Conrad J. Kulik

Flotation machine and process for removing impurities from coals

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

PROCESS ENGINEERING STUDIES OF THE PERCHLOROETHYLENE COAL CLEANING PROCESS

ABSTRACT The perchloroethylene coal cleaning process has proven to be very effective in removing both organic and pyritic sulfur from high-sulfur coals. The process removes 30%- 70% of the organic sulfur and 90%- 99% of the pyritic sulfur with very little loss (<1.0 wt%) of hydrocarbons and their heating value. The process has been investigated on a bench- scale and a fully continuous, mini-pilot scale (5 kg/hr). This paper discusses scientific and technological issues related to the process engineering and the reaction chemistry of the process. The objective of this paper is to report the status of the process development and to address the important issues of the process commercializability.

A SINGLE-STAGE, LIQUID-PHASE DIMETHYL ETHER SYNTHESIS PROCESS FROM SYNGAS I. DUAL CATALYTIC ACTIVITY AND PROCESS FEASIBILITY

ABSTRACT A novel process for manufacturing dimethyl ether (DME) from CO-rich syngas in a single stage has been developed. This novel approach was based on the application of dual catalysis in the liquid phase process, in which two functionally different catalysts are slurried in the inert mineral oil. The experimental reaction rate studies for methanol and dimethyl ether synthesis were conducted in a three-phase, mechanically agitated slurry reactor. The effects of catalyst ratio, temperature, and pressure on the dual catalytic activity were studied. The experimental data bear additional significance because this is the first study of such kind to be conducted on the liquid phase methanol synthesis process.

The roles of carbon dioxide in methanol synthesis

ABSTRACT The roles played by carbon dioxide in the chemistry of methanol synthesis over CuO/ZnO/A12O3 catalysts have been experimentally investigated. It was concluded based on reaction rate measurements and thermodynamic considerations, that the two reactions that best describe the chemical system of methanol synthesis are the CO2-hydrogenation and water-gas shift reactions. It was also found experimentally that the presence of CO2 is vital for maintaining the catalytic activity. The significance of the study is enhanced by the fact that this was the first such investigation of the global chemistry of methanol synthesis to be based on the novel liquid phase process. It was also observed that the rates of methanol synthesis attained a maximum when the concentration of carbon dioxide in the reactor feed was controlled at a certain optimal value. The optimal CO2 content was found to be a function of the operating temperature and syngas composition. The experimental data are especially important because the ...

SELECTIVE REMOVAL OF ORGANIC SULFUR FROM COAL BY PERCHLOROETHYLENE EXTRACTION

ABSTRACT Desulfurization of coal involves the removal of both the inorganic and organic forms of sulfur. Several physical methods are available for the removal of inorganic sulfur which is normally represented by pyritic and sulfatic sulfur. Removal of organic sulfur requires the use of chemical cleaning methods. This paper presents the results of an organic sulfur removal technique which employs an organic solvent. This desulfurization technique is selective enough to reject organic sulfur without significantly reducing the calorific value of the treated coal. The sulfur containing organic species in the liquid product from the desulfurization procedure have been completely characterized using GC/MS techniques. These results provide further insights into the nature of the sulfur forms in the parent coal as well as the metamorphism of sulfur species in the coal, and the selective nature of the desulfurization process.

Perchloroethylene extraction desulfurization of weathered coals

Abstract The perchloroethylene extraction process has proven to be an effective pre- combustion coal desulfurization process which offers a complete process package including wet grinding, organic sulfur removal, pyrite and mineral matter separation, solvent recovery, and byproducts and sulfur recovery. In this paper, coal weatherability was investigated for various Midwestern and Eastern U.S. coals, and its effect on organosulfur extractability by the perchloroethylene process was identified. Both “natural” and “artificial” weathering of these coals were experimentally investigated. A statistically significant difference in the extraction efficiency between fresh and weathered coals vas observed. A strong relation between the extractability and degree of weathering of the coal was established. The results provide a valuable insight into the process engineering of this process.

KINETICS OF LIQUID PHASE CATALYTIC DEHYDRATION OF METHANOL TO DIMETHYL ETHER

ABSTRACT The kinetics of the liquid phase catalytic dehydration of methanol to dimethyl ether were investigated. The experiments were carried out under low concentrations of feed in a 1-L stirred autoclave, according to a statistical experimental design. The inert liquid phase used for this investigation was a 78:22 blend of paraffinic and naphthenic mineral oils. A complete thermodynamic analysis was carried out in order to determine the liquid phase concentrations of the dissolved species. A global kinetic model was developed for the rate of dimethyl ether synthesis in terms of the liquid phase concentration of methanol. The activation energy of the reaction was found to be 18,830 cal/gmol. Based on a step-wise linear regression analysis of the kinetic data, the order of the reaction which gave the best fit was 0.28 with respect to methanol. Effects of the solid to liquid and the gas to liquid mass transfer resistances on the kinetic rate have also been investigated.

A SINGLE-STAGE, LIQUID-PHASE DIMETHYL ETHER SYNTHESIS PROCESS FROM SYNGAS IV. THE WODYNAMIC ANALYSIS OF THE LPDME PROCESS SYSTEM

Abstract In the LPDME process, methanol synthesis catalyst (composed of CuO, ZnO, and Al2O3) and the methanol dehydration catalyst (gamma-alumina) are slurried in the inert liquid phase. The catalysts constitute the solid phase. Syngas components (H2, CO, CO2, and CH4) and the products (CH3OH, H2O, and DME) constitute the vapor phase. At least three chemical reactions, viz., methanol synthesis, water-gas shift, and methanol dehydration also occur simultaneously in the liquid phase. The multicomponent phase equilibrium and the simultaneous chemical reaction equilibrium for this process system have been studied. The thermodynamic analysis has been presented in terms of the equilibrium conversions for H2and CO, syngas, and the concentration driving forces for H2 and CO. Methanol synthesis alone and co-production of methanol and DME are compared. The effects of water and CO2addition to the feed syngas on the equilibrium conversions are also investigated.

A SINGLE-STAGE, LIQUID-PHASE DIMETHYL ETHER SYNTHESIS PROCESS FROM SYNGAS II. COMPARISON OF PER-PASS SYNGAS CONVERSION, REACTOR PRODUCTIVITY AND HYDROGENATION EXTENT

ABSTRACT In part I of this series on the development of a single-stage, liquid-phase dimethyl ether (DME) synthesis process from syngas, the process feasibility and the process variable effects on the dual catalyst activity were discussed. This part focuses on the comparison of the single-stage reactor productivity of liquid phase methanol synthesis to that of the co-production of methanol and DME. It is experimentally demonstrated that the single-stage reactor productivity for the co-production of methanol and DME could be as much as 60% higher than that for liquid phase methanol synthesis alone. Along with this, a 50% increase in the syngas conversion is also obtained. Further, this approach is shown to co-produce methanol and DME in any fixed proportion, ranging from 5% DME to 95% DME, at significant synthesis rates of DME.

MODELING OF A LIQUID ENTRAINED REACTOR FOR LIQUID PHASE METHANOL SYNTHESIS PROCESS

ABSTRACT The liquid phase methanol (LPMeOHTM) synthesis process is to be commercially carried out in a liquid entrained reactor (LER), where the catalyst-inert oil slurry is pumped through the reaction zone along with the syngas fed separately. A computer model was developed based on the experimental results, for the LPMeOHTM process in a liquid entrained reactor. This computer program accurately predicts the multicomponent phase equilibria, ultimate chemical equilibria and the compositions of each reactant and product species exiting in the entrained reactor. The prediction of the results of this modeling agrees well with the experimental data from the LaPorte pilot plant entrained reactor.