31 Matching Results

Search Results

Advanced search parameters have been applied.

Catalytic conversion of oxygenated compounds to low molecular weight olefins. Progress report, January 1--July 15, 1978

Description: The conversion of methanol or synthesis gas is an attractive route for producing ethylene and propylene from coal. Utilizing a chabazite ion exchanged with ammonium and rare earth chlorides, methanol is converted to ethylene and propylene with carbon yields of 70 to 90% at reaction temperatures of 375 to 425/sup 0/C and pressures to 100 psi. Carbon disulfide in the feed at concentrations less than 200 ppM increases the operating time between regenerations from four hours to twenty hours. At carbon disulfide concentrations of 300 ppM or greater, the catalyst goes through the stages of dehydrogenation catalysts, a producer of ethylene and propylene, and then a dehydration catalyst. Water has no detrimental effect on the catalyst, and appears to enhance its activity. When synthesis gas (a one-to-one mixture of hydrogen and carbon monoxide) is passed over the catalyst at 365/sup 0/C and atmospheric pressure, methane, carbon and carbon dioxide are produced.
Date: July 1, 1978
Creator: Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Catalytic conversion of oxygenated compounds to low molecular weight olefins. Progress report, January 1-July 31, 1979. [Methanol from synthesis gas from coal gasification]

Description: An attractive route for producing ethylene and propylene from coal is to gasify the coal to produce synthesis gas, convert the synthesis gas to methanol, and then convert methanol to the olefins. During this report period the reactions of methanol over chabazite ion exchanged with rare earth chlorides have been studied at reciprocal liquid hourly space velocities of 1.5 to 15, at temperatures of 259, 271, 304, 352, and 427/sup 0/C, and at pressure 2.7 atm. At 259 and 271/sup 0/C the principle product was dimethyl ether. As the temperature was increased the conversion of methanol to olefins and alkanes increased to 54% and 32%, respectively. A mixture of dimethyl ether, water, and methanol was fed to the Berty reactor. This mixture was near the equilibrium concentrations for converting pure methanol to dimethyl ether and water at 275/sup 0/C. The Berty reactor temperature was 427/sup 0/C. Initially the yields were similar to those obtained when feeding pure methanol. However, the catalyst activity decreased at a faster rate. Rate models are being developed to correlate the catalyst activity and rate as a function of time on stream and partial pressures. A promising model is presented.
Date: July 31, 1979
Creator: Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Catalytic conversion of oxygenated compounds to low molecular weight olefins. Annual report for January 1--December 31, 1978

Description: The conversion of methanol or synthesis gas is an attractive route for producing ethylene and propylene from coal. Utilizing a chabazite ion exchanged with ammonium and rare earth chlorides, methanol is converted to ethylene, propylene, and propane with carbon yields of 70 to 90% at reaction temperatures of 360 to 450/sup 0/C and pressures from 1 to 18 atmospheres. Carbon disulfide in the feed at concentrations less than 2000 ppm increases the operating time between regenerations from four hours to twenty hours. At carbon disulfide concentrations of 3000 ppm or greater, the catalyst goes through three stages. The first is that of a dehydrogenation catalyst that produces carbon monoxide and hydrogen. The second stage produces ethylene and propylene, and finally, the third stage is a dehydration catalyst that produces dimethyl ether. Water has no detrimental effect on the catalyst, and appears to enhance its activity. Increase in pressure increases the production of propylene and propane at the expense of ethylene. X-ray diffraction studies show the formation of an ultrastable zeolite. No permanent deactivation was observed even though the catalyst was overheated once, and had been deactivated and regenerated for as many as 21 times. Ethylene yields increase as the temperature increases from 360 to 450/sup 0/C. When synthesis gas is passed over the catalyst at pressures equal to or less than 500 psi, methane and carbon dioxide are produced.
Date: January 1, 1979
Creator: Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Catalytic conversion of oxygenated compounds to low molecular weight olefins. Progress report, March 1, 1980-August 31, 1980

Description: A possible route for producing low molecular weight olefins is to convert synthesis gas to methanol followed by conversion of methanol to olefins in a one-step process. During this report period the reaction apparatus suitable for reaction pressure of 500 to 1000 psig was constructed. A preliminary trial run was performed for the reaction of synthesis gas over an intimate mixture of methanol synthesis catalyst and Zeolon-500 (mixture of chabasite and erionite). The reaction temperature, pressure and space velocity were 400/sup 0/C, 800 psig, and 6000 h/sup -1/ (STP), respectively. The total carbon monoxide conversions were 15 to 24%. The major products were carbon dioxide and paraffins of C/sub 1/ to C/sub 4/. Deactivation of the catalyst occurred after 10 hours. X-ray diffraction patterns of the catalyst shows that crystal structure changed during the reaction, and the catalyst exhibited low crystallinity compared to synthetic erionite.
Date: September 30, 1980
Creator: Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Novel reactor configuration for synthesis gas conversion to alcohols

Description: Research continued on the conversion of synthesis gas to alcohols and reactor configuration. Our objective during this quarter was to complete Task IIIB, development of the algorithms for the dynamic response technique for parameter estimation; start Task IIIC, establishment of methodology for determination of the parameters of the trickle bed reactor in the microreactor assembly; and continue with Task IV, determination of the kinetics of the reaction in the slurry reactor. 3 figs.
Date: January 1, 1990
Creator: Akgerman, A. & Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, January 1, 1993--March 31, 1993

Description: The objectives of this project are to develop a new catalyst, the kinetics for this catalyst, reactor models for trickle bed, slurry and fixed bed reactors, and simulate the performance of fixed bed trickle flow reactors, slurry flow reactors, and fixed bed gas phase reactors for conversion of a hydrogen lean synthesis gas to isobutylene. The six main accomplishments for the quarter are the following: (1) activity testing with the 7% (wt) Ce-ZrO{sub 2}, (2) activity testing the same catalyst with CO from an aluminum cylinder, (3) preparation of ZrO{sub 2} by heating zirconyl nitrate, (4) preparation of an active zirconia prepared by a modified sol gel procedure and evaluation of the catalytic activity of a commercial zirconia and the catalysts prepared by the sol gel procedure, (5) determining the effect of separator temperatures and oil flow rate on the performance of a trickle bed reactor, and (6) calculation of the equilibrium composition of the C{sub 2} to C{sub 5} olefins, and initiation of the development of a macrokinetic model. The details of each of these accomplishments are discussed.
Date: April 17, 1993
Creator: Anthony, R.G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Final report, September 1, 1990--January 31, 1994

Description: Previous work on isosynthesis (conversion of synthesis gas to isobutane and isobutylene) was performed at very low conversions or extreme process conditions. The objectives of this research were (1) determine the optimum process conditions for isosynthesis; (2) determine the optimum catalyst preparation method and catalyst composition/properties for isosynthesis; (3) determine the kinetics for the best catalyst; (4) develop reactor models for trickle bed, slurry, and fixed bed reactors; and (5) simulate the performance of fixed bed trickle flow reactors, slurry flow reactors, and fixed bed gas phase reactors for isosynthesis. More improvement in catalyst activity and selectivity is needed before isosynthesis can become a commercially feasible (stand-alone) process. Catalysts prepared by the precipitation method show the most promise for future development as compared with those prepared hydrothermally, by calcining zirconyl nitrate, or by a modified sol-gel method. For current catalysts the high temperatures (>673 K) required for activity also cause the production of methane (because of thermodynamics). A catalyst with higher activity at lower temperatures would magnify the unique selectivity of zirconia for isobutylene. Perhaps with a more active catalyst and acidification, oxygenate production could be limited at lower temperatures. Pressures above 50 atm cause an undesirable shift in product distribution toward heavier hydrocarbons. A model was developed that can predict carbon monoxide conversion an product distribution. The rate equation for carbon monoxide conversion contains only a rate constant and an adsorption equilibrium constant. The product distribution was predicted using a simple ratio of the rate of CO conversion. This report is divided into Introduction, Experimental, and Results and Discussion sections.
Date: May 6, 1994
Creator: Anthony, R.G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, October 1, 1992--December 31, 1992

Description: The objectives of this project are to develop a new catalyst, the kinetics for this catalyst, reactor models for trickle bed, slurry and fixed bed reactors, and simulate the performance of fixed bed trickle flow reactors, slurry flow reactors, and fixed bed gas phase reactors for conversion of a hydrogen lean synthesis gas to isobutylene. The goals for the quarter include: (1) Conduct experiments using a trickle bed reactor to determine the effect of reactor type on the product distribution. (2) Use spherical pellets of silica as a support for zirconia for the purpose of increasing surface, area and performance of the catalysts. (3) Conduct exploratory experiments to determine the effect of super critical drying of the catalyst on the catalyst surface area and performance. (4) Prepare a ceria/zirconia catalyst by the precipitation method.
Date: February 1, 1993
Creator: Anthony, R.G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, July 1, 1992--September 30, 1992

Description: A series of zirconia catalysts prepared by a modified sol gel procedure, coprecipitation with ammonium hydroxide, and by a hydrothermal method were evaluated for catalytic activity. These catalysts were prepared containing silicon, thorium, titanium, cerium and the alkali metals. A catalyst containing 2% thorium on zirconia was the most active. The isobutylene and isobutane selectivity were 19.4 wt % and 1.82 wt %, respectively. Macro- and micro-kinetic models indicate that C0{sub 2} formation inhibits the rate of CO conversion, hydrogen is dissociatively adsorbed, and CO is molecularly adsorbed. The microkinetic model indicates the strengthening of the metaloxygen bond might increase the production rate of isobutylene.
Date: November 13, 1992
Creator: Anthony, R.G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalysts and process development for synthesis gas conversion to isobutylene. Quarterly report, July 1, 1991--September 30, 1991

Description: The objectives of this project are to develop a new catalyst, the kinetics for this catalyst, simulate the performance of fixed bed trickle flow reactors, slurry flow reactors, and fixed bed gas phase reactors for conversion of a hydrogen-lean synthesis gas to isobutylene. The goals for this year were to recruit and organize the project team, complete the literature and patent searches, complete the management plan and other reporting requirements, complete the revision and upgrading of existing bench scale units for the project, and synthesize, characterize and evaluate the catalytic activity of zirconia prepared (1) by co-precipitation of zirconyl nitrate with ammonium hydroxide and (2) by preparing a hydrous zirconium oxide using the modified sol gel method developed at the Sandia National Laboratories followed by calcination. The same preparation procedure would be used to prepare supports for impregnation with thorium nitrate, a potassium salt and a sodium salt. The synthesis of new crystalline zirconates were to be attempted with the objective of producing new compositions of matter which might have higher activities and selectivities than zirconia. Substantial progress on reactor and kinetic models for slurry and trickle bed reactors was to be achieved. Accomplishments for the year are described.
Date: November 6, 1991
Creator: Anthony, R.G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Novel reactor configuration for synthesis gas conversion to alcohols

Description: Research is ongoing to develop a reactor to convert synthesis gas to alcohol. Our objective during this quarter was to complete Task 2, calibration and automation of GC analysis protocols, and Task 3B, development of a dynamic response technique to determine the relevant parameters and of the algorithms for data acquisition and analysis for parameter estimation including the computer codes. In addition, we have started to work on Task 4, determination of the reaction kinetics in the CSTR we have designed. 3 figs., 1 tab.
Date: January 1, 1990
Creator: Akgerman, A. & Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Novel reactor configuration for synthesis gas conversion to alcohols

Description: Research continued on the design of a chemical reactor for synthesis gas conversion. During the second quarter our objective was to continue with Task 2 and start on Task 3. Task 2 involved standardization and automation of GC analysis protocols. Task 3, as stated in the work breakdown schedule, was the modification and automation of the trickle bed reactor and performing the initial factorial design experiments. We have decided to modify this task by expanding it to incorporate determination of the hydrodynamic and transport parameters of the trickle bed reactor in order to isolate and study just the reaction parameters. 1 fig.
Date: January 1, 1990
Creator: Akgerman, A. & Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Novel reactor configuration for synthesis gas conversion to alcohols

Description: Our objectives during this quarter were to complete construction and shake down runs on our new reactor assemblies, obtain activity data on the catalyst employing the slurry reactor, incorporate pressure drop and change in number of moles options into our reactor simulation code and start experiments in the trickle bed reactor.
Date: January 1, 1991
Creator: Akgerman, A. & Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Novel reactor configuration for synthesis gas conversion to alcohols

Description: Our objectives during this quarter was to complete studies on the kinetics of methanol synthesis reaction in the slurry reactor with long periods of on stream studies, start experimentation in the trickle bed reactor assembly, investigate simulation studies using the piston-exchange (PE) and piston-dispersion-exchange (PDE) models, and introduce water gas shift reaction as the second reaction in our simulation studies.
Date: January 25, 1992
Creator: Akgerman, A. & Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene

Description: A rate equation for carbon monoxide consumption showing first order in CO and 0.5 order in hydrogen indicates the rate controlling step involves dissociated hydrogen. The inhibition of the rate with carbon dioxide is also shown. Examination of the hydrocarbon distributions indicates a see-saw effect with the C[sub 4]s representing the fulcrum and methane and C[sub 5][sup +] the end points. The shift in the distributions tends to be towards the C[sub 5][sup +] for high pressures and long residence times. This distribution can be shifted by incorporating Ti into the catalysts, but the optimum amount of Ti needs to be determined. The sol gel method of preparing the catalysts tends to produce a less active catalyst than by precipitation of a zirconyl salt. The most active catalyst contained approximately 2% Th/ZrO[sub 2]
Date: July 27, 1992
Creator: Anthony, R.G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene

Description: The objectives of this project are to develop a new catalyst, the kinetics for this catalyst, reactor models for trickle bed, slurry and fixed bed, and simulate the performance of fixed bed trickle flow reactors, slurry flow reactors, and fixed bed gas phase reactors for conversion of a hydrogen lean synthesis gas to isobutylene.
Date: May 26, 1992
Creator: Anthony, R.G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, April 1, 1992--June 30, 1992

Description: A rate equation for carbon monoxide consumption showing first order in CO and 0.5 order in hydrogen indicates the rate controlling step involves dissociated hydrogen. The inhibition of the rate with carbon dioxide is also shown. Examination of the hydrocarbon distributions indicates a see-saw effect with the C{sub 4}s representing the fulcrum and methane and C{sub 5}{sup +} the end points. The shift in the distributions tends to be towards the C{sub 5}{sup +} for high pressures and long residence times. This distribution can be shifted by incorporating Ti into the catalysts, but the optimum amount of Ti needs to be determined. The sol gel method of preparing the catalysts tends to produce a less active catalyst than by precipitation of a zirconyl salt. The most active catalyst contained approximately 2% Th/ZrO{sub 2}
Date: July 27, 1992
Creator: Anthony, R. G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, April 1, 1993--June 30, 1993

Description: The presence of potassium or calcium in sol gel catalysts increase the production of C{sub 4} hydrocarbon and that of methane while maintaining high activities. Characterization of catalysts using temperature programmed desorption of carbon dioxide indicates that activity and product distribution over an isosynthesis catalyst depend on its acid-base properties. Low activity was observed for catalysts with very weak basicity, and high oxygenate production for catalysts with strong basicity. An optimum strength of basic sites is crucial to achieve high activity while minimizing the amount of oxygenates. A kinetic model was developed based on the reaction mechanisms, and the simulation from the model produces reasonable fit with the experimental data.
Date: October 6, 1993
Creator: Anthony, R. G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, July 1, 1993--September 30, 1993

Description: Trickle bed reactor experiments using precipitated and commercial zirconia resulted in the production of more C{sub 2}-C{sub 3} hydrocarbons than the fixed bed gas phase reactor when using a hydrogen to CO ratio of 1. Because of problems associated with solvent cracking the reactor temperature for the trickle bed was limited to 400{degrees}C, whereas temperatures up to 450{degrees}C had been used for the fixed bed reactors. Co-feeding H{sub 2}S with the synthesis gas resulted in reduction of C{sub 1} to C{sub 3} production rates, an increase in C{sub 5} production and an increase in the production of 3-methyl-l-butene. Zirconia prepared with Ce resulted in a highly active and selective catalyst with isobutylene production rates of 4 to 8.5 kg/(m{sup 3} cat. h) for CO conversions of 15 to 34%. Kinetic models necessary for reactor design are first order for CO and one half order for hydrogen, indicating the dissociation of hydrogen on the catalyst surface. Carbon dioxide was found to be the most abundant specie on the surface of the catalyst and retards the rate of reaction. A modification of the Anderson Schultz Flory distribution resulted in an empirical procedure for estimating product distributions.
Date: November 23, 1993
Creator: Anthony, R. G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, October 1, 1993--December 31, 1993

Description: The objectives of this project are to develop a new catalyst; the kinetics for this catalyst; reactor models for trickle bed, slurry and fixed bed reactors; and to simulate the performance of fixed bed trickle flow reactors, slurry flow reactors, and fixed bed gas phase reactors for conversion of a hydrogen lean synthesis gas to isobutylene. A hydrogen-lean synthesis gas with a ratio of H{sub 2}/CO of 0.5 to 1.0 is produced from the gasification of coal, lignite, or biomass. Isobutylene is a key reactant in the synthesis of methyl tertiary butyl ether (MTBE) and of isooctanes. MTBE and isooctanes are high octane fuels used to blend with low octane gasolines to raise the octane number required for modern automobiles. The production of these two key octane boosters is limited by the supply of isobutylene. MTBE, when used as an octane enhancer, also decreases the amount of pollutants emitted from the exhaust of an automobile engine.
Date: May 1, 1994
Creator: Anthony, R. G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Novel reactor configuration for synthesis gas conversion to alcohols. Quarterly report, October 1, 1991--December 31, 1991

Description: Our objectives during this quarter was to complete studies on the kinetics of methanol synthesis reaction in the slurry reactor with long periods of on stream studies, start experimentation in the trickle bed reactor assembly, investigate simulation studies using the piston-exchange (PE) and piston-dispersion-exchange (PDE) models, and introduce water gas shift reaction as the second reaction in our simulation studies.
Date: January 25, 1992
Creator: Akgerman, A. & Anthony, R. G.
Partner: UNT Libraries Government Documents Department

Novel reactor configuration for synthesis gas conversion to alcohols. Quarterly report, July 1, 1991--September 30, 1991

Description: Our objectives during this quarter were to complete construction and shake down runs on our new reactor assemblies, obtain activity data on the catalyst employing the slurry reactor, incorporate pressure drop and change in number of moles options into our reactor simulation code and start experiments in the trickle bed reactor.
Date: December 31, 1991
Creator: Akgerman, A. & Anthony, R. G.
Partner: UNT Libraries Government Documents Department

Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, January 1, 1992--March 31, 1992

Description: The objectives of this project are to develop a new catalyst, the kinetics for this catalyst, reactor models for trickle bed, slurry and fixed bed, and simulate the performance of fixed bed trickle flow reactors, slurry flow reactors, and fixed bed gas phase reactors for conversion of a hydrogen lean synthesis gas to isobutylene.
Date: May 26, 1992
Creator: Anthony, R. G. & Akgerman, A.
Partner: UNT Libraries Government Documents Department

Crystalline titanate catalyst supports

Description: A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.
Date: December 31, 1991
Creator: Anthony, R. G. & Dosch, R. G.
Partner: UNT Libraries Government Documents Department