Amine unit in SAF production

Sour gas, originating from the hydrogenation and isomerisation units, typically contains around 75% unreacted hydrogen, along with CO₂, propane, and trace amounts of sulphides. The role of the amine unit is to absorb and remove sulphides and CO₂ from this sour gas stream, producing ‘sweet gas’.

A common amine gas treatment method is the Girbotol process, which consists of an absorber column and a regenerator unit. In the absorber, the amine solution absorbs hydrogen sulphide and carbon dioxide, converting the sour gas into sweetened gas. The amine solution, now ‘rich’ in acid gases, is routed to the regenerator, where the hydrogen sulphide and carbon dioxide are driven off as ‘acid gas’, allowing the lean amine to be reused in the absorber unit. The sweet gas can subsequently be processed to separate light hydrocarbons (propane, naphtha) from hydrogen. The purified hydrogen is then recycled back into the hydrogen process system.

The OPTISONIC 7300 is well suited for measuring corrosive sour gas flows. For the pure hydrogen stream, a dedicated set of ultrasonic transducers enables accurate measurement of hydrogen-rich gas. To measure the pressure in pure hydrogen, it is recommended to use ceramic pressure transmitters such as the OPTIBAR PC 5060. Ceramic sensors are not affected by hydrogen diffusion, are less temperature-dependent, and provide a faster response time, making them particularly suitable for hydrogen applications.