Olefins Conversion Technology(OCT)

Olefins Conversion Technology (OCT) of Lummus is one of the “on-purpose technologies”, which has emerged as a low-capital and low-energy propylene production route. OCT is also regarded as an effective utilization technique of low-value C4s since it enables catalytic conversion of butenes to propylene. Moreover OCT unit can be designed as a stand-alone unit or can be integrated in steam cracker or FCC to improve flexibility and performance.
Together with Lummus, in the Asian region, TOYO offers OCT licensed by Lummus to boost production of propylene.

Because the metathesis reaction does not produce propane, it is not necessary to install a P-P splitter, which is typically installed in steam crackers and FCC. It helps to lower the investment cost and reduce utility consumption in the OCT process. Because metathesis reaction is an energy neutral reaction, utility consumption is significantly reduced. The major utility requirement is limited to fuel gas for controlling reactor inlet temperature and steam and cooling water for distillation. The OCT process is an excellent process in terms of investment cost and utility consumption compared to other propylene boosting processes such as catalytic cracking.

CDIsis^® can isomerize the isobutene to normal butene. Isobutene was often utilized for MTBE production which was additive of gasoline to enhance octane value. However, due to recent environmental requirements, the production of MTBE is phasing out and alternative utilization of isobutene is requested. Based on these backgrounds, CDIsis^® technology was developed by Lummus to convert isobutene to normal butenes. CDIsis^® technology can maximize a utilization of isobutene in mixed C4 feedstock via OCT process. Integration of CDIsis^® technology with OCT process allows an economical and cost effective solution to enhance propylene production.

＜Skeletal Isomerization Reaction＞

Available C4’s from steam cracker is being reduced due to the increasing demand of butadiene and the decreasing amount of liquid feed cracking. C5’s OCT process is developed by Lummus Technology to make up shortage of propylene production and extend the feedstock for propylene production. The reaction schemes of C5’s OCT process are very similar to that of butenes OCT, consisting of isomerization and metathesis reaction. C5’s OCT is being regarded as a new propylene boosting technology to make up for shortage of C4s feed.

＜Reaction Scheme in C5 OCT＞