Raj K Sharma - CokingAsia.com
Delayed Coker commissioning is always a unique experience every time. The safe and timely startup is the key. Proper planning and rich experience in the field plays an important role. Mega cokers with a capacity exceeding 9 MMTA require special attention. Trained and experienced manpower with an integrated team of process/Operations /Maintenance with Project team is very important.
Successful, seamless, and fire-free commissioning of 2 mega Delayed Cokers at Reliance Industries in India at Jamnagar was achieved in 1999 and 2009 respectively. Commissioning of 8 Coke drums with a single fractionator was a good challenge considering 50% turndown of the plant. Coke drums section was divided in 4 islands along with 2 Blowdown systems. Clear Identification of the coke drums and related valving/piping was done to avoid confusion and major mistakes.
This article focuses on the main efforts to avoid known pitfalls and prepare the manpower for unknown problems. The biggest challenge in the first coker in 1999 was due to reliability issues of power and utility supply. Unfortunately, we had to handle a Tarry coke drum on the very first day of commissioning due to sudden power and steam outage. This was handled in a careful and safe way by controlled cooling and controlled draining the coke drum contents using remotely controlled unheading cart device. There were also problems of newly trained manpower and not having a reliable coke drum safety interlocks and mix up of the coke drums island.
Next commissioning of Mega coker in 2009 was comparatively easier but last-minute delays in coke cutting system and yet to be proven coke drum level lead to a mild foam over which was handled promptly avoiding a shutdown. Micro-planning, breaking the coker into system wise ownership and final integration made it possible to start the coker in record time. Zero flaring and zero (minimum) slops generation was the main focus of these startups.
Reliance refinery (1.3 MMBPD-Crude) has the biggest delayed cokers in a single location.