Sulfuric Acid Alkylation

Owing to high gasoline prices and reformulated gasoline regulations, the refineries invest in additional sulfuric acid alkylation capacity, new alkylation units and smaller retrofit projects.

The problem involved in the motor fuel sulfuric acid iso-butylene alkylation process is that sulfuric acid concentration is critical to complete consumption of the iso-butylene. A highly variable concentration of iso-butylene in the feed stock upsets the sulfuric acid content in the process.

Monitor acid strength continuously to ensure that the proper amount of acid is added to the process

Download our application note to learn why it is important to determine the proper amount of acid to feed to the process This is done by combining the routine sample titration analysis with a continuous acid monitoring using Vaisala Polaris^TM Process Refractometer. Without the continuous measurement, the board operator would typically wait for a confirming titration result before making any changes to acid flow.

The continuous monitoring can prevent panic between the titration measurements. Vaisala refractometer better indicates any gradual changes in the acid flow control, which generally reduces unit acid consumption. It also helps prevent the scenario that's most unwanted by operating personnel, the acid runaway, a situation simply referred to as "when acid becomes wild".

The acid runaway may happen when the acid strength goes below 85-87%. Then the reactions between olefins and iso-butene turn into reactions of olefins only, producing polymers known as "acid sludge, ASO or red oil".

Download our application note in PDF by filling in the form.

Go back to all Oil & Gas Refining & Petrochemicals applications

Image