Recover liquid propane from an Isocracker gas plant
C&I effectively built a gas plant within a gas plant to help this Mid-Atlantic refinery client recover propane vapor, treat it to HD-5 specifications, and liquefy the treated product for storage. This challenging grassroots project involved meeting an aggressive overall C3+ recovery specification, as well as a late request to build facilities to support railcar loading and offloading. To free up the necessary capital, C&I revised the original ISBL processing scheme, altering the fractionation controls and treating section resulting in a capital cost savings of $5 million that could be reallocated for railcar facilities.
Because the revised design altered the sequencing of the gas plant towers from the original design, the isocracker startup was no longer the critical patch project for the refinery to restart. The new ISBL equipment could be designed, installed and put into service with the Hydrocracker onstream. The all-discipline process design effort involved installing a new high-pressure deethanizer, and converting the overhead system of the existing depropanizer to a total condensing system, amine treating, product dehydration and storage facilities (two large spheres and bullet).