Patent FR-2961802-A1 (FR)
Title: Combined production of hydrogen and carbon dioxide from hydrocarbon mixture comprises e.g. reforming hydrocarbon mixture to give synthesis gas, cooling the gas, oxidation reaction, cooling and drying the gas and separating the gas
Inventor: LOCKWOOD FREDERICK
IPC: C01B3/48
Filed: 2010-06-29
Abstract: Combined production of hydrogen (H 2) and carbon dioxide (CO 2) from a mixture of hydrocarbons comprises: (a) reforming hydrocarbon mixture to obtain a synthesis gas containing e.g. at least hydrogen, carbon monoxide and carbon dioxide; (b) cooling the gas; (c) conversion reaction (shift) of all or part of the gas cooled to oxidize major part of the carbon monoxide into carbon dioxide; (d) cooling the synthesis gas; (e) additional drying of cooled synthesis gas; (f) separating dry gas; (g) drying obtained R(psa) stream; and (h) capturing carbon dioxide and purifying R(psa) stream. Process for combined production of hydrogen (H 2) and carbon dioxide (CO 2) from a mixture of hydrocarbons comprises: (a) reforming hydrocarbon mixture to obtain a synthesis gas containing at least hydrogen, carbon monoxide, carbon dioxide, methane, water vapor and impurities; (b) cooling the synthesis gas with heat recovery; (c) conversion reaction (shift) of all or part of the synthesis gas cooled to oxidize major part of the carbon monoxide into carbon dioxide with corresponding production of hydrogen; (d) cooling the synthesis gas rich in H 2and CO 2obtained from step (c) with elimination of condensed water; (e) additional drying of cooled synthesis gas to obtain a dry synthesis gas; (f) separating dry synthesis gas in an adsorption unit by modulation of pressure (or PSA H2) to obtain H(I) stream at a pressure enriched in hydrogen and R(psa) stream of PSA residue gas containing at least carbon dioxide, hydrogen and impurities; (g) drying R(psa) stream; and (h) capturing carbon dioxide through a compression CPU step and purifying R(psa) stream to obtain a liquid or super critical stream rich in CO 2and a residual gas stream R1 enriched in hydrogen, where the process further comprises: (i) treating all or part of the residual R1 in a PSA H 2unit different from the PSA H2 unit of step (f) to produce H(II) stream at high pressure rich in hydrogen different from H(I) stream produced in step (f) and R(II) stream of residue gas of PSA different from R(psa) of residue gas produced in step (f). An independent claim is included for installation of combined production of hydrogen and carbon dioxide from a hydrocarbon mixture comprising at least: a module of reforming the hydrocarbon mixture to obtain a synthesis gas; at least a module for first cooling of synthesis gas with means for heat recovery; a module of reverse conversion to the steam (shift) of synthesis gas; a cooling module of synthesis gas converted with condensation of water vapor and recovery of condensed water; an optional module for converted and cooled synthesis gas drying; a first purification unit by adsorption by pressure modulation (PSA) of dry synthesis gas for obtaining hydrogen and a PSA residue, an optional module for drying of PSA residue, a CPU unit for capturing of carbon dioxide for implementing the step compression and purification of PSA residue to obtain a liquid stream or supercritical stream rich in CO 2and a CPU residue gas flow rich in hydrogen; a second PSA H 2unit, different from the first PSA H 2unit, able to treat any or part of the CPU residue to produce hydrogen stream and PSA residual gas stream; and means to convey the entire used stream.