Reactive diluent fluid (22) is introduced into a stream of synthesis gas (or syngas) produced in a heat-generating unit such as a partial oxidation (POX) reactor (12) to cool the syngas and form a mixture of cooled syngas and reactive diluent fluid. Carbon dioxide and/or carbon components and/or hydrogen in the mixture of cooled syngas and reactive diluent fluid is reacted (26) with at least a portion of the reactive diluent fluid in the mixture to produce carbon monoxide-enriched and/or solid carbon depleted syngas which is fed into a secondary reformer unit (30) such as an enhanced heat transfer reformer in a heat exchange reformer process. An advantage of the invention is that problems with the mechanical integrity of the secondary unit arising from the high temperature of the syngas from the heat-generating unit are avoided.

The invention concerns a process and apparatus for cracking ammonia in which heated ammonia gas at super-atmospheric pressure is partially cracked catalytically in an adiabatic reaction unit to produce partially cracked ammonia gas which is heated and fed to catalyst-containing reactor tubes in a furnace to cause cracking of further ammonia and produce a cracked gas comprising hydrogen gas, nitrogen gas and residual ammonia gas. At least some, preferably all, of the duty required to heat the partially cracked ammonia gas is provided by heat exchange with the cracked gas, enabling more efficient heat integration within the process.

A system is provided for reforming a hydrocarbon feedstock. The system comprises: first prereformer units and first preheating unit arranged upstream a bayonet tube steam methane reformer. The system is arranged to provide a temperature of the heated partially-reformed process stream at the inlet of the bayonet tube steam methane reformer of at least 600? C. and a temperature of the gas at the bottom of the bayonet steam methane reformer tubes of at least 800? C. This arrangement allows higher bayonet tube inlet temperatures, with reduced risk of increased metal dusting. A process is also provided for reforming a hydrocarbon feedstock in the system of the invention.

The present invention concerns a process and apparatus for cracking ammonia gas at super-atmospheric pressure in catalyst-filled reactor tubes in a furnace. The tubes each have an upstream layer of a first catalyst and a downstream layer of a second catalyst, the first catalyst being more active than the second catalyst. Having the more active catalyst upstream reduces the temperature of the outer walls of the tubes in the region of the burner flames and the temperature of the inner walls of the tubes in the region with the highest mole fraction of ammonia. Nitriding of the metal of the tubes in this region is thereby reduced.

The invention concerns a process and apparatus for cracking ammonia in which heated ammonia gas at super-atmospheric pressure is partially cracked in at least two adiabatic reactors in series with interstage heating in which the feed temperature to a first reactor is higher than the feed temperature to a further reactor to produce a partially cracked ammonia gas which is then fed to catalyst-containing reactor tubes in a furnace to produce a cracked gas comprising hydrogen gas, nitrogen gas and residual ammonia gas. The use of the adiabatic reactors enables more efficient heat integration within the process and the higher temperature in the first reactor enables the use of a nickel-based catalyst in that reactor as an alternative solution to the potential problem of the presence of oil in the ammonia.

The present invention concerns a process for cracking ammonia comprising providing an ammonia-containing feed gas at a temperature of over 600? C. and a pressure in a range from about 5 bar to about 50 bar; combusting a fuel with an oxidant gas in a furnace to heat reactor tubes to achieve a maximum inner wall temperature of over 700? C. and produce a flue gas, each reactor tube comprising a catalyst bed comprising a first row transition metal-based catalyst; and feeding the ammonia-containing feed gas to the reactor tubes to produce a cracked gas at a temperature of over 600? C. on exit from the reactor tubes.

Hydrogen-producing fuel processing systems and related methods. The systems include a hydrogen-producing region configured to produce a mixed gas stream from a feedstock stream, a hydrogen-separation membrane module having at least one hydrogen-selective membrane and configured to separate the mixed gas stream into a product hydrogen stream and a byproduct stream, and an oxidant delivery system configured to deliver an oxidant-containing stream to the hydrogen-separation membrane module in situ to increase hydrogen permeance of the hydrogen-selective membrane. The methods include operating a hydrogen-producing fuel processing system in a hydrogen-producing regime, and subsequently operating the hydrogen-producing fuel processing system in a restoration regime, in which an oxidant-containing stream is delivered to the hydrogen-separation membrane module in situ to expose the at least one hydrogen-selective membrane to the oxidant-containing stream to increase the hydrogen permeance of the at least one hydrogen-selective membrane.

A method for revamping a front-end of an ammonia plant, said front-end comprising a reforming section (1, 2) with air-fired secondary reformer or autothermal reformer (2), a treatment section (3) of the effluent from said reforming section, and an air feed compressor (6), wherein an O.sub.2-containing stream (8) is directed to said reforming section (2) for use as oxidant, at least one nitrogen stream (9) is introduced at a suitable location of the front-end, to provide a desired molar ratio between hydrogen and nitrogen in the product gas, and at least part of said nitrogen stream (9) is compressed via said feed compressor (6).

Systems and methods for sorbent enhanced reformation to produce high purity hydrogen. Such systems and methods utilize a reforming unit to process a feed containing methane and steam to produce a reformer product stream containing hydrogen and carbon dioxide, a sorbent unit to absorb at least a portion of the carbon dioxide from the reformer product stream to produce a sorbent unit product stream containing H.sub.2 and used sorbent, a first separation unit to separate H.sub.2 from the used sorbent, a calciner unit to calcine at least a portion of the used sorbent to form a calciner product stream containing regenerated sorbent material and residual gases, a second separation unit to separate the regenerated sorbent material from the residual gases, and a return line to return regenerated sorbent material to the sorbent unit.

Hydrogen-producing fuel processing systems and related methods. The systems include a hydrogen-producing region configured to produce a mixed gas stream from a feedstock stream, a hydrogen-separation membrane module having at least one hydrogen-selective membrane and configured to separate the mixed gas stream into a product hydrogen stream and a byproduct stream, and an oxidant delivery system configured to deliver an oxidant-containing stream to the hydrogen-separation membrane module in situ to increase hydrogen permeance of the hydrogen-selective membrane. The methods include operating a hydrogen-producing fuel processing system in a hydrogen-producing regime, and subsequently operating the hydrogen-producing fuel processing system in a restoration regime, in which an oxidant-containing stream is delivered to the hydrogen-separation membrane module in situ to expose the at least one hydrogen-selective membrane to the oxidant-containing stream to increase the hydrogen permeance of the at least one hydrogen-selective membrane.