The demand for biogas as vehicle fuel has risen sharply and there is a great need for increased production. A possible addition of vehicle gas can be produced by upgrading landfill gas which is formed by degradation of organic waste. This thesis investigates the potential of producing vehicle fuel from landfill gas in the region of Biogas Öst. In 2008, an amount of 32 million Nm3 landfill gas was extracted in the region. This level can be maintained for another ten years if the efficiency of gas extraction is improved. The annual production will decrease with time since landfills aren’t allowed to receive more organic waste. Landfill gas is hence a large but not lasting source of vehicle fuel. The amount of available landfill gas that is possible to upgrade to vehicle gas is limited by technical and financial issues. With certain limitations taken into account, an estimation of the regions potential gives an annual production of 8.2 million Nm3 vehicle gas. This means that more than 7 000 private cars or 250 buses could be operated with vehicle fuel from landfills in the region.

The biogas production in Sweden year 2014 was 1,8 TWh where almost 1 TWh was upgraded to biomethane for use in vehicles. The production of biomethane is mainly located at the biogas plants that have a production over 200-400 Nm3/h. This is mainly due to the fact that the investment and operating costs becomes too high for the small producers with low biogas flows. The government of Sweden has a highly ambitious goal of having a vehicle fleet that runs on at least 80 % renewable fuels in the year 2030. To reach that goal even the small biogas producers needs to start upgrading their gas to be able to replace fossil fuels with renewable biomethane. The aim of this master thesis has been to supply enough information to Norrmejerier about whether or not to upgrade the biogas by summarizing relevant research papers and calculate energy flows and costs for each upgrading technology.The limitation of the thesis has been that the production of biogas with different incoming substrates have been neglected due to it being constant in each scenario that has been compared. After a thorough literature study about relevant upgrading technologies the water scrubber and membrane technology was chosen as the best fit for Norrmejerier’s biogas plant. This was mostly due to that the water scrubber is in no need for chemicals duting operation and that some waste water could be used from the dairy plant at Norrmejerier. In the case for the membrane technology it had a low investment cost coupled with a stable operation without the need for surveillance. A relatively new ash upgrading technique was also considered briefly where the need for ash was estimated to 10 000 – 17 000 metric tonnes a year with the assumed biogas production of Norrmejerier. The supply of ash in Umeå municipality were about 5000 metric tonnes which is far below the demand for the biogas upgrading plant. The production of biogas at Norrmejerier is enough to sustain all their own truck transports with biomethane plus that they can sell the excess to the public. The cost-estimates were calculated for the scenario if Norrmejerier builds their own refilling station and in the scenario if they would sell it to a fuel supplier instead. The cost of upgrading for both upgrading technologies ranged from 0,53 to 0,54 SEK/kWh independent of the two previously mentioned scenarios. Both technologies had a payback period of two years and a few months. The membrane technology however gave a higher economical value with a greater yearly capital income mainly because of its longer economical lifetime. The limited lifecyle assessment compared the different uses of the produced biogas to calculate the emissions of carbon dioxide equivalents for each scenario. The assessment revealed that the emissions can be reduced by about 1700 metric tonnes carbon dioxide equivalents per year if the biogas is upgraded to biomethane and Norrmejerier supplies its own trucks with this renewable fuel.

<p>Abstract</p><p>The dependency of fossil fuels in the transport sector causes large emissions of carbon</p><p>dioxide. This problem can we reduce by using vehicle gas from digested solid manure and left</p><p>over of pasture. I have studied the potential for this in the county of Västernorrland. The</p><p>purpose is to investigate how much vehicle gas that can be extracted.</p><p>One central, large scale digestion and upgrade plant should be placed in Härnösand. The</p><p>amount of pasture and manure that is economical and practical available is enough to produce</p><p>2,7-3,5 millions Nm3 vehicle gas. It corresponds to 1 800- 2 400 cars, each driving 17 860 km</p><p>per year.</p><p>The heating value of the vehicle gas is 26-34 GWh. To extract this energy you have to supply</p><p>energy corresponding to a heating value of 4,9 GWh for transport of raw material and</p><p>digested sludge together with 13-14 GWh for process heat and electricity.</p><p>If the gas replaces petrol the emissions from the lifecycle of the fuel decrease with 5 600-7</p><p>400 ton CO2-equivalents. The emissions by the vehicle decreases with 640-840 kg NOx, the</p><p>emissions of hydrocarbon increases with 60-80 kg and the emissions of particles remains the</p><p>same.</p><p>The increased content of easy available nitrogen is about 40 tons, it can replace about 5 % of</p><p>the nitrogen supplied as synthetic fertilizer. The contribution to the nitrogen resource by</p><p>digested sludge is greater than its contribution to the supply of fuel.</p><p>The cost for the gas is 12-14 kr per petrol equivalent, that is little more than the today’s price</p><p>of petrol of 11,28-12,24 kr. Above all, it is the cost of transport that cause the high cost.</p>

<p>Varje månad produceras 100 000Nm3 (normalkubikmeter) biogas vid centrala reningsverket i Kristianstad. Denna gas används primärt som uppvärmning till lokaler på området genom tre gaspannor lokaliserade i källaren under huvudbyggnaden. På gasnätet finns även en uppgraderingsanläggning inkopplad som kan ta ut gas som sedan uppgraderas till fordonsgas. Gasen som går till uppgraderingsanläggningen generar en årlig intäkt på cirka 700 000:-. Överbliven gas lagras i en gasklocka och när denna är full facklas överskottet av gas upp. Diskussioner har under en längre tid förts gällande ett annat sätt att tillvarata gasen, nämligen genom att installera kraftvärmeverk som förutom värme även producerar el. Kristianstads kommun har tidigare erhållit KLIMP bidrag för detta ändamål men av diverse anledning installerades aldrig kraftvärmeverket och pengarna nyttjades ej utan återfördes till staten. Med skenande el-priser under vintern 2009-2010 har diskussionen om kraftvärmeverk återigen blivit aktuell. Jag har med hjälp av litteraturstudier via Internet sammanställt en rapport som på ett tydligt och lättöverskådligt sätt beskriver hur biogas bildas och vilka processer som ligger bakom när uppgradering till fordonsgas sker. Rapporten utreder även frågan om det är ekonomin eller miljön som tjänar mest på att kraftvärmeverk installeras.</p>

Varje månad produceras 100 000Nm3 (normalkubikmeter) biogas vid centrala reningsverket i Kristianstad. Denna gas används primärt som uppvärmning till lokaler på området genom tre gaspannor lokaliserade i källaren under huvudbyggnaden. På gasnätet finns även en uppgraderingsanläggning inkopplad som kan ta ut gas som sedan uppgraderas till fordonsgas. Gasen som går till uppgraderingsanläggningen generar en årlig intäkt på cirka 700 000:-. Överbliven gas lagras i en gasklocka och när denna är full facklas överskottet av gas upp. Diskussioner har under en längre tid förts gällande ett annat sätt att tillvarata gasen, nämligen genom att installera kraftvärmeverk som förutom värme även producerar el. Kristianstads kommun har tidigare erhållit KLIMP bidrag för detta ändamål men av diverse anledning installerades aldrig kraftvärmeverket och pengarna nyttjades ej utan återfördes till staten. Med skenande el-priser under vintern 2009-2010 har diskussionen om kraftvärmeverk återigen blivit aktuell. Jag har med hjälp av litteraturstudier via Internet sammanställt en rapport som på ett tydligt och lättöverskådligt sätt beskriver hur biogas bildas och vilka processer som ligger bakom när uppgradering till fordonsgas sker. Rapporten utreder även frågan om det är ekonomin eller miljön som tjänar mest på att kraftvärmeverk installeras.

Abstract The dependency of fossil fuels in the transport sector causes large emissions of carbon dioxide. This problem can we reduce by using vehicle gas from digested solid manure and left over of pasture. I have studied the potential for this in the county of Västernorrland. The purpose is to investigate how much vehicle gas that can be extracted. One central, large scale digestion and upgrade plant should be placed in Härnösand. The amount of pasture and manure that is economical and practical available is enough to produce 2,7-3,5 millions Nm3 vehicle gas. It corresponds to 1 800- 2 400 cars, each driving 17 860 km per year. The heating value of the vehicle gas is 26-34 GWh. To extract this energy you have to supply energy corresponding to a heating value of 4,9 GWh for transport of raw material and digested sludge together with 13-14 GWh for process heat and electricity. If the gas replaces petrol the emissions from the lifecycle of the fuel decrease with 5 600-7 400 ton CO2-equivalents. The emissions by the vehicle decreases with 640-840 kg NOx, the emissions of hydrocarbon increases with 60-80 kg and the emissions of particles remains the same. The increased content of easy available nitrogen is about 40 tons, it can replace about 5 % of the nitrogen supplied as synthetic fertilizer. The contribution to the nitrogen resource by digested sludge is greater than its contribution to the supply of fuel. The cost for the gas is 12-14 kr per petrol equivalent, that is little more than the today’s price of petrol of 11,28-12,24 kr. Above all, it is the cost of transport that cause the high cost.

<p>Biogas is a renewable energy source that is produced by anaerobic digestion of organic mate-rial. In Sweden, biogas predominately comes from sewage water sludge and landfills or from organic waste of households and industries. Small scale digestion plants at farms are espe-cially expected to contribute to increased biogas production in the future. Biogas can be ob-tained directly in it’s raw form and used as fuel in a combustion chamber. However, gas en-gines require biogas purification from hydrogen sulphide and drying from water to avoid cor-rosion. In order to increase the calorific value, carbon dioxide is separated and the Swedish Standard Type A requires the methane content to be 97 % for vehicle gas.</p><p>In the gas treatment process from biogas to vehicle gas, the upgrading step when carbon diox-ide is separated represents the highest cost since conventional upgrading techniques require high investments. This makes the upgrading costs for smaller biogas plants relatively high. In this master thesis, six upgrading methods have been evaluated and four of them are expected to be commercialized within two years. The following upgrading methods are of interest for Sweden:</p><p>- In situ methane enrichment; air desorbs carbon dioxide from the sludge in a</p><p>desorption column. The method is intended for digestion of sewage water sludge and the total upgrading cost is approximately 0,13 kr/kWh by a raw biogas flow 62,5 Nm3/h.</p><p>- Small scale water scrubber; carbon dioxide is absorbed in water under enhanced pressure. The upgrading process is very similar to the conventional water scrub-bing technique and the total upgrading cost is approximately 0,42 kr/kWh by a raw biogas flow of 12 Nm3/h.</p><p>- Cryogenic upgrading; the biogas is chilled to under -85 °C under a pressure of at least 5,2 barg and carbon dioxide can be separated in the liquid phase. The total upgrading cost is approximately 0,12 kr/kWh by a raw biogas flow of 150 Nm3/h. The total upgrading cost can be reduced if the recovered liquid carbon dioxide can be sold.</p><p>- Membrane technique; biogas is upgraded with polymeric membranes that are per-meable for carbon dioxide but not for methane molecules. The method is expected to be adaptable for both smaller and bigger biogas plants and the total upgrading cost is approximately 0,14 kr/kWh by a raw biogas flow of 180 Nm3/h.</p><p>All above mentioned upgrading techniques have methane losses less than two percent and all methods except for the in situ methane enrichment are expected to upgrade biogas to vehicle gas according to the Swedish Standard. In situ methane is expected to upgrade biogas up to 95 % methane content.</p><p>By combustion of unpurified landfill gas in a gas engine, corrosive combustion products and white deposits are formed. Purification of landfill gas can decrease maintenance costs for gas engines. Two landfill gas purification methods have been evaluated and with the first method, contaminants are trapped in ice crystals when the gas is chilled to -25 °C. The second method purifies landfill gas with condensed carbon dioxide.</p><p>An important result of the master thesis is that the in situ methane enrichment has a chance to become an interesting alternative for smaller sewage treatment plants but the method requires additional upgrading to reach 97 % methane content. The most important conclusion is that cryogenic upgrading and membrane technique are expected to satisfy the Swedish Standard. The methods have relatively low upgrading costs and the methane losses are less than two percent. This gives them a good chance to establish in Sweden.</p>

Biogas är en förnybar energikälla som kan framställas genom rötning av organiskt material som gödsel eller grödor. Trots att lantbruket står för 76 % av den totala biogaspotentialen i Sverige producerades endast en procent av biogasen 2008 i gårdsanläggningar. Uppsatsens syfte är att ge en översikt över vad som orsakar den långsamma utvecklingen av småskalig biogas, samt att ge förslag till lösningar som kan leda till en snabbare expansion. Aspekter som studeras är politiska styrmedel, anläggning och produktion samt information och kunskap. Det största hinder som påträffas är produktionens bristande lönsamhet, vilken föreslås hanteras med ett produktionsstöd, tekniska effektiviseringar, förenklade och mer fördelaktiga lagar och regler för småskalig produktion samt en långsiktig nationell biogasstrategi. En snabbare ökning av antalet småskaliga biogasanläggningar tros inte inträffa innan lönsamhetsproblematiken är löst. / Biogas is a renewable energy source that can be produced by anaerobic digestion of organic material such as manure or crop. Although agriculture accounts for 76 % of the total biogas potential in Sweden, only one percent of the gas was produced on farm biogas plants in 2008. The paper aims to find the conditions and barriers regarding policy instruments, construction and production, and information and knowledge that are causing the slow development of small-scale biogas. Based on the findings, suggestions for solutions that can lead to a faster expansion are given. The biggest obstacle found is that the production is unprofitable, which is suggested can be dealt with by introducing a production-based financial support system, technical efficiency, simplified and more favorable laws and regulations for small-scale production, and a long-term national strategy for biogas. A rapid increase in the number of small-scale biogas plants is not believed to occur before the profitability problems are resolved.

Biogas is a renewable energy source that is produced by anaerobic digestion of organic mate-rial. In Sweden, biogas predominately comes from sewage water sludge and landfills or from organic waste of households and industries. Small scale digestion plants at farms are espe-cially expected to contribute to increased biogas production in the future. Biogas can be ob-tained directly in it’s raw form and used as fuel in a combustion chamber. However, gas en-gines require biogas purification from hydrogen sulphide and drying from water to avoid cor-rosion. In order to increase the calorific value, carbon dioxide is separated and the Swedish Standard Type A requires the methane content to be 97 % for vehicle gas. In the gas treatment process from biogas to vehicle gas, the upgrading step when carbon diox-ide is separated represents the highest cost since conventional upgrading techniques require high investments. This makes the upgrading costs for smaller biogas plants relatively high. In this master thesis, six upgrading methods have been evaluated and four of them are expected to be commercialized within two years. The following upgrading methods are of interest for Sweden: - In situ methane enrichment; air desorbs carbon dioxide from the sludge in a desorption column. The method is intended for digestion of sewage water sludge and the total upgrading cost is approximately 0,13 kr/kWh by a raw biogas flow 62,5 Nm3/h. - Small scale water scrubber; carbon dioxide is absorbed in water under enhanced pressure. The upgrading process is very similar to the conventional water scrub-bing technique and the total upgrading cost is approximately 0,42 kr/kWh by a raw biogas flow of 12 Nm3/h. - Cryogenic upgrading; the biogas is chilled to under -85 °C under a pressure of at least 5,2 barg and carbon dioxide can be separated in the liquid phase. The total upgrading cost is approximately 0,12 kr/kWh by a raw biogas flow of 150 Nm3/h. The total upgrading cost can be reduced if the recovered liquid carbon dioxide can be sold. - Membrane technique; biogas is upgraded with polymeric membranes that are per-meable for carbon dioxide but not for methane molecules. The method is expected to be adaptable for both smaller and bigger biogas plants and the total upgrading cost is approximately 0,14 kr/kWh by a raw biogas flow of 180 Nm3/h. All above mentioned upgrading techniques have methane losses less than two percent and all methods except for the in situ methane enrichment are expected to upgrade biogas to vehicle gas according to the Swedish Standard. In situ methane is expected to upgrade biogas up to 95 % methane content. By combustion of unpurified landfill gas in a gas engine, corrosive combustion products and white deposits are formed. Purification of landfill gas can decrease maintenance costs for gas engines. Two landfill gas purification methods have been evaluated and with the first method, contaminants are trapped in ice crystals when the gas is chilled to -25 °C. The second method purifies landfill gas with condensed carbon dioxide. An important result of the master thesis is that the in situ methane enrichment has a chance to become an interesting alternative for smaller sewage treatment plants but the method requires additional upgrading to reach 97 % methane content. The most important conclusion is that cryogenic upgrading and membrane technique are expected to satisfy the Swedish Standard. The methods have relatively low upgrading costs and the methane losses are less than two percent. This gives them a good chance to establish in Sweden.

This thesis evaluates the energy system effects off co-localizing solar photovoltaics (PV)  production with a filling station for compressed vehicle gas. A MATLAB model was constructed based on gas and electricity consumption data from three actual filling stations for vehicle gas in Sweden. The model was used to simulate how the introduction of a PV  and PVB (photovoltaic battery) system would affect the amount of electricity bought from  and sold to the grid as well as the economic implications connected to this. The results show that a self-consumption of 42 % can be reach already without available energy  storage for an installed power of PV panels matching the power of the gas compressor. A battery storage with capacity corresponding to one hour of electricity generation doubles the self-consumption. The increased self-sufficiency has the potential to decrease the strain on the electricity grid, depending on spatial and temporal factors. The simplistic economic model in this project shows that the return of investment is just over 15 years for a PV system, and less than 21 years for a small battery storage with capacity to store less than one hour of electricity production, however, this should be examined in greater detail if the system is to be implemented.  Since transport has an important societal function, the access to fuel is key from an energy  security point of view. Filling stations require access to electricity to operate, meaning fuel can’t be obtained in case of an interruption. Therefore, the possibility of self-sufficiency during the summer months (May through September) through the added PVB system was evaluated, resulting in enough electric energy to supply 31 % of the current fuel volume supplied yearly at normal conditions. This corresponds to 145 tons of vehicle gas, which could power a private car around 3 220 000 kilometers. The connection between the electricity and transport sectors could be furthered integrated by installing the proposed system which turns the filling station into a prosumer, ideally with some opportunity of self-sufficiency if needed. The modelled filling station handles gaseous fuel, however the conceptual design applies also to liquid fuels. To cover an even larger portion of the fleet, charging of electric vehicles at the filling station could also be examined.