Michael E. Prudich

Novel Separation Processes for Solid/Liquid Separations in Coal Derived Liquids

Abstract The removal of the mineral matter found in coal derived liquids is a very difficult solid/liquid separation process. Clays, pyrites and other minerals that occur in coal ultimately find their way into the liquefied product. This is the case, e.g., for both the solvent refined coal (SRC-I) and H-Coal processes. The ash content of bituminous coals which may be fed to coal liquefaction processes normally rangesfrom 6 to 11 wt.%. The ash content of the coal liquid product can range from 4 to 20 wt.% depending upon the lique-faction .process. Ash levels must be reduced to, e.g., 0.4 wt.% in the case of boiler fuel and less than 0.1 wt.% for gas turbine fuels.

Flue Gas Desulfurization for Acid Rain Control

This chapter is a reprint of a literature review prepared for the Ohio Coal Development Office by the Ohio Coal Research Consortium in 1990. It represents an assessment of the state of the art in flue gas desulfurization technologies at that time. It also served to motivate the work of the consortium starting in 1991, the results of which are presented in the following chapters.

Shale Oil Denitrogenation with Ion Exchange

Abstract The nitrogen-containing aromatics normally found in crude retorted shale oils have been shown to be involved in reactions leading to the deposition of insoluble gums and sediments. These nitrogen-containing compounds must be removed in order to permit the effective utilization of the shale oil product. A process is proposed in which the nitrogen-containing compounds found in raw shale oil are removed by mild hydrodenitrogenation followed by resin ion exchange. Ion exchange data from experimentation involving six jet fuel (15M-271°C) and diesel fuel (271–343°C) boiling point cuts are presented. Amberlyst A-15, a macroreticular, strongly acidic, cation exchange resin is used in this study. Three types of experiments were performed: batch sorption equilibrium experiments, batch sorption kinetics experiments, and dynamic ion-exchange column performance tests. The Langmuir isotherm was found to describe the equilibrium sorption behavior of the shale oil/ion-exchange resin system fairly Well. The sorpt...

Simulation and Optimization of a Granular Limestone Flue Gas Desulfurization Process

This chapter presents a process simulation model developed for the Limestone Emission Control process. The process involves contacting flue gas with a densely packed, wet bed of granular limestone. The process model includes the chemistry, mass transfer, and heat transfer associated with this system along with sorbent screening and recycle steps occurring outside the scrubber. Approximate cost correlations are applied to various system components and used to drive a design optimization for four different cases corresponding to two levels of sulfur capture and two levels of sulfur content in the coal. The results indicate that this technology is best suited for high-sulfur, small-scale applications. Future experimental work should evaluate the use of larger (1/4 inch) sorbent.

Fundamental Studies Concerning Calcium-Based Sorbents

Sorbent preparation techniques used today have generally been adapted from techniques traditionally used by the lime industry. Traditional “dry” hydration and slaking processes have been optimized to produce materials intended for use in the building industry. These preparation techniques should be examined with an eye to optimization of properties important to the SO2 capture process.

Low Temperature Dry Scrubbing/LEC Process Support

Dry scrubbing that takes place after the air preheater (<350°F) is the mode of operation that is the primary focus of this chapter. At the relatively low temperatures that occur in this region of operation, the rate of the gas-solid reaction that drives SO2 capture in the convective (800–1200°F) and the combustion (1600–2400°F) zones is too slow to be significant. At lower temperatures, the presence of either liquid-phase or vapor-phase water is required in order to mediate SO2 capture and to produce reasonable capture rates.

SO2 scrubbing by ultrafine Ca(OH)2 aerosol

The objective of the present study was to generate submicrometer calcium hydroxide aerosols and to investigate the effectiveness of such aerosols in sulfur capture. The effectiveness of SO 2 removal by Ca(OH) 2 aerosol has been investigated in an isothermal reactor. Ca(OH) 2 aerosol was generated by a novel fluidizer system in which submicrometer-sized powders were entrained in gases. SO 2 was added to this aerosol to a concentration of 2000 ppm. The aerosol-SO 2 mixture was heated to 550°C-750°C in an isothermal tube reactor. The SO 2 removal efficiency, which varied from 20% to 70%, was determined to be a function of the aerosol concentration, reactor temperature and residence time. The fraction of aerosol reacted was not affected strongly by the aerosol concentration. The reaction kinetics were determined from the experimental data using a simple analytical model in which the rate is first order in both SO 2 and calcium hydroxide aerosol concentrations