Abstract: Hydrocarbon feedstocks containing relatively high levels of nitrogen contaminants are converted to products of lower average molecular weight by first mixing the feedstock with a dicarboxylic acid such as oxalic acid and then contacting the resultant mixture with a cracking catalyst in a cracking zone under cracking conditions in the substantial absence of added molecular hydrogen. The use of a dicarboxylic acid in lieu of a mineral acid such as sulfuric acid or nitric acid results in less corrosion to FCC unit internals and less emissions of sulfur and nitrogen oxides from the FCC unit regenerator.

Abstract: A sulfur sorbent for use in reducing the emissions of sulfur oxides from regenerators of cyclic catalytic cracking units comprises a rare earth component or mixture of rare earth components in combination with a porous, inorganic refractory oxide component. The rare earth components used as a portion of the sorbent are preferably derived from the mineral bastnaesite by treating the bastnaesite to remove at least 50 weight percent of its fluorine, calculated as the element. The activity of the sulfur sorbent for removing sulfur oxides during catalytic cracking processes is increased to unexpectedly high levels by including in the composition cobalt or other transition metal component comprising an element selected from Group IB, Group IIB Group IVA, Group VA, Group VIA, Group VIIA, and Group VIII of the Periodic Table of Elements.

Abstract: A sulfur sorbent for use in reducing the emissions of sulfur oxides from regenerators of cyclic catalytic cracking units comprises a rare earth component or mixture of rare earth components in combination with a porous, inorganic refractory oxide component. The rare earth components used as a portion of the sorbent are preferably derived from the mineral bastnaesite by treating the bastnaesite to remove at least 50 weight percent of its fluorine, calculated as the element. The activity of the sulfur sorbent for removing sulfur oxides during catalytic cracking processes is increased to unexpectedly high levels by including in the composition cobalt or other transition metal component comprising an element selected from Group IB, Group IIB, Group IVA, Group VA, Group VIA, Group VIIA, and Group VIII of the Periodic Table of Elements.