PEP Review 87-1-2
Ethylene from Ethane by Oxydehydrogenation
Published: May 1988
A recent European patent assigned to Phillips Petroleum discloses a new process to produce ethylene by oxidative dehydrogenation of ethane. The reaction is conducted in the presence of "solid contact materials" composed of Li-SnCI2MgO. In comparison with the conventional steam cracking process, the new process gives higher ethylene selectivity at the same degree of conversion. The new process also consumes less external fuel.
SRI's cost estimates show that the fixed capital investment for a 1,000 million lb (454,000 metric ton)/yr ethylene plant on the U.S. Gulf Coast by the new process is about 13% less than for a corresponding plant by the conventional steam cracking process. Similarly, the production cost for the new process is lower, largely reflecting its lower investment. However, there is a high degree of uncertainty in both the investment and production cost estimates. For example, one significant drawback of the new process at present appears to be that, after about 1 hr of operation, the ethane conversion decreases with reaction time. SRI has assumed that the contact materials either can be continuously replenished or periodically regenerated. If this cannot be successfully achieved through further R&D, the value of the process is doubtful.