BIOCATALYTIC DESULPHURIZATION OF LCO | Original Article
Refinery FCC units produce a high sulphur (0.2 to 3.0 wt. %) and high aromatics (40-80%) distillate with low cetane number (15-25) known as Light cycle oil (LCO). Conventional desulphurization requir es severe hydrogenation (HDS) to remove the organo-sulphur compounds. Whole cell biocatalytic desulphurization of LCO is one preferred method to upgrade LCO. In this paper, we report biodesulphurization of LCO by a novel Rhodococcus sp. IIPS7 (MTCC 5313) with more than 80% sulphur reduction in 24 h. IIPS7 was initially adapted in LCO after optimizing sulphur to cell biomass ratio of 1:5. IIPS7 has been shown to desulphurise nonhydrotreated LCO with 7300 ppm sulphur to1250 ppm sulphur in 24 h with more than 82% reduction in a single stage reactor. Presence of 4-S metabolic pathway for sulphur degradation has been confirmed for IIPS7 through PCR amplification of dszABC gene. Removal of sulphur from LCO has been confirmed through GC-SCD analyses.