What made the revamp necessary?
A client wanted to increase the H2 production capacity of his steam reformer plant by 15% after the plant had been in operation for several years.
Besides that, the available feedstock had changed from light naphtha to a heavier type of naphtha.
How the Linde specialists managed this situation?
They performed a high load test run in order to pinpoint the plant bottlenecks and conducted detailed process simulations. Pressure profiles for the process gas route were created to reveal the plant‘s hydraulic limits. The figure below shows the pressure profiles of the plant for the original design case as well as the plant after revamping. In addition the design pressures for the plant equipment are shown.
To make the best use of the available design pressure levels, the original safety valves have been replaced with pilot-driven safety valves. This made it possible to minimize the approach between process pressure and design pressure. The plant throughput was increased to an optimum. The resulting H2 production capacity increase was 10%. Greater plant throughput was limited by the hydraulic constraints of the piping and equipment.
To increase the H2 production capacity further a low temperature shift reactor was installed downstream of the existing high temperature shift reactor. The process flow diagram at the bottom shows the additionally installed piping and equipments in red. An overall H2 production capacity increase of 15% could be brought about by shifting additional CO to H2.
Linde Engineering‘s revamp of this plant was carried out successfully. The estimated consumption and production figures were approved in a guarantee test run.
The revamp boosted the steam reformer plant‘s H2 production capacity from 53,000 Nm3/h to 61,000 Nm3/h.
