Abstract: A combined process for the conversion of solid starting particles into solid intermediate particles and reducing the median diameter of the intermediate particles to obtain product particles. This process involves flowing a suspension of starting particles through a series of at least two conversion vessels, thereby converting at least part of the starting particles into intermediate particles, adding a supercritical fluid to one or more of the conversion vessels, thereby forming a supercritical suspension, and releasing pressure from the supercritical suspension, thereby expanding the suspension and converting the intermediate particles into product particles.

Abstract: The present invention pertains to A cyclic process for testing FCC catalysts with resid feedstock on a small scale wherein in a first cycle: a) the feed to be cracked is heated to a temperature between 50 and 500° C., b) the heated feed is injected into a riser reactor containing the FCC catalyst to be tested having a temperature between 500 and 800° C., the injection time being less than 2 seconds, c) an inert gas is injected into the lower end of said reactor riser together in the vicinity of the feed injection in a volume ratio of inert gas to vaporized feed of about 0.03 and 10, the mixing of feed and inert gas occurring in said riser reactor; d) the feed is contacted with the FCC catalyst under fluidized conditions for a contact time of less than 8 seconds; e) the feed is stripped from the FCC catalyst and the properties of the product are analyzed; and in a second cycle a quench liquid is injected into said riser reactor in an amount of up to about 20 wt.