A process synthesizes C.sub.5 and higher hydrocarbons from natural gas through intermediate conversion of natural gas to synthesis gas and subsequent conversion of CO and H.sub.2 by Fischer-Tropsch synthesis. The process includes steam reforming of natural gas in a steam reforming reactor to form synthesis gas, separating carbon dioxide from the synthesis gas by a liquid absorption method to a residual carbon dioxide content in the synthesis gas no more than 5 vol. %, separating an excess of hydrogen from the synthesis gas by a hydrogen-permeable membrane apparatus to a H.sub.2:CO molar ratio in the range of 1.9 to 2.3 and synthesizing liquid hydrocarbon from the synthesis gas by Fischer-Tropsch synthesis.

A process for the production of hydrogen comprising the steps of subjecting a gaseous mixture comprising a hydrocarbon and steam and having a steam to carbon ratio of at least 2.6:1, to steam reforming in a gas-heated reformer followed by autothermal reforming with an oxygen-rich gas in an autothermal reformer to generate a reformed gas mixture, increasing the hydrogen content of the reformed gas mixture by subjecting it to one or more water-gas shift stages in a water-gas shift unit to provide a hydrogen-enriched reformed gas, cooling the hydrogen-enriched reformed gas and separating condensed water therefrom, passing the resulting de-watered hydrogen-enriched reformed gas to a carbon dioxide separation unit to provide a carbon dioxide gas stream and a crude hydrogen gas stream, and passing the crude hydrogen gas stream to a purification unit to provide a purified hydrogen gas and a fuel gas.

A process of hydrogen production comprising the steps of: subjecting a gaseous mixture comprising a hydrocarbon and steam, and having a steam to carbon ratio of at least 0.9:1, to adiabatic pre-reforming in a pre-reformer followed by autothermal reforming with an oxygen-rich gas in an autothermal reformer to generate a reformed gas mixture, optionally adding steam to the reformed gas mixture, increasing the hydrogen content of the reformed gas mixture by subjecting it to one or more water-gas shift stages in a water-gas shift unit to provide a hydrogen-enriched reformed gas, cooling the hydrogen-enriched reformed gas and separating condensed water therefrom, passing the resulting de-watered hydrogen-enriched reformed gas to a carbon dioxide separation unit to provide a carbon dioxide gas stream and a crude hydrogen gas stream, passing the crude hydrogen gas stream to a purification unit to provide a purified hydrogen gas and a fuel gas.

A process of hydrogen production comprising the steps of: subjecting a gaseous mixture comprising a hydrocarbon and steam, and having a steam to carbon ratio of at least 0.9:1, to adiabatic pre-reforming in a pre-reformer followed by autothermal reforming with an oxygen-rich gas in an autothermal reformer to generate a reformed gas mixture, optionally adding steam to the reformed gas mixture, increasing the hydrogen content of the reformed gas mixture by subjecting it to one or more water-gas shift stages in a water-gas shift unit to provide a hydrogen-enriched reformed gas, cooling the hydrogen-enriched reformed gas and separating condensed water therefrom, passing the resulting de-watered hydrogen-enriched reformed gas to a carbon dioxide separation unit to provide a carbon dioxide gas stream and a crude hydrogen gas stream, passing the crude hydrogen gas stream to a purification unit to provide a purified hydrogen gas and a fuel gas.

In a hydrocarbon-fed steam methane reformer hydrogen-production process and system, carbon dioxide is recovered in a pre-combustion context, and optionally additional amounts of carbon dioxide are recovered in a post-combustion carbon dioxide removal, to provide the improved carbon dioxide recovery or capture disclosed herein.

In a hydrocarbon-fed steam methane reformer hydrogen-production process and system, carbon dioxide is recovered in a pre-combustion context, and optionally additional amounts of carbon dioxide are recovered in a post-combustion carbon dioxide removal, to provide the improved carbon dioxide recovery or capture disclosed herein.

The invention relates to a plant for production of hydrogen, and to a method for operating this plant, comprising a steam reforming reactor having a furnace, in which reactor water and at least one carbonaceous energy carrier are reacted to form a hydrogen-containing crude synthesis gas, and at least one cleaning device for purifying the crude synthesis gas, to which the crude synthesis gas is fed from the steam reforming via at least one feed line. According to the invention, upstream of one of the at least one cleaning devices at least one return line branches off from the feed line, through which the crude synthesis gas is at least in part recirculated into the furnace of the steam reforming reactor.

The invention relates to a plant for production of hydrogen, and to a method for operating this plant, comprising a steam reforming reactor having a furnace, in which reactor water and at least one carbonaceous energy carrier are reacted to form a hydrogen-containing crude synthesis gas, and at least one cleaning device for purifying the crude synthesis gas, to which the crude synthesis gas is fed from the steam reforming via at least one feed line. According to the invention, upstream of one of the at least one cleaning devices at least one return line branches off from the feed line, through which the crude synthesis gas is at least in part recirculated into the furnace of the steam reforming reactor.

Acid gas compounds are removed from a process gas such as, for example, syngas or natural gas, by flowing a feed gas into a desulfurization unit to remove a substantial fraction of sulfur compounds from the feed gas and flowing the resulting desulfurized gas into a CO.sub.2 removal unit to remove a substantial fraction of CO.sub.2 from the desulfurized gas.

Acid gas compounds are removed from a process gas such as, for example, syngas or natural gas, by flowing a feed gas into a desulfurization unit to remove a substantial fraction of sulfur compounds from the feed gas and flowing the resulting desulfurized gas into a CO.sub.2 removal unit to remove a substantial fraction of CO.sub.2 from the desulfurized gas.