HR unit feed is normally fed from H2 rich sour gas header which consists of CCR offgas, ARD off gas and HCR off gas. During the normal operation of all units, H2S content in HR feed is around 2.3 vol% (design 2.9 vol%). The HR feed line and Absorber was designed for 11 vol% H2S and there was opportunity to run two ARD offgas compressors during both CCR units shutdown due to lower HR unit feed availability. The benefit from the above opportunity is to recover H2 from all ARD off gas for meeting the H2 requirements during overall H2 shortage across KNPC refineries, maximize conversion unit capacity utilization.

Normally C-48-051 will be running and 20 KNM3/Hr of ARD off gas processed in HR unit. During both CCR units shutdown (25/04/15 to 26/05/15), C-81-051 was also run and additionally 8 to 10 KNM3/HR ARD off gas was processed in HR unit. Around 3 KNM3/HR of additional H2 produced from processing of all ARD off gas resulted in maximizing the HCR unit capacity utilization by around 1500 BPD. The equivalent benefit is around 30,000$/day for 20$/bbl HCR net back (Operational Planning to confirm the benefit).