AndreaBozzo/ceres-open-data-index huggingface dataset:
Gas separation and hot-gas cleanup

Catalytic gasification of coal to produce H{sub 2}-, CO-, and CH{sub 4}-rich mixtures of gases for consumption in molten carbonate fuel cells is currently under development; however, to optimize the fuel cell performance and extend its operating life,it is desired to separate as much of the inert components (i.e., CO{sub 2} and N{sub 2}) and impurities (i.e., H{sub 2}S and NH{sub 3}) as possible from the fuel gas before it enters the fuel cell. In addition, the economics of the integrated gasification combined cycle (IGCC) can be improved by separating as much of the hydrogen as possible from the fuel, since hydrogen is a high-value product. Researchers at the Energy & Environmental Research Center and Bend Research, Inc., investigated pressure-driven membranes as a method for accomplishing this gas separation and hot-gas cleanup. These membranes are operated at temperatures as high as 800{degrees}C and at pressures up to 300 psig. They have very small pore sizes that separate the undesirable gases by operating in the Knudsen diffusion region of mass transport (30 -50{Angstrom}) or in the molecular sieving region of mass transport phenomena (<5{Angstrom}). In addition, H{sub 2} separation through a palladium metal membrane proceeds via a solution-diffusion mechanism for atomic hydrogen. This allows the membranes to exhibit extremely high selectivity for hydrogen separation. The objective of this study was to determine the selectivity of the ceramic membranes for removing undesirable gases while allowing the desired gases to be concentrated in the permeate stream.

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Analysis and control of the METC fluid-bed gasifier. Quarterly report, October 1994--January 1995

This document summarizes work performed for the period 10/1/94 to 2/1/95. The initial phase of the work focuses on developing a simple transfer function model of the Fluidized Bed Gasifier (FBG). This transfer function model will be developed based purely on the gasifier responses to step changes in gasifier inputs (including reactor air, convey air, cone nitrogen, FBG pressure, and coal feedrate). This transfer function model will represent a linear, dynamic model that is valid near the operating point at which the data was taken. In addition, a similar transfer function model will be developed using MGAS in order to assess MGAS for use as a model of the FBG for control systems analysis.

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Advanced sulfur control concepts for hot gas desulfurization technology. Quarterly report, October--December 1995

In the area of gas analysis, most of the attention during the past quarter was devoted to gaining an understanding of the operation of the Antek total sulfur analyzer, and making appropriate modifications in the unit. The primary problem is that the resistance of the capillary flow restrictor is not large enough, and the amount of sulfur which reaches the UV-analyzer results in the analyzer becoming saturated. We have added a N{sub 2} diluent flow downstream of the pyrotube tube which, we believe, will permit the unit to be operated at pressures to about 50 psig. Use of larger diluent flow rates to permit higher pressure operation is not feasible since larger diluent rates increase the back pressure on the quartz pyrotube (which operates at 1050{degrees}C) to unsafe levels. In the meantime, Antek is studying the redesign of the capillary flow restrictor to provide larger flow resistance. Studies on the regeneration of FeS in the atmospheric pressure reactor were almost completed during the quarter. Only a series of multicycle sulfidation-regeneration tests remains. The effects of reactive gas mol fraction and temperature have been examined using both O{sub 2}/N{sub 2} and H{sub 2}O/N{sub 2} atmospheres. The initial rate of regeneration was found to be a weak function of temperature and first-order in both O{sub 2} and H{sub 2}O concentration. In a test series in which the reactive gas contained both O{sub 2} and H{sub 2}O, the experimental initial rate was effectively equal to the sum of the individual initial rates, suggesting that the two reactions proceed independently of one another. Detailed correlation and statistical analysis of the data is currently being done. Principal effort during the quarter using the high pressure electrobalance was devoted to studying the regeneration of FeS in a H{sub 2}O/N{sub 2} atmosphere.

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Catalyst for utilization of methane in selective catalytic reduction of NO{sub x}, Task 2.6

Selective catalytic reduction (SCR) of nitrogen oxides(NO{sub x}) in flue gas or engine exhaust gas with hydrocarbons as the reductant has great potential for less expense, less pollution, and easier operation than SCR with ammonia. Methane is the preferred reducing gas because of its low cost and low toxicity. Stable, low-cost catalysts for SCR with methane are required to demonstrate this technology for controlling NO{sub x} emissions. Several cobalt and nickel catalysts on synthetic clay and uranium oxide supports were investigated for their activities in reducing NO{sub x} with methane in the presence of air. The efficiency of the synthetic clay-supported nickel and cobalt catalysts for nitric oxide (NO) reduction with methane as the reducing gas was poor. The nickel oxide-uranium oxide catalyst, which was chosen for its high stability, was also ineffective. Results from the two-step experiments conducted at two-temperatures produced some interesting information on the reactions of methane with the catalysts and the reactivity of the carbonaceous intermediate. The carbonaceous material formed from methane dissociation at 450{degrees}C not only reduces NO to N{sub 2}O at lower temperatures, but also prevents oxidation of NO to NO{sub 2}. Unfortunately, the carbonaceous forms that reduce the NO are not available for reactions at 400{degrees}C in the presence of oxygen. A two-step process employing this chemistry would be difficult because the catalyst would have to be cycled between the two temperatures. Also the desired reduction to nitrogen is not very efficient.

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Utilization of low NO{sub x} coal combustion by-products. Quarterly report, January--March 1995

The status of the following tasks is described: (1) laboratory characterization, which includes sample collection, material characterization, and laboratory testing of ash processing operations; (2) pilot plant testing; (3) product testing including concrete testing, concrete block/brick, plastic fillers, and activated carbon; and (4) market and economic analysis. Appendices contain data on material characterization size distribution, loss-on-ignition by size, and lab tests of ash processing operations.

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Sorbent carbon development Task 5.2

The primary objective of this study is to transform low-rank coals (LRCs) into effective sorbent carbons economically for gas- and liquid-phase contaminant removal. The work carried out in this project primarily involved -12 x  30-mesh North Dakota leonardite or lignite, a highly oxygenated LRC. The ash content of the Georesources leonardite, the principal char source, was significantly higher than expected. Reduction of ash content was partially accomplished by grinding the coal and preparing the activated carbon from the -12 x 30-mesh fraction. Preliminary carbon preparation testing was carried out on the small thermogravimetric analyzer (TGA). The sample was carbonized at one temperature (250{degrees}, 350{degrees}, 480{degrees} or 550{degrees}C) under inert gas for selected time, then activated at a higher temperature (700{degree}-1000{degrees}C) under inert or reactive gas for a selected time, then cooled. The resulting carbon was characterized by SO{sub 2} adsorption at ambient temperature or 100{degrees}C. The activated chars prepared on a larger scale was characterized using the following: TGA proximate analysis; SO{sub 2} sorption at ambient temperature; iodine number; BET surface area; and porosity.

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SoilSaw{trademark} demonstration. Final report, September 1992--January 1995

The US Department of Energy (DOE) has identified leaking underground storage tanks and buried mixed waste at numerous sites within the DOE complex. Preventing these wastes from entering the environment is a challenging task. One method of preventing waste migration is to isolate the contaminants using subsurface containment barriers. Isolation and containment can be accomplished by both in situ and ex situ methods. This report describes a novel in situ construction method of forming vertical containment barriers (slurry walls) using the SoilSaw{trademark} Barrier System. The SoilSaw{trademark} Barrier System is shown to be a feasible process for constructing subsurface vertical containment barriers to depths of fifty feet. The process is most efficient in sandy soil (including free flowing sand) with barrier construction rates of over 130 square feet per minute. Productivity diminishes to approximately 30 square feet per minute as soils become harder and more cohesive. The present hardware is designed to form a barrier of approximately 12 inch in width. Additional barrier widths can be constructed with this technology by application of wider jet heads. The requirement for a varied arrangement of barrier widths is an increase in hydraulic horse power and additional jet heads.

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Advanced turbine systems program conceptual design and product development Task 8.3 - autothermal fuel reformer (ATR). Topical report

Autothermal fuel reforming (ATR) consists of reacting a hydrocarbon fuel such as natural gas or diesel with steam to produce a hydrogen-rich {open_quotes}reformed{close_quotes} fuel. This work has been designed to investigate the fuel reformation and the product gas combustion under gas turbine conditions. The hydrogen-rich gas has a high flammability with a wide range of combustion stability. Being lighter and more reactive than methane, the hydrogen-rich gas mixes readily with air and can be burned at low fuel/air ratios producing inherently low emissions. The reformed fuel also has a low ignition temperature which makes low temperature catalytic combustion possible. ATR can be designed for use with a variety of alternative fuels including heavy crudes, biomass and coal-derived fuels. When the steam required for fuel reforming is raised by using energy from the gas turbine exhaust, cycle efficiency is improved because of the steam and fuel chemically recuperating. Reformation of natural gas or diesel fuels to a homogeneous hydrogen-rich fuel has been demonstrated. Performance tests on screening various reforming catalysts and operating conditions were conducted on a batch-tube reactor. Producing over 70 percent of hydrogen (on a dry basis) in the product stream was obtained using natural gas as a feedstock. Hydrogen concentration is seen to increase with temperature but less rapidly above 1300{degrees}F. The percent reforming increases as the steam to carbon ratio is increased. Two basic groups of reforming catalysts, nickel - and platinum-basis, have been tested for the reforming activity.

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Tubular solid oxide fuel cell prospect

Driven by technological achievement and rational projection of commercial product cost, expectations for tubular SOFC commercialization are improving. Tubular SOFCs have surpassed 7 yrs operation and have recently demonstrated remarkable toughness in thermal cycling. Customer-owned systems with 25 kW stacks utilizing air electrode supported (AES) cells continue to operate directly on natural gas without degradation after multiple thermal cycles and over 4000 hrs operation. AES cell operation at elevated pressure corroborates theoretical estimates of performance gain without evidence of deleterious effect. Commercial class AES cell of 22 mm dia and 1500 mm length, is now in production for application to 100 kW, 50% efficient (ac/LHV), atmospheric pressure systems. This same cell applied to pressurized systems in combination with conventional turbo machinery (gas turbines) can yield an efficiency approaching 70% for power plants as small as 5 MW. Total installed system cost for commercial 5 MW SOFC/CT units for distributed power generation and on-site cogeneration should approach $1000/kW. A major challenge is formation of funded projects to demonstrate at the turn of the century prototype MW class SOFC/CT combined cycle power plants and to complete the development of commercial fuel cell manufacturing processes.

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Imaging data analyses for hazardous waste applications. Final report

The paper presents some examples of the use of remote sensing products for characterization of hazardous waste sites. The sites are located at the Los Alamos National Laboratory (LANL) where materials associated with past weapons testing are buried. Problems of interest include delineation of strata for soil sampling, detection and delineation of buried trenches containing contaminants, seepage from capped areas and old septic drain fields, and location of faults and fractures relative to hazardous waste areas. Merging of site map and other geographic information with imagery was found by site managers to produce useful products. Merging of hydrographic and soil contaminant data aided soil sampling strategists. Overlays of suspected trench on multispectral and thermal images showed correlation between image signatures and trenches. Overlays of engineering drawings on recent and historical photos showed error in trench location and extent. A thermal image showed warm anomalies suspected to be areas of water seepage through an asphalt cap. Overlays of engineering drawings on multispectral and thermal images showed correlation between image signatures and drain fields. Analysis of aerial photography and spectral signatures of faults/fractures improved geologic maps of mixed waste areas.

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Stabilization of vitrified wastes: Task 4. Topical report, October 1994--September 1995

The goal of this task was to work with private industry to refine existing vitrification processes to produce a more stable vitrified product. The initial objectives were to (1) demonstrate a waste vitrification procedure for enhanced stabilization of waste materials and (2) develop a testing protocol to understand the long-term leaching behavior of the stabilized waste form. The testing protocol was expected to be based on a leaching procedure called the synthetic groundwater leaching procedure (SGLP). This task will contribute to the US DOE`s identified technical needs in waste characterization, low-level mixed-waste processing, disposition technology, and improved waste forms. The proposed work was to proceed over 4 years in the following steps: literature surveys to aid in the selection and characterization of test mixtures for vitrification, characterization of optimized vitrified test wastes using advanced leaching protocols, and refinement and demonstration of vitrification methods leading to commercialization. For this year, literature surveys were completed, and computer modeling was performed to determine the feasibility of removing heavy metals from a waste during vitrification, thereby reducing the hazardous nature of the vitrified material and possibly producing a commercial metal concentrate. This report describes the following four subtasks: survey of vitrification technologies; survey of cleanup sites; selection and characterization of test mixtures for vitrification and crystallization; and selection of crystallization methods based on thermochemistry modeling.

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Enhancement of methane conversion using electric fields. Quarterly report, April--June 1995

The goal of this project is the development of novel, economical processes for the conversion of natural gas to more valuable products such as methanol, ethylene, and other organic oxygenates or higher hydrocarbons. The methodologies of the project are to investigate and develop low temperature electric discharges and electric field- enhanced catalysis for carrying out these conversions. In the case of low temperature discharges, the conversion is carried out at ambient temperature which in effect trades high temperature thermal energy for electric energy as the driving force for conversion. The low operating temperatures relax the thermodynamic constraints on the product distribution found at high temperatures and also remove the requirements of large thermal masses required for current technologies. With the electric field-enhanced conversion, the operating temperatures are expected to be below those currently required for such processes as oxidative coupling, thereby allowing for a higher degree of catalytic selectivity while maintaining high activity.

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Advanced sulfur control concepts in hot-gas desulfurization technology. Quarterly technical progress report, July--September 1995

Both the Antek total sulfur analyzer and the modifications to the Shimadzu GC-14A gas chromatograph to be used for analysis for SO{sub 2} and H{sub 2}S were delivered during the quarter. Problems were faced during the installation and calibration phases of both instruments. By the end of the quarter we believe that the GC problems have been solved, but problems remain with the Antek analyzer. It appears that too much sulfur (as SO{sub 2}) reaches the UV detector and causes it to become saturated. This shows up as a maximum in the instrument calibration curve. At 200 psia, the capillary flow restrictor allows a total flow rate of about 180 sccm, and the maximum occurs at about 1 % H{sub 2}S in the calibration gas. Reducing the pressure so that the total flow is reduced to about 25 sccm shifts the calibration curve maximum to about 5.7% H{sub 2}S. It appears that we must reduce the total flow rate to the detector or provide additional dilution. This may be accomplished by increasing the resistance of the capillary restrictor, by diverting a portion of the flow leaving the pyrotube to vent, or adding an inert such as N{sub 2} to the gases exiting the pyrotube. We are in contact with Antek representatives about the problem. Both the atmospheric pressure and high pressure electrobalances were used during the quarter to study the regeneration of FeS in atmospheres of O{sub 2}/N{sub 2} or H{sub 2}O/N{sub 2}. In the atmospheric pressure unit the effects of temperature (600 - 800{degrees}C), flow rate (130 - 500 sccm), and reactive gas mol fraction (0.005 to 0.03 O{sub 2} and 0.1 to 0.5 H{sub 2}O) are being studied. Regeneration tests completed to date in the high pressure unit have utilized only O{sub 2}/N. and the parameters studied include temperature (600 - 800{degrees}C), flow rate (500 - 1000 sccm), pressure (1 - 15 atm) ad O{sub 2} mol fraction (0.005 - 0.03).

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Developments of advanced hot-gas desulfurization sorbents. Quarterly technical progress report, April--June 1995

The objectives of this project are to develop hot-gas cleanup sorbents for relatively lower temperature application, with emphasis on the temperature range from 343-538{degrees}C. The candidate sorbents include highly dispersed mixed metal oxides of zinc, iron, copper, cobalt and molybdenum. The specific objective in the successful preparation of H{sub 2}S absorbents will be to generate as high and as stable a surface area as possible, in order to develop suitable sorbent, that are sufficiently reactive and regenerable at the relatively lower temperatures of interest in this work. A number of formulations will be prepared and screened for testing in a 1/2-inch fixed bed reactor at high pressure (1 to 20 atm) and high temperatures using simulated coal-derived fuel-gases. Screening criteria will include, chemical reactivity, stability, and regenerability over the temperature range of 343{degrees}C (650{degrees}F) to 538{degrees}C (1000{degrees}F). Each formulation will be tested for up to 5 cycles of absorption and regeneration. To prevent sulfation, catalyst additives will be investigated, which would promote a lower ignition of the regeneration. Selected superior formulation will be tested for long term (up to least 30 cycles) durability and chemical reactivity in the reactor.

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Sonic enhanced ash agglomeration and sulfur capture. Quarterly technical progress report, April--June 1995

A major concern with the utilization of coal in directly fired gas turbines is the control of particulate emissions and reduction of sulfur dioxide, and alkali vapor from combustion of coal, upstream of the gas turbine. Much research and development has been sponsored on methods for particulate emissions control and the direct injection of calcium-based sorbents to reduce SO{sub 2} emission levels. The results of this research and development indicate that both acoustic agglomeration of particulates and direct injection of sorbents have the potential to become a significant emissions control strategy. The Sonic Enhanced Ash Agglomeration and Sulfur Capture program focuses upon the application of an MTCI proprietary invention (Patent No. 5,197,399) for simultaneously enhancing sulfur capture and particulate agglomeration of the combustor effluent. This application can be adapted as either a {open_quotes}hot flue gas cleanup{close_quotes} subsystem for the current concepts for combustor islands or as an alternative primary pulse combustor island in which slagging, sulfur capture, particulate agglomeration and control, and alkali gettering as well as NO{sub x} control processes become an integral part of the pulse combustion process. The goal of the program is to support the DOE mission in developing coal-fired combustion gas turbines. In particular, the MTCI proprietary process for bimodal ash agglomeration and simultaneous sulfur capture will be evaluated and developed. The technology embodiment of the invention provides for the use of standard grind, moderately beneficiated coal and WEM for firing the gas turbine with efficient sulfur capture and particulate emission control upstream of the turbine. The process also accommodates injection of alkali gettering material if necessary. The proposed technology provides for practical, reliable, and capital (and O&M) cost-effective means of protection for the gas turbine from impurities in the coal combustor effluent.

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