Recovery of light olefins from dry hydrocarbon gas from refinery and petrochemical production processes for production of alkylate

A method of treating an olefin-containing stream comprising ethylene and one or more light components selected from the group consisting of hydrogen (H2), carbon monoxide (CO), and methane, the method comprising:

• providing the olefin-containing stream comprising a 0.80 vapor fraction to an absorber column,
• separating the ethylene from the one or more light components by contacting the olefin-containing stream with a hydrocarbon solvent in the absorber column operating at a pressure of about 135 psi and at a temperature ranging from −30 F at the top of the column to 0 F at the bottom of the column to absorb at least a portion of the ethylene in the solvent to provide an ethylene-enriched solvent stream, wherein the solvent is an alkylation precursor,
• providing the ethylene-enriched solvent stream to an alkylation reactor,
• reacting the ethylene with the solvent in the alkylation reactor to produce an alkylation reactor effluent stream comprising alkylate and excess solvent,
• separating the alkylation reactor effluent stream into alkylate product and a lean solvent stream,
• recycling a first portion of the lean solvent stream to the alkylation reactor, wherein the amount of the first portion is controlled to maintain a predetermined ratio of solvent to olefin in the alkylation reactor to maintain an alkylation equilibrium that favors an isooctane product when reacting the ethylene with the solvent, and
• recycling a second portion of the lean solvent stream to the absorber column.