Abstract: Improved methods and apparatus for particle precipitation and coating using near- or supercritical fluid conditions are described. A fluid dispersion having a continuous phase dispersant and at least one precipitatable substance therein is contacted with a supercritical fluid (SCF) antisolvent so as to generate focused high frequency antisolvent sonic waves, breaking up the dispersion into extremely small droplets; the enhanced mass transfer rates between the droplets and the antisolvent causes precipitation of very small particles on the order of 0.1-10 .mu.m. In coating processes, a turbulent fluidized flow of core particles is created using an SCF antisolvent in an enclosed zone. The core particles are contacted therein at near- or supercritical conditions by a fluid dispersion containing a dispersant together with a precipitatable substance. The antisolvent depletes the dispersant and the substance is precipitated onto the fluidized core particles.

Abstract: A method to minimize catalyst deactivation rate and coke laydown, and maximize desired reaction rate in processing of industrially significant reactions under supercritical conditions to generate a reaction mixture stream including formed reaction products and reactants, said contacting at a desired catalyst temperature of about 1-1.2 critical temperature of the resulting reaction mixture and at a pressure between the critical pressure of the reaction mixture and a pressure necessary to establish said reaction mixture fluid density of greater than 0.65 gm/cc.

Abstract: An improved process is provided for in situ mitigation of coke buildup and porous catalyst used for the processing of hydrocarbon feed stocks. The process exhibits improved catalyst activity over extended periods and the process comprises the pretreatment of hydrocarbon feed stocks to reduce impurities in the feed stocks in the form of peroxides and oxygen compounds that promote the formation of coke precursors, which precursors are typically in the form of olefinic oligomers. The process includes contacting the pretreated feed stream with a suitable catalyst under sub-critical, near-critical and supercritical conditions.

Abstract: The present invention relates to buckminsterfullerenes or related condensed carbon molecules covalently bonded to a polymer particle or a siliceous support particle and their use for packing media for column chromatography.

Abstract: A process has been developed to effectively separate and recover essentially pure amounts of both C.sub.60 and C.sub.70 from carbon soot and higher molecular weight fullerenes. This process first extracts the fullerenes from carbon soot and then sequentially separates the C.sub.60 and C.sub.70 molecules using high performance or low pressure adsorption chromatography packed column containing a gel polymer having aromaticity and a pore size ranging from 10 to 500 .ANG..In this process, a first stage of fractionation of the fullerenes is preferably accomplished by selective supercritical fluid extraction (SFE) of C.sub.60. Unrecovered C.sub.60 and C.sub.70 molecules are then extracted by supercritical fluid extraction at a higher pressure and/or higher temperature.

Abstract: An integrated sample extraction and separation system includes a number of substantially identical supercritical fluid extraction modules and sample separation modules connected in common to a source of supercritical fluid and modifier and to instruments for sample analysis. Each of the supercritical fluid extraction columns is provided with separate pressure and temperature controls. Preferably, each sample separation module provides the choice of sample separation by dissolving the extracted sample in solvent, by adsorption, or by size exclusion chromatography. Either the supercritical fluid or various solvents may be used as the mobile phase in the sample separation step.