| 主权项 |
1. Method for the production of hydrogen from biogas comprising at least the following steps:
a step (a) of making available a raw biogas containing 45% to 70% CH4, 30% to 50% CO2, as well as at least one of a sulphide, siloxane and/or VOC compound, a step (b) of purifying a first portion of the raw biogas for producing biomethane, comprising:
a step (b0) of pre-purification intended-to eliminate at least any of the sulphide compound from the raw biogas. anda step (b1) of eliminating CO2 so as to produce biomethane containing less than 8% CO2, a step (c) of steam reforming of the biomethane produced in step (b), in a steam methane reformer having a furnace burner to obtain a synthesis gas containing at least hydrogen and carbon monoxide, carbon dioxide, methane, and water vapour, a step (d) of shift reaction for oxidising the majority of carbon monoxide into carbon dioxide in the presence of water with the corresponding production of hydrogen to forma dry synthesis gas, a step (e) of separating constituents of the dry synthesis gas in an adsorption unit by pressure modulation (or H2 PSA) to obtain a hydrogen-rich flow and a flow of PSA waste gas depleted of hydrogen, a step (f) of recycling all or a portion of the PSA waste gas to supply the burners of the steam reforming furnace of step (c) with secondary fuel, a step (g) of supplying the steam reforming furnace burner with a primary fuel provided from a second portion of the raw biogas of step (a). |
