Methods and apparatus for increasing the recovery of hydrogen from fractionation section offgas are described. The methods include reducing the pressure of a liquid effluent from a high-pressure reaction zone, and introducing the effluent into a flash drum forming a low pressure liquid effluent. The low pressure effluent is introduced into a low-pressure stripper column, and separated into an overhead vapor stream and at least one additional stream. The stripper column overhead vapor stream is compressed in a one cylinder of a compressor, which has at least one additional cylinder, to an intermediate pressure. The compressed overhead stream is introduced to an intermediate pressure knockout drum forming a gas stream and a liquid stream. The gas stream is introduced into a pressure swing adsorption zone to produce a hydrogen rich gas stream at an intermediate pressure.