Hydrogen refuelling station with integrated metal hydride compressor: Layout features and experience of three-year operation

Hydrogen compression is a main contributor in the capital and operation costs of the H-2 refuelling infrastructure. The use of metal hydrides (MH) for thermally-driven H-2 compression can provide efficient solution to mitigate this challenge. MH compressors are particularly promising for industrial customers who possess necessary infrastructure including pipeline H-2, sources of low-grade heat, etc. Here we present the details about layout of the H-2 refuelling station and its operation at Impala Platinum refineries in Springs, South Africa, since its start-up in September 2015. The station provides H-2 dispensing at the pressure up to 185 bar and uses pipeline H-2 (P = 50-60 bar) available at the customer site. H-2 compression to P = 200 bar with productivity up to 13 Nm(3)/h is provided by the integrated 1-stage MH H-2 compressor which uses steam (T similar to 140 degrees C) for the heating and circulating water (T similar to 20 degrees C) for the cooling; both steam and water are also available from the customer infrastructure. The station also includes H-2 dispenser, buffer tank (standard gas cylinder pack), and control block on the basis of Siemens Program Logic Controller (PLC) which provides fully automated system operation. Switching H-2 and steam/water flows is carried out with the help of remotely controlled, pneumatically actuated valves and auxiliary check valves. Additionally, at P = 200 bar the control block switches the system into standby mode when MH compression modules are cooled down and their gas manifolds are connected to the H-2 supply line. The H-2 dispensing is independent on the compressor operation and takes from 6 to 15 min. The refuelling station complies with South African safety regulations for operation in a fire and explosion hazardous environment. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.