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209 Uppsatser om Methane emission - Sida 12 av 14
Reglerstrategi för fria ventiler : ? Utveckling av en fyrtakts förbränningsmodell för att prediktera optimala ventilinställningar
As emission legislations across the world continuously pushes engine development forward,engineers constantly need to come up with and implement fuel saving technologies. During thelast decade, variable cam phasing has become a popular solution to increase gas exchangeefficiency. This configuration is typically mechanically constrained by camshaft limitations, anda solution to circumvent this problem would be to use a different valve actuation principle.One example of this is to use pressurized air controlled by electrical solenoids. Such a systemhas been developed byCargine Engineering and this provides the starting point for this work. Tobe able to operate the valvetrain on an actual engine, a control system is needed.
Optimering och effektivisering av biogasprocessen vid biogasanläggningen Kungsängens gård
Under år 2008 användes globalt en energimängd motsvarande nästan 144 000 TWh ochav dessa stod fossila bränslen för 81 %. I Sverige uppgick energitillförseln under år2010 till totalt 616 TWh och av detta stod råolja/oljeprodukter för 30,4 %. Vidförbränning av fossila bränslen frigörs koldioxid, en gas som bidrar till att förstärkaväxthuseffekten. År 2000 uppmättes halten av koldioxid i atmosfären till 370 ppmv ochför att den globala temperaturen inte ska öka med mer än 2°C bör halten stanna på 450ppmv innan år 2100. Ett sätt att minska andelen av fossila bränslen är att öka andelen avförnybara energikällor, som t.ex.
Nord Pools systempris - en studie av prispåverkande faktorer
The intention of this thesis is, from a basic statistical viewpoint, to capture the relationship between the price of electricity and a sample of factors influencing the price. The thesis also aims at investigating whether knowledge about the relationship is useful when investing on Nord Pool. Tested factors are temperature, import, price of emission rights as well as a number of hydrological factors. The investigated period stretches from year 2000 until week 32 year 2007. The relevance of each factor was also evaluated yearly as well as for shorter periods in order to get a more comprehensive view of the relationship.
Kan mjölkkors utnyttjande av vallprotein bli bättre? : utfodringsstrategier och konserveringsmetoder
The purpose with this literature study was to investigate the possibilities for improvement of forage protein in dairy cows with focus on feeding strategies and conservation of forage protein. The utilization of forage protein in dairy cows is often not that efficient as it could be. The feed crude protein consists of both true proteins and non protein nitrogen. The digestion of proteins in the rumen depends on the protein degradation rate and the ability of the microbes to synthesize microbial protein. The microbes need a balance between carbohydrates that provide them with energy and proteins that are degradable in the rumen.
Bil- och järnvägstrafikens inverkan på inomhusmiljön med avseende på ljud och luft : - I planerade bostäder på Haga
NCC has given us a commission to investigate a planned housing area in Haga, Karlstad, situated close to the traffic route Hagaleden and the railway. The housing area consists of one hundred apartments in five different houses. The houses are linked to each other by balconies with glass panels. A long carport is situated between Hagaleden and the housing area to absorb part of the noise from the road. The design of the housing area is creating a silent backyard.
Klimat i miljökonsekvensbeskrivningar : hantering av klimatförändringar och extrema väderhändelser i MKB
There has always been global warming on earth and it is because of it that the earth is inhabitable. Without global warming the temperature on earth would be around -18 ° C instead of today's + 15 ° C. Global warming is generated by greenhouse gases like carbon dioxide and methane which trap long wave radiation in the earth's atmosphere. The problem today is that the global concentration of green house gases has significantly increased since the 1750's as a result of human activity. Today's values widely exceed the preindustrial values.
Kaffesump som substrat i biogasanläggningar eller som bränsle i fjärrvärmeverk : en studie av effekter på växthusgasutsläpp och kostnader
Each year, the coffee machines at Ericsson in Kista produce around 100 tons of ground coffee waste.The companies Coor Service Management, Löfbergs Lila and Selecta are all responsible for differentstages in the logistical chain in delivering coffee and, together with Ericsson, they want to increasetheir environmental benefit. The plan is to produce biogas through anaerobic digestion instead ofincinerating the coffee waste in a heating plant. The results are to be presented as different businesscases in which different biogas plants are compared with the reference case (heating plant),comparing costs and environmental impacts.There are two major environmental benefits from producing biogas; reduced carbon dioxideemissions from when fossile fule is replaced by carbon neutral biogas, and reduced emissions fromreturning digestate from the bio reactor to farmland instead of using industrial fertelizer.In order to determine the biogas potential in coffee waste, a couple of properties had to bedetermined in a laboratory. Properties such as the dry substance content, heating value, moisturecontent and ash content. The results show that 100 tons coffee waste could produce around 16 500Nm3 biogas which would contain 163 MWh.The biogas reactor and upgrade plant both need energy gas to function and uses around 14 MWh ofthe produced gas.
Förbehandlingstekniker och LCA för rötning av organiskt avfall : Modellkonstruktion och Utvärdering med ORWARE
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.
Towards sustainable rye cultivation : soil carbon and yield modelling for crop rotations with rye
Using the Introductory Carbon Balance Model, ICBM, five different crop rotations with rye
1. Rye-Ley-Ley-Rye-Beans-Rye
2. Rye-Rye-Rapeseed-Rapeseed
3. Rye-Ley-Ley-Rye-Potatoes-Rye
4. Rye-Rye-Potatoes-Wheat
5. Rye-Rye-Potatoes-Beans-Wheat-Rye-Potatoes-Rapeseed
were tested theoretically in four different cultivation scenarios
? Straw left on the field, biogas digestate added as fertilizer. Labelled ?+straw+BD?.
? Straw left on the field, only synthetic fertilizer. Labelled ?+straw-BD?.
? Straw harvested, biogas digestate added as fertilizer.
Effekter av Zeoliter i Biogasproduktion
Biogas är benämningen för metangas (CH4) som är producerad via anaerob (syrefri) rötning av biologiskt material. I Linköping finns en av Sveriges största biogasanläggningar. Anläggningen drivs av Svensk Biogas AB som ägs av Tekniska Verken i Linköping AB (publ.). I anläggningen rötas stora mängder proteinrikt substrat vilket leder till höga halter av ammoniak (NH3) och ammonium (NH4+) i rötkammaren. Ammoniak (NH3) är toxiskt för de metanbildare som i en välmående process står för den största delen av metangasproduktionen.
Flödesanalys av spårelement från källa till slam
I det svenska samhället tillför diffusa och direkta föroreningskällor metaller till avloppsreningsverk, metaller som sedan hamnar i avloppsslam och recipient. Avloppsslam innehåller höga halter av växtnäringsämnen som bör återföras till jordbruksmark, men om detta ska ske får inte metallhalterna i slammet vara för höga. REVAQ är ett certifieringssystem vars syfte är att utveckla och systematisera avloppsreningsverkens uppströmsarbete och därmed möjliggöra en återföring av det växtnäringsrika slammet till jordbruksmark. Flera REVAQ-certifierade avloppsreningsverk prioriterar antimon, guld, kadmium, silver och vismut i uppströmsarbete på grund av att ackumulationshastigheten för dessa spårelement är hög i jordbruksmark som gödslas med avloppsreningsverkens slam. Source Finder (SoFi) är ett verktyg som kan användas vid uppströmsarbete för att kvantifiera identifierade källor till utsläpp av kadmium, koppar, krom, kvicksilver och zink.Syftet med examensarbetet var att vidareutveckla och anpassa verktyget SoFi till att göra beräkningar på spårelementen antimon, guld, silver och vismut samt att utveckla källan hushåll så att emissioner inom hushåll kartläggs för spårelementen och kadmium.
Oljetemperaturens inverkan på motoroljans degradering i lastbil
The market for heavy duty engines is constantly requiring engines that should be more andmore powerful, while still maintaining low fuel consumption. As a result of increasing enginepower, the engine and coolant temperature increases as well due to insufficient coolingperformance (because of design issues, cost etc.).Also, emission legislations, both current and future, require more and more measures to betaken by engine manufacturers. One way of meeting the legislations is the use of cooled EGR(Exhaust Gas Recirculation), which also lead to increased coolant temperatures.Both these factors also naturally lead to increased engine oil temperatures, the consequencesof which are not thoroughly investigated.This thesis project aims to investigate effects of high temperatures on engine oil degradation,with focus on the greatest degradation process: oxidation. To do this several engine runs havebeen performed on a 310 hp engine with EGR to see what happens to the engine oil in a realengine when exposed to high temperatures. During the tests oil samples have been taken andanalysed for important parameters.As a complement to these engine tests some laboratory oxidation testing have also beenperformed, to be able to compare engine test data with laboratory tests.One goal of the project was to try to formulate an empirical oxidation model, which would beable to predict oil oxidation levels in an engine, given any running parameters.
Hållbara transporter : Överföring från väg till järnväg
Road transports stand for a great part of Sweden?s total CO2-emissions. Transports are expected to increase over the coming years, and with those the emissions. A greater environmental awareness leads to increased demands for environmentally friendly transport. The aim of this thesis is to study the consequences of changing transportation modes from road to railway.
Termisk hantering av litium-jon- batterier i elektriska drivsystem
The automotive market is currently undergoing a historical change where stricter emission legislations and ever increasing fuel costs have intensified the search for effective alternatives to the conventional internal combustion engine, which has resulted in a substantial trend towards electrification of powertrains. Storage of electrical energy is the fundamental component in this technology where the lithium-ion batteries are currently considered as the most appropriate solution. Lithium-ion batteries, however, as other types of batteries, can only be used efficiently and durably within a specific temperature range.This Master thesis has been carried out in collaboration with Electroengine in Sweden AB, situated in Uppsala, which has an ongoing project regarding development of a modular battery system for electric powertrains. The project is at a stage where an initial prototype has been developed which provides the foundation for this thesis. The study has addressed the battery system performance from a thermal perspective, in order to validate the ability of the system to create a thermally serviceable environment for the lithium-ion battery cells.
Att gestalta en socialt hållbar begravningsplats
This thesis aims to present the essential background on how to perform climate changeimpact assessments, and to present the results from a climate impact assessment on waterbalance and nitrate leaching for an arable Swedish soil. The soil is a sandy soil in southwesternSweden, grown with spring cereals. This study is meant to be a benchmark example,and cannot be seen as a regional or national assessment for Sweden, rather as an approachto present and analyze the most important parts of these kinds of assessments.A dynamical simulation model (COUP, Jansson and Karlberg, 2004) was used for thisstudy. The model was parameterized and calibrated against data from an experimental site,located in Mellby in Hallands county, south western Sweden. Measurements were carriedout between 1st of April 1988 and 1st of April 1991.