A process and/or system for producing fuel that includes providing biogas, removing carbon dioxide from the biogas, transporting the upgraded biogas to a hydrogen plant; providing the transported upgraded biogas and fossil-based natural gas as feedstock for hydrogen production. The carbon intensity of the fuel is less than 11 gCO.sub.2-eq/MJ, at least in part because carbon dioxide removed from the biogas and carbon dioxide from hydrogen production is captured and stored.

Proposed is a process and a plant for production of pure carbon monoxide and hydrogen by steam reforming of hydrocarbons, preferably methane or naphtha, to afford a raw synthesis gas and subsequent, multistage workup, purification and fractionation of the raw synthesis gas to afford the target products, wherein the material streams obtained as by-products of the process chain are also to be advantageously utilized. This is achieved according to the invention by providing the recirculating compressor provided for recycling of the by-product material streams with a plurality of parallel, independently operable compressor stages.

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.

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.

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.

Methods for producing hydrogen from ammonia are described. The methods involve the use of a two-stage hydrogen PSA configuration. The effluent stream from the ammonia cracking reaction zone is sent to the first hydrogen PSA unit where it is separated into a high purity, high-pressure hydrogen stream and a low-pressure tail gas stream. The high-pressure hydrogen stream can be recovered. The low-pressure tail gas stream is compressed and sent to the second hydrogen PSA unit where it is separated into a second high-pressure stream and a second low-pressure tail gas stream. The second high-pressure hydrogen stream can be recycled to the first hydrogen PSA unit for further separation.

A process for the manufacture of a useful product from carbonaceous feedstock of fluctuating compositional characteristics, comprising the steps of: continuously providing the carbonaceous feedstock of fluctuating compositional characteristics to a gasification zone; gasifying the carbonaceous feedstock in the gasification zone to obtain raw synthesis gas; recovering at least part of the raw synthesis gas from the gasification zone and supplying at least part of the recovered raw synthesis gas to a partial oxidation zone; equilibrating the H.sub.2:CO ratio of the raw synthesis gas in the partial oxidation zone to obtain equilibrated synthesis gas; recovering at least part of the equilibrated synthesis gas from the partial oxidation zone and treating the gas to remove impurities and generate a fine synthesis gas; and converting the optionally adjusted fine synthesis gas into the useful product in a further chemical reaction requiring a usage ratio.

Offshore systems and methods may be configured for offshore power generation and carbon dioxide injection for enhanced gas recovery for gas reservoirs. For example, a method may include: providing an offshore facility including a gas turbine, and a gas separator; producing a produced gas from a gas reservoir to the offshore facility; combusting the produced gas in a gas turbine to produce power and a flue gas; at least partially removing nitrogen from the flue gas in a gas separator to produce a carbon dioxide-enriched flue gas and a nitrogen-enriched flue gas; compressing the carbon dioxide-enriched flue gas in a gas compressor to produce a compressed gas; and injecting the compressed gas from the gas compressor into the gas reservoir, wherein 80 mol % or more of hydrocarbon in the produced gas is combusted and/or injected into the gas reservoir.