149 Matching Results

Search Results

Advanced search parameters have been applied.


Description: Progress is reported on the gross solubility of U in digestions of Mallinokrodt feed materials, studies of variables affecting U purity in a TBP hexane extraction cycle, low-acid flowsheet for TBP--hexane extraction process based on a 440 g U/liter in lM HNO/sub 3/ digest liquor, hacking studies in the pilot plant pumperdecanter system, recovery of U from residues from the dingot process, lowering the H level in dingot metal, forging of dingot bar stock, dingot extrusion, fubrication of UO/sub 2/ fuel elements, and the determination of H content of derby and ingot metal. (W.L.H.)
Date: May 1, 1957
Creator: Kuhlman, N. ed.
Partner: UNT Libraries Government Documents Department

Separation of Fischer-Tropsch wax from catalyst by supercritical extraction. Quarterly progress report, October 1, 1996--December 31, 1996

Description: One of the major objectives of this research project is to predict the phase behavior of model wax compounds in dense supercritical fluids such as hexane. Because initial results with the SAFT equation have been less promising than expected, the group at North Carolina State University has focused their recent attention on cubic equations of state, in particular the Peng-Robinson and Soave-Redlich-Kwong versions. The focus of this work has been on developing correlations that can be used to predict binary interaction parameters (i.e., k{sub ij}s) for a given binary wax-solvent system. As a first step, k{sub ij}s were first calculated from experimental data on systems containing alkanes between nC{sub 4} and nC{sub 23} at temperatures between 25 and 357{degrees} C. Attempts were then made to correlate these parameters with specific pure component properties of the alkanes of interest. Reasonably good agreement between experimental and predicted k{sub ij}s was found using a correlation that incorporates both temperature and the molecular size of the alkanes. As phase equilibrium data becomes available for higher molecular weight model wax compounds, the ability of the correlation to handle such systems will need to be tested. The phase equilibrium apparatus is currently undergoing modifications that will allow the system to run components that are solids at ambient temperatures. Some problems are still being resolved, as the heavy component tends to precipitate in the sample lines. Modifications have been made that should allow the system to operate reliably.
Date: January 1, 1997
Creator: Joyce, P.C. & Thies, M.C.
Partner: UNT Libraries Government Documents Department

In situ measurement of volatile organic compounds in groundwater by methods coupled to the cone penetrometer

Description: The objective of this investigation is to interface an in situ, on-line sparging system with a cone penetrometer to provide direct analysis of volatile organic compounds (VOCS) in groundwater by on-site analysis. Transfer line materials (15 m {times} 0.160--0.216 cm ID) composed of stainless steel, nickel, aluminum and Teflon{reg_sign}PFA, PTFE, and FEP were evaluated for their ability to quantitatively transfer chloroform, 1,1,1-trichloroethane, carbon tetrachloride, tetrachloroethylene, n-hexane, benzene, toluene, and o-xylene in the gas phase. The water content of the gas stream had an insignificant effect on the quantitative transfer of VOCs through Teflon{reg_sign} tubing but was critical to quantitative transfer of the compounds through metal tubing, particularly for nickel. Transfer efficiencies for all 7 analytes in moist gas streams through stainless steel tubing were greater than 95%. Toluene, tetrachloroethylene, and o-xylene were transferred with 93, 81 and 80% efficiency, respectively when drawn through Teflon{reg_sign}PFA tubing at 25 C. The sorption of these VOCs by Teflon{reg_sign} tubing was reversible and their transfer efficiencies improved to 94% when the tubing was flushed with 16 equivalent volumes of air. In general, the retention of the VOCs by Teflon{reg_sign} increased with decreasing aqueous solubility of the analyte. The efficiency at which VOCs were sparged from aqueous standards in Teflon{reg_sign}PFA, Type 304 stainless steel, and glass vessels were similar.
Date: March 1, 1995
Creator: Doskey, P.V.; Aldstadt, J.H.; Kuo, J.M.; Costanza, M.S. & Erickson, M.D.
Partner: UNT Libraries Government Documents Department

Fischer-tropsch synthesis in supercritical fluids. Quarterly technical progress report, October 1, 1994--December 21, 1994

Description: Progress reports are presented for the following two tasks: (1) diffusion coefficients of F-T products in supercritical fluids; and (2) Fischer-Tropsch reaction related studies. The objectives for this quarter for task 1 were to measure molecular diffusion coefficients and effective diffusivities at the same conditions. The objectives for task 2 were to conduct two additional tests with the Ruhrchemie catalyst and a catalyst synthesized in our laboratory under supercritical conditions.
Date: January 31, 1995
Creator: Akgerman, A. & Bukur, D.B.
Partner: UNT Libraries Government Documents Department

Fischer-Tropsch synthesis in supercritical fluids. Final report

Description: The objective of this study was to investigate Fischer-Tropsch Synthesis (FTS) in the supercritical phase employing a commercial precipitated iron catalysts. As the supercritical fluid the authors used propane and n-hexane. The catalyst had a nominal composition of 100 Fe/5 Cu/4.2 K/25 SiO{sub 2} on mass basis and was used in a fixed bed reactor under both normal (conventional) and supercritical conditions. Experimental data were obtained at different temperatures (235 C, 250 C, and 260 C) and synthesis gas feed compositions (H{sub 2}/CO molar feed ratio of 0.67, 1.0 and 2.0) in both modes of operation under steady state conditions. The authors compared the performance of the precipitated iron catalyst in the supercritical phase, with the data obtained in gas phase (fixed bed reactor) and slurry phase (STS reactor). Comparisons were made in terms of bulk catalyst activity and various aspects of product selectivity (e.g. lumped hydrocarbon distribution and olefin content as a function of carbon number). In order to gain better understanding of the role of intraparticle mass transfer during FTS under conventional or supercritical conditions, the authors have measured diffusivities of representative hydrocarbon products in supercritical fluids, as well as their effective diffusion rates into the pores of catalyst at the reaction conditions. They constructed a Taylor dispersion apparatus to measure diffusion coefficients of hydrocarbon products of FTS in sub and supercritical ethane, propane, and hexane. In addition, they developed a tracer response technique to measure the effective diffusivities in the catalyst pores at the same conditions. Based on these results they have developed an equation for prediction of diffusion in supercritical fluids, which is based on the rough hard sphere theory.
Date: December 31, 1998
Creator: Akgerman, A. & Bukur, D.B.
Partner: UNT Libraries Government Documents Department

Catalytic steam gasification of carbon

Description: Unsupported carbide powders with high specific surface area, namely {alpha}-WC (35 m{sup 2}/g, hexagonal), {beta}-WC{sub 0.61} (100 m{sup 2}/g, cubic face centered) and {beta}-WC{sub 0.5} (15 m{sup 2}/g, hexagonal) have been prepared. The key element in this preparation is the successful removal of surface polymeric carbon by careful gasification to methane by means of dihydrogen. These tungsten carbide powders have been used in catalytic reactions of oxidation of H{sub 2} and hydrogenolysis of alkanes, such as butane, hexane, and neopentane.
Date: December 31, 1990
Creator: Boudart, M.
Partner: UNT Libraries Government Documents Department

Separation of Fischer-Tropsch wax from catalyst using supercritical fluid extraction. Quarterly technical progress report, 1 October 1995--31 December 1995

Description: The objective of this research project is to evaluate the potential of supercritical fluid (SCF) extraction for separating the catalyst slurry of a Fischer-Tropsch slurry bubble column (SBC) reactor into two fractions: (1) a catalyst-free wax containing less than 10 ppm particulate matter and (2) a concentrated catalyst slurry that is ready for recycle or regeneration. The wax will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300{degrees}C. Initial work is being performed using n-hexane as the solvent. During the reporting period, work on the small-scale, continuous-flow apparatus continued. Initial experiments have been performed on a binary mixture of n-hexane (solvent) and squalane (model compound) at 200{degrees}C. A total of fifteen samples were collected at 135, 160, and 208 psig, with pressures being controlled to within {plus_minus}2 psi. Results indicate that the equilibrium phase compositions can in principle be measured to a reproducibility of {plus_minus}0.5% in the squalane-rich bottomphase and {plus_minus}2% in the hexane-rich top phase, with respect to the minor component. However, other data measured at these same conditions at another time exhibited scatter that was as much as 5 times greater. We believe that improvements in (1) the method of preheating the feed to the view cell/phase separator and to (2) the sample collection technique are required before data of high accuracy can consistently be generated. The apparatus modifications required to effect these improvements are currently underway and should be completed by the middle of February.
Date: June 1, 1996
Creator: Thies, M.C. & Joyce, P.C.
Partner: UNT Libraries Government Documents Department

A comparison of the costs of treating wastes from a radio analytical laboratory

Description: The Radiological and Environmental Sciences Laboratory (RESL) is a government-owned, government-operated facility at the Idaho National Engineering Laboratory (INEL). RESL`s traditional strengths are in precise radionuclide analysis and dosimetry measurements. RESL generates small quantities of various types of waste. This study identified potential waste management options for a solvent extraction process waste stream and the cost differences resulting from either process changes, improved technology usage, or material substitutions or changes at RESL. Where possible, this report identifies changes that have resulted or may result in waste reduction and cost savings. DOE P2 directs the lab to review processes, evaluate waste practices, and estimate potential reductions in waste volumes and waste management costs. This study focused on selected processes, but the processes are illustrative of potential waste volume reductions and cost minimizations that may be achieved elsewhere at the INEL and throughout the DOE complex. In analyzing a waste disposal process, the authors allocated component costs to functional categories. These categories included the following: (1) operational costs, included waste generation and collection into a storage area; (2) administrative costs, including worker training, routine inspections, and reporting; and (3) disposal costs, including preparing the waste for shipment and disposing of it.
Date: April 1, 1996
Creator: Moore, R. & Pole, S.B.
Partner: UNT Libraries Government Documents Department

Refining of fossil resin flotation concentrate from western coal. Final report

Description: During the past several years, significant research efforts have been made to develop process technology for the selective flotation of fossil resin from western coals. As a result of these efforts, several new flotation technologies have been developed. Operation of a proof-of-concept continuous flotation circuit showed the selective flotation process to be sufficiently profitable to justify the development of a fossil resin industry. However, little attention has been given to the refining of the fossil resin flotation concentrate although solvent refining is a critical step for the fossil resin to become a marketable product. In view of this situation, DOE funded this two-year project to evaluate the following aspects of the fossil resin refining technology: 1) Characterization of the fossil resin flotation concentrate and its refined products; 2) Kinetics of fossil resin extraction; 3) Effects of operating variables on solvent extraction; 4) Extraction solvents; 5) Proof-of-concept continuous refining tests; and 6) Technical and economic analysis. The results from this research effort have led to the following conclusions: Hexane- or heptane-refined fossil resin has a light-yellow color, a melting point of 140 - 142{degrees}C, a density of 1.034 gram/cm, and good solubility in nonpolar solvents. Among the four solvents evaluated (hexane, heptane, toluene and ethyl acetate), hexane is the most appropriate solvent based on overall technical and economic considerations. Batch extraction tests and kinetic studies suggest that the main interaction between the resin and the solvent is expected to be the forces associated with solvation phenomena. Temperature has the most significant effect on extraction rate. With hexane as the solvent, a recovery of 90% cam be achieved at 50{degrees}C and 10% solids concentration with moderate agitation for 1 hour.
Date: February 16, 1995
Creator: Jensen, G.F. & Miller, J.D.
Partner: UNT Libraries Government Documents Department


Description: The objective of this research project is to evaluate the potential of supercritical fluid (SCF) extraction for the recovery and fractionation of the wax product from the slurry bubble column (SBC) reactor of the Fischer-Tropsch (F-T) process. The wax, comprised mostly of branched and linear alkanes with a broad molecular weight distribution up to C{sub 100}, will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Initial work is being performed using n-hexane as the solvent. The success of the project depends on two factors. First, the supercritical solvent must be able to dissolve the F-T wax; furthermore, this must be accomplished at conditions that do not entrain the solid catalyst. Second, the extraction must be controlled so as not to favor the removal of the low molecular weight wax compounds. That is, a constant carbon-number distribution in the wax slurry must be maintained at steady-state column operation. Three major tasks are being undertaken to evaluate our proposed SCF extraction process. Task 1: Equilibrium solubility measurements for model F-T wax components in supercritical fluids at conditions representative of those in a SBC reactor. Task 2: Thermodynamic modeling of the measured VLE data for extending our results to real wax systems. Task 3: Process design studies of our proposed process. Additional details of the task structure are given.
Date: July 31, 1998
Partner: UNT Libraries Government Documents Department

Vapor space characterization of waste tank 241-TY-103: Results from samples collected on 4/11/95

Description: This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-TY-103 (referred to as Tank TY-103). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water (H{sub 2}O). Sampling for hydrogen cyanide (HCN) and sulfur oxides (SO{sub x}) was not requested. In addition, quantitative results were obtained for the 39 TO-14 compounds plus an additional 14 analytes. Of these, 16 were observed above the 5-ppbv reporting cutoff. Sixteen tentatively identified compounds (TICs) were observed above the reporting cutoff of (ca.) 10 ppbv and are reported with concentrations that are semiquantitative estimates based on internal-standard response factors. The 10 organic analytes with the highest estimated concentrations are listed in Table 1 and account for approximately 95% of the total organic components in Tank TY-103. Two permanent gases, carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O), were also detected.
Date: October 1, 1995
Creator: Ligotke, M.W.; Clauss, T.W. & Pool, K.H.
Partner: UNT Libraries Government Documents Department

Autoignition chemistry of the hexane isomers: An experimental and kinetic modeling study

Description: Autoignition of the five distinct isomers of hexane is studied experimentally under motored engine conditions and computationally using a detailed chemical kinetic reaction mechanism. Computed and experimental results are compared and used to help understand the chemical factors leading to engine knock in spark-ignited engines and the molecular structure factors contributing to octane rating for hydrocarbon fuels. The kinetic model reproduces observed variations in critical compression ratio with fuel structure, and it also provides intermediate and final product species concentrations in very dose agreement with observed results. In addition, the computed results provide insights into the kinetic origins of fuel octane sensitive.
Date: June 1, 1995
Creator: Curran, H.J.; Gaffuri, P.; Pitz, W.J.; Westbrook, C.K. & Leppard, W.R.
Partner: UNT Libraries Government Documents Department


Description: The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Various chemicals that inhibit the growth and/or the metabolism of corrosion-associated microbes such as sulfate reducing bacteria, denitrifying bacteria, and methanogenic bacteria were evaluated to determine their ability to inhibit corrosion in experiments utilizing pure and mixed bacterial cultures, and planktonic cultures as well as mature biofilms. Planktonic cultures are easier to inhibit than mature biofilms but several compounds were shown to be effective in decreasing the amount of metal corrosion. Of the compounds tested hexane extracts of Capsicum pepper plants and molybdate were the most effective inhibitors of sulfate reducing bacteria, bismuth nitrate was the most effective inhibitor of nitrate reducing bacteria, and 4-((pyridine-2-yl)methylamino)benzoic acid (PMBA) was the most effective inhibitor of methanogenic bacteria. All of these compounds were demonstrated to minimize corrosion due to MIC, at least in some circumstances. The results obtained in this project are consistent with the hypothesis that any compound that disrupts the metabolism of any of the major microbial groups present in corrosion-associated biofilms shows promise in limiting the amount/rate of corrosion. This approach of controlling MIC by controlling the metabolism of biofilms is more environmentally benign than the current approach involving the use of potent biocides, and warrants further investigation.
Date: December 1, 2004
Creator: Bogan, Bill W.; Lamb, Brigid M.; Husmillo, Gemma; Lowe, Kristine; Paterek, J. Robert & II, John J. Kilbane
Partner: UNT Libraries Government Documents Department

Refining of fossil resin flotation concentrate from Western coal. Ninth quarterly report, January 1--March 31, 1995

Description: Heptane showed a consistently higher extraction than hexane even through heptane contains only one more methylene group in its molecular structure. However economic factors must also be considered in the overall evaluation of the process. In this regard a simple economic evaluation was carried out taking into consideration the operating costs for the resin concentrate refining process. First of all, the price of industrial grade heptane is about the same as hexane. Because the process operates in a recycle mode, the initial cost would be about the same for both solvents. But in order to obtain the final resin product, the extracted resin has to be recovered from solution using evaporation techniques, which consume energy. Due to the significant difference in boiling points between the two solvents, approximately 25--35% more energy will be required for resin recovery by evaporation if heptane is used as the solvent for extraction. This represents a very significant increase of the operating cost. Secondly, based on bench scale tests the same yield can be achieved with hexane if the average residence time is increased. Such an increase in retention time only increases the capital cost by a small amount. It appears then from an economic perspective that hexane is the most appropriate solvent.
Date: March 31, 1995
Creator: Jensen, G.F. & Miller, J.D.
Partner: UNT Libraries Government Documents Department

Recovery of semi-volatile organic compounds during sample preparation: Compilation for characterization of airborne particulate matter

Description: Semi-volatile compounds present special analytical challenges not met by conventional methods for analysis of ambient particulate matter (PM). Accurate quantification of PM-associated organic compounds requires validation of the laboratory procedures for recovery over a wide volatility and polarity range. To meet these challenges, solutions of n-alkanes (nC{sub 12} to nC{sub 40}) and polycyclic aromatic hydrocarbons PAHs (naphthalene to benzo[ghi]perylene) were reduced in volume from a solvent mixture (equal volumes of hexane, dichloromethane and methanol), to examine recovery after reduction in volume. When the extract solution volume reached 0.5 mL the solvent was entirely methanol, and the recovery averaged 60% for n-alkanes nC{sub 12} to nC{sub 25} and PAHs from naphthalene to chrysene. Recovery of higher MW compounds decreased with MW, because of their insolubility in methanol. When the walls of the flasks were washed with 1 mL of equal parts hexane and dichloromethane (to reconstruct the original solvent composition), the recovery of nC{sub 18} and higher MW compounds increased dramatically, up to 100% for nC{sub 22}-nC{sub 32} and then slowly decreasing with MW due to insolubility. To examine recovery during extraction of the components of the High Capacity Integrated Gas and Particle Sampler, the same standards were used to spike its denuders and filters. For XAD-4 coated denuders and filters, normalized recovery was > 95% after two extractions. Recovery from spiked quartz filters matched the recovery from the coated surfaces for alkanes nC{sub 18} and larger, and for fluoranthene and larger PAHs. Lower MW compounds evaporated from the quartz filter with the spiking solvent. This careful approach allowed quantification of organics by correcting for volatility- and solubility-related sample preparation losses. This method is illustrated for an ambient sample collected with this sampler during the Texas Air Quality Study 2000.
Date: May 1, 2002
Creator: Swartz, Erick; Stockburger, Leonard & Gundel, Lara
Partner: UNT Libraries Government Documents Department


Description: This first quarter report of 2001 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf (service mark of Gas Research Institute) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. During this reporting period tests were done to determine the effect of hydrocarbons such as n-hexane on catalyst performance with and without H{sub 2}S present. The experiments showed that hexane oxidation is suppressed when H{sub 2}S is present. Hexane represents the most reactive of the C1 to C6 series of alkanes. Since hexane exhibits low reactivity under H{sub 2}S oxidation conditions, ...
Date: August 1, 2001
Creator: Srinivas, Girish; Gebhard, Steven C. & DeBerry, David W.
Partner: UNT Libraries Government Documents Department


Description: The efficiency of a 0.5 in. dia packed column with 1/16 in. nickel helices for the separation of the binary system UF/sub 6/-- BrF/sub 5/ was investigated. Several distlllations were performed wlth the system methylcyclohexane and nheptane for purposes of callbration. For both systems, pressure-drop measurements at various flow rates were determined and the flooding rates were determined from these. Experiments to determlne the equilibrium time were also conducted with both the organic and inorganic systems used for calibration. The separation efficiency was calculated as Htu/sub g/. The flooding rates determined were 570 for methylcyclohexane, 2680 for uranlum hexafluoride, and 2200 lb/(hr) (ft//sup 2/) for bromine pentafluoride. Equilibrium times of 34 and 24 hr were found for the organic and inorganic systems, respectively. The Htu/sub g/ was found to be 1.2 in. for flows of 50 to 450 lb/(hr)(ft//sup 2/) for the organic system. The Htu/sub g/ for the inorganic system was 1.3 in. at flow rates above 285 lb/(hr)(ft/sup 2/) and was found to increase to almost 3 in. at flow rates below this. (P.C.H.)
Date: May 1, 1962
Creator: Ivins, R.O.
Partner: UNT Libraries Government Documents Department

Process and analytical studies of enhanced low severity co-processing using selective coal pretreatment. Quarterly technical progress report, June--August 1991

Description: This report describes progress on research during the 12th and final quarter of this contract dealing with applications of coal pretreatment techniques in coal/oil co-processing and direct hydroliquefaction. The overall objectives of the project are to investigate various coal pretreatment techniques and to determine the effect of these pretreatment procedures on the reactivity of the coal. Reactivity enhancement will be evaluated under both direct hydroliquefaction and co-processing conditions. Coal conversion utilizing low rank coals and low severity conditions (reaction temperatures generally less than 350{degree}C) is the primary focus of the liquefaction experiments, as it is expected that the effect of pretreatment conditions and the attendant reactivity enhancement will be greatest for these coals and at these conditions.
Date: December 31, 1991
Creator: Baldwin, R. M.; Gaur, S. & Miller, R. L.
Partner: UNT Libraries Government Documents Department

NMR studies of molecules in liquid crystals and graphite

Description: NMR experiments to measure proton dipole couplings were performed on a series of n-alkanes (n-hexane through n-decane) dissolved in nematic liquid crystals. Computer modeling of the experimental NMR-spectra was done using several different models for intermolecular interactions in these systems. The model of Photinos et al. was found to be best in describing the intermolecular interactions in these systems and can provide a statistical picture of the conformation and orientation of the alkane molecules in their partially-oriented environment. Order parameters and conformational distributions for the alkanes can be calculated from the modeling. The alkanes are found to have conformational distributions very much like those found in liquid alkanes. Proton NMR spectra of tetrahydrofuran (THF) intercalated in two graphite intercalation compounds were also measured. Computer simulations of these spectra provide a picture of THF in the constrained environment between the graphene layers where the THF is oriented at a particular angle, can translate and rotate freely, but does not appear to pseudorotate.
Date: June 1, 1992
Creator: Rosen, M. E.
Partner: UNT Libraries Government Documents Department

The role of the resid solvent in coprocessing with finely divided catalysts. Quarterly report, October--December 1993

Description: The reactions with anthracene as a hydrogen acceptor were performed to determine how much hydrogen could be transferred by the hexane soluble resid fraction and hydrogen atmosphere to anthracene. The product distributions obtained by anthracene are given in Table 4. The products obtained from anthracene (ANT) were dihydroanthracene (DHA) and hexahydroanthracene (HHA). When FHC-365 was the resid used in the reaction, very similar amounts of ANT, DHA, and HHA were present after the reaction in both the catalytic and noncatalytic reaction. The predominant product was DHA at 51 to 53 mol%. Slightly more than one-fourth of the ANT remained unreacted. The production of HHA was between 20 and 22%. The amount of H{sub 2} accepted by ANT was the same for both catalytic and noncatalytic reactions. For the reactions with Maya, ANT reacted differently under noncatalytic and catalytic conditions. The reaction products produced were DHA and HHA, with DHA being the predominant product. In the catalytic reaction, substantially more DHA was produced under catalytic conditions and substantially less ANT remained than in the noncatalytic reaction. Under both reaction conditions nearly the same amount of HHA was produced. Under catalytic conditions, nearly twice as much hydrogen was accepted by ANT than under noncatalytic conditions. The product distribution from ANT obtained for the noncatalytic reaction with Maya was similar to dig obtained from ANT when ANT was reacted with FHC-365. The catalyst only seemed to have an effect with Maya resid. The catalyst also had a strong effect on the GC fraction obtained from the reaction using hexane solubles of Maya with ANT. The average boiling point showed a substantial shift toward low boiling constituents.
Date: December 31, 1993
Creator: Curtis, C. W.
Partner: UNT Libraries Government Documents Department

Fischer-Tropsch synthesis in supercritical reaction media. Progress report, October 1, 1992--December 31, 1992

Description: Our goals for this quarter were to complete construction of the reactor and analytical units for carrying out Fischer-Tropsch (F-T) synthesis in liquid (n-hexadecane) and in supercritical n-hexane phases. Progress during this quarter was slower than expected.
Date: January 1, 1993
Creator: Subramaniam, B.; Bochniak, D. & Snavely, K.
Partner: UNT Libraries Government Documents Department

Investigation of coal structure. Quarterly report, October 1, 1992--December 31, 1992

Description: The method was applied to standard polymers under the same condition above. The particle size distribution with volume diameters of polyvinylpyrrolidone (average molecular mass; 10,000) was measured at sample/solvent = 0.50 g/100 ml. This polymer readily dissolve in methanol and water, while the polymer does not dissolve in n-hexane and toluene, and toluene is a slightly better solvent than n-hexane. Figure 3 shows the particle size distributions in n-hexane (a) and toluene (b-1 and -2). The distribution in toluene changed time to time, and two representative distributions are shown. The mean volume diameters-were 14 {mu}m in n-hexane and 18 and 31 {mu}m in toluene. The particle size distribution of cross-linked polyvinylpyrrolidone was further examined in methanol and n-hexane. Figure 4 compares these distributions with scanned counts at sample/solvent = 0.50 g/100 ml. As a significant portion of particles was over 250 {mu}m with volume diameters, the distributions are presented with scanned counts. Figure 4 compared the specific swelling ratio (Q`) versus sample/solvent (w/w %) in the same solvents for this sample. It is seen that methanol is a good solvent than n-hexane and swells the sample. It is also seen that the swelling is dependent on the sample concentration. Therefore, the particle size in good solvent methanol is expected to be larger due to swelling. However, the particle size was smaller in methanol than in n-hexane (Figure 4). The dependence of sample concentration on solvent swelling in methanol (Figure 5) is interpreted as follows: Polymer particles disaggregated at low sample concentration and the interparticle voidage of the swollen polymer after centrifugation changed depending upon disaggregation.
Date: January 1, 1993
Partner: UNT Libraries Government Documents Department

Fischer-Tropsch synthesis in supercritical reaction media. Progress report, July 10, 1992--September 30, 1992

Description: The goal of this research is to thoroughly investigate the feasibility of using supercritical fluid (SCF) solvent medium for carrying out Fischer-Tropsch (FT) synthesis. Research will address the systematic experimental investigations of FT synthesis over supported Fe and Co catalysts in a CSTR and in a fixed-bed reactor at typical synthesis temperatures (240-260{degrees}C). The SCF medium to be employed is n-Hexane (P{sub c} = 29.7 bar; {Tc} = 233.7{degrees}C), while n-Hexadecane will be employed as the liquid reaction medium. Overall conversion, product distribution and catalyst deactivation will be measured in each case for various feed H{sub 2}/CO ratios ranging from 0.5 to 2. Product analyses will be carried out using GC/TCD, GC/FID and GC/MS systems. The fresh and used catalysts will be characterized with respect to active metal dispersion, surface area and pore size distribution.
Date: October 1, 1992
Creator: Subramaniam, B.
Partner: UNT Libraries Government Documents Department