Browsing by Subject "biodiesel"
Now showing 1 - 8 of 8
Results Per Page
Sort Options
Item Applications of Highly Cross Linked Mixed Bed Ion Exchange Resins in Biodiesel Processing(2010-10-12) Jamal, YousufBiofuels are a promising solution to society's quest for sustainable energy. In the transportation sector, biodiesel is the leading alternative diesel fuel currently in use today. However, the current global and domestic production of biodiesel is far below the petro-diesel consumption and demand. To increase the availability of biodiesel in the market, new methods of biodiesel production must be developed to take advantage of the plentiful low quality waste derived feed stocks that currently present problems to biodiesel production using conventional methods. This research presents one new approach based upon using heterogeneous highly cross linked mixed bed solid phase catalysts to facilitate the production of biodiesel from feed stocks with high concentrations of free fatty acids (FFA). The performance of the heterogeneous mixed bed catalysts method developed in this research was evaluated and optimized for catalyst concentration and reaction duration while the mixing rate, reaction temperature, initial FFA composition of the feed stock and the alcohol-to-oil molar ratio were kept constant. The presented method reduces the FFA content of the starting feed stock while limiting the release of water into the reaction. Through experimentation, it was found that FFA removal with the mixed bed resin is due to ion exchange with the quaternary ammonium functional group and not catalysis to form esters. A model describing the heterogeneous processing method is presented. The outcome of this research is the development of a new processing method that can be used to create biodiesel from poor quality raw feed stock materials.Item Design and Analysis of Flexible Biodiesel Processes with Multiple Feedstocks(2011-10-21) Pokoo-Aikins, Grace AmarachukwuWith the growing interest in converting a wide variety of biomass-based feedstocks to biofuels, there is a need to develop effective procedures for the design and optimization of multi-feedstock biorefineries. The unifying goal of this work is the development of systematic methodologies and procedures for designing flexible multifeedstock biorefineries. This work addresses four problems that constitute building blocks towards achieving the unifying goal of the dissertation. The first problem addresses the design and techno-economic analysis of an integrated system for the production of biodiesel from algal oil. With the sequestration of carbon dioxide from power plant flue gases, algae growth and processing has the potential to reduce greenhouse gas emissions. Algae are a non-food oil feedstock source and various pathways and technologies for obtaining algal oil were investigated. Detailed economic and sensitivity analysis reveal specific scenarios that lead to profitability of algal oil as an alternative feedstock. In the second problem, a new safety metric is introduced and utilized in process design and selection. A case study was solved to assess the potential of producing biodiesel from sewage sludge. The entire process was evaluated based on multiple criteria including cost, technology and safety. The third problem is concerned with incorporating flexibility in the design phase of the development of multi-feedstock biofuel production processes. A mathematical formulation is developed for determining the optimal flexible design for a biorefinery that is to accommodate the use of multiple feedstocks. Various objective functions may be utilized for the flexible plant depending on the purpose of the flexibility analysis and a case study is presented to demonstrate one such objective function. Finally, the development of a systematic procedure for incorporating flexibility and heat integration in the design phase of a flexible feedstock production process is introduced for the fourth problem. A mathematical formulation is developed for use in determining the heat exchange network design. By incorporating the feedstock scenarios under investigation, a mixed integer linear program is generated and a flexible heat exchange network scheme can be developed. The solution provides for a network that can accommodate the heating and cooling demands of the various scenarios while meeting minimum utility targets.Item Engine performance and exhaust emissions from a diesel(2009-05-15) Powell, Jacob JosephNon-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.Item Engine Performance and Exhaust Emissions of a Diesel Engine From Various Biodiesel Feedstock(2011-02-22) Santos, Bjorn SanchezIncreasing fuel prices, stricter government policies, and technological developments made it possible to seek for renewable alternatives, called biofuels, to petroleum fuel. Biodiesel, a biofuel that is produced from chemically mixing animal fat, vegetable oils, or recycled restaurant grease with alcohol and catalyst, is gaining popularity in recent years as a substitute for petroleum diesel. Ninety percent (90%) of U.S. biodiesel industry makes use of soybean oil as its feedstock. However, soybean oil alone cannot meet such a huge demand on biofuel production. Hence, it is important to identify and get more information about other feedstocks, specifically on its effects on the performance and exhaust emissions of diesel engines. The purpose of this study is to investigate the performance and emissions of two diesel engines operating on different biodiesel fuels (i.e. canola oil, sunflower oil, safflower oil, peanut oil, and chicken fat) and compare them to the performance and emissions when the engine is operated on soybean oil-based biodiesel and petroleum-based diesel. Results indicated that an engine operating on biodiesel generates a little less power and torque at any given speed than one running on diesel. Such power and torque loss were attributed to the biodiesel's lower energy content. The lower heating value (energy content) of biodiesel can be reflected in the specific fuel consumption, i.e., to generate the same power, more biodiesel is needed. The reduction in torque and power of less than 10% indicates that in some cases biodiesel has better combustion than diesel. Unfortunately, the high efficiency of combustion may give rise to increased combustion temperature which may lead to higher exhaust emissions. The gradual decrease in the total hydrocarbon and CO2 emissions, as blends were increased from B20 to B100, was also found to be an indication of better combustion using biodiesel fuels than petroleum diesel. However, NOx emissions were higher, predominantly at low speeds for most biodiesel and blends and therefore may require some additives or engine modifications/or adjustments to equalize the NOx emissions of diesel. Other emissions particularly SO2 were lower than standards require.Item Impacts of Biofuel Production and Navigation Impediments on Agricultural Transportation and Markets(2013-08-22) Ahmedov, ZafarbekThis study investigated the impacts of U.S. biofuel production and barge navigation impediments on agricultural transportation and markets. Both past and future impacts of U.S. biofuel production levels mandated by the Renewable Fuel Standards of the Energy Policy Act of 2005 (RFS1) and the Energy Independence and Security Act of 2007 (RFS2) were examined. Examination of barge navigations impediments included analysis of the impact of lock failure and low water levels on rivers due to drought, on agricultural transportation, and on consumer welfare. All scenarios were simulated using the International Grain Transportation Model, a price endogenous mathematical programming model. The results showed that RFS-associated (RFS1 and RFS2) U.S. corn ethanol production increased the total corn supply and diverted corn from non-ethanol consumption, reduced regional grain transportation volumes, and contributed to a rise in corn prices. The results of the forward-looking scenarios indicated that grain exports and transport volumes were increased. Exports from Gulf ports increased by 41%, while grain movements by rail increased by 60%. Additional investments in the expansion of the grain handling capacities of Gulf ports and the railroad industry are needed in the near future unless a large increase in biofuel production occurs. The results of navigation impediment scenarios indicated that both lock failures and low water levels on rivers adversely affect U.S. grain exports. The Gulf ports were most negatively impacted, relative to Pacific Northwest and Atlantic ports. Truck and barge freight volume declined while rail freight volume increased. Because trucks deliver grain from grain elevators to barge locations, truck volume also decreased in response to the decline in barge volume. The scenarios imposed welfare losses on society with most accruing to consumers, while the barge industry lost $10-154 million in revenue. The low water levels were more expensive than the lock failures. Major rehabilitation of the locks is needed to avoid lock failures and more dredging of the shallow parts of the river system is required because of frequent droughts.Item Investigation on Nitric Oxide and Soot of Biodiesel and Conventional Diesel using a Medium Duty Diesel Engine(2012-07-16) Song, HoseokBiodiesel has been suggested as an alternative fuel to the petroleum diesel fuel. It beneficially reduces regulated emission gases, but increases NOx (nitric oxide and nitrogen dioxide) Thus, the increase in NOx is the barrier for potential growth of the biodiesel fuel. In general, NOx formation is dominated by flame temperature. Interestingly, soot can play a role as a heat sink as well as a heat transfer media to high temperature gases. Thus, the cooling effect of soot may change the flame temperature and therefore, NOx emissions. In this study, emphasis is placed on the relationship between soot and NO (Nitric oxide) formation. For the experimental study, a metallic fuel additive is used since barium is known to be effective to suppress soot formation during combustion. The barium additive is applied to #2D (Number 2 diesel fuel) by volume basis: 0.1, 0.25 and 0.5 %-v, and to the palm olein oil by 0.25 %-v. All the tests are carried out in a four-cylinder medium duty diesel engine, 4045 DI diesel engine, manufactured by John Deere. For the analysis, an analytical model is used to estimate combustion temperature, NO concentration and soot emissivity. The results show that NO concentration does not have the expected trade-off relation with soot. Rather, NO concentration is found to be more strongly affected by ambient temperature and combustion characteristics than by soot. The results of the analytical model show the reasonable NO estimation and the improvement on temperature calculation. However, the model is not able to explain the detailed changes of soot emissivity by the different fuels since the emissivity correlation is developed empirically for diesel fuel.Item Process simulation, integration and optimization of blending of petrodiesel with biodiesel(2009-05-15) Wang, TingWith the increasing stringency on sulfur content in petrodiesel, there is a growing tendency of broader usage of ultra low sulfur diesel (ULSD) with sulfur content of 15 ppm. Refineries around the world should develop cost-effective and sustainable strategies to meet these requirements. The primary objective of this work is to analyze alternatives for producing ULSD. In addition to the conventional approach of revamping existing hydrotreating facilities, the option of blending petrodiesel with biodiesel is investigated. Blending petrodiesel with biodiesel is a potentially attractive option because it is naturally low in sulfur, enhances the lubricity of petrodiesel, and is a sustainable energy resource. In order to investigate alternatives for producing ULSD, several research tasks were undertaken in this work. Firstly, base-case designs of petrodiesel and biodiesel production processes were developed using computer-aided tools ASPEN Plus. The simulations were adjusted until the technical criteria and specifications of petrodiesel and biodiesel production were met. Next, process integration techniques were employed to optimize the synthesized processes. Heat integration for petrodiesel and biodiesel was carried out using algebraic, graphical and optimization methods to maximize the integrated heat exchange and minimize the heating and cooling utilities. Additionally, mass integration was applied to conserve material resources. Cost estimation was carried out for both processes. The capital investments were obtained from ASPEN ICARUS Process Evaluator, while operating costs were calculated based on the updated chemical market prices. The total operating costs before and after process integration were calculated and compared. Next, blending optimization was performed for three blending options with the optimum blend for each option identified. Economic comparison (total annualized cost, breakeven analysis, return on investment, and payback period) of the three options indicated that the blending of ULSD with chemical additives was the most profitable. However, the subsequent life-cycle greenhouse gas (GHG) emission and safety comparisons demonstrated that the blending of ULSD with biodiesel was superior.Item The Future of Biofuels: An Economic Analysis of the Design and Operation of a Microalgae Facility in Texas and the Southwestern United States(2011-10-21) Allison, Marc S.The world of energy is changing. With rising energy costs and concerns over the supply of energy materials, more research is being conducted into alternative sources of fuel and microalgae is one of the sources being researched, although much research had been conducted on it as a part of the Aquatic Species Program from the 1970s to the early 1990s. With the emergence of microalgae as a source of alternative energy, the need for an economic analysis of microalgae has arisen. This research studies the economic feasibility of the design and operation of a microalgae production facility in two Texas locations (Pecos and Corpus Christi) and in southeastern New Mexico using a stochastic simulation model. It examines the production levels needed for the facility to be profitable and also some facility designs necessary for that profitability. It also measures several annual financial indicators so that potential investors have some estimates of the future profitability of the microalgae industry. The results show that for microalgae to become a viable commercial operation, production must be improved beyond the current levels and the levels suggested by the literature. Production needs to be at least 0.8 g/L/day with 40 percent oil content and 24 inches of water depth. Production must be improved through increasing growth rates and oil contents at greater water depths. Production can be improved through nutrient and carbon dioxide usage, two elements that are being heavily researched. Water usage will become a major focus because of the limited resources and the quantities necessary to operate a commercial-scale facility. With the necessary improvements in technology and research, microalgae could prove to be a viable source of alternative energy.