South America or Asia will be fierce. This situation may however change if the demand and price level continue to rise.

Datum
2007
Författare

Emma Gunnarsson

Integrerad vätgas- och kraftproduktion från naturgas utan utsläpp av koldioxid

I ett tidigare projekt sponsrat av ÅF Forskningsstiftelse (02-171) och CF Miljöfond har lämpliga syrebärare för processen ’Integrerad vätgas- och kraftproduktion’ identifierats med hjälp av reaktivitetsförsök i en batch fluidiserad bädd reaktor samt en TGA. Här identifierades system NiO/MgAl2O4 som ett mycket lämpligt system för att använda för vätgasproduktion med sk. ’chemical-looping reforming’. Målet med detta projekt var att testa några syrebärare i en mindre 300 W kontinuerligt fungerande reaktor baserad på ihopkopplade fluidiserade bäddar. Emellertid har det inte funnits utrymme att studera mer än just en syrebärare baserad på NiO och MgAl2O4. I detta projekt har en syrebärare av detta system tillverkats med frysgranulering och undersökts i den kontinuerliga reaktorn med stor framgång, och därmed har processen för första gången demonstrerats. Vidare har även en kinetisk undersökning av syrebäraren utförts i en TGA och resultaten modellerats med en enkel gas-fastfas modell. Två publikationer har skrivits inom projektet, och dessa finns med i appendix till rapporten.

Datum
2006-02-09
Författare

Tobias Mattisson, Chalmers Tekniska Högskola

Treatment of Fission Waste Radioactivity by Means of Fusion Neutrons

The project was a small part of the collaboration with Baltic Infrastructure for Research, Technology and Innovation (BIRTI) activity. Within the framework of this project spherical tokamak with parameters major radius 0,5 m, minor radius 0,3 m, toroidal fiel 1.5 T and current 1.5 MA, heating power to 6 MW and outpur of neutrons 2 MW is being designed and constructed in collaboration with other partners supporting the Salaspils Fusion Neutron Source (SFNS). There is the plan to upgrade this device employing superconductive  technology developed at ITER. The secondary goals is to assist European Spallation Source project in Lund preparing for Latvian heavy involvement in this project. Kurchatov Institute has plans to built its own neutron source and also to build hybrid fission - fusion reactor in Sosnovy Bor.

Two hybrid devices Multi Functional Experiment Reactor MFER and Spent Fuel Burner SFB with participation of the projct are planned in China.

Datum
Författare

Kungliga Tekniska Högskolan; Michael Tendler

Techniques for reducing intake of ammonia-nitrogen in strong gases and methanol to kraft recovery boilers

The aim of this study was to identify and evaluate efficient ways to reduce the ammonium-nitrogen content in gases and methanol fed to kraft revcovery boilers or dedicated incinerators within the kraft pulp mill. The effect-goal if a feasible process in implemented could be a reduction of NOx-formation but was not within the scope of present the study. The study was performed as a desk-top study utilizing data from public articles and in ÅF files data archives.

A reference mill wide nitrogen mass balance was developed for the bleached softwood market kraft pulp model mill as defined in the FRAM (STFI-Packforsk, 2005) research programs (2 000 ADt bleched SW pulp/d). Identification and configuration of mill areas, process systems and production rate was thereby identical to the FRAM modell mill. Regarding foul condensate strong gases and methanol the modell includes stream stripping of foul condensates followed by condensation of stripper gases and further distillation in a methanol column. Basic input data for the refence balance was mainly nitrogen content in Scandinavian softwood and concentration of nitrogen in foul condensate. Concentration of total nitrogen in other process streams was based  on mass balance and data on nitrogen-split between process streams, e.g. strong black liquor ot recovery boiler and smelt to dissolving tank etc.

Datum
Författare

ÅF-Industry AB; Anders Norberg, Janice Törmälä, Fredrik Lundqvist

Captivating Metal Complexes for Sustainable Light Harvesting

The sustainability of our society's energy production is of pivotal importance, and many factors point toward solar power as a major contributor to the solution of the energy probklem, However, the capture of solar energy still needs to become more cost effectice and new methods need to use cheap and bundant materials while still providing an efficient energy conversion.

The project has focused on the development of new light-absorbin metal complexes that can efficiently harvest light energy and make use of it in solar energy applications. One such application is the Dye Sensitized Solar Cells (DSSC), thar are based on cheap and abundant TiO2 and have received a lot of attention as cheaper alternatives to the current standard semi-conductor type of solar cells. Some of the more efficient DSSCs uses ruthenium based metal complexes as dyes, but they often suffer from instability and poor energy transfer.

The metal complexes developed in the project are novel in that they ar combining two very different functional groups that both bind to the metal but have different properties. Our studies have shown that the electronic properties and stability are influenced by subtle changes in the structures. The groups used are pyrazole and quinoline moieties that have been synthetically linked. They are shown to provide a very favorable binding of the metal, in the manner that we predicted in the proposal, but also to selectively influence different electronic properties. A detailed spectroscopic and theoretical study of on of the complexes has revealed intricate details in how ground- and excited-state properties are tuned by structural and electronic factors. The study further shows that several of these factors need to be taken into account to further tune the complexes in a predicatable manner, in order to be able to achieve higher efficiencies in solar energy applications in the future.

Datum
Författare

Lunds Universitet; Martin Jarenmark

Toward reliable tolerance analysis of cracked mechanical components in nuclear power facilities using advanced finite element computation

In this report, defect tolerance analyses of mechanical components in nuclear power facilities, containing cracks or crack-like defects, using advanced finite element computation are addressed. A deterministic procedure recommended by Swedish Radiation Safety Agenccey, which is currently used in Swedish nuclear power industries for the prediction of safety reservation margin due to fracture and plastic failure, is reviewed in order to gain an in-depth understanding of the methodologies, assumptions and limitations behind this procedure. Among issues addressed, our emphasis is placed on mixed mode cracking, dissimilar materials, multiple cracks, fatigue damage and its evaluation using advanced finite element analysis in accordance with the ASME BPV code. It is demonstrated that for cases under a complex loading or in the presence of dissimilar materials and multiple cracks, such a deterministic defect tolerance analysis, which is purely based on a single mode I driven crack in one material of a simplified geometry, may lead to a non-conservative resultat and cautions are necessary when this procedure applied. Practical suggestions are given and it is concluded that for such cases there is a great need for alternative procedures for fully achieving a reliable and accurate safety assessment.

Datum
Författare

Lingfu Zeng
ÅF-Industry / Nuclear Technology

Specifika förutsättningar för CO2-avskiljning i Sverige

In this report, the possibilities for carbon capture at four Swedish industrial companies are investigated. The companies are: Cementa in Slite (cement  producer), Preeemraff in Lysekil (refinery), SSAB in Oxelösund (integrated steel mill), and Södra Cell Mönsterås (kraft pulp mill). These companies were all part of the fourteen Swedish carbon dioxide emissions sources with emissions greater than one million tonnes during 20062 . The companies are also situated in the relative vicinity of potential geological storage sites for CO2 . Hence, some of the necessary features for cost-effective carbon capture and storage are satisfied at these facilities.

Datum
Författare

Stefan Grönkvist, ÅF

Kartläggning och analys av förutsättningar att avskilja och lagra koldioxid i Sverige

This report focuse on the possibilities to utilize carbon capture and storage (CCS) as a method to mitigate climate change in Sweden. It concentrates on the potential for cost effective carbon capture from Swedish point emission sources of carbon dioxide (CO2 ). Technical, economic, and regulatory aspects covering all parts of the chain capture, transport, and storage of CO2 are also discussed.

Datum
Författare

Stefan Grönkvist, ÅF

Long term pv performance results from Swedish case studies

PV-modules based on crystalline silicon are often purchased with a warranty of 25 years. The modules that are tested and approved according to the IEC 61215 standard are considered to have an expected lifetime of 20-30 years. Although the tests are designed to simulate the stresses that modules are exposed to in real operation, it is not until analyses are made of modules that have been in operation for many years that definite statements about module lifetime can be made. Today more and more systems are approaching these long lifetimes and thereby providing us with true examples of module lifetime. Elektroporation för forcerad och hygienisk metanutvinning

Datum
Författare

L. Palmblad, Energibanken AB, Stockholm C.
Martinsson, ÅF-Consult AB, Stockholm
J. Hedström, Energibanken AB, Stockholm
M. Andersson, Energibanken AB, Gnarp