Hydrotreating in the oil & gas industry

Hydrotreating, often called hydro-desulfurisation, is a refinery process applied to the distillation column sidecuts that that are heavier oil products. The objective is to reduce the sulphur and other components, such as nitrogen and aromatics, by creating a reaction between them and hydrogen, when they are exposed to a catalyst at high temperature. In this way the refinery can meet the requirements for clean fuel specifications, for example for low sulphur/sulfur diesel.

In the steady operational state, the liquid output from the furnace heats the input fluids, which are a mixture of the oils for treatment and hydrogen gas, these then pass into the reactor, over the catalyst. The liquid output is then treated with wash water, and passed to a separator, where some hydrogen is recovered, and sour water is passed for treatment. The oil drawn off is passed through a stripper, where it is mixed with steam. The upper output from the stripper once again goes through a separator, which produces sour water and sour gas: the desulfurized product emerges from the base of the stripper.

KROHNE offers a complete portfolio of hydrotreating process instrumentation, including several different types of flowmeter to control the hydrotreatment. The portfolio varies from specially developed ‘harsh environment’ electromagnetic flowmeters that are used for sour water measurement, up to vortex and ultrasonic flowmeters that are applied to measure the hydrogen gas flows. TDR guided wave radar systems are used to monitor fluid levels, particularly to control the interfaces within the separators.