Recommended pre-operation cleanup procedures for hydrogen fueling station

The stainless steel (SS) tubing and in-line filters are found to be sources of particulates in hydrogen fuel from new hydrogen stations. The internal coating of fueling nozzle can be delaminated during fueling as another particulate source. Organic residues, acetone, heptanes, and C4Cl4F6 isomers are found in new SS tubing, which also emits hydrogen sulfide and carbonyl sulfide. Nitrogen contained in new storage tanks, if not properly removed, can elevate the nitrogen concentration in hydrogen fuel. We find that high pressure hydrogen flow can remove particulates, sulfur compounds and residual organic compounds from SS tubing. However, in-line filters should be cleaned by sonication and nitrogen contained in new storage tank pumped away. It is recommended that internal coating of fueling nozzle or SS tubing should not contain oxygen in chemical composition.