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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Engine performance and exhaust emissions from a diesel

Powell, Jacob Joseph 15 May 2009 (has links)
Non-road diesel engines are significant contributors to air pollution in the United States. Recent regulations put forth by EPA and other environmental agencies have laid out stringent guidelines for engine manufacturers and fuel producers. Recent increases in oil prices and foreign energy dependency has led to a push to produce renewable fuels, which will supplement current reserves. Biodiesel is a clean-burning renewable fuel, that can be blended with petroleum diesel. It is important to understand the effect on engine performance and exhaust emissions when using biodiesel from different feedstocks. The objective of this research was to determine the relationship between engine performance and emissions and cottonseed oil biodiesel used in a diesel engine rated for 14.2 kW. When using cottonseed oil biodiesel blends, CO, hydrocarbon, NOx, and SO2 emissions decreased as compared to petroleum diesel. Carbon dioxide emissions had no definitive trend in relation to cottonseed oil biodiesel blends. Carbon monoxide emissions increased by an average 15% using B5 and by an average of 19% using B100. Hydrocarbon emissions decreased by 14% using B5 and by 26% using B100. Nitrogen oxide emissions decreased by four percent with B5, five percent with B20, and 14% with B100. Sulfur dioxide emissions decreased by an average of 86% using B100, and by 94% using B50 blended with ultra-low sulfur diesel. The difference between peak output power when using biodiesel and diesel was insignificant in blends less that B40. Peak measured power using B100 was about five percent lower than for diesel fuel. Pure cottonseed oil biodiesel achieved and maintained a peak corrected measured power of 13.1 kW at speeds of 2990, 2875, and 2800 rpm at loads of 41.3, 42.7, and 43.8 N-m. Using B5 produced a peak power of 13.6 kW at 2990 rpm and 43.9 N-m and at 2800 rpm and 46.7 N-m, while using B20 produced a peak power of 13.4 kW at 2990 rpm and 43.7 N-m. Brake-specific fuel consumption at peak measured load and torque using B100 was 1238 g/kW-h. Brake-specific fuel consumption at peak measured power and loads using B5 and B20 were 1276 and 1155 g/kW-h.
82

Performance Characterization of a Medium-Duty Diesel Engine with Bio-Diesel and Petroleum Diesel Fuels

Esquivel, Jason 16 January 2010 (has links)
In the wake of global warming and fossil fuel depletion, renewed attention has been paid to shifting away from the use of petroleum based fuels. The world?s energy demand is commencing its dependency on alternative fuels. Such alternative fuels in use today consist of bio-alcohols (such as ethanol), hydrogen, biomass, and natural oil/fat derived fuels. However, in this study, the focus will be on the alternative fuel derived from natural oils and fats, namely biodiesel. The following study characterizes the performance of a medium-duty diesel engine fuelled with biodiesel and conventional diesel. The objective is accomplished by taking measurements of manifold pressure and temperature, fuel flow, air flow, and torque. The study first characterizes a John Deere 4.5 liter 4 cylinder direct injection engine with exhaust gas recirculation (EGR), common rail fuel injection, and variable turbo-charging with conventional petroleum diesel to set a reference for comparison. The study then proceeds to characterize the differences in engine performance as a result of using biodiesel relative to conventional diesel. The results show that torque decreases with the use of biodiesel by about 10%. The evaluation of engine performance parameters shows that torque is decreased because of the lower heating value of biodiesel compared to conventional diesel. The insignificant difference between the other performance parameters shows that the ECM demands the same performance of the engine regardless of the fuel being combusted by the engine.
83

Research on the pollutants of catalytic oxidation for gasoline and emission reduction of bio-diesel fuel

Yang, Hung-wen 12 January 2010 (has links)
How effective would the implementation of biodiesel fuel in reducing emissions caused by automobiles and motorcycles in the densely populated regions? The goal of this research is targeted at determining the most proficient methods in depleting the harmful substances emitted from refueling stations and the efficiency of biodiesel fuel in emissions reduction. The initial stages in the research involved the use of aluminum oxide and molecular sieve, which would act as active metals for copper and manganese. Impregnation and solgel method of catalytic production were utilized with 12 sets of oxidized copper, and molecular sieve catalysts, totaling at 24 sets. With results from the primary testing, initial selection of impregnation production methods based on its conversion rate had a carrying capacity of 20% CuMn/ oxidized copper catalyst (Cu: Mn ratio at 1:1), and a 20% CuMn/molecular sieve catalyst (Cu: Mn ratio of 1:1) with the solgel method. The two exogenous tests were not only found to be the most efficient rate of conversion as base standards, but were also found to be the most competent method to date. Approximate calculations from the two catalytic testing showed that CuMn/oxidized copper catalyst conversion are less affected by variation in concentration density. Furthermore, the CuMn/oxidized copper and CuMn/molecular sieve catalysts faced a positive conversion rate when reacted with a decreased space velocity, but leveled off once it reached a specific level. Moreover, the two catalysts also faced an increased conversion rate when conducted with an increase in oxygen concentration, and reached maximized efficiency at 30% concentration. Secondary stage of the research focuses on operational efficiency of the biodiesel fuel, with emphasis on its pollutant emissions and economical standpoint. The initial testing concluded that not only did the fuel has a lower cost in reducing greenhouse gas emission than alternative energy sources, but it can also reduce SOx emissions by 7,200kg, 23 metric tons of PM10, and 262,400 metric tons of CO2 annually when applied with B2 fuel. Pollution reduction assessment indicated that if all diesel powered automobiles utilized the B10 biodiesel fuel, then it¡¦s estimated that it would have an annual THC reduction rate of 2.83x102 metric tons, 1.98x103 tons in COs, 4.56x103 in NOx, and 5.66x101 metric tons in PM gases. Furthermore, if the B20 fuel cells were incorporated, then it¡¦s estimated to have an annual reduction rate of 2.83x102 metric tons in THC, 2.83x103 metric tons of CO, 1.14x103 metric tons of NOx, and 1.16x102 metric tons of PM. Results from the beta stage testing indicated that if B10 fuel were incorporated into all diesel powered automobiles, with a budget of NT$1million would result in an annual reduction rate of 0.57 metric tons of THC, 9.12 metric tons of NOx, 0.11 metric tons of PM and a totaled 9.8 metric tons of reduction. Furthermore, if B20 were implemented, again with NT$1 million budget, we would expect to see annual reductions of 0.06 metric tons of THC, 0.25 metric tons of NOx, 2.51 tons of PM gases, totaling at 2.81 metric tons of reductions.
84

Non-linear reparameterization of complex models with applications to a microalgal heterotrophic fed-batch bioreactor

Surisetty, Kartik. January 2010 (has links)
Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on Jan. 22, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Process Control, Department of Chemical and Materials Engineering, University of Alberta. Includes bibliographical references.
85

Evaluation of biodiesel from used cooking sunflower oil as substitute fuel.

Steyn, Christoffel Bernadus. January 2010 (has links)
Thesis (MTech. degree in Mechanical Engineering)--Tshwane University of Technology, 2010. / This study evaluates the use of biodiesel as an alternative fuel for diesel engines. The fuel properties, performance, emission characteristics and combustion characteristics of a four-stroke, four-cylinder water cooled, high speed direct injection (DI) diesel engine operated on biodiesel, 30% biodiesel and 70% biodiesel blended fuels were measured. Results related to the direct use of biodiesel as a diesel engine fuel indicate that this is possible but not preferable because of its high viscosity and cetane number. Biodiesel could be used in the blends with diesel fuel, because most of the measured properties of the biodiesel-diesel blended fuels were close to those of the diesel fuel. It was found that the performance parameters of the biodiesel-diesel blended fuels did not differ greatly from those of diesel fuel. A slight power decrease, with an increase in brake specific fuel consumption (BSFC), was noticed with the blend fuels. Smoke emissions were reduced for the blends while NOx was increased remarkably for the biodiesel-blended fuels. The test results demonstrated that the combustion carbon deposits (CCD) of biodiesel are a little less than that of the diesel fuel. The peak combustion pressure of the B70 blended fuel was found to be the highest amongst the four tested fuels. It is consequently argued that biodiesel appears to offer a potential alternative "greener" energy substitute for fossil fuel.
86

Development and characterization of biodiesel from shea nut butter

Enweremadu, CC, Alamu, OJ 21 August 2009 (has links)
A b s t r a c t. Shea nut butter was extracted from shea nut by cold press method and was investigated as feedstock for the production of biodiesel. Biodiesel yield was used to verify the optimization, while density and viscosity were chosen to serve as an indicator for the effectiveness and completeness of the ester conversion process. Based on the amount of shea butter used, the final product yield obtained was 94.55% mass and the percentage conversion of FFA in shea butter to biodiesel was 92.3% using a methanol/oil ratio of 6:1 and 1.0% mass KOH at 60 min and 55°C, respectively. The important properties of the biodiesel (density, kinematic viscosity, cloud point, pour point, cetane number, neutralization number, iodine value, methyl ester content and high heating value) were compared to those of ASTM and EN standards for biodiesel. The comparison shows that the shea butter methyl ester could be used as an alternative to diesel.
87

Study on a biodiesel fuel produced from restaurant waste animal fats

顧振彪, Koo, Chun-piu, Benedict. January 2001 (has links)
published_or_final_version / Mechanical Engineering / Master / Master of Philosophy
88

Experimental and modelling studies on the separation of glycerol from biodiesel

Abeynaike, Arjan January 2011 (has links)
No description available.
89

From Waste to Worth

Vice President Research, Office of the 06 1900 (has links)
As the irreversible decline of oil availability looms in the not-so distant future, Naoko Ellis is using a grassroots UBC research project to promote the widespread environmental and economic benefits of biodiesel.
90

ENZYMATIC TRANSESTERIFICATION OF WASTE ANIMAL FATS FOR PRODUCTION OF BIODIESEL

Kumar, Santhosh 03 July 2013 (has links)
The process of transesterification is the exchange of the organic group R” of an ester with the organic group R’of an alcohol, often catalyzed by acid, base or enzyme. Biodiesel, a mixture of monoalkyl esters of long chain fatty acids, is produced from vegetable oils, animal fats and fish oils by transesterification in presence of alcohol. Biodiesel is a fuel which can be used in a mixture of other fuels or alone. The base catalyzed transesterification method of biodiesel production is not suitable for waste animal fat as it contains 10–15% free fatty acids which result in higher soap formation and cause extensive downstream processing. Enzyme catalyzed transesterification can overcome the problem of soap formation and multi-step purification of end products and results in a higher purity biodiesel. Lipase is the enzyme widely used in the process of enzymatic transesterification. Various lipases have been used to transesterify triglycerides with short chain alcohols to alkyl esters. The objectives of this study were to screen lipase enzymes for the transesterification process and to use the best lipase for biodiesel production from waste animal fat. Enzymatic transesterification by individual and combined enzyme catalysts (Novozyme 435 and NS88001) was first carried out to investigate the effects of reaction time (4, 8, 12 and 16 hour), oil : alcohol molar ratios (1:1, 1:2, 1:3, 1:4 and 1:5), the effects of alcohol type (methanol and 2-butanol) and reaction temperature (35, 40, 45 and 50°C) on biodiesel yield in solvent and solvent-free systems. The highest conversion yield of biodiesel (96.67%) was obtained from a combination of Novozyme and NS88001 lipase with the optimal reaction condition of oil : 2-butanol molar ratio of 1:4, enzyme concentration of 25% (12.5% w/w of each enzyme), hexane as solvent, a 45°C reaction temperature, a reaction time of 16 h and a mixing speed of 200 rpm. The reusability of lipase enzymes by individual and combination of enzyme catalysts (Novozyme 435 and NS88001) with solvent and solvent-free systems was also investigated in order to reduce the cost of the process. The lipase enzymes lost their activity after being reused for 30 cycles in solvent-free systems and after 10 cycles in solvent system.

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