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.

Det finns två stationer på Boxholm Stål AB med produktionssågar. Den ena är en bandsåg och två fasmaskiner med hanteringsutrustning för transport mellan såg och fasar samt en automatisk buntmaskin. Fasarna på den stationen är utslitna och håller inte de toleranser som Boxholm Stål AB har på sina produkter. En önskan att kunna planfräsa ändarna har också tillkommit vilket utrustningen i dagsläget inte klarar av. Det innebär att fasarna ska bytas ut. En utredning av vilka företag som kan leverera utrustning med önskad kravspecifikation har gjorts samt ett kostnadsförslag har inhämtats. Den andra stationen är en klingkap från början av 80-talet. Även den har fasmaskiner samt hanteringssystem men ingen automatisk buntmaskin. Den gamla klingkapen är utsliten och måste därför bytas ut. Säljare för olika sågar har kontaktas för att undersöka vilka som kan leverera en såg med önskad kravspecifikation. Tre säljare har träffats och samtliga har förslag på sågar som klarar de krav som ställts från Boxholm Stål AB. Bara en säljare har lämnat ett kostnadsförslag. Utöver det har en klockning av processer på stationen med bandsåg gjorts för att kartlägga eventuella flaskhalsar i stationen. Den klockning som hann göras visade att hanteringssystemet var ganska bra synkat med ca 30-35 sekunder per process. Det som tog längst tid var själva kapningen. Fasmaskinerna skapar en del spånor som sprätter runt en del vilket kräver städning. För att underlätta för operatören att städa kan man kapsla in fasen med plastduk så spånorna leds ner i spånlådan, lägga mattor eller en glatt beläggning på golvet. Mattorna fångar upp spånorna och sen kan mattorna skakas ur i en spånlåda. Ett glatt golv gör att spånorna blir lättare att sopa upp men är olämpligt eftersom det tillsammans med olja blir mycket halt.

Bakgrund och problemdiskussion: Efterfrågan på en mer harmoniserad redovisnings- lagstiftning på grund av ökad globalisering och mer fria gränser ledde fram till införandet av IFRS, som implementerades år 2005. IFRS är obligatoriskt för noterade bolag i Sverige, men även onoterade bolag kan välja att frivilligt tillämpa IFRS. K-regelverket infördes i sin helhet år 2014 och sedan dess har större onoterade bolag möjligheten att frivilligt uppgradera sin redovisningsstandard från K3 till IFRS. Syfte: Uppsatsens syfte är att identifiera vilka faktorer som bidrar till att bolag väljer att frivilligt uppgradera sin redovisningsstandard. Metod: Uppsatsen består av två delstudier. Den första delstudien är en kvantitativ studie med en deduktiv forskningsansats och den andra delstudien är en kvalitativ studie med en abduktiv forskningsansats. Att kombinera de två delstudierna möjliggör identifiering av faktorer som studeras genom data från årsredovisningar och utifrån en intervjuserie med ekonomi- eller redovisningsansvariga på åtta bolag. Resultat och slutsatser: Studiens resultat tyder på att det finns vissa faktorer som påverkar bolag att frivilligt uppgradera sin redovisningsstandard. Den första delstudiens resultat visar att storlek och bransch har en påverkan på bolag att frivilligt uppgradera sin redovisningsstandard. Delstudie två visar att flera av första delstudiens faktorer i kombination påverkar bolagens förhållande till att frivilligt uppgradera sin redovisningsstandard, men även att ägarnas preferenser och riskbenägenhet är avgörande. / Background and problem diskussion: The demand for a more harmonized accounting legislation due to increased globalization and more free borders led to the introduction of IFRS, which was implemented in 2005. IFRS are mandatory for listed companies in Sweden, but also unlisted companies may choose to voluntarily adopt IFRS. The K- regulatory framework was introduced in its entirety in 2014 and since then larger unlisted companies has the opportunity to voluntarily upgrade their accounting standard from K3 to IFRS. Purpose: This paper aims to identify the factors contributing to why companies choose to voluntarily upgrade their accounting standard. Method: The thesis consists of two studies. The first study is a quantitative study with a deductive research approach and the second study is a qualitative study with an abductive research approach. Combining the two sub-studies allow identification of factors studied through data from annual reports and factors through a series of interviews with finance or accounting officers of eight companies. Results and conclusions: The study's results suggest that there are certain factors that affect the companies to voluntarily upgrade their accounting standard. The results from the first part of the study show that the size and industry have an impact on companies to voluntarily upgrade their accounting standard. Part two of the study shows that factors from the first part of the study in combination with each other affect companies to voluntarily upgrade their accounting standard, but also that owners' preferences and willingness to take risks is crucial.

Detta examensarbete är gjort på uppdrag av ABB i Ludvika. ABB har fått en beställning på en uppgradering av en högspänd likströmstation, på engelska High Voltage Direct Current (HVDC). Det finns huvudsakligen två olika tekniker gällande HVDC. Det är HVDC med Line Commutated Converters (LCC) och HVDC med Voltage Source Converters (VSC). LCC-tekniken är den äldsta och mest använda tekniken och är den teknik som stationen som uppgraderas använder. VSC-HVDC är en något nyare teknik som har fördelen att den inte kräver ett genererande nät på båda sidor av HVDC-länken men nackdelen att den inte klarar av lika höga effekter som LCC gör. Den har med dessa egenskaper blivit en populär teknik att använda för att till exempel överföra energi från vindkraftsparker ute till havs in till fastlandet eller för att förse oljeplattformar med energi. VSC-tekniken introducerades för första gången 1997 av ABB där den går under namnet HVDC-Light. Den aktuella HVDC-länken är en förbindelse mellan två länder och har en överföringskapacitet på totalt 600 MW. Uppgraderingen innefattar även uppdatering av befintliga scheman för att de skall finnas tillgängliga i den nya programvaran Engineering Base. Ritningarna har ritats i Microsoft Visio. Den utrustning som har ritats om och behandlas i denna rapport gäller utrustningen på likströmssidan av HVDC-stationen. Det innefattar jordknivar, frånskiljare, strömtransformatorer, spänningsdelare, överströmsskydd och genomföringar. / This thesis was conducted on behalf of ABB in Ludvika. ABB has received an order for an upgrade of a high voltage direct current (HVDC) station. There are two main technologies that HVDC is based on; line commutated converters (LCC) and voltage source converters (VSC). The LCC technology is the oldest and most widely used. It's also the technology that the upgraded station is based on. VSC HVDC is a newer technology that has the advantage of not requiring a generating power grid on both sides of the HVDC link but has the disadvantage that it cannot handle as high power as LCC can. With these qualities it has become a popular technology to use to transfer energy from offshore wind farms to the mainland or to provide oil platforms with energy. VSC technology was first introduced in 1997 by ABB where it is called HVDC Light. The revised HVDC link is a connection between two countries and has a total power transmission of 600 MW. The upgrade also includes updating existing circuit diagrams for the HVDC station to be available in the new software Engineering Base. The circuit diagrams have been drawn in Microsoft Visio. The equipment which have been designed and examined in this report applies to equipment on the DC side of the HVDC station. This includes grounding knives, disconnectors, power transformers, voltage dividers, current protection units and wall bushings.

<p>Despite big expansion of biogas plants in the world, does not have the levels in the Swedish market succeeded very good. Presently are not so many expanded biogas plants in Sweden. Especially biogas plants that are based on rest products from the industry. This study checks the possibility and takes up the profitability in producing biogas off spill products from rape oil production. The spill product that is interesting in this case is process water with high-energy contents that currently are given away to the local farmers for fertilization of farmland.</p><p> Results from the study show that the process water in itself is not appropriate substrate for digestion in a biogas plant. On the other hand if you use an involvement corresponding 20- 25% graft in the process water can the result become really good. But to use this biogas to heat power plant or upgrading to vehicle fuel can it be unsuitable on the basis of economic calculations. This entirely depends on that production of the process water is too little and that will give a result with smaller amount biogas production. This amount will not be neither enough to be sold to other companies for upgrading or other purposes.</p><p> This problem can be solved through cooperation with the municipality’s sewage treatment or local farmers that will supply their energy needs by themselves. If the cooperation takes in force can biogas plant becomes profitable irrespective of what the biogas will be used to.</p><p> Using biogas in heat power plant to force electricity and heat with minimum 200-kilowatt gas engine can investment be profitable, regardless of if the electricity will be sold on the market or it be used internal. It is also economic to upgrade biogas to vehicle fuel with a minimum prise of 7, 5 SEK/Nm³ biogas.   </p><p> Investment on biogas plant is depending on factors like interest rate, economic contribution, costs and political arrangements so. The results will be changed if the economic factors changed, for examples lower interest rate and higher economic contributions brings profitability in the investment. On the other hand higher raw materials or less economic contribution will make that the investment becomes uneconomical.</p>

<p>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. Sewagesludge is mostly used but also other substrates, like food waste. The time for processing is in average25 days before the content is taken out for drying and finally for use as cover material. The producedgas will be cleaned in a water scrubber before pressurization and after that used as fuel for vehicles.The usage of support energy in the biogas process is essentially district heating, electricity and oil. Theoverall efficiency term is the energy produced in the gas minus the supporting energy divided with theenergy from possible biogas production of the substrates. For calculation of a continuous process thefact that there is always a part of the substrates which not will be digested has to be considered.Another thing to think about is that the inserted energy as material will not be converted to gasimmediately, several days is needed. In 2009 the overall efficiency in Ekeby biogas plant was inaverage 70.5%, and the value was higher during the summer than the winter. Calculation of overallefficiency of a biogas plant will always involve some uncertainties because differences of thecomposition of the substrates, the condition of the micro-organisms, digestion of many substrates atthe same time etc.</p>

<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>

Despite big expansion of biogas plants in the world, does not have the levels in the Swedish market succeeded very good. Presently are not so many expanded biogas plants in Sweden. Especially biogas plants that are based on rest products from the industry. This study checks the possibility and takes up the profitability in producing biogas off spill products from rape oil production. The spill product that is interesting in this case is process water with high-energy contents that currently are given away to the local farmers for fertilization of farmland.  Results from the study show that the process water in itself is not appropriate substrate for digestion in a biogas plant. On the other hand if you use an involvement corresponding 20- 25% graft in the process water can the result become really good. But to use this biogas to heat power plant or upgrading to vehicle fuel can it be unsuitable on the basis of economic calculations. This entirely depends on that production of the process water is too little and that will give a result with smaller amount biogas production. This amount will not be neither enough to be sold to other companies for upgrading or other purposes.  This problem can be solved through cooperation with the municipality’s sewage treatment or local farmers that will supply their energy needs by themselves. If the cooperation takes in force can biogas plant becomes profitable irrespective of what the biogas will be used to.  Using biogas in heat power plant to force electricity and heat with minimum 200-kilowatt gas engine can investment be profitable, regardless of if the electricity will be sold on the market or it be used internal. It is also economic to upgrade biogas to vehicle fuel with a minimum prise of 7, 5 SEK/Nm3 biogas.     Investment on biogas plant is depending on factors like interest rate, economic contribution, costs and political arrangements so. The results will be changed if the economic factors changed, for examples lower interest rate and higher economic contributions brings profitability in the investment. On the other hand higher raw materials or less economic contribution will make that the investment becomes uneconomical.

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. Sewagesludge is mostly used but also other substrates, like food waste. The time for processing is in average25 days before the content is taken out for drying and finally for use as cover material. The producedgas will be cleaned in a water scrubber before pressurization and after that used as fuel for vehicles.The usage of support energy in the biogas process is essentially district heating, electricity and oil. Theoverall efficiency term is the energy produced in the gas minus the supporting energy divided with theenergy from possible biogas production of the substrates. For calculation of a continuous process thefact that there is always a part of the substrates which not will be digested has to be considered.Another thing to think about is that the inserted energy as material will not be converted to gasimmediately, several days is needed. In 2009 the overall efficiency in Ekeby biogas plant was inaverage 70.5%, and the value was higher during the summer than the winter. Calculation of overallefficiency of a biogas plant will always involve some uncertainties because differences of thecomposition of the substrates, the condition of the micro-organisms, digestion of many substrates atthe same time etc.

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.