OMEGA process

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The OMEGA process (for O nly- M ONO E thylene- G lycol- A dvanced process) is a process in 2007 patented the Royal Dutch Shell , for high selectivity of mono-ethylene glycol from ethylene oxide , carbon dioxide and water to produce. In October 2008 this technology received the Sellafield Ltd Award.

process

Mono-ethylene glycol (MEG) is traditionally prepared by reacting ethylene oxide with water. It cannot be prevented that ethylene oxide also reacts with already formed ethylene glycol. By-products such as di- and triethylene glycol make it necessary to work up by distillation . The selectivity to mono-ethylene glycol is approx. 90%.

In the OMEGA process, it was possible to carboxylate ethylene oxide in water with the help of water-soluble catalysts and, in a second step, to hydrolyze the ethylene carbonate selectively to give ethylene glycol . The reaction of the water-soluble epoxide is strongly exothermic , whereas the hydrolysis reaction is endothermic , which is why the carbonate has to be hydrolyzed with water vapor . The carbon dioxide that is split off is fed back into the process cycle.

Substituted ammonium or phosphonium bromides and iodides are suitable as carboxylation catalysts, and potassium hydroxide , carbonate or bicarbonate are suitable as hydrolysis catalysts . A mixture of potassium iodide and potassium molybdate in ethylene glycol is equally suitable for both reactions .

Synthesis of ethylene glycol (OMEGA Shell process)

The process can be carried out in one stage, with a preferred two-stage procedure the selectivity reaches 99.5% mono-ethylene glycol.

Shell's first large-scale plant with an annual capacity of 750,000 t went into operation in Singapore ( ) in 2009 ; in 2014, 2,000,000 t of ethylene glycol were already produced there. World icon

Today, new systems are only designed under license using the OMEGA process. By 2014 Shell had issued 73 licenses to producers, 43 of which were already using this procedure.

Individual evidence

  1. ↑ OMEGA process shell
  2. ↑ a b Patent WO2009071651 : Process for the preparation of alkylene glycol. Registered on December 5, 2008 , published on June 11, 2009 , applicant: Shell Internationale Research Maatschappij BV, inventor: Hendrik Johannes van Milligen, Peter Veenstra (priority from December 6, 2007). ‌
  3. ↑ Comparison of the classic MASTER process with the new OMEGA process
  4. ↑ SHELL: Mono-ethylene Glycol Plant, Singapore

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