Refining in the oil & gas industry

Refining is a series of processes that convert crude oil into finished products: it is generally referred to as being the ‘downstream’ sector of the oil industry. The large industrial complex that creates a refinery treats the crude oil with heat, steam, hydrogen, water, chemicals and catalysts to split the oil, in several stages, into different types of liquid and gas: some of these are used as fuel to provide the heat and steam needed. After the initial stages, where major impurities are washed out of the crude oil, the main initial processing takes place in a fractionating column: this separates the crude oil into different fractions. Fractions with lower boiling points come out from the top of the fractionating column: those with a higher boiling point emerge lower down, as side-cuts, or from the bottom of the column. Cracking stages then convert the heavy bottom fractions into more useful, lighter products. Further processing then removes some undesirable components, such as hydrogen sulfide and carbon dioxide.

Refinery design engineers can choose from over 200 different processes to suit their crude oil properties, their geographical location, and the desired mix of saleable product, as required by the market. Refineries store the different refined products in tank farms, and these are blended into the final products, such as kerosene, diesel and gasoline. Accurate refinery instrumentation is important to ensure the blended products meet the required specification, without using too much of the more expensive fractions derived from the crude oil, and this can vary throughout the year.

KROHNE has a vast experience as a supplier of downstream measurement solutions to refineries. For key refinery processes KROHNE has developed dedicated flow and level instrumentation, such as both vortex and ultrasonic flowmeters for steam flow measurement, and ultrasonic flowmeters suitable for the harsh conditions and extremely high temperatures experienced with the oil feeds to the Delayed Coker. KROHNE straight tube Coriolis flowmeters offer the high accuracies needed for blending processes, and fiscal measurement solutions for truck loading applications.