The Model 8800C Optimizes Production of
Alkylate at Refineries

The sulfuric acid alkylation process mixes an isobutane stream and olefin feed (consisting of propane/propylene and/or butane/butylene) with a stream of sulfuric acid. The mixture is chilled to 40 °F and fed to two parallel reactors. The chemical reaction is highly exothermic, and runaway high temperatures may cause an explosion. To control temperature in the reactors, the system manipulates the flowrate ratio of the hydrocarbon and sulfuric acid feeds.

High reliability and low downtime are key requirements for equipment in a continuous refinery process like sulfuric acid alkylation. To optimize the process, measurements must be available at all times. Maintenance due to clogging of impulse lines or ports is unacceptable. In addition, customers want to minimize exposure of personnel to hazardous acids.

The reliability of vortex flowmeters is superior to other flowmeter technologies for the alkylation process because of the physical nature of the feed. Customers have reported regular plugging of DP/Orifice plate impulse lines by crystalline precipitates, causing loss of measurement, high maintenance costs, and process down time.