At the Skoghall pappermill, sulphatepaper pulp is produced in a continuous digester originally from 1969. To be able to maintain a high level of production there is a need for a process with few disturbances. Variations in how well the wooden Chips are packed in the digester is one form of disturbance. Today there are no available measurements on how well the Chips are packed. Instead this is regarded as being constant.

With the elevated oil prices of today it is necessary to look for other heating alternatives. If the oil price continues to develop in the same way it has done the last years it will soon be impossible for many producing garden companies to survive. The purpose of this diploma work is to compare three different fuel options in order to find the most economic one considering the conditions of Katrinebergs Handelsträdgård AB. In relation to oil it is profitable to change to any of the three alternatives: wood Chips, wood pellets and grain. The most profitable option is to change to wood Chips. This alternative has a payoff time less than three years and after that the annual saving compared to the oil is relatively high. The annual cost is 65 % of the cost of the oil alternative.

This study was carried out at the request of the bio energy company Naturbränsle. The company handles annually 750 000 m3 of Chips from logging residues from a large area, from Östergötland in the south to Härjedalen in the north. In that area, about 50 bio fuel plants are customers. When Naturbränsle deliver Chips from logging residues to their customers, the moisture content varies from 30 % to 60 %. The aim of the study was to sort out the affecting factors on the moisture content in the Chips during handling and storage processes.

This report is a bachelor's thesis of two students from the Energy and Environment degree at KTH Stockholm. Grinda is an island situated Stockholm archipelago. Skärgårdsstiftelsen is landowners and manages the area. Grinda Wärdshus, a guest house located in the island, currently uses an oil-fired boiler as a heating system. The aim of this thesis is to investigate whether wood Chips or pellets is, from a sustainability standpoint, a suitable heating method for the guest house.

The background for my thesis is the fact that with rising electricity and oil prices it becomes interesting to calculate on alternative heating systems. I have chosen to calculate upon my parents? farm, which today heats the dwelling house with wood. This is very time-consuming work, time which could be spent on other work. The main objective for this study is to compare three different heating systems to decide how they differ considering effort and cost. The result from the calculations was that grain-heating system demanded the least amount of work, but the total cost was a little higher compared to Chips heating. Chips heating required half as much work as today?s wood heating and had a little lower total costs compared with the corn heating. Which system to choose largely depends on how the own work is valued.

As demand for renewable energy is increasing rapidly, the market for biomass pellets is expected to continue to grow in the near future. Most of the new raw materials that are discussed for pellet production have one thing in common; the production costs will increase compared to using traditional raw materials such as sawdust and planer shavings. The aim of this thesis is to investigate to what degree increased use of new raw materials for pellet production will affect the general pellet prices in Sweden and to survey what plans Swedish pellet producers have concerning new raw materials. To investigate the raw material situation of the Swedish pellet producers an industry survey was performed. Literature studies were also made on previous research in the subject field. Calculations of the production costs for pellets were done for the raw materials sawdust, wet sawmill Chips and energy wood respectively. New raw materials are already used by the large-scale pellet producers in Sweden.

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.

At the end of 70s and the beginning of 80s, 18 terminals was built and used for chipping wood residue from clear cuttings. Most of the terminals was terminated before the 2000s but with the high oil- and energy prices that we can see today there might be a place for these terminals again. The goal with the study was to analyze and compare economical differences between 5 different logistical systems, collected data was used with a set of formulas. The systems include long range transport of slash, Chips and bundles. Three of the systems include transport by lorry to industry the last two includes a terminal with access to train transport.

I want to look at the possibilities to start selling hot water from a small district heating plant with bioenergy. My reason for doing this project is to look at a new business opportunity for our farm. Our company have less work during the winter time compared to the spring and this project will give us more work during the winter. I also want to take as much material as possible for heating from our farm in order to increase the value of the products from the farm. The project is in a village near us, where we should support a school, a churh, a home for the aged, a kindergarten and a parish hall with heat. In my work I have compared two different alternatives with each other. The first alternative is to put a central heater in one of the buildings, the home for the aged, in which we will burn oat.

The Swedish pulp and paper industry meets higher demand for energy efficiencyi mprovements with increasing energy prices and changes in the Swedish renewable energy certificate system. One action of energy efficiency improvement is by using secondary heat, that otherwise would have been treated as waste heat, for use in a system with lower temperature demands. The aim of this Master´s thesis is to identify possible secondary heat sources in a typical Swedish pulp and paper mill and to investigate what economic benefits the secondary heat will provide when being used for pre heating of wood Chips to a kraft digester.The Master´s thesis focuses on three secondary heat sources; dry warm air, warm water and moisture saturated warm air located inside the pulp or paper mill. Two types of kraft digesters are simulated within this study, a typical Scandinavian digester and a modern twin vessel steam phase digester.Due to quality aspects and low temperature level drying is the drying technology with dry warm air rejected. Using warm water in direct contact with wood Chips increases the quantity of water to the evaporation plant and thus reduced pulp or paper production and is therefore also rejected.

En energikartla?ggning har gjorts hos Chips AB fo?r att underso?ka hur energin fo?rdelas o?ver de olika produktionslinjerna. Energianva?ndningen fra?n processer som a?r gemensamma fo?r alla produktionslinjer har ocksa? underso?kts. Energianva?ndningen fo?r dessa har fo?rdelats o?ver pro- duktionslinjerna eftersom produkterna a?ven ska ba?ra upp dessa energikostnader.

Stump biomass is energy rich and stump harvesting for use as fuel become more and more interesting in Sweden. Swedish Forest Agency (2009) has estimated that stump harvesting in Sweden would respond to an annual energy supply of 57 TWh/year. However, stump has not been recognized as a bioenergy resource in Sweden. Suitable methods for pre-treatment of stump are probably of great importance to make it accepted as fuel. It is therefore rewarding to carry out an investigation in this area for stump. This report represents results from a diploma project, which was aimed to develop a fixed bed reactor for experimental study of biomass torrefaction, followed by TG analysis and kinetic modelling employing Ozawa method and different kinetic models including one-step and three-pseudo-component models.

The moisture content in 10 deliveries of tree parts and 10 deliveries of wood residues were measured with different methods to analyze the quality of procedure used at Dåvamyran today. At the same time a survey was made on the measure procedures used at heating plants in Sweden The majority of the heating plants in Sweden use weight and moisture content as base for payment but at some plants only volume. The moisture content is usually estimated by drying wood Chips in an oven but few plants a visual estimation is used. At few plants moisture content is estimated spectroscopicily. The techniques using near infra read light and other electromagnetic are still at a test stage. The methods of measurement used today are quit unreliable for the individual deliveries and there is a risk for systematic mistakes.

In this thesis an energy analysis of ethanol production at the ethanol plant of Lantmännen Agroetanol in Norrköping has been performed. The ethanol plant has been studied in combination with Händelöverket, the combined heat and power plant which provides the ethanol process with steam. The purpose of this study was to determine the energy consumption for the whole production chain from grain to ethanol. The analysis has included the energy consumption for cultivation of grain, production of chemicals, the production chain for wood Chips, the steam production and the ethanol plant. The grain and wood Chips are both considered raw materials there for the energy content in these are not included as energy input in the system.

In this thesis an energy analysis of ethanol production at the ethanol plant of Lantmännen Agroetanol in Norrköping has been performed. The ethanol plant has been studied in combination with Händelöverket, the combined heat and power plant which provides the ethanol process with steam. The purpose of this study was to determine the energy consumption for the whole production chain from grain to ethanol. The analysis has included the energy consumption for cultivation of grain, production of chemicals, the production chain for wood Chips, the steam production and the ethanol plant. The grain and wood Chips are both considered raw materials there for the energy content in these are not included as energy input in the system.