Download or read book Fixed Bed Testing of a Molybdenum promoted Zinc Titanate Sorbent for Hot Gas Desulfurization written by and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experimental test program for the molybdenum-promoted zinc titanate with Zn/Ti ratio of 1.91, consists of two series of test: six half-cycle (sulfidation phase) parametric tests and four multi-cycle (sulfidation and regeneration phase) tests. Results of the parametric tests were utilized to select the optimum conditions for multi-cycle tests. The intent of the multi-cycle test series was to demonstrate durability and regenerability of the molybdenum-promoted zinc titanate sorbent. During the parametric tests, sorbent bed temperature and linear velocity were varied. However, system pressure was fixed at 150 psia (1.03 MPa) for sulfidation test phases and 50 psia (0.34 MPa) for regeneration test phases for both single and multi-cycle tests. Figure 2 shows the effect of gas flow rate and temperature on hydrogen sulfide removal during the half-cycle (sulfidation) parametric tests. Simulated KRW coal gas which contained 15 vol% H2, 21 vol% CO, 9.0 vol% H2O and 800 ppmv H2S was used during the parametric tests. As can be seen from the data, sorbent efficiency and capacity were only weak functions of bed temperature. However, increasing the space velocity substantially reduced sorbent efficiency and capacity as indicated on the rapid breakthrough of H2S for the high space velocity. Breakthrough period is defined here as corresponding to H2S concentration of 200 ppmv in exit gas.
Download or read book Fixed Bed Testing of a Molybdenum promoted Zinc Titanate for Hot Gas Desulfurization written by and published by . This book was released on 1993 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The following conclusions were made, based upon this study of T-2535 molybdenum-promoted zinc titanate: (1) Results of the half-cycle sulfidation experiments showed that sorbent efficiency and capacity of this formulation of zinc titanate were weak functions of operating-bed temperature. Evidence of diffusion limitations on the sulfidation reaction were observed, particularly at superficial velocities greater than 30 cm/s (1 ft/s). Sorbent performance appeared to be affected by the concentration of reducing gases and/or water content of the simulated coal gas mixtures. Sorbent capacity and efficiency deteriorated during the first three cycles, but stabilized thereafter. (2) Sorbent spalling was observed and appeared to increase with sulfur loading. Possible causes of spalling may be attributed to the induced crystal lattice stresses due to the formation of ZnS and especially ZnSO4, which have relative molar volumes that are approximately 1-1/2 and 3 times larger, respectively, than that of the original ZnO. (3) Based on these results, it is apparent that the molybdenum-promoted zinc titanate with Zn/Ti molar ratio of 1.91 may not be a suitable sorbent for hot gas desulfurization in the fixed bed reactor for the Pinon Pine project, due to problems with spalling and loss of reactivity during sulfidation/regeneration cycling.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acid Precipitation written by and published by . This book was released on 1994 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Integration and Testing of Hot Desulfurization and Entrained flow Gasification for Power Generation Systems Phase 2 Process Optimization written by and published by . This book was released on 1991 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Research Triangle Institute performed four high-temperature desulfurization tests of zinc titanate sorbents for Texaco, Inc. Two zinc titanate sorbents (L-3196 and L-3014) were tested in fixed-bed mode with simulated oxygen-blown (medium Btu) and air-blown (low Btu) Texaco gas. The zinc titanate sorbents were manufactured as 3/16-in. cylindrical extrudates by United Catalysts, Inc. Tests were performed in a high-temperature, high-pressure, fixed-bed sorbent test unit originally constructed and used on Department of Energy (DOE) contract DE-AC21-86MC23126, DOE Office of Fossil Energy, Morgantown Energy Technology Center (METC). The test unit is described in detail in the December 1988 final report for this contract. Of the four tests conducted, two tests were conducted for the L-3014 sorbent and two tests were conducted for the L-3196 sorbent. The main difference between the two sorbents was their zinc to titanium molar ratio (0.8 for L-3014, 1.5 for L-3196). Properties of these sorbents are described in detail in the Final Report for DOE Contract No. DE-AC2l-86MC23126. Two tests were conducted for each sorbent; one test was conducted with simulated Texaco air-blown gasifier gas and one test was conducted with simulated Texaco oxygen-blown gasifier gas. Each test consisted of five cycles. Each cycle was composed of reductive regeneration, sulfidation, and oxidative regeneration steps. After the fifth sulfidation and after the fifth oxidative regeneration of each test, samples were collected and sent to Texaco. In the following sections, the test procedures are briefly described followed by details of the important results.
Download or read book Coal Abstracts written by and published by . This book was released on 1993 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Integration and Testing of Hot Desulfurization and Entrained flow Gasification for Power Generation Systems written by and published by . This book was released on 1991 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Research Triangle Institute performed four high-temperature desulfurization tests of zinc titanate sorbents for Texaco, Inc. Two zinc titanate sorbents (L-3196 and L-3014) were tested in fixed-bed mode with simulated oxygen-blown (medium Btu) and air-blown (low Btu) Texaco gas. The zinc titanate sorbents were manufactured as 3/16-in. cylindrical extrudates by United Catalysts, Inc. Tests were performed in a high-temperature, high-pressure, fixed-bed sorbent test unit originally constructed and used on Department of Energy (DOE) contract DE-AC21-86MC23126, DOE Office of Fossil Energy, Morgantown Energy Technology Center (METC). The test unit is described in detail in the December 1988 final report for this contract. Of the four tests conducted, two tests were conducted for the L-3014 sorbent and two tests were conducted for the L-3196 sorbent. The main difference between the two sorbents was their zinc to titanium molar ratio (0.8 for L-3014, 1.5 for L-3196). Properties of these sorbents are described in detail in the Final Report for DOE Contract No. DE-AC2l-86MC23126. Two tests were conducted for each sorbent; one test was conducted with simulated Texaco air-blown gasifier gas and one test was conducted with simulated Texaco oxygen-blown gasifier gas. Each test consisted of five cycles. Each cycle was composed of reductive regeneration, sulfidation, and oxidative regeneration steps. After the fifth sulfidation and after the fifth oxidative regeneration of each test, samples were collected and sent to Texaco. In the following sections, the test procedures are briefly described followed by details of the important results.
Download or read book Testing of Zinc Titanate Desulfurization Sorbents for Moving bed Applications written by and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sorbents developed for moving-bed systems must comply with a minimum of chemical and mechanical durability performance characteristics in order to be considered acceptable for long-term operation. Among the desired properties, a sorbent must have: (1) High chemical reactivity, as measured by the rate of sulfur absorption and the total sulfur loading on the sorbent. (2) High mechanical strength, as measured by the pellet crush strength and the attrition resistance; (3) Suitable pellet morphology, as given by pellet size and shape to promote good bulk flow ability and seasonable porosity to increase reactivity. Formulation 2A1.7M (UCI designation L-3787M) was selected by DOE as the baseline formulation for performance evaluation of Option 3 sorbents. This baseline formulation is a rounded zinc titanate sorbent containing a 2:1 Zn:Ti molar ratio, 1.7% molybdenum (equivalent to 2.5% MoO3), and 3% bentonite binder that had been previously tested under the Option 2 program. Zinc titanate sorbents were prepared by UCI as rounded spherical or ellipsoidal pellets. The fabrication procedure is targeted at achieving a balance of mechanical strength (crush strength and attrition resistance) and chemical reactivity by controlling the pellet internal porosity.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1995-05 with total page 1096 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1748 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hot Gas Desulfurization with Sorbents Containing Oxides of Zinc Iron Vanadium and Copper written by and published by . This book was released on 1991 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this research is to evaluate the desulfurization performance of novel sorbents consisting of different combinations of zinc, iron, vanadium and copper oxides; and to develop a sorbent which can reduce H2S levels to less than 1 ppmv, which can stabilize zinc, making operations above 650°C possible, and which can produce economically recoverable amounts of elemental sulfur during regeneration. This objective will be accomplished by evaluating the sorbent performance using fixed-bed and TGA experiments supported by sorbent characterization at various reaction extents. The work done in the fourth quarter can be summarized as follows: (1) Calibration of the gas chromatograph for low and high H2S and SO2 is completed. (2) The determination of surface areas and densities of the promoted sorbents is completed. (3) Preliminary screening of the promoted sorbents in the packed bed reactor has started.
Download or read book Characterization and Fixed bed Testing of a Nickel based Hot Gas Desulfurization Sorbent written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hot Gas Desulfurization with Sorbents Containing Oxides of Zinc Iron Vanadium and Copper Quarterly Technical Progress Report written by and published by . This book was released on 1991 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this research is to evaluate the desulfurization performance of novel sorbents consisting of different combinations of zinc, iron, vanadium and copper oxides; and to develop a sorbent which can reduce H2S levels to less than 1 ppmv, which can stabilize zinc, making operations above 650°C possible, and which can produce economically recoverable amounts of elemental sulfur during regeneration. This objective will be accomplished by evaluating the sorbent performance using fixed-bed and TGA experiments supported by sorbent characterization at various reaction extents. The work done in the fourth quarter can be summarized as follows: (1) Calibration of the gas chromatograph for low and high H2S and SO2 is completed. (2) The determination of surface areas and densities of the promoted sorbents is completed. (3) Preliminary screening of the promoted sorbents in the packed bed reactor has started.
Download or read book An Attrition resistant Zinc Titanate Sorbent for Sulfur Technical Report 1 March 31 May 1994 written by and published by . This book was released on 1994 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the continuing search for good sorbent materials to remove sulfur from hot, coal-derived gases, zinc titanate sorbents have shown great promise. The objective of this project is to extend the effort started last year on sorbents with little or no loss in chemical reactivity. The principle is to contain Zn2TiO4 in a structural matrix of excess TiO2. Progress on several tasks was made during the third quarter. The new fixed bed apparatus at SIUC was made operational, and experiments in it have started. The feasibility of using turbine exhaust gas diluted with N2 for sorbent regeneration was demonstrated through experiments at both SIUC and RTI. The third of four ten-cycle tests was completed at RTI. It was a fixed bed test on one to two promising formulations developed last year. The results followed the pattern of the fluidized bed tests completed earlier in that the chemical reactivity was good, except for the first few cycles. Lastly the undergraduate student design project on hot gas desulfurization hardware was completed this quarter.
Download or read book Newspaper Clippings Related to George Washington and His Family written by and published by . This book was released on 193? with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: A volume of newspaper clippings related to Martha Washington, Mary Ball Washington and George Washington. Clippings are undated and their sources are not identified. The collection was possibly assembled on the occasion of the 1932 commemoration of the 200th anniversary of George Washington's birth.
Download or read book Composition Modification of Zinc Titanate Sorbents for Hot Gas Desulfurization written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Enhanced Durability of High temperature Desulfurization Sorbents for Moving bed Applications Option 2 Program written by and published by . This book was released on 1993 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most advantageous configurations of the integrated gasification combined cycle (IGCC) power system is coupling it with a hot gas cleanup for the more efficient production of electric power in an environmentally acceptable manner. In conventional gasification cleanup systems, closely heat exchangers are necessary to cool down the fuel gases for cleaning, sometimes as low as 200--300°F, and to reheat the gases prior to injection into the turbine. The result is significant losses in efficiency for the overall power cycle. High-temperature coal gas cleanup in the IGCC system can be operated near 1000°F or higher, i.e., at conditions compatible with the gasifier and turbine components, resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for IGCC power systems in which mixed-metal oxides are currently being used as desulfurization sorbents. The objective of this contract is to identify and test fabrication methods and sorbent chemical compositions that enhance the long-term chemical reactivity and mechanical durability of zinc ferrite and other novel sorbents for moving-bed, high-temperature desulfurization of coal-derived gases. Zinc ferrite was studied under the base program of this contract. In the next phase of this program novel sorbents, particularly zinc titanate-based sorbents, are being studied under the remaining optional programs. This topical report summarizes only the work performed under the Option 2 program. In the course of carrying out the program, more than 25 zinc titanate formulations have been prepared and characterized to identify formulations exhibiting enhanced properties over the baseline zinc titanate formulation selected by the US Department of Energy.
