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.

The present specification discloses a membrane reactor comprising a reaction region; a permeate region; and a composite membrane disposed at a boundary of the reaction region and the permeate region, wherein the reaction region comprises a bed filled with a catalyst for dehydrogenation reaction, wherein the composite membrane comprises a support layer including a metal with a body-centered-cubic (BCC) crystal structure, and a catalyst layer including a palladium (Pd) or a palladium alloy formed onto the support layer, wherein ammonia (NH.sub.3) is supplied to the reaction region, the ammonia is converted into hydrogen (H.sub.2) by the dehydrogenation reaction in the presence of the catalyst for dehydrogenation reaction, and the hydrogen permeates the composite membrane and is emitted from the membrane reactor through the permeate region.

A transfer line between the outlet of a steam cracker and the inlet for the quench system has metallic or ceramic inserts having a pore size from about 0.001 to about 0.5 microns inside the line forming a gas tight barrier with the inner surface of the line and having a vent for the resulting gas tight pocket are used to separate H.sub.2, CH.sub.4, CO and CO.sub.2 from cracked gases reducing the load on the down-stream separation train of the steam cracker.

Methods for purifying a hydrogen gas stream are provided that can include: introducing the hydrogen gas stream into the hydrogen pumping cell, and collecting a purified hydrogen gas from the hydrogen pumping cell. The hydrogen gas stream can include hydrogen sulfide in an amount of about 10 ppm to about 1,000 ppm, and can have a relative humidity of about 0.1% or more at the operational temperature and pressure of the hydrogen pumping cell.

Method and system for producing CO2, purified hydrogen and electricity from a reformed process gas feed using a solid oxide fuel cell. The method having the steps of: introducing the reformed process gas into the solid oxide fuel cell; converting hydrogen and CO of the reformed process gas in combination with oxygen into an anode off-gas including steam, CO.sub.2 and unconverted process gas; introducing the anode off-gas into a high temperature water gas shift reactor; in the high temperature water-gas shift reactor, converting CO and steam into CO.sub.2 and hydrogen, introducing the gas exiting the high temperature water-gas shift reactor into a low temperature water-gas shift membrane reactor, in the low temperature water-gas shift membrane reactor, converting CO and steam into CO.sub.2 and hydrogen, whereby the low temperature water-gas shift membrane reactor comprises a hydrogen pump producing purified hydrogen on a permeate side, while removing hydrogen from a feed side.

A membrane is described for purifying or separating hydrogen from a multi-component gas stream such as syngas. This membrane uses a molecular pre-treatment, a transition metal, fluorine containing polymer, carbon fibers and carbon matrix sintered on a supportive screen. The membrane may be a bilayer membrane comprised of a layer containing high surface area carbon and another layer containing lower surface area carbon.

An autothermal reforming catalytic structure for generating hydrogen gas from liquid hydrocarbons, steam and an oxygen source. The autothermal reforming catalytic structure includes a support structure and nanosized mixed metal oxide particles dispersed homogenously throughout the support structure.

The present invention comprises a process for producing hydrogen, wherein in a first stage hydrocarbons are decomposed into solid carbon and into a hydrogen-containing gaseous product mixture, the hydrogen-containing gaseous product mixture, which has a composition in respect of the main components CH4, N2, and H2 of 20% to 95% by volume H2 and 80% to 5% by volume CH4 and/or N2, is discharged from the first stage at a temperature of 50 to 300° C., and this is supplied at a temperature differing from this exit temperature by not more than 100° C. to an electrochemical separation process and, in this second stage, the hydrogen-containing product mixture is separated in the electrochemical separation process at a temperature of 50 to 200° C. into hydrogen having a purity of >99.99% and a remaining residual gas mixture.

A hydrogen recycle system comprises a processing device, an electrochemical hydrogen purification device and a dewatering device. The processing device is used to receive and process a mixed gas and to remove harmful substances; the electrochemical hydrogen purification device is connected with the processing device and used to remove non-hydrogen gases and impurities in the mixed gas; and the dewatering device is connected with the electrochemical hydrogen purification device and used to remove moisture in the purified hydrogen.

A pair of fuel cells are configured as a hydrogen purity monitor. A first cell, acting as a reference cell, is configured to generate electrical current from the electrochemical reaction of hydrogen and oxidant and has a first fuel inlet configured to receive hydrogen from a first hydrogen source. A second fuel cell, acting as a test cell, is configured to generate electrical current from the electrochemical reaction of hydrogen and oxidant and has a second fuel inlet configured to receive hydrogen from a second hydrogen source. A control system is configured to apply an electrical load to each fuel cell and determine an electrical output of each fuel cell. The control system has a comparator for comparing the electrical outputs of the first and second fuel cells and a purity monitor output configured to give an indication of hydrogen purity based on an output of the comparator.