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 Composition Modification of Zinc Titanate Sorbents for Hot Gas Desulfurization Quarterly Report 1 December 1994 28 February 1995 written by and published by . This book was released on 1995 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: For new coal gasification systems, zinc titanate sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined cycle turbines and high temperature fuel cells. Although most of the properties of these sorbents are very attractive, there are still concerns about durability over many sulfidation-regeneration cycles and zinc losses due to vaporization. Doping the zinc titanate with other metal ions could alleviate both concerns, which are the objectives of this project. A screening study was completed during the second quarter in which Ni, Cr, Cu, Mg, and Al were evaluated as dopants in zinc titanate. Measurements that were made include solubility, crush strength, and sulfidation-regeneration behavior in a thermogravimetric analyzer. A formulation containing Cr showed the most promise. It and other formulations containing Cr will be emphasized during the remainder of the year. Fixed bed experiments will start during the third quarter.

Download or read book Composition Modification of Zinc Titanate Zn2TiO4 Based Sorbents for Hot Coal Gas Desulfurization written by Kimberly S. Walton and published by . This book was released on 1995 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Composition Modification of Zinc Titanate Sorbents for Hot Gas Desulfurization Technical Report March 1 May 31 1995 written by and published by . This book was released on 1995 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: For new coal gasification systems, zinc titanate sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined cycle turbines and high temperature fuel cells. Although most of the properties of these sorbents are very attractive, there are still concerns about durability over many sulfidation-regeneration cycles and zinc losses due to vaporization. Doping the zinc titanate with other metal ions could alleviate both concerns, which are the objectives of this project. After a screening study was completed, it was decided that Cr offered more promise as a dopant than Ni, Cu, Mg, and Al. Therefore six new sorbent formulations containing Cr were prepared, and they are now being evaluated with a series of bulk density, X-ray diffraction, crush strength and thermogravimetric analysis (TGA) measurements. Results to date suggest that, while Zn vaporization losses can be reduced with Cr additions, a penalty in chemical reactivity occurs. A fixed bed test was also completed this quarter on a Cr-containing formulation. The H2S breakthrough time was about 11 hours, and utilization of Zn in the sorbent was 60.5%.

Download or read book Composition Modification of Zinc Titanate Sorbents for Hot Gas Desulfurization Quarterly Technical Report September 1 1994 November 30 1994 written by and published by . This book was released on 1995 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: For new coal gasification systems, zinc titanate sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined cycle turbines and high temperature fuel cells. Although most of the properties of these sorbents are very attractive, there are still concerns about durability over many sulfidation-regeneration cycles and zinc losses due to vaporization. Doping the zinc titanate with other metal ions could alleviate both concerns, which are the objectives of this project. During the first quarter of effort, several sorbent formulations were prepared and testing begun. The dopants presently under study are Ni, Cr, Cu, and Al. Crush strength results obtained to date show that Ni and Cu dopants have a large positive effect, while Cr gives a small improvement. Measurements were also made of sulfur capacity and sulfidation rates with a thermogravimetric analyzer. Of the three formulations, only the one containing Cr had a high sulfur capacity. X-ray measurements will be relied upon heavily to obtain an understanding of solubility effects and sulfidation mechanisms. Screening experiments will continue on the doped sorbents mentioned above next quarter, and Mg will be studied also.

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.

Download or read book Enhanced Durability of High temperature Desulfurization Sorbents for Fluidized bed Applications Zinc Titanate written by and published by . This book was released on 1992 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this project are to identify and demonstrate methods for enhancing long-term chemical reactivity and attrition resistance of zinc ferrite and zinc titanate sorbents to be employed for desulfurization of hot coal-derived gases in a high-temperature, high-pressure (HTHP) fluid-bed reactor. The sorbent formulation specified for study during the base period of this project was zinc ferrite. Zinc titanate sorbents are being studied under two options to the base contract. Specific objectives of the zinc titanate sorbent development work are the following: The effect of following process variables was investigated o the performance of zinc titanate sorbents: Method of sorbent preparation, Composition of fuel gas, Zn to Ti ratio of the sorbent, Sulfidation temperature, and Superficial gas velocity. The effect of first three variables has been covered in RTI's 1991 paper (Gupta and Gangwal, 1991b), while the effect of temperature and superficial gas velocity is described here.

Download or read book Desulfurization of Hot Coal Gas in a Fluidized Bed with Regenerable Zinc Titanate Sorbents written by Wahab Mojtahedi and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Final Technical Report written by Illinois Clean Coal Institute and published by . This book was released on 1998 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Desulfurization of Hot Coal Gas written by Aysel T. Atimtay and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Economic and environmental requirements for advanced power generating systems demand the removal of corrosive and other sulfurous compounds from hot coal gas. After a brief account of the world energy resources and an overview of clean coal technologies, a review of regenerable metal oxide sorbents for cleaning the hot gas is provided. Zinc oxide, copper oxide, calcium oxide, manganese oxide based as well as supported and mixed metal oxide sorbents are treated. Performance analysis of these sorbents, effects of various parameters on the desulfurization efficiency, kinetics of sulfidation and regeneration reactions, sulfiding and regeneration mechanisms are discussed. Two chapters present recent results in the direct production of elemental sulfur from regeneration or SO2-rich gases.

Download or read book Department of the Interior and Related Agencies Appropriations for 1996 Secretary of Energy written by United States. Congress. House. Committee on Appropriations. Subcommittee on Department of the Interior and Related Agencies and published by . This book was released on 1995 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Bench scale Testing of Novel High temperature Desulfurization Sorbents written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Extrudates of regenerable mixed-metal oxide sorbents including zinc ferrite, copper-modified zinc ferrite, zinc titanate, copper aluminate, copper-iron aluminate, and copper manganate were prepared and tested for their potential to remove hydrogen sulfide (H/sub 2/S) from coal gasifier gas in a high-temperature high-pressure (HTHP) fixed-bed reactor. The zinc containing sorbents were found to be more promising than those containing combinations of copper, aluminum, iron, and manganese. Reductions in H/sub 2/S concentration were achieved depending on sorbent, reactor temperature, and steam concentration. The copper-modified zinc ferrite sorbent reduced the H/sub 2/S concentration to less than 1 ppmv at up to 1100/degree/F with 20 volume % steam in the gas. The zinc ferrite sorbent showed no apparent loss in capacity over 15 sulfidation-regeneration cycles but underwent significant strength reduction in a coal-derived gas with 15% or less steam due to soot formation. Zinc titanate exhibited excellent strength and capacity retention at steam levels as low as 5% and temperatures as high as 1350/degree/F. 13 refs., 64 figs., 75 tabs.

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 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 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 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project was to support Texaco's effort to develop the zinc titanate hot-gas desulfurization process for gases produced from their oxygen-blown coal gasifier by answering two key questions that had remained unanswered to date. These questions were: Will chloride in the coal gas affect the performance of the sorbent? Where would the chloride end up following sulfidation and regeneration? Previously, Research Triangle Institute (RTI) completed a bench-scale test series, under a subcontract to Texaco, Inc., for their contract with the US Department of Energy/Morgantown Energy Technology Center (DOE/METC), in which zinc titanate was shown to be a highly promising sorbent for desulfurizing the Texaco O2-blown simulated coal gas. The next step was to evaluate the effect of coal gas contaminants, particularly chloride, on the sorbent. No tests have been carried out in the past that evaluate the effect of chloride on zinc titanate. If ZnO in the sorbent reacts with the chloride, zinc chloride may form which may evaporate causing accelerated zinc loss. Zinc chloride may revert back to the oxide during oxidative regeneration. This may be enhanced in the presence of steam. This report provides results of a three-test series which was designed to give some definitive answers about the fate of chloride in the hot-gas desulfurization process and the effect of chloride on the performance of zinc titanate.