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Fundamental studies of retrograde reactions in direct liquefaction

Description: Most of the proposed processing schemes for improving liquefaction yields involve favoring bond-breaking and radical stabilization reactions over the retrograde reactions. The retrograde reactions are often encountered before liquefaction temperatures are reached. The objective of this program is to elucidate and model the retrograde reaction chemistry in direct coal liquefaction through the application of experimental techniques and theoretical models which have been successfully employed at Advanced Fuel Research (AFR) and SRI International (a subcontractor) to understand and predict coal reaction behavior. The study of retrograde reactions is being done using an integrated approach using extensive characterization of the liquefaction chemistry of three kinds of systems: (1) model polymers; (2) coal; and (3) modified coals.
Date: January 1, 1989
Creator: Serio, M.A.; Solomon, P.R.; Bassilakis, R. & Kroo, E.
Partner: UNT Libraries Government Documents Department

Fundamental studies of water pretreatment of coal

Description: The goals of this project are to gain an understanding of the chemistry of water or steam coal pretreatments and to assess the importance of such pretreatments on subsequent coal liquefaction. For the achievement of these goals, coals, modified coals and model-polymers will be treated with water or steam. This study will include three coals, five modifications (dried, demineralized, ion-exchanged, Ca-loaded, Ba-loaded), three polymers and two polymer modifications (e.g., acid chlorides, amides). Experiments will be performed to investigate both conventional steam pretreatment and the possibility of using the CO/H{sub 2}O system of Ross and coworkers as a pretreatment method. The main experimental variables will be sample type and temperature. Detailed characterization of the gas, liquid and solid products from the pretreatment stage will be done. This will include analysis of gases by GC or FT-IR, liquids by capillary GC, FT-IR and FIMS, and residues by solvent swelling, solvent extraction, and elemental analysis. Selected residues will also be evaluated by a standard liquefaction test. Analysis of the raw coals and pretreatment samples will be performed using the above techniques to study changes in the crosslinking, donatable hydrogen, heteroatom composition, evolved gases, functional group composition, extraction yields, molecular weight distributions, etc. Standard tubing bomb liquefaction tests will be used to determine the effect of pretreatment on coal reactivity toward coal liquefaction. A previously developed model for coal liquefaction, the FG-DVC liquefaction model, will be used (after appropriate modifications) to model the physics and chemistry of water pretreatment.
Date: January 1, 1991
Creator: Serio, M.A.; Kroo, E.; Solomon, P.R.; Charpenay, S. & Bassilakis, R.
Partner: UNT Libraries Government Documents Department

Fundamental studies of retrograde reactions in direct liquefaction

Description: The overall objective of the program was to improve the understanding of retrograde reactions and their dependencies on coal rank and structure, and/or coal modifications and reaction conditions. Because retrograde reactions are competitive with bond breaking reactions, an understanding of both is required to shift the competition in favor of the latter. Related objectives were to clarify the conflicting observations reported in literature on such major topics as the role of oxygen groups in retrograde reactions and to provide a bridge from very fundamental studies on pure compounds to phenomenological studies on actual coal. This information was integrated into the FG-DVC model, which was improved and extended to the liquefaction context.
Date: December 17, 1991
Creator: Serio, M.A.; Solomon, P.R.; Kroo, E.; Charpenay, S. & Bassilakis, R.
Partner: UNT Libraries Government Documents Department

Fundamental studies of water pretreatment of coal

Description: During the seventh quarter, water pretreatment experiments were done at lower pressures (1000 psig), with early H{sub 2}O injection or continuous H{sub 2}O injection, and with demineralized coals. In addition, a set of blank experiments was done with all four coals in helium at the following conditions: 350{degrees}C; 4000 psig; 20 minutes. An additional experiment was done with the Zap lignite at atmospheric pressure. Helium was used instead of nitrogen since it can be obtained in highly pure grades. The purpose of the blank experiments is to determine how much of the water pretreatment process is a thermal and/or pressure effort. The residues from the standard water pretreatment experiments with Illinois and Pittsburgh coals were subjected to analysis by TG-FTIR, solvent extraction, solvent swelling, oxygen reactivity index and donor solvent liquefaction. The pyridine extractables were analyzed. With regard to liquefaction behavior, improvements in the yields of oils and toluene solubles are observed for selected Illinois and Pittsburgh coals at longer pretreatment times ({ge} 60 minutes).
Date: October 25, 1991
Creator: Serio, M.A.; Solomon, P.R.; Kroo, E.; Charpenay, S. & Bassilakis, R.
Partner: UNT Libraries Government Documents Department

The dual role of oxygen functions in coal pretreatment and liquefaction: Crosslinking and cleavage reactions

Description: One objective of this program is to prepare polymer models having phenolic, carboxylic, and/or aryl ether groups considered to be important in low rank coals. In order to study the chemistry of these functional groups in a polymeric matrix, it is necessary that the polymer backbone itself should not be subject to cleavage under the reaction conditions. It is expected that poly(phenylene) would fulfill this requirement as a backbone, while providing simple mechanical routes for attaching other functional groups. During this reporting period, the synthesis of oligomeric species such as sexi(phenylene) and octa(phenylene) was explored. The procedure of Bamfield and Quam was followed, which involves heating a paste of bromoarenes, water, sodium formate and Pd/C. The reaction products turned out to be very insoluble and difficult to purify. The insolubility of these products makes them difficult to work with, and it is doubtful that we will be able to prepare well-characterized polymers in the 10,000 Da range. We are presently considering other polymeric substrates that might serve as the backbone. Pending the resolution of the polymeric substrate issue, the thermal behavior of the carboxyl and phenolic functions and the effect of ion-exchange will be studied using monomeric models. These studies will be needed to establish the baseline for considering the effect of the polymeric environment.
Date: January 1, 1991
Creator: Serio, M.A.; Kroo, E.; Teng, Hsisheng; Charpenay, S. & Solomon, P.R.
Partner: UNT Libraries Government Documents Department

Fundamental studies of water pretreatment of coal

Description: The goals of this project are to gain understanding of the chemistry of water or steam coal pretreatments and to assess the importance of such pretreatments on subsequent coal liquefaction. For the achievement of these goals, coals, modified coals and model-polymers will be treated with water or stream. This study will include three coals, five modifications (dried, demineralized, ion-exchanged, Ca-loaded, Ba-loaded), three polymers and two polymer modifications (e.g. acid chlorides, amides). Experiments will be performed to investigate both conventional steam pretreatment and the possibility of using the CO/H{sub 2}O system of Ross and coworkers as a pretreatment method. The main experimental variables will be sample type and temperature. Detailed characterization of the gas, liquid and solid products from the pretreatment stage will be done. This will include analysis of gases of GC or FT-IR, liquids by capillary GC, FT-IR and FIMS, and residues by solvent swelling, solvent extraction, and elemental analysis. Selected residues will also be evaluated by a standard liquefaction test. Analysis of the raw coals and pretreatment samples will be performed using the above techniques to study changes in the crosslinking, donatable hydrogen, heteroatom composition, evolved gases, functional group composition, extraction yields, molecular weight distributions, etc. Standard tubing bomb liquefaction tests will be used to determine the effect of pretreatment on coal reactivity toward coal liquefaction. A previously developed model for coal liquefaction, the FG-DVC liquefaction model, will be used (after appropriate modifications) to model the physics and chemistry of water pretreatment. 1 ref., 2 figs., 1 tab.
Date: January 1, 1990
Creator: Serio, M.A.; Solomon, P.R.; Kroo, E.; Charpenay, S. & Bassilakis, R.
Partner: UNT Libraries Government Documents Department

Fundamental studies of water pretreatment of coal

Description: The goals of this project are to gain understanding of the chemistry of water or steam coal pretreatments and to assess the importance of such pretreatments on subsequent coal liquefaction. Coals, modified coals and model-polymers will be treated with water or steam. This study will include three coals, five modifications (dried, demineralized, ion-exchanged, Ca-loaded, Ba-loaded), three polymers and two polymer modifications (e.g. acid chlorides, amides). Experiments will be performed to investigate both conventional steam pretreatment and the possibility of using the CO/H{sub 2}O system of Ross and coworkers as a pretreatment method. The main experimental variables will be sample type and temperature. Detailed characterization of the gas, liquid and solid products from the pretreatment stage will be done. This will include analysis of gases by GC or FT-IR, liquids by capillary GC, FT-IR and FIMS, and residues by solvent swelling, solvent extraction, and elemental analysis. Selected residues will also be evaluated by a standard liquefaction test. Analysis of the raw coals and pretreatment samples will be performed using the above techniques to study changes in the crosslinking, donatable hydrogen, heteroatom composition, evolved gases, functional group composition, extraction yields, molecular weight distributions, etc. Standard tubing bomb liquefaction tests will be used to determine the effect of pretreatment on coal reactivity toward coal liquefaction. A previously developed model for coal liquefaction, the FG-DVC liquefaction model, will be used (after appropriate modifications) to model the physics and chemistry of water pretreatment. 3 figs., 3 tabs.
Date: January 1, 1990
Creator: Serio, M.A.; Solomon, P.R.; Kroo, E.; Charpenay, S. & Bassilakis, R.
Partner: UNT Libraries Government Documents Department

Fossil fuel conversion -- Measurement and modeling

Description: The main objective of this program is to understand the chemical and physical mechanisms in coal conversion processes and incorporate this knowledge in computer-aided reactor engineering technology for the purposes of development, evaluation, design, scale up, simulation, control and feedstock evaluation in advanced coal conversion devices. To accomplish this objective, this program will: (1) provide critical data on the physical and chemical processes in fossil fuel gasifier and combustors; (2) further develop a set of comprehensive codes; and (3) apply these codes to model various types of combustors and gasifier (fixed-bed, transport reactor, and fluidized-bed for coal and gas turbines for natural gas). Results are presented on the devolatilization of large coal particles; transport reactor modeling; fluidized bed model; nitrogen evolution from small and large coal particles; modeling of hydrogen cyanide and ammonia release during coal pyrolysis; oxidation rates for large coal particles at high pressures; advanced fixed-bed model development and evaluation; application of ACERC combustion and gasification codes to AFR diagnostic capabilities to systems of interest to METC; and submodel for lean premixed combustion of natural gas in industrial gas turbines.
Date: November 1, 1995
Creator: Solomon, P.R.; Smoot, L.D.; Serio, M.A.; Hamblen, D.G.; Brewster, B.S. & Radulovic, P.T.
Partner: UNT Libraries Government Documents Department

Measurement and modeling of advanced coal conversion processes

Description: The objectives of this study are to establish the mechanisms and rates of basic steps in coal conversion processes, to integrate and incorporate this information into comprehensive computer models for coal conversion processes, to evaluate these models and to apply them to gasification, mild gasification and combustion in heat engines. (VC)
Date: September 25, 1991
Creator: Solomon, P.R.; Serio, M.A.; Hamblen, D.G. (Advanced Fuel Research, Inc., East Hartford, CT (United States)); Smoot, L.D. & Brewster, B.S. (Brigham Young Univ., Provo, UT (United States))
Partner: UNT Libraries Government Documents Department

Measurement and modeling of advanced coal conversion processes

Description: The overall objective of this program is the development of predictive capability for the design, scale up, simulation, control and feedstock evaluation in advanced coal conversion devices. This technology is important to reduce the technical and economic risks inherent in utilizing coal, a feedstock whose variable and often unexpected behavior presents a significant challenge. This program will merge significant advances made at Advanced Fuel Research, Inc. (AFR) in measuring and quantitatively describing the mechanisms in coal conversion behavior, with technology being developed at Brigham Young University (BYU) in comprehensive computer codes for mechanistic modeling of entrained-bed gasification. Additional capabilities in predicting pollutant formation will be implemented and the technology will be expanded to fixed-bed reactors. The foundation to describe coal-specified conversion behavior is ARF's Functional Group (FG) and Devolatilization, Vaporization, and Crosslinking (DVC) models, developed under previous and on-going METC sponsored programs. These models have demonstrated the capability to describe the time dependent evolution of individual gas species, and the amount and characteristics of tar and char. The combined FG-DVC model will be integrated with BYU's comprehensive two-dimensional reactor model, PCGC-2, which is currently the most widely used reactor simulation for combustion or gasification. The program includes: (1) validation of the submodels by comparison with laboratory data obtained in this program, (2) extensive validation of the modified comprehensive code by comparison of predicted results with data from bench-scale and process scale investigations of gasification, mild gasification and combustion of coal or coal-derived products in heat engines, and (3) development of well documented user friendly software applicable to a workstation'' environment.
Date: January 1, 1990
Creator: Solomon, P.R.; Serio, M.A.; Hamblen, D.G. (Advanced Fuel Research, Inc., East Hartford, CT (United States)); Smoot, L.D. & Brewster, B.S. (Brigham Young Univ., Provo, UT (United States))
Partner: UNT Libraries Government Documents Department

Measurement and modeling of advanced coal conversion processes

Description: The objective of this study are to establish the mechanisms and rates of basic steps in coal conversion processes, to integrate and incorporate this information into comprehensive computer models for coal conversion processes, to evaluate these models and to apply them to gasification, mild gasification and combustion in heat engines.
Date: January 1, 1991
Creator: Solomon, P.R.; Serio, M.A.; Hamblen, D.G. (Advanced Fuel Research, Inc., East Hartford, CT (United States)); Smoot, L.D. & Brewster, B.S. (Brigham Young Univ., Provo, UT (United States))
Partner: UNT Libraries Government Documents Department

Measurement and modeling of advanced coal conversion processes

Description: The overall objective of this program is the development of predictive capability for the design, scale up, simulation, control and feedstock evaluation in advanced coal conversion devices. This program will merge significant advances made in measuring and quantitatively describing the mechanisms in coal conversion behavior. Comprehensive computer codes for mechanistic modeling of entrained-bed gasification. Additional capabilities in predicting pollutant formation will be implemented and the technology will be expanded to fixed-bed reactors.
Date: January 1, 1991
Creator: Solomon, P.R.; Serio, M.A.; Hamblen, D.G.; Smoot, L.D. & Brewster, B.S. (Advanced Fuel Research, Inc., East Hartford, CT (United States) Brigham Young Univ., Provo, UT (United States))
Partner: UNT Libraries Government Documents Department

Measurement and modeling of advanced coal conversion processes, Volume II

Description: A two dimensional, steady-state model for describing a variety of reactive and nonreactive flows, including pulverized coal combustion and gasification, is presented. The model, referred to as 93-PCGC-2 is applicable to cylindrical, axi-symmetric systems. Turbulence is accounted for in both the fluid mechanics equations and the combustion scheme. Radiation from gases, walls, and particles is taken into account using a discrete ordinates method. The particle phase is modeled in a lagrangian framework, such that mean paths of particle groups are followed. A new coal-general devolatilization submodel (FG-DVC) with coal swelling and char reactivity submodels has been added.
Date: June 1, 1993
Creator: Solomon, P. R.; Serio, M. A. & Hamblen, D. G.
Partner: UNT Libraries Government Documents Department

Measurement and modeling of advanced coal conversion processes, Volume I, Part 1. Final report, September 1986--September 1993

Description: The objective of this program was the development of a predictive capability for the design, scale up, simulation, control and feedstock evaluation in advanced coal conversion devices. The foundation to describe coal specific conversion behavior was AFR`s Functional Group and Devolatilization, Vaporization and Crosslinking (DVC) models, which had been previously developed. The combined FG-DVC model was integrated with BYU`s comprehensive two-dimensional reactor model for combustion and coal gasification, PCGC-2, and a one-dimensional model for fixed-bed gasifiers, FBED-1. Progress utilizing these models is described.
Date: September 1, 1995
Creator: Solomon, P.R.; Serio, M.A. & Hamblen, D.G.
Partner: UNT Libraries Government Documents Department

Measurement and modeling of advanced coal conversion processes, Volume I, Part 2. Final report, September 1986--September 1993

Description: This report describes work pertaining to the development of models for coal gasification and combustion processes. This volume, volume 1, part 2, contains research progress in the areas of large particle oxidation at high temperatures, large particle, thick-bed submodels, sulfur oxide/nitrogen oxides submodels, and comprehensive model development and evaluation.
Date: September 1, 1995
Creator: Solomon, P.R.; Serio, M.A. & Hamblen, D.G.
Partner: UNT Libraries Government Documents Department