Method of making hydrogen by pressure swing adsorption in a PSA unit from a charge gas containing hydrogen at a first pressure

摘要

The compressed residue is sent to a fuel gas mixture distributor at a second pressure (P 2) and contains hydrogen. A fraction of the fuel gas mixture circulating in the distributor is sampled, compressed to the first pressure (P 1) and injected as additional charge gas into the PSA unit. The fraction of fuel gas mixture is injected into the charge gas. The first pressure (P 1) is between 15 and 45 bars and the second pressure (P 2) is between 3 and 8 bars. The residue is extracted from the PSA unit at a third pressure (P 3) of between 1.1 and 2 bars. The fuel gas mixture contains at least 30 % hydrogen, preferably between 35 and 50 % hydrogen. An independent claim is made for a device to carry out the above process, comprising a charge gas supply line (3), a fuel gas mixture circulation pipe (10), at least one PSA unit (1) with an inlet (2), an outlet for production gas (4) and an outlet for residual gas (7). A first compressor (9) connected the residual gas outlet to the fuel gas mixture circulation pipe and a second compressor (13) connects the fuel gas mixture circulation pipe to the inlet to the PSA unit or to the charge gas supply line. The second compressor is connected to the fuel gas mixture circulation pipe upstream of its connection to the first compressor. The two compressors use common sub-assemblies and have a common driving shaft (14).