The sludgebark and to a certain extent the bark were until a decade ago waste products without any economic value that were thrown away. A number of environmental laws and increcing energy prices have improved the prerequisites for increasing the use of these materials. At Seskarö sawmill they burn the sludgebark and a great deal of the bark in the sawmill furnace. The sludgebark has a number of disadvantages compared to bark during burning. The sludgebark is often wet which means the energy net from burning often gets low.

To save energy it?s popular to build houses with low energy loss. In these houses the walls are keeping a lower temperature in the external side which leads to a higher relative humidity. In addition more material, such as wood studs, are used which means that there is more moisture to dry. More moisture in combination with higher relative humidity may pose a higher risk of microbial growth.

In the pulp industry, digesters are used to disolve lignin in wood chips. The concentration of lignin is measured and is called the Kappa number. In this thesis, the question of whether an online Kappa sensor, taking samples from the mid-phase of the digester, is useful or not is analyzed. For the samples to be useful, there has to be a relationship between the measured Kappa at the mid- phase and the measured Kappa in the blowpipe at the bottom of the digester. An ARX model of the lower part of the digester has been estimated.

This thesis concerns an energy audit of a food industry. The company's business consists of boiling and peeling shrimps, and producing mayonnaise-based salads. This type of work involves energy-intensive processes, such as steam generation, compression of air and refrigeration of large spaces. These needs are supplied with electricity. Furthermore, the industry is a major consumer of district heating, particularly for heating the supply air in the ventilation system.

Dead wood is important for many species. The amount of coarse dead wood (diameter >10 cm) is much lower in managed forest than in unmanaged forests. Stumps constitute the largest proportion of the volume of coarse dead wood in managed forests. Since stump harvest for biofuel may increase, the amount of dead wood will decrease even more, which may threaten biodiversity. The first aim of this study was to compare the amounts of fine woody debris (FWD, .

The private forest owners play a key role in the supply of round wood to the Swedish forest industry. Today it is a keen competition between forest companies about the wood from private forest owners. In order to get access to the wood from the private forestry you need to be an attractive collaboration partner, who can offer long-term collaboration, service at top-level, and acting for good prices to the forest owners. This work aims at analysing the situation on the market today. It gives Sveaskog purchase department a good view of the forest owners? opinion in general about the existing purchase activities. Forestry service level and timber prices are determining factors for a successful relationship between forest company and forest owner.

In today's society, the availability of energy plays an integral part in our everyday lives. Unfortunately, the price of energy in Sweden has increased in recent decades. A large part of our energy consumption goes to heating modules for houses, where heating methods that depend on energy sources such as electricity, district heating, fuel oil, gas and biofuels are the most common ones. During the winter period, the increase in energy costs becomes significantly evident, especially for small property owners. This increase in energy cost is most noticeable for home owners with electric heating.This thesis is written at the Halmstad University, in cooperation with a company, which makes parts of this thesis confidential.

In Sweden, the demand for bio energy has increased in recent years due to the current energy and climate debate. In 2008, the energy supply of Sweden was 612 TWh, biofuels accounted for 123 TWh of these. Stumps have been highlighted as a potential fuel in recent years and the Swedish Forest Agency expects a technically and biologically feasible potential of 20.7 TWh annually between 2010 and 2019. The idea of utilize stumps is not new. During the 19th century stumps were used for tar production and during the 70?s and 80?s attempts were made to use stumps in the pulp industry.

The purpose of this master thesis is to investigate different types of measures for making buildings more energy efficient and to estimate their profitability. The calculations were performed with the building simulation program VIP+ and the evaluation of the profitability with the life cycle cost method. Furthermore, it was examined how losses in the distribution of secondary systems of district heating can be avoided. Options to replace district heating with a local district heating system based on bio-energy have been investigated. The possibilities of achieving more efficient thermal energy consumption and production for the chosen estate were also examined.The object of the study has been a residential estate with 133 detached houses in Uppsala, built in 1974.

The basic ingredient of paper is the individual wood fibers. The property of the fibers depends on a variety of factors e.g., method of pulp production and processing. The final sheet quality depends in part on how the fibers interface between each other and therefore factors that affect the fiber size are of interest.The flexibility of the fibers depends in part on the pore water i.e., the fiber swelling. The sheet becomes less flexible at low water content which gives a loss in strength. Thus it becomes desirable to increase the water uptake.The experimental investigation described in this report consists of exposing the wood fibers to different ions and ionic strength and then measure the pore size by thermoporosimetry where a DSC (Differential Scanning Calorimeter) is used.

The Work has been performed to, and in cooperation with Vetlanda Energi och teknik AB.District heating for commercial purpose started in the USA in 1877. Today the network has grown into big and complex systems, which demand maintenance and service to keep up the security of the delivery. When a district heating network expand, it becomes difficult to perform reliable calculations. For this purposes there are a few suppliers who design and deliver systems for documentation and calculation of district heating networks.Vetlanda Energi och Teknik AB is in the position where they must get a system for documentation and calculation for district heating, and therefore they need a basis to get a system. The target is to write a requirement specification that will follow the basis.The Swedish market has been inventoried, and suitable systems have been selected.

The Work has been performed to, and in cooperation with Vetlanda Energi och teknik AB.District heating for commercial purpose started in the USA in 1877. Today the network has grown into big and complex systems, which demand maintenance and service to keep up the security of the delivery. When a district heating network expand, it becomes difficult to perform reliable calculations. For this purposes there are a few suppliers who design and deliver systems for documentation and calculation of district heating networks.Vetlanda Energi och Teknik AB is in the position where they must get a system for documentation and calculation for district heating, and therefore they need a basis to get a system. The target is to write a requirement specification that will follow the basis.The Swedish market has been inventoried, and suitable systems have been selected.

What is located on the bottom in the water outside of Birka? Remains of a water palisade or jetties and other constructions.Birka a Viking Age town that existed between AD 750 and 975 was located on the northwestern part of the small island of Björkö, in the Mälar archipelago of the Baltic Sea in Sweden. The Town was protected onshore by a hill fort and a town rampart. It is a widely spread assumption that Birka had a water palisade as a part of its defense. There are logs and other remnants on the bottom of the lake dating back to the Viking age.

We are heading towards a huge switch of how energy is produced with fossil fuels being replaced by renewable energy sources. It is not difficult to replace the energy you use in the house and there is no need for futuristic technology. There are already many established products on the market such as high efficiency vacuum solar collectors, heat pumps & small wind power stations that can supply the energy being used in a house. The company Sol & Energiteknik SE AB in Huskvarna has many different products which can reduce the need for an outside energy distributor. An average house in Sweden uses 15 000 kWh for heating, 5000 kWh for tap water and 5000 kWh for electricity.

This thesis consider alternatives for heating and cooling planned office buildings at Arlanda airport. The thesis is divided into three parts where the third part is a shorter synthesis of the two first. In the first part the energy demands of the buildings are modelled in a computer program. Two different building models are created, one more conventional and one with good energy properties. The results shows that with proper construction and ventilation systems etc.