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Modeling of metallic aerosol formation in a multicomponent system at high temperatures using a discrete-sectional model. Appendix 7

Description: A multicomponent discrete-sectional model was used to simulate the fate of lead in a high temperature system. The results show the ability of the developed model to simulate metallic aerosol systems at high temperatures. The PbO reaction and nucleation rate can be determined by comparing the simulations and the experimental data. Condensation on SiO{sub 2} particle surfaces is found important for removing the PbO vapor. The value of the accommodation factor that is applied to account for nonidealities in the condensation process are determined. The differences between the nanosized particles and the bulk particles are elucidated. The use of such a model helped to understand the effects of various mechanisms in determining the metal oxide vapor concentration profile and in establishing the ultimate particle size distribution.
Date: February 1, 1997
Partner: UNT Libraries Government Documents Department

Ohio Coal Research Consortium fifth year final reports summary, September 1, 1994--February 29, 1996

Description: As part of its efforts to improve the use of high-sulfur Ohio coal within environmental limits, the Ohio Coal Development Office, an entity within the Ohio Department of Development (OCDO/ODOD), in late 1988 established a consortium of four Ohio universities. The purpose of the Ohio Coal Research Consortium is to conduct a multi-year fundamental research programs focused on: (1) the enhancement or development of dry sorption processes for the economical removal of high levels of SO{sub 2} and other pollutants, and (2) an increased understanding of methods for reduction in air toxics emissions from combustion gases produced by burning high-sulfur Ohio coal. This report contains summaries of eleven studies in these areas.
Date: December 1, 1996
Partner: UNT Libraries Government Documents Department

Advanced emissions control development project. Phase I, Final report, November 1, 1993--February 19, 1996

Description: The primary objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of air toxics from coal-fired boilers. Ideally, the project aim is to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESP`s), fabric filters (baghouse), and wet flue gas desulfurization. B&W`s Clean Environment Development Facility (CEDF) and the AECDP equipment combined to form a state-of-the-art facility for integrated evaluation of combustion and post-combustion emissions control options. Phase 1 activities were primarily aimed at providing a reliable, representative test facility for conducting air toxic emissions control development work later in the project. This report summarizes the AECDP Phase I activities which consisted of the design, installation, shakedown, verification, and air toxics benchmarking of the AECDP facility. All verification and air toxic tests were conducted with a high sulfur, bituminous Ohio coal.
Date: February 29, 1996
Partner: UNT Libraries Government Documents Department

Ohio Coal Research Consortium fourth year final summary report, September 1, 1993--August 31, 1994

Description: As a part of its efforts to improve the use of high-sulfur Ohio coal within environmental limits, the Ohio Coal Development Office, an entity within the Ohio Department of Development (OCDO/ODOD), in late 1988 established a consortium of four Ohio universities. The purpose of the Ohio Coal Research Consortium is to conduct a multi-year fundamental research program focused on (1) the enhancement or development of dry sorption processes for the economical removal of high levels of SO{sub 2} and other pollutants and (2) an increased understanding of methods for reduction in air toxics emissions from combustion gases produced by burning high-sulfur Ohio coal. This report contains summaries of twelve studies in these areas.
Date: May 1, 1995
Partner: UNT Libraries Government Documents Department

SOx-NOx-Rox Box{trademark} flue gas clean-up demonstration. Final report

Description: The SNRB{trademark} Flue Gas Cleanup Demonstration Project was cooperatively funded by the U.S. Department of Energy (DOE), the Ohio Coal Development Office (OCDO), B&W, the Electric Power Research Institute (EPRI), Ohio Edison, Norton Chemical Process Products Company and the 3M Company. The SNRB{trademark} technology evolved from the bench and laboratory pilot scale to be successfully demonstrated at the 5-MWe field scale. Development of the SNRB{trademark} process at B&W began with pilot testing of high-temperature dry sorbent injection for SO{sub 2} removal in the 1960`s. Integration of NO{sub x} reduction was evaluated in the 1970`s. Pilot work in the 1980`s focused on evaluation of various NO{sub x} reduction catalysts, SO{sub 2} sorbents and integration of the catalyst with the baghouse. This early development work led to the issuance of two US process patents to B&W - No. 4,309,386 and No. 4,793,981. An additional patent application for improvements to the process is pending. The OCDO was instrumental in working with B&W to develop the process to the point where a larger scale demonstration of the technology was feasible. This report represents the completion of Milestone M14 as specified in the Work Plan. B&W tested the SNRB{trademark} pollution control system at a 5-MWe demonstration facility at Ohio Edison`s R. E. Burger Plant located near Shadyside, Ohio. The design and operation were influenced by the results from laboratory pilot testing at B&W`s Alliance Research Center. The intent was to demonstrate the commercial feasibility of the SNRB{trademark} process. The SNRB{trademark} facility treated a 30,000 ACFM flue gas slipstream from Boiler No. 8. Operation of the facility began in May 1992 and was completed in May 1993.
Date: September 1, 1995
Partner: UNT Libraries Government Documents Department

SNRB{trademark} air toxics monitoring. Final report

Description: Babcock & Wilcox (B&W) is currently conducting a project under the DOE`s Clean Coal Technology (CCT II) Program to demonstrate its SO{sub x}NO{sub x}-Rox Box{trademark} (SNRB{trademark}) process in a 5 MWe Field Demonstration Unit at Ohio Edison`s R. E. Burger Plant near Shadyside, Ohio. The objective of the SNRB{trademark} Air Toxics Monitoring Project was to provide data on SNRB{trademark} air toxics emissions control performance to B&W and to add to the DOE/EPRI/EPA data base by quantifying the flow rates of selected hazardous substances (or air toxics) in all of the major input and output streams of the SNRB{trademark} process as well as the power plant. Work under the project included the collection and analysis of representative samples of all major input and output streams of the SNRB{trademark} demonstration unit and the power plant, and the subsequent laboratory analysis of these samples to determine the partitioning of the hazardous substances between the various process streams. Material balances for selected air toxics were subsequently calculated around the SNRB{trademark} and host boiler systems, including the removal efficiencies across each of the major air pollution control devices. This report presents results of the SNRB{trademark} Air Toxics Monitoring Project. In addition to the Introduction, a brief description of the test site, including the Boiler No. 8 and the SNRB{trademark} process, is included in Section H. The concentrations of air toxic emissions are presented in Section II according to compound class. Material balances are included in Section IV for three major systems: boiler, electrostatic precipitator, and SNRB{trademark}. Emission factors and removal efficiencies are also presented according to compound class in Sections V and VI, respectively. A data evaluation is provided in Section VII.
Date: January 1, 1994
Partner: UNT Libraries Government Documents Department

The use of ethanol to remove sulfur from coal. Final report, September 1991--December 1992

Description: In developing the new Ohio University procedure the thermodynamic limitations of the reactions for removal of both pyritic and organic sulfur from coal at 400--600{degrees}C were studied using copper as a very strong H{sub 2}S-acceptor. Copper serves as a catalyst for ethanol dehydrogenation to form nascent hydrogen. Copper also serves as a scavenger to form copper sulfide from the hydrogen sulfide evolved during the reaction. Copper sulfide in turn serves as a catalyst for organic sulfur hydrodesulfurization reactions. If the coal to be desulfurized contains pyrite (FeS{sub 2}) or FeS, the copper scavenger effect reduces any back reaction of hydrogen sulfide with the iron and increases the removal of sulfur from the carbonaceous material. The desired effect of using copper can be achieved by using copper or copper containing alloys as materials of construction or as liners for a regenerable reactor. During the time period that Ohio Coal Development Office supported this work, small scale (560 grams) laboratory experiments with coals containing about 3.5% sulfur have achieved up to 90% desulfurization at temperatures of 500{degrees}C when using a copper reactor. Results from the autoclave experiments have identified the nature of the chemical reactions taking place. Because the process removes both pyritic and organic sulfur in coal, the successful scale up of the process would have important economic significance to the coal industry. Even though this and other chemical processes may be relatively expensive and far from being commercial, the reason for further development is that this process may hold the promise of achieving much greater sulfur reduction and of producing a cleaner coal than other methods. This would be especially important for small or older power plants and industrial boilers.
Date: April 15, 1993
Partner: UNT Libraries Government Documents Department

Kinetics studies, thermal decomposition and carbonation. Final report

Description: The purpose of this project is to study the fundamental nature of the sorbent reactivity and reaction kinetics in the medium temperature range from 600 to 1200{degrees}F available in the convective pass of a boiler upstream of the economizer, where dry sorbents and anhydrous ammonia are injected to reduce SO{sub 2}, and NO{sub 2}, from the flue gas. The following conclusions are drawn from the results of the third year of study. The dehydration conversion increased with reaction temperature from 3% at 600{degrees}F to 36% at 1100{degrees}F. The fresh CaO from the dehydration reaction of Ca(OH){sub 2} is very active in air. The carbonation conversion increases slightly with residence time from 50ms to 75ms. In the simultaneous carbonation/sulfation reaction the carbonation conversion increased continuously with the reaction temperature from 600{degrees}F to 1100{degrees}F. By comparing the sulfation conversion of Ca(OH){sub 2} and CaO at 900{degrees}F and residence times from 50 to 75ms, it is found that the sulfation conversion of CaO at this temperature range was significant and could not be ignored. The carbonation reaction took place simultaneously with sulfation reaction under the fixed bed and drop-tube reactor conditions.
Date: September 1, 1993
Partner: UNT Libraries Government Documents Department

Investigation of the use of fly-ash based autoclaved cellular concrete blocks in coal mines for air duct work. Final report, January 25, 1993--December 31, 1994

Description: Coal mines are required to provide ventilation to occupied portions of underground mines. Concrete block is used in this process to construct air duct walls. However, normal concrete block is heavy and not easy to work with and eventually fails dramatically after being loaded due to mine ceiling convergence and/or floor heave. Autoclaved cellular concrete block made from (70{plus_minus}%) coal fly ash is lightweight and less rigid when loaded. It is lighter and easier to use than regular concrete block for underground mine applications. It has also been used in surface construction around the world for over 40 years. Ohio Edison along with eight other electric utility companies, the Electric Power Research Institute (EPRI), and North American Cellular Concrete constructed a mobile demonstration plant to produce autoclaved cellular concrete block from utility fly ash. To apply this research in Ohio, Ohio Edison also worked with the Ohio Coal Development Office and CONSOL Inc. to produce autoclaved cellular concrete block not only from coal ash but also from LIMB ash, SNRB ash, and PFBC ash from various clean coal technology projects sponsored by the Ohio Coal Development Office. The purpose of this project was to demonstrate the potential for beneficial use of fly ash and clean coal technology by-products in the production of lightweight block.
Date: June 19, 1995
Creator: Horvath, M.L.
Partner: UNT Libraries Government Documents Department

New high-capacity, calcium-based sorbents, calcium silicate sorbents. Final report

Description: A search is being carried out for new calcium-based SO{sub 2} sorbents for induct injection. More specifically, a search is being carried out for induct injection calcium silicate sorbents that are highly cost effective. The current year objectives include the study of sorbents made by hydrating ordinary or Type I portland cement or portland cement clinker (a cement intermediate) under carefully selected conditions. Results of this study show that an excellent portland cement sorbent can be prepared by milling cement at 120{degrees}C at 600 rpm for 15 minutes with MgO-stabilized ZrO{sub 2} beads. They also show that clinker, which is cheaper than cement can be used interchangeably with cement as a starting material. Further, it is clear that while a high surface area may be a desirable property of a good sorbent, it is not a requisite property. Among the hydration reaction variables, milling time is highly important, reaction temperature is important and stirring rate and silicate-to-H{sub 2}O ratio are moderately important. The components of hydrated cement sorbent are various combinations of C-S-H, calcium silicate hydrate:Ca(OH){sub 2};AFm. a phase in hydrated cement.
Date: February 28, 1996
Creator: Kenney, M.E.
Partner: UNT Libraries Government Documents Department

IGR combined NO{sub x}/SO{sub x} control technology. Phase 1, volume 1.

Description: The objective of this project is to develop and demonstrate the feasibility of a new, simple, modular, all solid-state electrochemical technology for the simultaneous removal of NO{sub x} and SO{sub x} pollutants from coal-fired combustors, in a cost effective, reliable and practical manner. The work accomplished in this Phase 1 project involved the formulation and testing of proprietary materials for NO{sub x} and SO{sub x} removal under conditions appropriate to coal-fired combustors for electric power production. The Phase 1 work also explored methods for reduction of the operating temperatures of the process, reduction of its power requirements, and increasing the levels of NO{sub x} and SO{sub x} removal at higher levels of oxygen. The Phase 1 work has demonstrated the basic technical feasibility of IGR`s NO{sub x}/SO{sub x} removal technology. We have successfully achieved NO{sub x} and SO{sub x} removal in the presence of large concentrations of oxygen (including the range of oxygen levels in coal-fired combustors). We have demonstrated successful operation of IGR`s NO{sub x}/SO{sub x} removal technology at greatly reduced operating temperatures. Significant progress has been made in the reduction of the electrical power requirement of the removal process. In particular, NO{sub x} removal has been accomplished at power consumption levels that are economically feasible. In addition, the ability of this technology to remove SO{sub 2} from a high concentration gas stream (such as that generated from the copper oxide absorption process) has been demonstrated. In summary, the Phase 1 work has served to resolve the basic feasibility questions associated with this technology. The importance of the Phase 1 work is that it has greatly reduced the technical risk associated with IGR`s NO{sub x}/SO{sub x} removal technology, which makes the development of commercially feasible devices highly probable.
Date: October 1, 1995
Creator: Gordon, A.Z.
Partner: UNT Libraries Government Documents Department

The effect of additives on lime dissolution rates. Final report

Description: Based on the previous years` studies concerning the efficiency of SO{sub 2} removal by spray dryers with high sulfur coal flue gas, the work for year five included investigations of lime dissolution rates at different slaking conditions and with the effect of additives. The prominent additives that have significant effects on lime dissolution rates were tested with the mini pilot spray drying absorber to see their effects on spray drying desulfurization applications. The mechanisms of these additive effects along with the properties of hygroscopic additives have been discussed and incorporated into the spray drying desulfurization model ``SPRAYMOD-M.`` Slaking conditions are very important factors in producing high quality lime slurry in spray drying desulfurization processes. At optimal slaking conditions, the slaked lime particles are very fine (3-5{mu}m) and the slaked lime has high BET surface areas which are beneficial to the desulfurization. The slaked lime dissolution rate experiments in our study are designed to determine how much lime can dissolve in a unit time if the initial lime surface area is kept constant. The purpose of the dissolution rate study for different additives is to find those effective additives that can enhance lime dissolution rates and to investigate the mechanisms of the dissolution rate enhancement properties for these additives. The applications of these additives on spray drying desulfurization are to further verify the theory that dissolution rate is a rate limiting step in the whole spray drying desulfurization process as well as to test the feasibility of these additives on enhancing SO{sub 2} removal in spray dryers.
Date: July 31, 1996
Creator: Khang, S.J.
Partner: UNT Libraries Government Documents Department

Adsorption and desorption of sulfur dioxide on novel adsorbents for flue gas desulfurization. Final report, September 1, 1993--August 31, 1994

Description: Dry regenerative sorption processes have recently attracted increasing attention in flue gas desulfurization (FGD) because of their several advantages over the conventional wet-scrubbing processes. Dry sorbents are usually made by coating a transition or alkaline earth metal precursor on the surface of a porous support. Major disadvantages of these sorbents prepared by the conventional methods include relatively poor attrition resistance and low SO{sub 2} sorption capacity. The physical and especially chemical attrition (associated with the sulphation-oxidation-reduction cycles in the process) deteriorates the performance of the sorbents. The low SO{sub 2} sorption capacity is primarily due to the small surface area of the support. Materials with a high surface area are not used as the supports for FGD sorbents because these materials usually are not thermally stable at high temperatures. In the past year, the research supported by Ohio Coal Development Office was focused on synthesis and properties of sol-gel derived alumina and zeolite sorbents with improved properties for FGD. The sol-gel derived alumina has large surface area, mesopore size and excellent mechanical strength. Some alumina-free zeolites not only posses the basic properties required as a sorbent for FGD (hydrophobicity, thermal and chemical stability, mechanical strength) but also have extremely large surface area and selective surface chemistry. The major objectives of this research program were to synthesize the sol-gel derived sorbents and to explore the use of the zeolites either directly as adsorbents or as sorbent support for FGD. The research was aimed at developing novel FGD sorbents possessing better sorption equilibrium and kinetic properties and improved physical and chemical attrition resistance.
Date: February 1, 1995
Creator: Lin, Y.S.
Partner: UNT Libraries Government Documents Department

Development of new sorbents to remove mercury and selenium from flue gas. Final report, September 1, 1993--August 31, 1994

Description: Mercury (Hg) and selenium (Se) are two of the volatile trace metals in coal, which are often not captured by conventional gas clean up devices of coal-fired boilers. An alternative is to use sorbents to capture the volatile components of trace metals after coal combustion. In this project sorbent screening tests were performed in which ten sorbents were selected to remove metallic mercury in N{sub 2}. These sorbents included activated carbon, char prepared from Ohio No. 5 coal, molecular sieves, silica gel, aluminum oxide, hydrated lime, Wyoming bentonite, kaolin, and Amberite IR-120 (an ion-exchanger). The sorbents were selected based on published information and B&W`s experience on mercury removal. The promising sorbent was then selected and modified for detailed studies of removal of mercury and selenium compounds. The sorbents were tested in a bench-scale adsorption facility. A known amount of each sorbent was loaded in the column as a packed bed. A carrier gas was bubbled through the mercury and selenium compounds. The vaporized species were carried by the gas and went through the sorbent beds. The amount of mercury and selenium compounds captured by the sorbents was determined by atomic absorption. Results are discussed.
Date: February 1, 1995
Creator: Shiao, S.Y.
Partner: UNT Libraries Government Documents Department

Supported-sorbent injection. Final report

Description: A new retrofitable, wastefree acid-rain control concept was pilot-tested at Ohio Edison`s high-sulfur coal-fired R.E. Burger generating station at the 2-MWe level. During the project, moistened {open_quotes}supported{close_quotes} sorbents, made from a combination of lime and vermiculite or perlite, were injected into a humidified 6,500-acfm flue-gas slipstream. After the sorbents reacted with the sulfur dioxide in the flue gas, they were removed from ductwork with a cyclone and baghouse. The $1.0 million project was co-funded by Sorbent Technologies Corporation, the Ohio Edison Company, and the Ohio Coal Development Office. The project included a preliminary bench-scale testing phase, construction of the pilot plant, parametric studies, numerous series of recycle tests, and a long-term run. The project proceeded as anticipated and achieved its expected results. This duct injection technology successfully demonstrated SO{sub 2}-removal rates of 80 to 90% using reasonable stoichiometric injection ratios (2:1 Ca:S) and approach temperatures (20-25F). Under similar conditions, dry injection of hydrated lime alone typically only achieves 40 to 50% SO{sub 2} removal. During the testing, no difficulties were encountered with deposits in the ductwork or with particulate control, which have been problems in tests of other duct-injection schemes.
Date: July 1, 1997
Creator: Nelson, S. Jr.
Partner: UNT Libraries Government Documents Department

Ohio Coal Testing and Development Facility - Construction and operation. Final report

Description: On June 14, 1987, the Ohio Coal Development Office (OCDO) executed a grant agreement with ICF Kaiser Engineers (ICF Kaiser) for the planning and design (Phase I) of a Demonstration Advanced Technology Coal Preparation Facility. Subsequently, on December 1, 1990, OCDO executed a grant agreement with the American Electric Power Service Corporation (AEPSC) through its subsidiary, the Ohio Power Company, for the final design and construction (Phase II), testing and operation (Phase III), and marketing and future operation (Phase IV) of the facility. These phases were subcontracted to ICF Kaiser. AEPSC co-sponsored the project and donated a site at the Central Ohio Coal Company`s Unionville Coal Preparation Plant for locating the test plant. Central Ohio Coal supplied coal handling services, waste-product disposal, and water. The Ohio Power Company provided project oversight, electric power, and the test coals. The test results from the operation of the 30 tph advanced coal cleaning plant demonstrated that combining conventional physical coal cleaning with emerging advanced physical coal cleaning technologies was a cost-effective method to reduce sulfur emissions of Ohio coals. The following is a summary of the key findings of this project.
Date: March 1, 1996
Creator: Ferris, D.D.
Partner: UNT Libraries Government Documents Department

Development of advanced, dry, SO{sub x}/NO{sub x} emission control technologies for high-sulfur coal. Final report, April 1, 1993--December 31, 1994

Description: Dry Scrubbing is a common commercial process that has been limited to low- and medium-sulfur coal applications because high-sulfur coal requires more reagent than can be efficiently injected into the process. Babcock & Wilcox has made several advances that extend dry scrubbing technologies to higher sulfur coals by allowing deposit-free operation at low scrubber exit temperatures. This not only increases the amount of reagent that can be injected into the scrubber, but also increases SO{sub 2} removal efficiency and sorbent utilization. The objectives of this project were to demonstrate, at pilot scale, that advanced, dry-scrubbing-based technologies can attain the performance levels specified by the 1990 Clean Air Act Amendments for SO{sub 2} and NO{sub x} emissions while burning high-sulfur coal, and that these technologies are economically competitive with wet scrubber systems. The use of these technologies by utilities in and around Ohio, on new or retrofit applications, will ensure the future of markets for high-sulfur coal by creating cost effective options to coal switching.
Date: December 23, 1994
Creator: Amrhein, G.T.
Partner: UNT Libraries Government Documents Department

Demonstration of an advanced circulation fludized bed coal combustor phase 1: Cold model study. Final report

Description: It was found that there was a strong dependence of the density profile on the secondary air injection location and that there was a pronounced solid separation from the conveying gas, due to the swirl motion. Furthermore, the swirl motion generated strong internal circulation patterns and higher slip velocities than in the case of nonswirl motion as in an ordinary circulating fluidized bed. Radial solids flux profiles were measured at different axial locations. The general radial profile in a swirling circulating fluidized bed indicated an increased downward flow of solids near the bed walls, and strong variations in radial profiles along the axial height. For swirl numbers less than 0.9, which is typical for swirling circulating fluidized beds, there is no significant increase in erosion due to swirl motion inside the bed. Pending further investigation of swirl motion with combustion, at least from our cold model studies, no disadvantages due to the introduction of swirl motion were discovered.
Date: March 20, 1993
Creator: Govind, R.
Partner: UNT Libraries Government Documents Department

Application of a new sorbent for combined SO{sub 2} and NO{sub x} removal. Final report

Description: The overall objective of this project was to further develop the application of a new class of dry, granular, SO{sub 2}/NO{sub x}-sorbent materials to bring them closer towards commercial usage in utility and industrial air-pollution control systems. The new sorbents are composite materials consisting of magnesium oxide (MgO) or calcium oxide (CaO) bonded to and reacted with vermiculite, a low-cost expanded silicate carrier. The sorbents possess some very unique and desirable properties. These properties include a higher-than-normal affinity for sulfur and nitrogen oxides in stack gases, excellent SO{sub 2}-removal efficiencies and attractive utilization rates at common stack gas temperatures, and the ability to be regenerated. The materials typically remove 99 percent of the SO{sub 2} and a significant percentage of the NO{sub x} in flue gases with high sorbent utilizations. Specific objectives of the project were to evaluate the performance of different continuous methods of employing the new sorbent materials in removing SO{sub 2} and NO{sub x} from a power plant flue gas, to examine the regeneration of one particularly promising sorbent composition: 45 wt % MgO-55 wt % Vermiculite, and to develop a sorption-regeneration system and cost estimates based on this material. The objectives were met in the project. The cost of the 15-month project was $229,717, of which OCDO provided $149,972 and Sanitech provided the remainder. In additions Sanitech and Ohio Edison made significant in-kind contributions to the project, in the form of existing facilities and equipment. The results of this project should help move the new technology forward toward commercialization. Required now are scale-ups of the new technology at more meaningful sizes.
Date: September 1, 1989
Creator: Nelson, S. G.
Partner: UNT Libraries Government Documents Department

Extraction of potential pollutants from Ohio coal by synergistic use of supercritical fluids. Final report

Description: A synergistic supercritical extraction process was developed and its feasibility demonstrated using a semi-batch extraction process unit. The process was found to be effective in selectively cleaning organic sulfur from Ohio coals. Optimal case involved a mixture of CO{sub 2}, H{sub 2}O, and CH{sub 3}OH, and the removal of organic sulfur ranged from 35 to 55%. Combined with pyrite and mineral matter removal by gravity, the resulting coals would have 20--30% increased heating values and SO{sub 2} emissions would be down to 1.2--1.5 pounds per million Btu, thus meeting compliance requirements. Estimated cleaning cost including pyrite removal is $25 to 45 per ton. The most important cost factor is the operation at high pressures.
Date: August 3, 1990
Creator: Lee, S.
Partner: UNT Libraries Government Documents Department

Slurry combustion. Volume 1, Text: Final report

Description: The project described in this Report was to investigate the possibility of using sorbent added to coal-water fuel (CWF) mixtures as a means of reducing SOX emissions when burning Ohio coal. The results are significantly encouraging, with SOX concentrations reduced by amounts ranging from 25% to 65%, depending on the sorbent type and the firing conditions, where one major condition identified was the residence time in the flame gases. With the sorbent-loaded slurrys, the trend generally showed increasing SO{sub 2} capture with increasing sorbent loading. There were significant differences between the two different mixture formulations, however: The calcite/No. 8-seam mixture showed significantly higher SO{sub 2} capture at all times (ranging from 45% to 65%) than did the dolomite/No. 5 seam mixture (ranging from 25% to 45%). If the successes so far achieved are not to be wasted, advantage should be taken of these encouraging results by extending the work at both the present scale to determine the other unknown factors controlling sorption efficiency, and at larger scale to start implementation in commercial systems.
Date: June 21, 1993
Creator: Essenhigh, R.
Partner: UNT Libraries Government Documents Department

Sulfur release from Ohio coals and sorbent kinetics in pulverized coal flames. Final report

Description: In this report we describe the results of investigations into the structure of combustion and sulfur release profiles from coal burning in One-Dimensional P.C. flames using a furnace of unique design for the measurements. Selected measurements were also-carried out in a special high-intensity furnace also of unique design. The formal project work started in late Fall 1989, with unfunded preliminary work in the months prior to that. The process of limestone injection into the flame to control sulfur oxides emissions is a long-standing concept that has been given particular formulation in the LIMB process, and studies of such systems provide bases for commercial system economics. Problems with LIMB and related systems indicated need for better understanding of, jointly, the sulfur release from the coal and the sorbent behavior by the limestone. The investigations as reported in Vol. 1 of this Report used 14 different coals under a range of different initial and operating conditions, and the resulting measurements have provided a database of major proportions, as tabulated in the attached Volumes 2, 3, 4, 5, 6, and 7 of this report. This database consists of sets of measurements totalling about 45,000 entries for all independent and dependent parameters involved. The independent parameters included: coal type (analysis), firing rate, stoichiometry (fuel/air ratio), and sorbent content of the
Date: August 1, 1992
Creator: Essenhigh, R.
Partner: UNT Libraries Government Documents Department

Coal desulfurization by bacterial treatment and column flotation. Final report

Description: A review of the literature showed that bacterial leaching, using the microorganism Thiobacillus ferrooxidans, was a very effective technique for removing pyrite from coal, as it could dissolve even the finest pyrite particles without the need for expensive reagents or extreme processing conditions. Unfortunately, bacterial leaching is also rather slow, and so the initial goal of this research was to decrease the leaching time as much as possible. However, this still left the bacteria needing approximately a week to remove half of the pyritic sulfur, and so a faster technique was sought. Since it had been reported in the literature that T. ferrooxidans could be used to depress the flotation of pyrite during froth flotation of coal, this was investigated further. By studying the recovery mechanisms of coal-pyrite in froth flotation, it was found that pyrite was being recovered by entrainment and by locking to coal particles, not by true flotation of hydrophobic pyrite. Therefore, no pyrite depressant could be of any significant benefit for keeping pyrite out of the coal froth product, and it was much more important to prevent entrainment from occurring. Countercurrent flotation columns were invented to essentially eliminate entrainment effects, by washing the froth and reducing mixing of the froth and tailings products. Existing flotation columns tend to be quite simple, and in order to give reasonable product quality they must be very tall (typically 30--45 feet). As a result, they have difficulty in handling the high froth volumes which occur in coal flotation, and are awkward to install in existing plants. The bulk of this project therefore concentrated on developing an improved coal flotation column, and testing it under actual plant conditions.
Date: June 1, 1994
Creator: Kawatra, S. K.
Partner: UNT Libraries Government Documents Department