LPI process: Significant energy savings, ultra-low xylenes losses, inexpensive debottlenecking
The LPI process is the latest addition to ExxonMobil’s portfolio of xylenes isomerization processes available for license. The technology operates at low temperature with xylene losses less than the best performing vapor phase isomerization technology, the XyMaxSM-2 process. The LPI process can be deployed in parallel with vapor phase isomerization units in existing plants, yielding both energy savings and debottlenecking opportunities. Because of its very low EB conversion per pass, the LPI process is often operated in combination with a vapor phase isomerization process, where most EB removal is achieved. However, in situations where the C8 aromatics stream to be isomerized contains very low EB, xylenes isomerization can be carried out via the LPI process only, and EB purge is managed by other means.
The following simplified flowscheme shows the LPI process in a typical fractionation and recovery section of an aromatics complex.