Case 11 Ethylene Plant in Kuwait

Equate, a joint venture between Petroleum Industrial Corporation in Kuwait and Union Carbide Corporation, built a grass-roots petrochemical 

Most ethylene plants operate continuously with the expander functioning at or near design point. However, by using inlet guide vanes, the expander can still provide optimum performance at off-design conditions. Also, the expansion process generates power, which is used by the compressor. The ethylene enters the expanders at approximately 26 bar (377 psia) and exits at approximately 6 bar (87 psia). The expanders generate over 2,000 hp for gas compression. 

Some 14,700 gal of MTBE are produeed eaeh day. The MTBE produetion faeility relies on an Olefiex design system that eonverts isobutane to isobutylene, the basie ingredient in MTBE. The Olefiex unit manages to reeyele isobutane so that ultimately 100% is eonverted to isobutylene, and byproduet hydrogen used in the proeess is reeyeled and proeessed to 99.9% purity. 

The hydrogen reeyeling proeess uses two turboexpanders that eool the gas stream to -120°E (-84°C), separating out 87% of the hydrogen. 

Energy released by the turboexpanders powers a two-stage eompressor for reeireulating the gas. The hydrogen is later purified to 99.9% through the removal of ehlorides and HjS. 

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