Patent ID: 6979394
Filing Date: 2005-12-27
Classification: C07C,Y02P

Abstract:
1. A process for controlling the bromine index of an alkylated product stream comprising a product aromatic compound, the process comprising: a) dehydrogenating a C b) selectively removing at least a portion of the aromatic byproducts from at least a portion of the dehydrogenation effluent stream in an on-stream aromatic byproducts removal bed containing a sorbent at sorption conditions effective to selectively sorb the aromatic byproducts; c) recovering an on-stream bed effluent stream comprising the monoolefin from the on-stream aromatic byproducts removal bed, wherein the on-stream bed effluent stream has a second concentration of the aromatic byproducts that is less than the first concentration; d) forming an olefinic feed stream from at least a portion of the on-stream bed effluent stream; e) passing an aromatic feed stream comprising a feed aromatic compound and the olefinic feed stream comprising the monoolefin to an on-stream selective alkylation reactor, selectively alkylating the feed aromatic compound by reacting the feed aromatic compound and the monoolefin in the presence of a solid alkylation catalyst in the on-stream selective alkylation reactor at alkylation conditions to form a product aromatic compound, the alkylation conditions being sufficient to at least partially deactivate the solid alkylation catalyst, and recovering from the on-stream selective alkylation reactor an on-stream reactor effluent stream comprising the product aromatic compound; f) passing at least a portion of the on-stream reactor effluent stream to a product recovery section, and recovering from the product recovery section an alkylated product stream comprising the product aromatic compound, wherein the alkylated product stream has a bromine index; g) passing a regenerant stream comprising the feed aromatic compound to an off-stream selective alkylation reactor containing the solid alkylation catalyst, wherein the solid alkylation catalyst in the off-stream selective alkylation reactor is at least partially deactivated, the off-stream selective alkylation reactor operates at regeneration conditions sufficient to at least partially reactivate the solid alkylation catalyst, and recovering an off-stream reactor effluent stream comprising the feed aromatic compound and color bodies from the off-stream selective alkylation reactor; h) passing at least a portion of the off-stream reactor effluent stream comprising the feed aromatic compound and the color bodies to an off-stream aromatic byproducts removal bed containing sorbent, the sorbent in the off-stream aromatic byproducts removal bed containing sorbed aromatic byproducts, to at least partially desorb the aromatic byproducts from the sorbent in the off-stream aromatic byproducts removal bed at desorption conditions; i) recovering from the off-stream aromatic byproducts removal bed an off-stream bed effluent stream comprising the aromatic byproducts, the feed aromatic compound, and the color bodies; j) passing at least a portion of the off-stream bed effluent stream comprising the aromatic byproducts, the feed aromatic compound, and the color bodies to a separation section, wherein the at least a portion of the off-stream bed effluent stream has a flow rate, and recovering from the separation section a return stream comprising the feed aromatic compound, a first heavy stream comprising the aromatic byproducts, and a second heavy stream comprising the color bodies; k) rejecting from the process at least a portion of the aromatic byproducts in the first heavy stream; l) rejecting from the process at least a portion of the color bodies in the second heavy stream; m) at least intermittently shifting the functions of the on-stream selective alkylation reactor and the off-stream selective alkylation reactor by operating the on-stream selective alkylation reactor to function as the off-stream selective alkylation reactor and operating the off-stream selective alkylation reactor to function as the on-stream selective alkylation reactor; n) at least intermittently shifting the functions of the on-stream aromatic byproducts removal bed and the off-stream aromatic byproducts removal bed by operating the off-stream aromatic byproducts removal bed to function as the on-stream aromatic byproducts removal bed and operating the on-stream aromatic byproducts removal bed to function as the off-stream aromatic byproducts removal bed; and o) measuring the bromine index of the alkylated product stream and adjusting the flow rate of the at least a portion of the off-stream bed effluent stream based on the bromine index.