If analytical equipment is available, purge system until oxygen content of residual gas is either less than or meets the process specification impurity level.
The aim and the method of mass spectrum analysis for residual gas and the differential pumping system, meanwhile, are introduced.
Industrial hydrogen, pure hydrogen are produced by residual gas of styrene plant by PSA method, high purity hydrogen and superpurity hydrogen are produced by above hydrogen by low temperature adsorption method.
It is shown that the recycling of residual gas can create great economic efficiency.
