The Caltex Oil refinery in Brisbane, Australia, upgraded its hydrofluoric acid (HF) alkylation unit at the end of 1998 to improve safety measures. The upgraded alkylation unit, operated under license from Phillips Petroleum Co., Bartlesville, Okla., carries a nameplate capacity of 3,600 b/sd.
Caltex employed Phillip's Inventory Management Process (IMP) to manage the scope of the upgrade. Improvements included a new reactor-settler, elevated acid coolers, and a gravity-feed dump drum. Should an accidental release occur, a rapid acid-transfer system will dump all the acid and hydrocarbons in the reactor/settler into a storage vessel in a short time, minimizing the amount of HF that would be released.
Even if refinery power or pumps fail, the rapid acid-transfer system will work, because it uses gravity to dump the reactor/settler.
In addition to the IMP system, the refinery also installed several remotely operated elevated water cannons and LPG gas detectors at strategic locations.
The canons can supply enough water to knock down any potential HF leak and contain the exposure to the process area. The gas detectors, located around the perimeter of the alkylation unit, identify any potential leak.
The installation of the water mitigation system and the IMP, coupled with the refinery's existing emergency shut down system, surpasses the level of risk reduction achieved by most other refiners with HF alkylation systems. These safety measures rank in the top 10% of implemented safety considerations on HF alkylation units worldwide.
Caltex can operate the IMP system and water-mitigation system in the confines of the master control room.
The HF alkylation process uses HF as a catalyst to combine with light hydrocarbons to produce alkylate, a high octane gasoline additive. The Caltex alkylate has a research octane number (RON) of 95 and a motor octane number (MON) of 91.
Phillips played key roles in the process design, vessel and piping size requirements, heat-exchanger layout, dump philosophy, and control schemes. Its licensing specialists helped review mechanical design drawings, inspected the finished product at the fabricator's yard, and provided support during precommissioning and start-up.
The Caltex staff performed detailed engineering and supervised the construction of the upgrade.
