The sun is essential to life on earth and no matter where you are, there is a constant need ofenergy. Nearly 800 000 years ago man learned for the first time to use fire in a controlled way.Since then, fire has given us the opportunity to inhabit places despite a cold climate. In Swedenthe resident sector accounts for a major part of the total consumption of energy. In a time whenenvironmental issues and greenhouse effects are increasing, we also see a future of rising energyprices. With this perspective, we have in this bachelor thesis in the Building Environment at theRoyal Institute of Technology, KTH, in Stockholm decided to focus on the renewable energysource, solar energy.The energy from solar radiation is a free resource and does not have any negative effects uponthe environment.

The ?civilized? world is in need of fossil fuel in order to function. Hybricon AB is a company in Umeå that is developing a technology that hopefully can reduce parts of this need. They are currently testing their two electrical busses (with Hybrid backup) in city traffic on the roads of Umeå in cooperation with the county of Umeå.                               The busses are originally diesel-busses, but the diesel motor has been replaced with two electrical hub-motors with a power of 145 kW each that are powered by batteries.The batteries are charged at the end station after each route. In case the batteries should run low on capacity during driving, they can be recharged by the so called genset.

This Master Thesis is a product development project that has been carried out in cooperation with Scania CV AB. The purpose has been to find the relationship between geometric parameters and the swirl number for an XPI- cylinder head in order to improve the design specification.The increased focus on environmental issues from society leads to tighter emission legislations for the truck manufactures. In order to drive the development forward considerable resources are spent on research and development on diesel engines and its Combustion process. The inlet air has a significant impact on the formation of emissions and the flow that is desired is called swirl. Swirl is achieved by making the air rotate around the vertical axis of the cylinder.Earlier cylinder heads that has been developed at Scania CV AB have shown clear relationships between geometric parameters of the cylinder head and the swirl number.

This thesis applies to a novel steam expander, one part of a steam engine system, a wobble plateengine. The piston in the expander moves axially with the outgoing rotating shaft and is locatedon a plate, why the engine type is called axial engine. When steam is applied to the plungers theplate wobbles creating a rotation on the shaft going thru the wobble plate. The steam expander issupposed to be used in exhaust gas recovery (bottoming cycle) applications and small scaleenergy production. The commissioner is Ranotor Utveckling AB.

Storage of biomass is often associated with problems such as heat development, dry matter losses and reduction of fuel quality. The rise in temperature can potentially cause a risk of self-ignition in the fuel storage. Moreover, emissions from storage piles can cause health problems in the surrounding. The dry matter losses and reduction of fuel quality can have economical effects. The aim of this thesis project is to develop guidelines on how to store large amount of biomass at Vattenfalls heat and power plants in an optimal way.

Föreliggande rapport är ett resultat av ett examensarbete utfört på Lulekraft AB (LUKAB), med syftet att dimensionera en återföring av rökgas. Målen är att sänka utsläppen av NOx, att minska fluktuationerna av temperaturen i överhettarna vid bränslebyte samt att undersöka ifall verkningsgraden ökar med implementerad rökgasåterföring.Ett flertal olika sätt att reducera utsläppen av NOx finns grundligt beskrivna i litteraturen, såväl i rökgasflödet som av modifikation av brännarna. Åtgärder i rökgasflödet är t.ex. rökgasåterföring (FGR, flue gas recirculation) och selektiv katalytisk reduktion (SCR, selecive catalytic reduction). Rökgasåterföringen sänker temperaturen på flamman, vilket leder till en sänkning av bildningen av termisk NOx.

The acid deposition of sulphur- and nitrogenoxides from Combustion of coal and oil cause acidification that lowers pH and gives increased contents of metals and altered aquatic biodiversity in the stream. The liming of lakes and streams, which was introduced to resist the acidification, demand large economic resourses despite of the decreased deposition of the acidifyng substances. Some of the streams are influenced by the acid deposition, while others are naturally acidic. It is therefore importaint to separate the anthropogenically acidified waters from the naturally acidic, in order to optimize the use of governmental fundings for liming. This thesis aims to estimate the acidity status and impact of acidification on 24 catchments upstream liming dispensers, which is part of the liming activities at the County of Dalarna.The acidity status of the streams was classified according to the Swedish Environmental Protection Agency old classification system (Naturvårdsverket 1999) as very acid to acid, with small ability to withstand a pH-change (alkalinity) due to acid deposition.

There have been changes in Earth?s climate system on both global and regional scale since the pre-industrial era and some of these changes are due to human activities such as the Combustion of fossil fuels. This calls for the development of engines with a higher efficiency and less harmful emissions. One interesting concept is the Homogeneous Charge Compression Ignition (HCCI) engine, which has the advantages of potentially low emissions combined with high efficiency. However, HCCI with diesel fuel requires a relatively long fuel/air mixing time to ensure a "homogenous" charge.

Using biofuels from regeneration cuttings is becoming more common in Sweden. Ash from the Combustion of biofuels contains many valuable nutrients and base cations. The Swedish Forest Agency recommends that ash should be recycled to clearings where biofuels have been removed, to avoid future impoverishment of Swedish woodlands. In Jämtland, in northern Sweden, a large quantity of biofuels are taken out from cuttings but ash recycling has not yet been tried. The aim of this thesis was to examine the conditions for ash recycling in Jämtland regarding to soil chemistry and heavy metal content in soil and biofuels.

This paper concerns a comparative analysis between two pre-Roman burial ground and the cremated individuals buried there, Skogome cemetery in Bohuslän and Smörkullen cemetery in Östergötland. The comparative analysis consists of several parts that concern both cemeteries inner and outer burial customs, and the osteological analysis of a total of 18 cremated invidvidulas. By studying the different parts separately, it has been possible to identify similarities and differences between the two contemporary cemeteries. There are great similarities between the cemeteries, differences were mainly observed in the osteological material relating to the amount of bone in each burial. The smaller amounts of bone in the graves of Skogome also holds a higher degree of fragmentation, but can not be explained by a higher Combustion rate than the skeletal material from Smörkullen.

In this thesis, the flows of reactive nitrogen (Nr) in Scania were investigated and quantified. The thesis was also intended to form a basis for comparison between the urban nitrogen flow and other flows of nitrogen within Scania. The management of nitrogen in society has disturbed the natural nitrogen cycle. This is linked to a series of environmental problems such as eutrophication, acidification, global warming and smog. The method used was Substance Flow Analysis (SFA) for Nr. For calculation and flow charts Scania was divided into three subsystems; air, water and society.

In the last few years people have become more and more aware of how humanity is affecting the climate. In the direction of reducing the greenhouse gases is to design engines with higher tensile properties and reduced weight, in order to achieve lower fuel consumption and cleaner fuel incineration in today's truck engines.In order to achieve these requirements it?s necessary to increase the Combustion pressure in the engine. This requires higher tensile properties and high thermal conductivity of the engine material. The department of Component Technology at the University of Jönköping in collaboration with Volvo Powertrain AB, Scania CV AB and DAROS Piston Rings AB has been commissioned to develop this material and to find knowledge of material properties used in truck engines and piston rings used for marine applications.The purpose with this work is to analyze the tensile properties of a series of cast iron, cast under different metallurgical conditions.Four different series of cast irons have been analyzed from four points of view, carbon concentration, nodularity, amount inoculation and cooling rate.After the tensile test all specimen data was analyzed in a mathematic calculation program called Matlab 2006a.

This Master Thesis covers the concept of Green Cars. The background to the research area is the high and rapidly growing number of cars, which together with other factors ad to the pollution of the environment. Under the Kyoto agreement the signing members agreed to lower the emissions of green house gases, further on the EU has a 3-pillar strategy on carbon dioxide and cars. Included in the EU strategy is a voluntary commitment from the car industry to reduce carbon dioxide emissions from new cars. The easiest way of lowering the emissions is by using alternative fuels and engines.

Scandinavian Biogas is involved in the planning of a combined ethanol and biogas factory in Karlskoga, Sweden. Besides biogas and ethanol large amounts of digester residues will be produced, about 450 000 liquid tonnes residue (~7,3 % Dry Substance( DS)). The objective of this thesis was to investigate possible uses of the residue from the biogas production process ScandgasEthanol developed by Scandinavian Biogas, and to derive a methodological approach how to evaluate and compare handling systems. Three systems where proposed and compared in this thesis; spreading of the untreated residue as fertilizer (system 1), dewatering to a higher DS content to reduce transportation before spreading as fertilizer (system 2) and production of a solid fuel by dewatering and drying the residue (system 3). The general conditions for the proposed systems were investigated in terms of practical viability, economical aspects, environmental impact and energy inputs/outputs.

Hemp is an annual energy crop that fits very well in Swedish crop rotations. It is an interesting crop with many benefits, for example its ability to establish a large quantity of biomass in one year. Hemp is easy to grow and out-competes unwanted weeds through its aggressive growth pattern without the need for pesticides. Interest in growing hemp and other energy crops is currently decreasing, apparently because of high grain prices. These high prices give a higher net profit that we believe could partly cover the cost of hemp cultivation, while the hemp in turn would improve the crop rotation and thus repay its debts in the form of increased yields of other crops. The great disadvantage of hemp is the lack of knowledge about spring harvest of the crop.