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Catalytic conversion of biomass-derived oils to fuels and chemicalsAdjaye, John Deheer 25 March 2009 (has links)
Experimental and kinetic modeling studies were carried out on the conversion a wood-oil obtained from high pressure liquefaction of aspen poplar wood to liquid hydrocarbon fuels and useful chemicals in a fixed bed micro-reactor using HZSM-5 catalyst. Similar experiments were conducted using silicalite, H-mordenite, H-Y and amorphous silica-alumina catalysts. <p>
Preliminary vacuum distillation studies showed that the wood-oil was made up of volatile and non-volatile fractions. A maximum yield of 62 wt% volatiles at 200 °C, 172 Pa was obtained. The volatile fraction consisted of over 80 compounds. These compounds were comprised of acids, alcohols, aldehydes, ketones, esters, ethers, furans, phenols and some hydrocarbons. The characteristics of the oil showed that it was unstable with time, i.e., its physical properties and chemical composition changed with time probably due to the reaction of free radicals or the oxidative coupling of some of the wood-oil components. However, when the oil was mixed with tetralin, the stability improved. <p>
Upgrading studies were first conducted over inert berl saddles in the presence and absence of steam (i. e. non-catalytic treatment/blank runs). Yields of hydrocarbons were between 16 and 25 wt% of the wood-oil. High residue fractions of between 32 to 56 wt% were obtained after processing. Some portions of wood-oil formed a carbonaceous material (char or coke) when exposed to the experimental temperatures. The chars (coke) fraction increased with temperature from 4.7 to 12.5 wt% when processing with steam and 8.0 to 20.4 wt% when processing without steam. <p>
Catalytic upgrading studies were first carried out using HZSM-5 catalyst in the presence and absence of steam. The results showed that approximately 40 to 65 wt% of the oil could be converted to a hydrocarbon-rich product (i.e. desired organic liquid product (distillate). This contained about 45 to 70 wt% hydrocarbons with selectivities ranging between 0.47 to 0.88. This fraction was highly aromatic in nature and consisted mainly of benzene, toluene, xylene (BTX compounds) and other alkylated benzenes within the gasoline boiling point range. The yield and selectivities were strong functions of the process time and temperature. A comparison between the two processes, i.e. upgrading in the presence and absence of steam, showed that about 30 to 45 % reduction in coke formation and 5 to 18 wt% increase in organic distillate could be achieved when processing in the presence of steam. These changes were probably due to changes in the rates of cracking, deoxygenation, aromatization and polymerization reactions
resulting from the competitive adsorption processes between steam and wood-oil molecules in addition to changes in contact time of molecules. However, the selectivity for hyqrocarbons decreased in the presence of steam. <p>
Yields of organic distillate fractions of between 72 to 93 wt% and hydrocarbon yields and selectivities of 44 to 51 wt% and 0.93 to 1.13, respectively, were obtained when wood-oil volatile fraction was upgraded over HZSM-5 after separation from the non-volatile fraction by vacuum distillation. <p>
The spent HZSM-5 catalyst could be easily regenerated and reused with little change in its performance. <p>
The yields and selectivities for hydrocarbons when upgrading with the other catalysts were between 9 and 22 wt%, and 0.12 and 0.29, respectively for silicalite, 16 and 28 wt%, and 0.22 and 0.28, respectively for H-mordenite, 15.5 and 21 wt%, and 0.17 and 0.21, respectively for H-Y and S.5 and 26.2, and 0.13 and 0.36, resrectively for silica-alumina. Compared to HZSM-5 (yield between 34 and 43 wt%, selectivity of 0.66 to O.SS) these yields and selectivities were much lower. These experiments also showed that the pore size, acidity and shape selectivity of the catalyst influenced the distribution of hydrocarbons in terms of the carbon number. The yield and selectivity of H-mordenite and H-Y (large pore zeolites) were mostly for kerosene range hydrocarbons (C<sub><font size=2>9</font></sub> to C<sub><font size=2>15</font></sub>) and for silicalite and HZSM-5 (medium pore zeolites) for gasoline range hydrocarbons. The hydrocarbon fraction from amorphous silica-alumina did not show any defined distribution. The performance followed the order: HZSM-5> H-mordenite> H-Y> Silicalite, Silica-alumina.<p>
With the aid of model compound reactions involving acetic acid methyl ester, propanoic acid, 4-methylcyclohexanol, methylcyclopentanone, 2-methylcyclopentanone, methoxybenzene, ethoxybenzene, phenol, 2-methoxy-4-(2-propenyl) phenol, a synthetic and wood-oil volatile, two reaction pathways were proposed to explain the chemical steps through which the final products of upgrading were obtained. Also, reaction pathways were proposed for each chemical group. These experiments showed that the final products were formed probably through cracking, deoxygenation, olefin formation, oligomerization, hydrogen and hydride transfer, cyclization, isomerization, alkylation and polymerization reactions. <p>
Rate models were derived based upon the two reaction pathways and the power law rate model. The rates of formation of products followed the general order: Organic distillate>
Hydrocarbons> Residue> Coke> Gas >Aqueous Fraction. Estimates of the values of the kinetic parameters showed that the rate constants ranged between 10<sup><font size=2>-6</font></sup> (aqueous fraction) and 1.81 (volatile fraction), activation energies between 6.7-76.0 x 10<sup><font size=2> 3</font></sup> KJ/Kmol and reaction orders from 0.7 (gas formation) to
2.5 (residue formation). Two mathematical models were derived based on the integral reactor design equation and on the two reaction pathways. This was used to estimate the yield of products. The models predicted the experimental results fairly accurately. Model discrimination showed that the model based on coke and residue formation from both volatile and non-volatile fractions of the wood-oil best predicted the experimental results.<p>
Hydrocarbon selectivity relations which were based on coke, residue and combined coke and residue as undesired products were also derived. Application of these relations showed that lower temperatures and concentrations were most appropriate for higher hydrocarbon selectivity. However, this was at the expense of higher conversions.
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Extraction and characterization of lipids from microalgae grown on municipal wastewater a Master's Thesis /Hutton, Matthew William. Lundquist, Tryg J. January 1900 (has links)
Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on January 12, 2010. Major professor: Tryg Lundquist, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Civil and Environmental Engineering." "October, 2009." Includes bibliographical references (p. 92-100).
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Fast and slow active control of combustion instabilities in liquid-fueled combustorsLee, Jae-Yeon, January 2003 (has links) (PDF)
Thesis (Ph. D.)--School of Mechanical Engineering, Georgia Institute of Technology, 2004. Directed by Ben T. Zinn. / Vita. Includes bibliographical references (leaves 136-141).
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United States synthetic fuels corporation : its rise and demisePriddy, Hervey Amsler 06 November 2013 (has links)
The energy crisis during the presidency of Jimmy Carter stimulated several major pieces of legislation that together produced the Department of Energy (DOE), the National Energy Plan (NEP), the windfall profits tax, and the Energy Security Act of 1980 (ESA). This dissertation focuses on the Energy Security Act, which was signed into law on June 30, 1980, and created the congressionally chartered United States Synthetic Fuels Corporation (SFC), one of the initial efforts to provide the United States energy security. John Sawhill, nominated by Carter as the first SFC chair, was responsible for managing the corporation along with six other directors. The Senate confirmed none of these seven individuals. This inaction forced Carter to make recess appointments of Sawhill and four others to the SFC board. With the election of former California governor Ronald Reagan as president in November 1980, emphasis on the SFC and financial assistance for development of a domestic synthetic fuels industry diminished -- so much so that the corporation closed its doors in April 1986. The SFC funded four synthetic fuels projects. None survive today. During its life, Synfuels Corporation spent approximately $960 million. Congress authorized funding of $88 billion plus $35 million in annual administrative expenses (adjusted for inflation) for the SFC, with a maximum of three hundred full-time professional employees, over its legislated twelve-year existence. The mandated goal was the production of at least five hundred thousand barrels of crude oil equivalent per day of synthetic fuels from domestic sources by 1987 and at least two million per day by 1992. The SFC was legislatively chartered to be free of normal government rules, regulations, and procedures. Carter did not want the synthetic fuels effort to be housed within the Department of Energy. He knew that to meet the goals of the act, any entity must be able to move with speed and be permitted to pay above government-level salaries. Reagan, who did not like the SFC or its mandate, preferred the free market with little or no government interference. Congress simply could not leave the SFC alone, however. So instead of a seven-member board of directors, the SFC ended up with a board of 542 -- counting members of Congress. This dissertation provides an in-depth look at the SFC, Carter's solution to the energy crisis as presented in his July 15, 1979 address to the nation on energy and national goals, commonly referred to as "The Malaise Speech." This talk from the Oval Office, was unique, and remains today the most unusual presidential address in the nation's history. Historians have written and analyzed the first half, a sermon emphasizing all that was wrong with America, but few writers have done the same for second half of the speech, which is the subject of this paper. In the latter part of his speech, Carter emphasized his solution to the country's malaise: solving America's energy shortage, to be accomplished by what he termed an "energy security corporation." Only two authors have examined the SFC. Sabrina Willis penned a 1987 essay titled "The Synthetic Fuels Corporation as an Organizational Failure in Policy Mobilization," which appeared in The Unfilled Promise of Synthetic Fuels, edited by Ernest J. Yanarella and William Green. She argued that SFC problems were "so many and so serious that it is difficult to determine exactly why the corporation failed to come [even] close to achieving the goals set for it by Congress . . . ." Willis was particularly critical of Ed Noble, appointed as chair of the board of directors by Reagan, when she wrote, "his [Noble] managerial style was too weak to effectively guide a controversial organization." Willis did not have access to the SFC papers, staff or members of the board of directors. Furthermore, she did not research or make use of the plethora of published congressional hearings. Although her examination was superficial, it was definitely pointed. In 2011, Ralph L. Bayrer, former SFC vice president of projects, published his account, The Saga of the U.S. Synthetic Fuels Corporation: A Cautionary Tale. Bayrer, an engineer by education and profession, addressed primarily the engineering aspects of the SFC projects. He presented a favorable assessment of Noble and his leadership. Noble, in Bayrer's opinion, "had a clear view of what he [Noble] wanted to achieve at the SFC," and several "accomplishments" while chair of the Synthetic Fuels Corporation. Bayrer dedicated his book to Noble, noting the SFC "came to a premature end," and had David Stockman, Reagan's director of the Office of Management and Budget not intervened, Noble would have been almost successful in his strategic vision. Bayrer, however, did not interview former employees, former board members, or congressional leaders and their staffs. He relied instead on congressional hearings and his own papers. Because Bayrer worked for the SFC from its beginning to the end, the viewpoints in his publication are thus clouded by personal involvement. He did provide invaluable assistance to the author though, answering questions about the projects and providing needed documents, for which the author is most grateful. Yet, after considerable research and numerous interviews, the author does not agree with Bayrer's assessment of the SFC. The United States Synthetic Fuels Corporation was a superb idea. Its objective was a bold step by a president to address America's addiction to imported crude oil, which had made the nation vulnerable to the vagaries of an unstable region of the world. Unfortunately, a vacuum of presidential leadership, congressional meddling, and embarrassingly poor management cursed the SFC from its very creation. Almost a full year -- 351 days -- passed from the date Carter offered the concept of the SFC to the nation until its enactment into law. Moreover, Carter's distraction with a possible primary opponent, Sen. Edward Kennedy (D-MA), whom he disliked intensely, hampered the president's ability to remain focused on the issue, as well as his view of the presidency as a trusteeship, above politics. After the election of Ronald Reagan to the presidency, all interest in supporting synthetic fuels evaporated. The SFC became merely a place to repay political donors and friends -- and minor ones at that. By thoroughly examining the rise and demise of the United States Synthetic Fuels Corporation, historians will be able to see prima facie evidence of the importance of commitment, persistence, and leadership -- both presidentially and managerially -- and how it is possible for a government entity to vanish into the dust bin of history. And, we will be able to answer the questions: what was the SFC, what did it accomplish, what happened to it, and why? / text
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Fleet fueling system economics: LPG versus gasoline and dieselMcDonald, Thomas Benton, 1935- January 1967 (has links)
No description available.
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Real-time quantitative PCR analysis of diesel-degrading genes of acinetobacter calcoaceticus isolates.Toolsi, Raksha. January 2009 (has links)
The diesel-degrading capabilities of Acinetobacter calcoaceticus isolates LT1, LT1A and V2 were established in previous studies. LT1 and LT1A were isolated from diesel-contaminated soil and V2 was from soil contaminated with used engine oil. Isolates were grown in Bushnell-Haas medium supplemented with 1% sterile diesel. Determination of diesel-degradation patterns by gravimetric analysis and harvesting of cells for RNA extraction were performed at regular time intervals over a 60 day period. The involvement of genes alkM, alkR, rubA, rubB, estB, lipA, lipB, and xcpR in hydrocarbon degradation has been reported in previous studies. LT1, LT1A, and V2 were compared in terms of gene expression levels by real-time quantitative PCR. Expression levels were assessed by relative quantification and normalized against the 16S rRNA reference gene using the Relative Expression Software Tool - XL (REST-XL). Amplification of all genes, except rubB, was achieved with a high degree of efficiency. The expression of rubA, alkM, alkR, xcpR, and lipB based on pair-wise randomization, was all down-regulated in LT1A in relation to LT1. Highest expression levels of the aforementioned genes were documented during the initial stages of incubation for LT1 while LT1A showed highest expression levels midway through the study period. LT1, LT1A, and V2 achieved 58.6%, 51.7%, and 48.3% diesel degradation after 5 days of incubation, respectively. The higher percentage of diesel degradation achieved by LT1 can be attributed to higher levels of overall gene expression in the initial stages of degradation. Amplification of alkane hydroxylase alkM of V2 revealed a possible second hydroxylase gene that was expressed after 20 days of incubation. Amplification of alkR and xcpR in V2 isolates also resulted in multiple product formation. Very low lipB and lipA expression was detected in LT1 and LT1A and the absence of lipA expression in V2 suggests that lipases were not involved in diesel degradation. In contrast, estB was predominantly expressed in V2, and suspected to be involved in the release of a bioemulsifier that was only observed in V2 samples. Although all three isolates were comparably efficient in degrading diesel, the results of this study suggest that different mechanisms may be employed in the degradation process. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009.
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Protein expressions of Acinetobacter sp. isolates LT1A and V2 during hydrocarbon degradation.Pretorius, Karyn. January 2012 (has links)
Bacteria of the genus Acinetobacter are known to be involved in the degradation, leaching and removal of various hazardous compounds from the environment. Several studies of Acinetobacter spp. have reported on the genes involved in alkane degradation; but less is known about the proteins that are expressed at certain points within the degradation period. Acinetobacter sp. LT1A and Acinetobacter sp. V2 were isolated from diesel- and used engine oil-contaminated soils respectively. In a previous investigation (Toolsi, 2008), these isolates have been shown to demonstrate different gene expression patterns during diesel degradation using real time PCR. The real time PCR data showed that isolate V2 made use of multiple alkane hydroxylases whereas LT1A made use of only one, and the expression of the alkane hydroxylase regulator alkR and secretory protein xcpR also revealed multiple product formations in isolate V2 as compared to LT1A. Thus the objectives for the current investigation were to monitor the hydrocarbon degradation ability of Acinetobacter sp. isolates V2 and LT1A using medium chain (C14) and long chain (C28) hydrocarbon substrates and to compare the hydrocarbon degradation abilities and protein expression patterns of both isolates. To achieve this, the isolates were grown for 20 days in Bushnell Haas liquid medium supplemented with tetradecane (C14) or octocosane (C28) as a sole carbon source. Gravimetric analysis was used to monitor degradation and whole cell protein was extracted from the culture medium throughout the 20-day study period. The protein expression patterns were visualized using 1D and 2D PAGE. The 2D PAGE images were analyzed using the PDQuest Advanced 2D image analysis software (BIORAD). By day 20, approximately 90% of C14 was degraded by both isolates, whereas only 36% of C28 had been broken down. In both the C14 and C28 degradation assays, the isolates achieved significant amounts of hydrocarbon degradation as compared to the abiotic controls. One-dimensional and 2D SDS-PAGE gels indicated that there are observable differences in protein expression patterns between the isolates during C14 and C28 degradation. Both isolates achieved similar rates of hydrocarbon usage, but appear to do so using different, unidentified, protein systems. Analysis of the 2D-SDS PAGE gel images revealed that more proteins were required for the utilization of the long chain alkane (C28) as compared to the medium chain alkane (C14) for both isolates. Potential spots of interest were identified from the 2D SDS-PAGE images and sequenced. The identities of these proteins were found to be: a conserved hypothetical protein, TonB-dependent receptor protein, Peptidyl-prolyl-cis-trans isomerase and a Protein containing DUF1559. No alkane hydroxylase components were detected in this study. This investigation demonstrated the need for more studies at the proteomic level. Future investigations should focus on the insoluble subproteome of the isolates and make use of larger sample sizes (replicates) to reduce variation in spot detection and quantification. Genomic sequencing of the isolates will also shed light on the genetics and biochemistry of alkane metabolism in these Acinetobacter sp. isolates. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
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Fuel pin optimization for a metal fueled light water reactorMarsh, Robert 12 1900 (has links)
No description available.
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Theory of cladding breach location and size determination using delayed neutron signals /Reece, Warren Daniel 08 1900 (has links)
No description available.
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Denatured breeder with extended burnup fuel cycleBencheikh, Allaoua 08 1900 (has links)
No description available.
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