Specialised valve design for Hydrogen plant PSA

Edited by the Processingtalk editorial team Nov 24, 2003

"Switching valves" are used in the PSA (Pressure Swing Adsorption) process that removes impurities from the hydrogen rich gas manufactured in steam methane reforming plant in a new plant in Italy

Known as "switching valves", the Severn Glocon globe valves are used in the PSA (Pressure Swing Adsorption) process that removes impurities from the hydrogen rich gas manufactured in the steam methane reforming plant.

The specialised plant is designed and manufactured by Axsia Howmar, who have ordered twenty-five of the valves for equipment to be installed at a refinery in Italy.

Ian Pattenden, Axsia Howmar Project Manager, explains: "Switching valves are used to divert the flow of Syngas - an impure gas containing approximately 75 percent hydrogen - between specially designed adsorber vessels under PLC control.

The process can produce up to 99.999 percent pure hydrogen product with recoveries as high as 90 percent.

The adsorption process operates in a cyclic manner and demands very rapid stroke times from the valves, with bubble tight shut off for flow in both directions.

The globe valve configuration is inherently suitable for this type of application, as long as the design is robust and reliable enough to cope with the critical and extremely arduous cyclic nature of the application over a long term operating period".

Two years ago, Severn Glocon began to work on modifications to the Series 5000 general service control valve design, specifically for this application.

Modifications to the valve seat, the pneumatic actuator yoke and linkage between actuator and valve were introduced, combined with special attention to the selection of all component materials.

The resulting design then had successful trials in the USA.

The Axsia Howmar order is its first European project to adopt these valves, which are being supplied in 3 and 6 inch sizes, pressure rated at ANSI Class 300.

The project, which is being built by a leading European contractor, will see hydrogen produced by the Axsia Howmar Hydrogen Generation Plant at the rate of 7,000 Nm3/hr when commissioned.