Methods for production of hydrogen
AssigneeResearch Triangle Institute
InventorsShaojun James Zhou, Raghubir P. Gupta, John Reeves Carpenter, Brian S. Turk
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Abstract
Synthesis gas containing nitrogen as the majority component is processed to increase the hydrogen to carbon dioxide ratio. Nitrogen, carbon dioxide, and other contaminants are subsequently removed by a purification unit to produce a purified hydrogen gas stream. A recycle stream within the purification unit helps achieve a hydrogen purity greater than 99.9 percent, and hydrogen recovery greater than 99 percent.
Claims12
A method for producing a purified hydrogen gas stream, the method comprising:
- flowing a fuel and an oxidizer into an internal combustion engine to produce a feed gas containing nitrogen gas (N2) as the majority component, hydrogen gas (H2), and carbon monoxide (CO) and having an initial H2 to CO ratio;
- flowing the feed gas into a processing unit to produce an enhanced gas containing carbon dioxide (CO2) and having a second H2 to CO ratio greater than the initial H2 to CO ratio;
- flowing the enhanced gas into a purification unit comprising a N2 removal unit to remove N2 and a CO2 removal unit to remove CO2, wherein the purification unit produces a purified hydrogen gas stream and a tail gas containing residual H2;
- and
- recycling about 50 percent to about 100 percent of the tail gas containing residual H2 to a point upstream of the N2 removal unit so as to increase the H2 recovery.
A method for producing a purified hydrogen gas stream, the method comprising:
- flowing a fuel and an oxidizer into an internal combustion engine to produce a feed gas containing nitrogen gas (N2) as the majority component, hydrogen gas (H2), and carbon monoxide (CO) and having an initial H2 to CO ratio;
- flowing the feed gas into a processing unit to produce an enhanced gas containing carbon dioxide (CO2) and having a second H2 to CO ratio greater than the initial H2 to CO ratio;
- flowing the enhanced gas into contact with a membrane in a membrane unit to produce a permeate stream and a retentate stream, wherein the membrane has a H2 selective composition, and a concentration of H2 in the permeate stream is greater than a concentration of H2 in the enhanced gas, and the retentate stream comprises N2 that has been removed from the enhanced gas;
- flowing the permeate stream into contact with a sorbent material in one or more adsorption columns to produce a purified H2 gas stream, wherein the sorbent material comprises a sorbent compound effective for removing CO2 from the permeate stream;
- and
- regenerating the sorbent material in at least one of the one or more adsorption columns to produce a tail gas containing residual H2, and recycling about 50 percent to about 100 percent of the tail gas containing residual H2 to the enhanced gas stream at a point upstream of the membrane unit so as to increase the H2 recovery.
Dependencies are inferred from the claim text.