Many waste gas streams in processing plants contain volatile organic compounds (VOCs), which must be removed. Recovery of the VOCs may be accomplished by several separation methods, including: (1) absorption, (2) adsorption, (3) condensation, (4) freezing, and (5) membrane separation. Discuss the advantages and disadvantages of each method, paying particular attention to the fate of the VOC. For the case of a stream containing 3 mol% acetone in air, draw a flow diagram for a process based on absorption. Choose a reasonable absorbent and include in your process a means to recover the acetone and recycle the absorbent.