In a production process for fatty alcohols, hydrogen is used as a circulating gas. Within the process, hydrogen fulfills a double role - being one of the raw materials but also the primary carrier medium.
The primary raw material, methyl ester, gets carried by the hydrogen flow into a shaft reactor. The synthesized fatty alcohols, which are created through a fixed bed catalytic reaction, are then, again by use of the hydrogen flow, carried out of the reactor. Thus, to act as a reaction agent and carrier medium, the hydrogen has to be used in stochiometric excess. Moreover, the hydrogen also acts as a discharging medium for the significant thermal energy created in the exothermic process.
For the most efficient amount of hydrogen gas to be circulating, the process control is relying on an accurate and reliable volume flow measurement.
Previously used turbine gas flow meters have been subject to heavy mechanical wear as of the occurrence of pulsating and gushing liquid flows into the piping. Their necessary frequent removal, which could only happen during plant downtime, proved to be very costly - also due to the high pressure stages they had to be designed for.
These difficulties do not exist with FLEXIM's non-intrusive FLUXUS gas flow meters based on the clamp-on ultrasonic flow measurement technology. Since these hydrogen flow meters are simply clamped on to the pipe externally, they are not subject to wear by the medium. Moreover, the system is totally independent of the pressurization levels inside and the installation of these hydrogen gas flow meters is done without any process interruption.
Moreover, the mandatory pressure tests within the piping, to be carried out with water at regular five-year intervals, can now be done without the expensive temporary removal of inline flow meters.