Patent ID: 8034988

Claim:
A process for alkylation of propylene, the process comprising: contacting a stream comprising propylene and propane with sulfuric acid in a first reaction zone under conditions to form propylene sulfate esters; contacting the propylene sulfate esters with isoparaffin and sulfuric acid in an alkylation reaction zone under conditions to react the propylene sulfate esters and the isoparaffin to form a reactor effluent comprising an acid phase and a hydrocarbon phase comprising unreacted isoparaffin and alkylate product; separating the hydrocarbon phase from the sulfuric acid; separating the hydrocarbon phase to form a fraction comprising unreacted isoparaffin and a fraction comprising the alkylate product; wherein a molar ratio of the sulfuric acid to the propylene fed to the first reaction zone is in the range from 1:1 to 3:1; and wherein the sulfuric acid fed to the first reaction zone has a strength that titrates as less than 75 weight percent H 2 SO 4 /water mixtures.