Sök:

Sökresultat:

584 Uppsatser om Wood fuels - Sida 1 av 39

Teknisk och ekonomisk analys av en bränslekonvertering vid SIA TallOils pelletsfabrik :

At SIA TallOil's pellets factory in Latvia wood shavings and saw dust are dried with flue gases from a gas burner. TallOil wants to replace the gas with a biofuel that is available at the pellet plant. The reason for this is the unstable gas market in Europe in combination with the fact that TallOil wants to improve its profile as supplier of renewable bio fuels. In this project the technical and economical possibilities for a fuel conversion to ether bark powder, wood shavings or wood powder have been investigated. These fuels should be burned in one of the following applications: TPS BioSwirl, VTS Multifuel burner or Saxlunds bio fuel combustion plant Due to the fact that the fuel alternatives available are relatively common except for bark powder, the work has mainly been focused on bark powder.

Pellets - en framtidsmarknad?

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.

Fossilfria godstransporter : En undersökning av alternativ till diesel som drivmedel för lastbilar

Our modern society is in many ways built with and dependent on fossil fuels, which are used for energy production as well as for transporting humans and goods. Without the oil, many of the things we take for granted would not be possible. During the last century, the use of oil has increased steadily and will probably keep increasing as the world population and the economic well-being for many people increase. Since the oil is a finite resource, we will have to find other fuels that can replace it if we want to keep the same rate of development in the future as the availability of petrol fuels will decrease with rising prices as a result. Furthermore, fossil fuels have the disadvantage that they produce harmful emissions when combusted and thus affect the climate and air quality locally and globally.

Uppgradering av biogas med aska från trädbränslen

The Swedish production of biogas was 1,5 TWh 2011. About half of the production was used as vehicle fuels. The cost for upgrading biogas depends on the size of the biogas plant and its gas production. If the gas flow is low the cost will be high. However, further development of existing upgrading technologies or development of new ones, have good potential to decrease the upgrading cost for small scale biogas plants.

Skogs- och energibolagens attityd till förnybara drivmedel vid upphandling av transporttjänster i norra Sverige

Sweden's government is dedicated to the goal of having a vehicle fleet that is independent of fossil fuels by 2030. Achieving these goals requires, among other things, new types of fuel that give lower net emissions of carbon dioxide. The present market includes stations offering lowlevel blends of renewable fuels in conventional diesel as well as some stations offering renewable fuels only. The purpose of this study is to survey purchasers? attitudes to the use renewable fuels in roundwood and bioenergy transport in forest- and energy companies. The study was based on qualitative interviews through a combination of face-to-face meetings and telephone interviews with each sample group. The total number of respondents was ten (10), consisting of five (5) from forest companies and five (5) from energy companies. Transport service purchasers were generally positive to renewable fuels and considered these necessary in the future.

Alternativa drivmedel : Vilket alternativt drivmedel uppfyller bäst Försvarsmaktens behov?

This essay is written within my education for Technical Officer in the Swedish armed forces. The essay describes the alternative fuels that the Swedish armed forces can make use of if the supply of fossil fuels is insecure. The alternative fuels that are described and compared are; Synthetic diesel, Organic diesel, Methanol and Ethanol. The essay describes the process of producing the alternatives, the need for modification and the economics for each alternative. The alternatives are compared and assessed for their ability to secure the supply of fuel to the Swedish Armed Forces.

Effekt på värdeutfallet av sågad vara vid övergång från 30 till 60 cm moduler : - en fallstudie av Moelven

The purpose of this study is to explain how the value of sawn wood changes when sawn wood are cut in 30 respective 60 cm lengths. The raw material into the saw mill will mainly be bucked in 30cm and 60 cm modules. There will also be two alternatives where the timber will be bucked special lengths, 370, 490 and 550 cm but also in 490 and 550 cm.The method used for the study is to simulate both cutting and sawing the woods. For cutting the simulator Timan is used and for sawing the simulator Timberopt is used. When data is generatedfrom the simulators, calculations of some key figures is done and also how much the revenue need to be increased for the sawn wood in order to cover for the increased costs of changing sawn woodfrom 30 cm to 60 cm modulesThe conclusion is that the single biggest reason, impacting the value of the sawn wood is the cutting at the saw mill.When going from 30 to 60 cm modules, the impact will be that the customers to the saw mill must pay more to increase the revenue by at least 10% for the sawn wood in order to justifice the changein production.It is also possible to increase the value of the products further by bucking the timber in three lengths, 370, 490 and 550 cm, in order to get 12 % increase of the share of longer sawn wood (>= 480 cm)..

Skogsbrandens påverkan på död ved :

Fire is an important ecological factor, but its consumption of coarse woody debris, CWD, has hardly received any attention. In this study, I investigate the consumption in relation to the time of initial flame exposure and propensity for continued combustion of standing CWD of pine (Pinus sylvestris). Two types of CWD were studied. Firstly, wood that had been dead for one to ten years. Secondly, wood that had been dead for several decades. In the burning experiments, logs of approx.

Trä som fasadmaterial ? behandling och beständighet

Since prehistoric time man has used wood to build their environment. The material?s availabilitycombined with its good mechanical properties has often made it the material of choice. Like allmaterials exposed to natures degradative processes the properties of wood decreases over time.Rot, UV radiation and attacks by insects and pests damage wood if not protected. Since we wantwhat we build to consist, optimizing our building materials durability is of great interest.Techniques and methods for increasing the endurance of wood have been developed in severaldifferent places and for a long time.

Epoxidised linseed oil as hydrophobic substance for wood protection : technology of treatment and properties of modified wood

Public concern about the release of toxic compounds from wood-based products drives legislation towards enforcing industries to find and use more sustainable solutions for wood treatment. Plant oils are good alternatives to treat wood, minimizing or even neutralizing the impact on the environment. Wood modification with epoxidised linseed oil (ELO) and acetic acid as catalyst has proven a suitable method to impregnate and protect wood. However, the mixture presents a serious inconvenience because of the quick polymerization of the ingredients that limits its practical application. Therefore, this study was designed to evaluate an alternative method using a two-step process which bypassed the problem above.

Visuell handelsortering av furu och gran

This essay concerns the visual trade grading of pine and spruce.In the 1800s developed rules for sorting of wood. The rules used to facilitate the export trade.The terms of the regulatory sorting systems developed in the 1900s. While it still used some of the older terms.The essay deals with how the grading rules affect the use of wood and how the rule work and how the terminology works.Some of the terms used for sorting are O/S, Kvinta, Utskott and A,B,C,D.You sorting by counting the numbers of knots, cracks and other characteristics of each piece of wood.The sawmills have much influence in how the rules developed.Today it is often already determined in the sawmills which uses each piece of wood most have..

Betydelsen av skogsbruksplaner som verktyg vid anskaffning av virke

Forest management plans have been sold to private forest owners by wood supplying companies for a long time. These plans are considered to be effi-cient tools to identify measures and wood volumes, and are simply a starting point for discussions between private forest owners and round wood pur-chasers. However, large variations are observed between different purchas-ers, in their usage of the plans. The purpose of this report is to identify to what extent a forest management plan can promote an increase in the amount of wood which a round wood purchaser can obtain and to find differences in the way of using the plans between different wood purchasers. Furthermore, the purpose is also to ana-lyse if varying owner structures can be underlie variations in the selling of forest management plans. Qualitative interviews with nine of Stora Enso?s round wood purchasers were performed.

Stubbtransporter och bränslekvalitet hos stubbved :

Stump wood is a hot alternative when the heating plants demands more and more forest fuel. The aim with the study has bean to calculate the costs in four different systems for transportations of stump wood, examine if there are any differences in fuel quality for the stump wood in the different systems, analyse if the fuel quality in stump wood is affected with the time it lays by the road side and how much space the stump wood demands on the road side. To calculate the costs for the different systems a system analysis was carried out, where some of the costs were collected through field studies on Holmen Skog stump experiment and other costs were collected from literature and contacts. Data for the fuel quality study was collected from Eons heat plant in Norrköping. Data for the study of how much space stump wood takes along a roadside was collected from field studies.

Alternativa drivmedel i den svenska vägtrafiken år 2030 : En utvärdering av den svenska regeringens målbilder

The Swedish government has set up the overall goal that no net emissions of greenhouse gases can occur after 2050. A sub-target has been developed for road transports which states that the use of fossil fuels must be reduced with 80% to 2030 in order to be completely abolished to 2050. A public inquiry mapping how this can be achieved was handed in to the government late in 2013. The use of alternative fuels for road transport, both biofuels and electricity, is expected to give the biggest contribution to the reduction of the use of fossil fuels. The inquiry sets up a number of goals for how much the use of alternative fuels must increase to 2030 in order to reach the overall goal and which instruments that are needed in order to do so.The aim of this thesis is to evaluate how these goals can be reached and what the most likely obstacles that may hinder the reaching of these goals may be.

Förnybara bränslen är lösningen, vad är problemet? En maktanalys av den svenska dagordningen för förnybara bränslen

The aim of the thesis is to examine how central collective actors in the Swedish subsystem of renewable fuels use their positions of power and influence to their own specific interests and needs. In particular the thesis looks at the problems of climate change and oil scarcity and how renewable fuels are described as a potential solution. Using agenda setting theory and Steven Lukes three dimensions of power as a framework, five actors are examined and analysed. The study has been done in two parts. In the first part policy documents are analysed concerning the actors general stance towards renewable fuels, and how this is communicated to the media, politicians and public.

1 Nästa sida ->