Since the acid feed control loop controls the hydroflouric acid being fed to the reactor, it is important that it is reliable and consistently operational to provide conversion from olefins to alkylate in the reactor. An upset in the control valve could cause a leakage of hydroflouric acid, leading to a major environmental and health risk.
The accumulated acid control loop uses a valve that controls the hydrofluoric acid level in the acid accumulator. Spent hydrofluoric acid is constantly circulating from the acid accumulator to the rerun column. An upset in this valve could cause a leakage of hydrofluoric acid, which would be a major environmental and health risk.
Should an unforeseen upset in a process arise and result in an overpressure scenario, it is imperative that the relief valves will operate when all else fails.
The alkylation process involves tight isolation and precise control to ensure that the proper ratios of olefins, isobutane and hydrofluoric acid are used in the reactor and other vessels. Due to hydrofluoric acid’s high corrosiveness and health and safety impact, the need for a very reliable, well-constructed isolation valve and actuator for physical containment is paramount as these valves need to be in operation without failure for years.
