Hydrocrackers are one of oil refining's most demanding process control challenges at all levels -- safety systems, regulatory control and advanced control. Economically, hydrocrackers are well situated in today's market, converting heavy oils and inexpensive natural gas into high-value fuels. Yet, most hydrocrackers in industry are under-automated, lacking basic excursion control, depressure prevention, and effective advanced control features.
The message that often fails to accompany auto-depressure projects is the need for much better excursion control to avoid reaching auto-depressure conditions in the first place. Auto-quench is a DCS control, but it can be one of the most important control functions in a refinery, since it is the final layer of hydrocracking reactor depressure prevention.
“These are controls that work for us, not the other way around.”
- Console Operator on a complex 2-stage hydrocracker with 13
individual beds and 3 separate ABT controls
Operating a highly exothermic reaction vessel, without reliable bed outlet temperature controls and other safeguards, no longer makes common sense, and should no longer pass a modern process hazard analysis (PHA). Contact APC Performance to discuss modern best practice hydrocracker controls.
