(53an) Economics of Hydrogen Purification in an Ethylene Plant

The increased supply of gas from shale deposits in North America has created increased profit opportunities for existing ethylene plants processing naphtha feed. Converting an existing facility form naphtha feed to ethane recovered from gas offers several advantages including lower feed cost and higher ethylene yields per unit of feed. Development of a functioning simulation model that integrates all of the various unit operations of the plant and is user friendly is mandatory not only for the design but of analyzing ongoing performance of the revamped facility. In this paper the approach and lessons learned from developing a complex, integrated simulation model for a recent project will be discussed.

The hydrogen yield per unit of ethylene product is almost three times greater with ethane feed compared to naphtha. Using the integrated model, this paper will also provide a case study that address the economics of recovering high purity hydrogen for use outside the ethylene unit compared to the more normal practice of internal usage as fuel.