OMEGA process
The OMEGA process ("Only MEG Advantage")
Ethylene oxidation
To produce ethylene oxide, ethylene is oxidized with dioxygen in the presence of a silver catalyst. Some ethylene is over-oxidized to carbon dioxide and water, which is wasteful; early processes only gave ~ 65% selectivity for ethylene oxide as a result. In the OMEGA process, over-oxidation is reduced by including
Ethylene oxide hydrolysis
Conventionally, monoethylene glycol (HOC2H4OH) is produced by the controlled hydrolysis of ethylene oxide (C2H4O). The monoethylene glycol product is also able to react with ethylene oxide to give
- C2H4O + H2O → HOC2H4OH
In the OMEGA process, the ethylene oxide reacts with carbon dioxide (CO2) to yield ethylene carbonate (C3H4O3). Ethylene carbonate is subsequently hydrolyzed to monoethylene glycol and carbon dioxide. The carbon dioxide is released in this step again and can be fed back into the process circuit. This process is 99.5% selective for monoethylene glycol.[2]
- C2H4O + CO2 → C3H4O3
- C3H4O3 + H2O → HOC2H4OH + CO2
This part of the OMEGA process was originally developed by Mitsubishi Chemicals, and it has been exclusively licensed to Shell.[2]
See also
References
- ^ a b "OMEGA delivers for ethylene glycol makers". Shell Chemicals. October 2008. Retrieved 2012-12-22.
- ^ a b c d Peter Taffe (2008-08-12). "Shell's Omega MEG process kicks off in South Korea". ICIS.com. Archived from the original on 2008-10-23.
- ^ "First start-up of Shell OMEGA process plant" (Press release). Shell Chemicals. 2008-06-16.
- ^ "Second Shell OMEGA process plant starts up in Saudi Arabia" (Press release). Shell Chemicals. 2009-06-02.
- ^ "Shell starts-up world-scale monoethylene glycol plant in Singapore" (Press release). Shell Chemicals. 2009-11-17.