The aim for the study was to examine a harwarder´s (combined harvester-forwarder) productivity when harvesting forest fuel in first thinning stands that contains Lodgepole pine and calculate the economy of the harvesting work and estimate the quality of the thinning . The field study area where located near Arvån, about 15 kilometres south ?east from the city of Lycksele. The field studies were taken place in three different stands. All tree stands had the same tree age, but the tree species combination and the density varied.

This study is based on AgroSeas business idea from environmental problems to valuable resource, with the objective to optimize a method to purify the already eutrophicated Baltic Sea by harvesting water plants, mainly reed. The nutrients will then be recirculated to arable land through residues from biogas production. The amount of nutrients that can be removed by harvesting the biomass depends on the amounts of biomass and the nutrient content of it, which in turn is strongly dependent on the nutrient concentration of the surrounding water. Vegetation suggested in the study for an effective nutrient uptake is helophytes: reed, cattails, reed canary grass, reed sweet grass in shallower water and lemnoideaes: duckweed and nymphaeids in the deeper parts. Competitive species has high purification ability but requires regular maintenance to avoid channeling and overgrowth. Regarding time and method of harvest, effectiveness may be improved by: harvesting plants above the water level and after flowering, a border is kept, harvesting twice a season, a bigger machine and a regular maintenance. This literature has illuminated a major environmental problem and it has been suggested optimizations for a method for cleaning the Baltic Sea through harvesting water plants, but to get a definite answer for the optimal method for each site tests should be carried out, this because many factors determine to what is suitable for each, specific environment. .

AbstractThis degree thesis was made in cooperation with Chematur Engineering in Karlskoga.Many of the environmental issues of today are a result of the motor traffic. Consumption of fossil fuels harms our environmental through formation of carbon dioxide and other greenhouse gases. To get under control with our environmental issues it?s important to find substitutes for oil that are both cheap and environmentally friendly. Ethanol has a long history as a motor fuel and is both enviromentally friendly has a high efficiency.According to the EU commissions directives for motor fuels, 5, 75 % of all the fuels in Sweden should be renewable in 2010.

Hylocomium splendens (Glittering wood-moss) is a common species in the Nordic countries and can be found in many different types of boreal forests. It usually forms dense moss carpets on the forest floor. The shoots grow in segments and new segments form annually on the previous years growth. The size of the segments is probably regulated in a high extent by local micro environmental conditions. Previous experiments suggest increased growth of H.

With higher prices for oil and increased focus on fossil fuels impact on the environment the heating sector are searching for alternative fuels. Pellets are a quite new product whose production has risen exponential in recent years. Today there are small-, medium-and large-scale users, where the large-scale consumers are the heating sector. The heating sector is mainly using oil to cover the increased demand during cold periods. The purpose of this study is to analyze the potential of pellets if it would replace thermal power plants oil and coal. The study will also analyze the economic impact a conversion would mean for a heating plant and if the pellet is a reasonable substitute. 2008 statistics from the Swedish district heating association were analyzed and a calculation was performed to determine how many tons of pellets is needed to replace coal and oil.

It is essential to reuse- and recycles residues to decrease the amount of deposit materials and reach sustainable energy use. Two ways to work towards this is to recycle wood ashes to the forest as nutrient compensation and extract biogas from combustion of biomass.The aim with this study was to decide whether wood ashes that been used for biogas upgrading with accelerated carbonation also can be used as a nutrient compensation in the woods according to recommendations from the Swedish Forest Agency (Skogsstyrelsen).The ashes that were used in this study came from Johan Andersson who works at JTI in Uppsala, who also treated the ashes with biogas. The ashes have, in both untreated and treated condition, been analyzed in this study according to contents of elements, leaching properties, hardening properties and contents of crystalline phases, to evaluate what impact carbonation with biogas has on the ashes.The accelerated carbonation led to hardening of the ash, and decreased amount of CaO- and increased amount of CaCO3. The CO2-uptake also entails a dilution of the elements, and the content of nutrients and trace elements decreases. However the results show an indication of an uptake of S from the biogas to the ash, since the dilution had a smaller impact on S than the rest of the elements.

In this study I have compared two systems of handling TMR, self-propelled/ self loading mixers and conventional towed mixers, what has been investigated is the time for filling, mixing and feeding TMR as well as maintenance and fuel consumption. The background of this study is the structural rationalization within the Swedish milk production that has put focus on efficiency and reducing of costs. Forage and labour are the two biggest costs in milk production today. The study has been performed by visiting three farms and with a stopwatch measured the times for filling, mixing and feeding TMR. At the time for the visits, the users have been interviewed regarding maintenance and fuel consumption. They have also had an opportunity to give comments of how they experience the mixers. The result of the study after processing is that the average stock in the study can save 74000 SEK a year by reducing time for filling, mixing and feeding TMR to cows with a self propelled/ self loading mixer . The conclusion I can make of this study is that it?s not the size of the stock that decides whether it?s interesting to invest in a self propelled/ self loading mixer, but the presumptions on the farms, for instance forage logistics and mechanical equipment..

The work covered in this report includes a literature study of the diesel dual fuel technology(hereinafter referred to as DDF). The literature study covers earlier work that has been doneregarding the use of compressed natural gas (CNG) and diesel in a DDF system. Moreover a onecylinder research diesel engine was fitted with a CNG fuel system for experimental testing. Theinstallation of the engine and the test cell is described. Results from the tests are presentedcovering emissions, heat release and pressure traces from the DDF-concept.During the literature study it was found that most research was related to heavy duty dieselengines.

Today we have more game species than ever before in our landscape, both regarding number of species and number of individuals. The increasing number of wild species is an increase in game recourse for the countryside. The increase of game species, however, has negative effects on forests and agriculture land. The negative effects for forestry are damages on economic important trees, due to losses in production and quality. However there are ways to decrease the damage on valuable and important trees.

To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.

A method for measuring the total impulse from a multi hole diesel injector, introduced inprevious thesis work, ?Development of a method and a device for measuring the momentumrate of fuel sprays?, by Mikael Lindström, has been further developed and tested. The conceptis to simultaneously deflect all sprays from a multi hole diesel injector by using a bell shapeddeflector. The fuel sprays are deflected straight down from their initial umbrella angle, andthe resulting deflection force is measured in a thin strained section of the load cell. The strainis given by three strain gauges, with quarter-bridge circuitry for each gauge.

As the Swedish governments long term goals include a reduction of fossil fuel dependency, increasing pressure is placed upon energy companies to create and develop new solutions for renewable energy. The following case study was done in collaboration with the company Sydved Energileveranser AB and one of their contractors, Enarssons Skogsentreprenad AB. The objective of the study is to examine the bioenergy situation in region of Skåne and evaluate the potential solutions in the region for a forest-fuel assortment, based on a bioenergy-cutting-system. As a part of this study I have compared ordinary manual cuttings done with a chain saw and cuttings made using the new ?bio- energy cutting system?. The cuttings made under both systems were tested in areas near agricultural fields or pasture land in order to maintain an open landscape.

To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.

To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.

This study concerns the energy future of the county of Stockholm up until 2050 and describes how the energy consumption can be compared to today with the use of scenario methodology. Within energy future studies the backcasting approach is well known and has been put to use in this study. Due to the characteristics of backcasting the study is self-fulfilling, i.e. the future energy scenarios presented in this study satisfy the targets set up in this study. In the light of what may be the largest challenge of our time ? the climate change - the aim of this study is to describe how the energy consumption in a fossil fuel free Stockholm county in the year of 2050 may be.