Liquified petroleum gas (LPG) is a vital component of the world’s energy supply. It largely consists of propane and butane in varying ratios and is mainly obtained from crude oil and natural gas processing. A typical LPG recovery plant essentially consists of four sections: (1) separation section, (2) dehydration section, (3) NGL (natural gas liquids) extraction section, and (4) LPG recovery section. Each of these sections in turn contains multiple process equipment to carry out the necessary unit operations.

            In this study, we present alternative process designs for an LPG recovery plant with detailed energy and economic analyses. First, a comprehensive base case simulation model of a conventional LPG recovery plant is developed using commercial process simulator Aspen Plus®. Energy efficiency and relative energy loss for each equipment is calculated. Then, alternative process designs are developed by re-routing the streams in various sections of the plant. Significant savings are demonstrated through improved heat integration within the process while maintaining the overall LPG recovery targets.