HYDROCARBON CRACKING IN A REGENERABLE MOLTEN MEDIA

摘要

1414779 Salts; double salts EXXON RESEARCH & ENG CO 12 Sept 1972 [5 Oct 1971 (3) 14 Aug 1972 (3)] 42305/72 Heading C1A [Also in Division C5] A hydrocarbon feedstock is cracked by contact with a melt at a temperature of 1200‹ to 2500‹ F. The melt consists, apart from impurities and contaminates formed in the cracking, of an oxide or hydroxide of an alkali metal or an alkaline earth metal and a "glass-forming" oxide of B, Al, Si, P,:Ti, V, Mo or W in a mole ratio (as oxides) of at least 1. Either or both of the oxides may be replaced by their precursors or the product of reaction between them. When the glass-forming oxide is of boron, the "basicity", defined according to a formula in the Specification as the weighted sum of the molecular proportions of oxides of Li, Na, K, Mg, Ca, Sr and Ba, should be in the range of 0À5 to 2À0. After cracking, the melt can be regenerated by contact at 1200‹ to 3000‹ F. with oxygen, carbon dioxide, steam or their mixtures. When the feedstock contains sulphur or ash-forming components, these are largely retained in the melt. They can be removed from it by the action of steam and CO 2 at 800‹ to 1800‹ F., or by cooling the melt, dissolving it in water, separating precipitated metals and ash and liberating H 2 S by passing CO 2 through the solution. If the sulphur compounds in the melt are not sufficiently reduced to sulphides in the cracking step, they may be reduced by contact with carbon, hydrogen, CO, CH 4 or C 2 H 6 in a separate step.