The demand for biogas as vehicle fuel has risen sharply and there is a great need for increased production. A possible addition of vehicle gas can be produced by upgrading landfill gas which is formed by degradation of organic waste. This thesis investigates the potential of producing vehicle fuel from landfill gas in the region of Biogas Öst.In 2008, an amount of 32 million Nm3 landfill gas was extracted in the region. This level can be maintained for another ten years if the efficiency of gas extraction is improved. The annual production will decrease with time since landfills aren?t allowed to receive more organic waste.

A one-cylinder research engine has been used for studies with a Diesel Dual Fuel concept (DDF). DDF is a concept that utilizes a pilot diesel injection to ignite a homogenous natural gas/air mixture. Emissions and engine efficiency have been analyzed in an emission cycle called European Stationary Cycle (ESC) and the knock/pre-ignition problems with this type of engine have been investigated.At low and mid torque levels, an early diesel injection around 60 crank angles degrees (CAD) before top dead center (TDC) was used. At these loads raw NOxemissions was below EURO 6 level (0.2 g/kWh). NOxwas at EURO 5 level over the complete ESC without after treatment and with SCR at high loads it should be possible to reach EURO 6.One issue with DDF is the high HC emission levels.

The purpose of this paper is to identify the current status of fuel cell technology and to establish whether said technology is mature enough to be implemented into the Swedish Armed Forces. The question to be answered in this paper is as follows: Can hydrogen gas and fuel cells be used as an alternative source of energy within the Swedish Armed Forces?This paper is based on theoretical studies and reports from prior research done on fuel cells. By studying these facts a predictive answer has been obtained. The answer I have come to, is that the maturity of fuel cell technology is currently inadequate for the Swedish Armed Forces to implement, especially considering its harsh working conditions..

In today?s fast growing and closely connected society, a reliable and energy efficient transportation system is more than ever desirable. Nowadays the significant part of the transportation sector?s energy demand is supplied by fossil fuels.Improving energy efficiency in combustion engines will result in reduction of fuel consumption and CO2 emissions. A modern internal combustion engine has an efficiency of 30-45 %, where the most energy loss occurs as result of heat losses in the exhaust and cooling systems.

Today when new and harder demands on CO2 emissions are developed, vehicle manufacturers must work to develop new engine solutions to new kinds of fuels to replace fossil fuels. A fuel that could be applied is hydrogen. When hydrogen is combusted only water vapor occurs. Hydrogen is known to be explosive and flammable. These properties are both good and bad for combustion.

The project focus on combustion of softwood pellets and pellets in a 40 kW grate fire reactor at TEC-Lab. Dept Applied Physics and Electronics at Umeå University. Experiments were performed at four primary airs to fuel ratios (0.7 to 1.3), where aspects such as temperature profile, levels of gases (CO and NO), sintering-/-slagging and unburned fraction of the ashes were studied. Four different fuel loads were used for wood pellets (10, 20 and 30 kW) and one fuel load for straw (10 kW). Combustion of straw proved very difficult to ignite, and also led to other combustion-related technical problem such as slag formation due to the relatively low melting temperature-/-slag temperature of the straw.

In published studies it is found that the fuel consumption on a forwarder is relatively constant, on time basis. A certain variation between different sizes of forwarders occurs as well as between different working elements. The aim of the study was to establish a forwarders comparatively fuel consumption when driving on road and in the terrain, loaded and unloaded, with high and low gear and with high and low speed as well as with hydrostatic and hydrodynamic transmission. A hypothesis was that low rpm gives lower fuel consumption on distance basic, at all trials. The test driving was made with a Hemek 750 which is a three geared hydrostatic machine and with a Hemek 700 which is a hydrodynamic machine with six gears.

This report is a thesis work for a B.Sc. in Forestry exam at the School for Forest Engineers, SLU. The aim of the work was to compare fuel consumption during work in practical field conditions with a standardized method developed by Skogforsk (The Forestry Research Institute of Sweden), (Brunberg, 2005) for harvesters and forwarders from different manufacturers and of different sizes in order to promote the development of more fuel efficient machines. Two studies were carried out. - Statistics of fuel consumption were collected. - An inquiry was sent out in order to get more detailed information of different aspects influencing the fuel consumption. The studied machines were divided into two classes, large machines (> 150 kW), and average size machines (100 ? 150 kW), and of the manufacturer Timberjack and Valmet. Our results shows a 15 % lower fuel consumption for average size harvesters and an 8 % higher fuel consumption for large harvesters compared with Skogforsks model.

  During the 2000s, the ship owners have become more and more concerned thattheir ships save fuel. Several projects have been undertaken to exploit the resourcesavailable on board today?s vessels to reduce fuel consumption. As a stepin this the Swedish Meteorological and Hydrological Institute (SMHI) today offera Weather Routing service to ships. By planning your route more effectivelymuch fuel can be saved.This thesis has been about developing a fuel prediction program (FPP) forhow much fuel a ship consumes in different sea conditions.

To achieve the requirements to decrease emissions of greenhouse gases by 20 % by 2020, Swedenneeds to increase its use of bioenergy. In doing so it seems natural that those who already haveaccess to large amounts of biofuels in the form of by-products such as straw, wood chips anddigestible materials take advantage of these assets locally. By combining production of heat withpower production at the farm it may be possible to not only reduce the direct use of fossil fuel forheating but also reduce energy costs.The purpose was to simulate different cases of using a small scale biofueled combined heat andpower plant for farm-based systems. A MatLab-model was developed and used to draw conclusionsabout the costs for production of heat and electricity with different conversion technologies.The model uses climate data to simulate the variations in heat energy demand on a day-to-day basis.The given heat demand is the base of the simulation and from this the possible electric output iscalculated. This study has focused on the impact of the following properties: electric-, heat- andtotal efficiency, fuel, fuel price and specific fuel requirements.

This final thesis is initiated by the wood fuel department at the Swedish forest company Sveaskog as part of a project which also involves two other final thesises. The overall goal of the project is to investigate Sveaskog´s possibilities to produce and sell different wood fuel assortments in Västerbotten and the southern parts of Norrland. The aim of this thesis is to investigate how much wood fuel Sveaskog can produce in the area during the next five years and what that would cost. Furthermore the thesis will investigate the total possible supply of wood fuel from all other possible producers in the area. Treated assortments are forest residues from final fellings, whole trees from direct wood fuel thinnings, non industrial wood and industrial by-products from sawmills. The main effort to investigate Sveaskog´s production possibilities has been made to calculate the possible annual amount of forest residues and fuel from wood fuel thinnings that can be produced.

Biogas is increasingly used for fuel in for example vehicles and it´s produced in a biogas processconsisting of the steps of pretreatment, digestion and gas cleaning. The pretreatment is a method usedto increase the gas production and / or destroy pathogens. The digestion is the stage when anaerobicmicroorganisms convert bio-mass of a substrate to a raw gas containing about 65% of methane. Thegas cleaning is used to increase the methane content to about 97% so the gas can be used for motors invehicles. The biogas part of the Ekeby sewage plant in Eskilstuna is using multiple substrates.

Several technical solutions are ready to step forward as the new generation of propellant, and this report aims to explore the possibility of commercializing fuel cell cars. The report is based on current research and data from today's technology and engineering solutions that are estimated to be commercially realized before 2020.A mapping of today?s different fuel cell options has shown that the most suitable fuel cell option is the Proton Exchange Membrane Fuel Cell, which uses hydrogen as fuel. The report is focusing on a techno-economic well-to-wheel analysis of hydrogen and the energy balance and costs in a system perspective. The basis for this analysis consists of two centralized methods of production, steam methane reforming (SMR), and alkaline water electrolysis.

Ethanol fuel is a biofuel, which been widely reported in the public debate and on the fuel market the last years. Ethanol is sold as both E85 and as a five percent admixture of all petrol sold in Sweden. Research studies on ethanol fuel often focus on environmental issues surrounding the production and utilization of ethanol as a fuel, and omits the private and business aspects of the subject. The purpose of this study is to illustrate the economics of ethanol as a fuel. How the Swedish market for ethanol is and how it evolved over time and what the future prospects are.

Stands where pre commercial thinning has been ignored or inadequate often tend to have high stem density and low average diameter when they reach heights of thinning. In such stands, it can often be expensive to do a conventional pulpwood harvest as a first thinning. This study investigates the development of the stands and the economic outcome of forest fuel extraction, or a combined harvest as alternatives to the ordinary pulpwood harvest. Simulations in Heureka StandWise were performed for two thin and dense stands, which were constructed by data from the Swedish National Forest Inventory. The simulations show that the extraction of forest fuel in first thinning at an early stage can provide higher net revenue compared to conventional pulpwood harvest at the same time or later.