Isomerization with improved RVP and C4 recovery
AssigneeUop LLC
InventorLynn H. Rice
Life of this patent
Estimating the term…
Abstract
A process for the isomerization of C.sub.4 -C.sub.6 paraffins that separates a low boiling or overhead fraction from a stabilizer in a stripping zone and provides a low RVP isomerization product and simplifies the recovery of LPG components. The process also lowers energy costs and capital investment for recovery of LPG components that are otherwise lost with the production of low RVP isomerization products. When used with a chloride promoted catalyst, the arrangement of this invention permits recovery of a low RVP isomerate product while reducing or eliminating corrosion problems associated with a condensation of overhead products to produce stream containing liquid HCl.
Claims17
A process for the isomerization of a feed stream comprising C.sub.4 -C.sub.6 hydrocarbons and separation of a reactor effluent, said process comprising:
- (a) contacting a feed stream comprising C.sub.4 -C.sub.6 hydrocarbons in an isomerization reaction zone with an isomerization catalyst at isomerization conditions to produce an isomerization zone effluent;
- (b) passing at least a portion of said isomerization zone effluent to a stabilizer zone and recovering from said stabilizer a stabilizer overhead stream comprising C.sub.4 and lighter hydrocarbons, a bottoms stream comprising C.sub.5 and heavier hydrocarbons and a stripper feed comprising C.sub.4 hydrocarbons and lower boiling material;
- (c) passing said stripper feed to a stripping zone and separating said stripper feed into a stripper overhead stream comprising C.sub.3 hydrocarbons and lower boiling material and a stripper bottoms stream comprising C.sub.4 hydrocarbons;
- (d) mixing at least a portion of said stripper overhead stream with a hydrocarbon fraction produced by said stabilizer having a boiling point at or below the boiling point of said stripper feed;
- and,
- (e) recovering said stripper bottoms stream from said stripping zone.
A process for the isomerization of a feed stream comprising C.sub.4 -C.sub.6 hydrocarbons and the separation of an isomerization zone effluent, said process comprising:
- (a) mixing hydrogen with a feed stream comprising C.sub.4 -C.sub.6 hydrocarbons;
- (b) contacting said feed stream and hydrogen mixture in a reaction zone with an isomerization catalyst comprising alumina, having from 0.01 to 25 wt. % platinum and from 2 to 10 wt. % of a chloride component at isomerization conditions;
- (c) maintaining a chloride concentration in the reaction zone of from 30 to 300 ppm;
- (d) recovering an isomerization effluent stream from said reaction zone containing HCl and at least 5 mol % C.sub.4 hydrocarbons;
- (e) passing said isomerization zone effluent to a stabilizer column at a feed entry point and recovering a stabilizer overhead stream comprising C.sub.4 and lower boiling hydrocarbons and HCl, a bottoms stream comprising C.sub.5 and heavier hydrocarbons and a sidecut stream comprising a stripper feed, said stripper feed comprising C.sub.4 and lower boiling hydrocarbons and HCl;
- (f) passing said stripper feed to a stripping column and separating said stripper feed into a stripper overhead stream comprising C.sub.3 and lower boiling hydrocarbons and HCl, and a stripper bottoms stream comprising C.sub.4 hydrocarbons;
- (g) returning said stripper overhead stream to said stabilizer column at a location above said feed entry point or to said stabilizer overhead stream;
- (h) recovering said stripper bottoms stream from said stripping column;
- and,
- (i) passing said stabilizer overhead stream to a receiver and recovering an overhead product stream containing HCl and consisting essentially of vapor from said overhead receiver.
Dependencies are inferred from the claim text.