Because of the increasing trends in energy consumption and increased environmental awareness, greater focus has been placed on improvement and development of renewable energy sources. An already proven and accepted method is biogas production from anaerobic Digestion at municipal wastewater treatment plants.In the waste water treatment process solid material and dissolved pollutants are separated from the water, forming a sludge. The sludge is separated from the process and stabilized during anaerobic Digestion or aerobic aeration. Most often, mesophilic anaerobic Digestion is used. Because of degradation by microorganisms, biogas with a high content of methane is formed during the Digestion.

Käppala wastewater treatment plant situated on the island of Lidingö northeast of Stockholm is running a project during 2004 and 2005 with the purpose to map out the capacity of anaerobic Digestion in the digesters that treat primary and excess sludge. The purpose of this thesis work, which is part of that project, was to characterize the present anaerobic Digestion process and to investigate its capacity to treat other organic wastes such as restaurant waste and waste from water works. To decide the potential of both methane and biogas production from different substrates batch laboratory tests were carried out. To imitate the anaerobic Digestion process at Käppala continuous tests with small scale reactors were carried out. These reactors were later fed with restaurant waste.The batch laboratory tests showed that primary sludge had a potential biogas and methane production of 0,62 and 0,35 Ndm3/g VS respectively after 40 days of Digestion.

Today's society is facing major challenges. In order to reduce the climate impact fossil fuels should be replaced with fuels that do not contribute to the greenhouse effect. The growing population generates organic waste originating from industry and households so called organic fraction of municipal solid waste (OFMSW). Through anaerobic Digestion, waste can be utilized to produce energy-rich methane gas. In this way, waste can be a resource instead of a burden on society.

Biogas is a renewable fuel that can be extracted from anaerobic Digestion of many differentsubstrates, for example biological household waste. An alternative handling of the waste is tomix it with other wastes and incinerate it in a combined heat and power (CHP) plant. Thisstudy uses life cycle assessment to investigate which type of waste handling that is betterfrom an environmental point of view, anaerobic Digestion with biogas production orincineration. The results are based on a case study of a biogas production plant owned by thecompany Ragn-Sells in Vänersborg. The alternative is incineration at a CHP plant inGothenburg.

Biogas is a renewable energy produced through anaerobic Digestion, which means that organic matter is degraded by microorganisms under anaerobic conditions. The produced biogas can then be used for cogeneration, electricity, heat or upgraded to vehicle gas. Eskilstuna Energy & Environment AB has four digesters at Ekeby water sewage treatment plant, Eskilstuna. One of the biogas reactor (RK4) is equipped with a jet-mixing system while the remaining digester uses top-mixing. The mixing system is an important parameter to achieve optimum operating conditions for the process regarding gas production and degree of Digestion.

To achieve the Government's milestones for 2018, which means that 50 % of food waste shall be separated from household waste and undergo biological treatment (composting or anaerobic Digestion).   Hultsfred, Högsby and Vimmerby are three adjacent municipalities of Kalmar, county Småland. During 2012 and 2013 analyzes were performed on their household waste to determine its composition. The household waste is currently collected in one fraction. The work, examines how much food waste the household waste contains. From the amount of food waste, the biogas potential is examined - how much food waste biogas generates and how much energy it corresponds to.   Food waste is broken down by microorganisms under anaerobic conditions (anaerobic Digestion) in a biogas plant.

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.

Until 2020, 49% of Sweden's use of energy must derive from renewable sources. Greenhouse gases must as well decline with 40% compared to 1990 as a part of Sweden's 16 environmental objectives. Biogas is part of the effort to achieve these objectives, but as the demand for biogas increases, more substrates are needed to meet the demand. The purpose is to investigate the conditions for pea residue as substrate by performing lab-scale mesophilic Digestion with different fractions and notch lengths and then to summarize pea residue as a substrate for biogas production. During anaerobic Digestion, 1000 ml bottles were used as reactors for Digestion.

The goal of this master thesis project was to develop computer models of some plausiblepretreatment techniques and to assess the potential benefits/costs of using pretreatment andanaerobic Digestion for waste management of organic waste from a system perspective. Forthis purpose a computer program called ORWARE has been used. ORWARE (organic wasteresearch) is a program for making life cycle assessments of waste management. As the mainpart of the project work the ORWARE system has been provided with three new models ofpretreatment techniques. The additions consist of: One model of pretreatment with ultrasound,one model of thermal hydrolysis and one model of a screw press.

Hästen är en grovtarmsjäsare anpassad för en gräsdiet vilket medför att grovfodret spelar en viktig roll för hästen ur utfodringssynpunkt. Inplastat vallfoder i form av ensilage och hösilage har ökat som grovfoder. Grovfoder kan genom olika metoder konserveras till hö, ensilage eller hösilage. De olika konserveringsmetoderna medför att fodret får olika biokemisk och mikrobiell sammansättning. Hö torkas till hög torrsubstans halt (ts-halt) för att förhindra oönskad mikrobiell tillväxt.

Swedish biogas is currently produced mainly by anaerobic Digestion of sewage sludgeat sewage treatment plants, landfills and anaerobic Digestion of household or industrialwaste. Also cattle ma-nure from farms can be used to produce biogas. Upgradingbiogas represents an increase in methane concentration from about 65 % to about 97%. In addition, particles and contaminants must be sepa-rated from the upgradedbiogas. There are various methods for upgrading and this report compares sixdifferent methods with respect to environment and economy: water scrubber,Biosling, cryo technology, chemical absorption, Pressure Swing Adsorption (PSA) andmembrane separation.According to the used ORWARE model, chemical adsorption with amine has the leastenvironmen-tal impact (methane emissions) and the lowest costs.

The biogas plant Kungsängens gård, owned by Uppsala Vatten och Avfall AB, produces biogas and biomanure from organic household waste, food processing waste and slaughterhouse waste. In year 2012, 4.4 million Nm3 of biogas were produced from 25 200 tons of waste. Before Digestion all substrate is sanitized by pasteurization at 70°C in order to kill pathogens. Another method, integrated thermophilic sanitation (ITS), is of interest in order to decrease the energy demand. The method implies that the substrate is sanitized during ten hours in the Digestion chamber, where the temperature is 52°C.

Feed intake in dairy cows is regulated by a variety of factors influencing hunger and satiety. One of the regulation systems includes the short chain fatty acids produced during feed degradation in the rumen. Starch can be digested either in the rumen where short chain fatty acids are produced or in the small intestine where glucose is the end product. Since glucose does not have the same effect on satiety that short chain fatty acids have, the site of starch Digestion might be an important factor that affects feed intake and milk production. The aim of this study was to investigate the effects of site of starch Digestion on feeding behaviour (feed intake, consumption time, and eating frequency) and milk production. Because feeding behaviour is closely connected to the cows? environment, the study also included observations of behaviour. Three different feed rations were compared.

Glycerol is essential for the lipid metabolism of both plants and animals. Glycerol is formed in the rumen by hydrolysis of lipids from the feed. Glycerol is also a by-product from the production of biodiesel from rapeseed oil and other fat sources. Glycerol might be used as a dietary glucose precursor for dairy cows in similar ways as propylene glycol. Due to increased production of biodiesel more glycerol has been available to a lower price.

Milk allergens were digested by allowing them to flow through a chromatography column, where pepsin was conjugated to the stationary phase of the column. The allergen fragments were then characterized both biochemically, by using SDS-PAGE and gel permeation chromatography, and immunologically, by examining their reactivity to IgE and monoclonal antibodies..