Process Economics Program Report 150
Ethylene from Refinery Gas
Published: October 1981
This report concerns the technology and economics in utilizing refinery gas as a feedstock in ethylene production. Refinery gas is a mixture of C4-and-lighter hydrocarbons, nitrogen, carbon oxides, and sulfur compounds. These are off-gases from various petroleum refining operations. For ethylene production, the most important components are ethylene (mainly from FCC and delayed coking operations), ethane, propane, and propylene (as a coproduct). The economics developed in this report are based on the following processes:
- Ethylene from refinery gas, including steam cracking of ethane and propane originally present in the feed gas stream.
- Ethylene from refinery gas by the expander process.
- Ethylene from refinery gas by the bimetallic salt complexing process (analogous to Tenneco's ESEP® process).
- Ethylene from refinery gas plus supplementary ethane-propane feed to increase ethylene production.
In addition, we have updated the investment and production costs for making ethylene from ethane, ethane-propane (50 wt% each), and propane that were originally developed in PEP Report 29B (March 1978). These updated costs are compared with the newly developed costs for refinery gas feeds in Section 8 of the present report.