Patent ID: 7070694

Claim:
A continuous process for separation of purified products from a fluid mixture by utilization of an integrated distillation and membrane separation apparatus which process comprises: providing a separation apparatus comprising (a) a fractional distillation column having an overhead vapor outlet in flow communication with a compressor, and an external heat transfer surface having one side disposed to contact fluid at the bottom of the column and the opposite side to contact compressed overhead vapor, (b) the compressor in fluid communication with means for proportioning compressed vapor between the heat transfer surface, a reflux condenser, and a cooler, said cooler is in flow communication with a per-selective membrane device, (c) the membrane device comprising a solid perm-selective membrane which under suitable differential of a driving force exhibits a permeability of at least 0.1 Barrer, channels having at least one inlet and one outlet for flow of fluid in contact with a first side of the membrane, and contiguous with the opposite side thereof a permeate chamber having at least one outlet for flow of permeate, and (d) Means for flow communication between the opposite side of the heat transfer surface and the fractional distillation column, Separating by fractional distillation a feedstock comprising a fluid mixture including a low-boiling point component and a high boiling point component, and thereby provide a vapor stream enriched in the low-boiling point component to the compressor; compressing the overhead vapor, and distributing portion thereof between the heat transfer surface, the reflux condenser, and the membrane device; and Separating from the stream distributed into the membrane device a permeate and non-permeate stream by selective permeation while controlling enthalpy of the distributed stream by controlling temperature thereof, and thereby maintain Membrane Efficiency Index of the non-permeate effluent stream within a range from about 0.5 to 1.5; and directing fluid from the opposite side of the heat transfer surface to the fractional distillation column.