A process and apparatus for producing a hydrogen-enriched product and recovering CO.sub.2 from an effluent stream from a hydrogen production unit are described. The effluent from the hydrogen production unit, which comprises a mixture of gases comprising hydrogen, carbon dioxide, water, and at least one of methane, carbon monoxide, nitrogen, and argon, is sent to a PSA system that produces at least two product streams for separation. The PSA system that produces at least two product streams separates the gas mixture into a high-pressure hydrogen stream enriched in hydrogen, optionally a second gas stream containing the majority of the impurities, and a low-pressure tail gas stream enriched in CO.sub.2 and some impurities. The CO.sub.2-rich tail gas stream is compressed and sent to a CO.sub.2 recovery unit, where a CO.sub.2-enriched stream is recovered. The CO.sub.2-depleted overhead gas stream is recycled to the PSA system that produces at least two product streams.

A bio-renewable conversion process for making fuel from bio-renewable feedstocks is combined with a hydrogen production process that includes recovery of CO.sub.2. The integrated process uses a purge gas stream comprising hydrogen from the bio-renewable hydrocarbon production process in the hydrogen production process.

Direct reduction process and plant for producing DRI comprising a reduction reactor and at least one reducing gas heater typically comprising a convective heating section and a radiant heating section for raising the reducing gas temperature to a level adequate for iron oxides reduction to metallic iron, typically above 850° C., wherein the reducing gas fed to the reduction reactor comprises a stream of reducing gas recycled from the reduction reactor and a make-up stream of coke oven gas containing carbon compounds which may form carbon deposits in the heating path of said heater, namely BTX and other complex carbon compounds. The heater is provided with means for feeding oxidizing agents, for example steam, steam and air and/or oxygen at predetermined heating tubes successively for eliminating the carbon deposits which may form inside the heating tubes of said heater without interrupting the operation of the plant. The make-up stream of cold COG can be combined with the recycled gas at a point in the gas heating path of the heater where the tubes have a skin wall temperature of at least 700° C., or when the mixture of recycled gas and COG is at a temperature above 700° C. for minimizing clogging or fouling of heating equipment.

The present invention provides: an electrode-supporting type of gas-separation membrane module for selectively effecting the passage of a gas via an electron exchange reaction due to a coupling-material layer and gas exchange via an ion-conducting separation layer; a tubular structure of same; a production method for the tubular structure; and a hydrocarbon-reforming method using the gas-separation membrane module. The present invention is advantageous in that outstanding chemical and mechanical durability can be ensured by using a fluorite-based ion-conducting membrane which is chemically stable in CO2 and H2O atmospheres in particular, at high temperature, and in that a pure gas can be produced inexpensively since the passage of gas occurs due to an internal circuit even without applying a voltage from the outside.

The present technology is directed to processes involving formation of hydrocarbons and oxygenated hydrocarbons through use of oxygen supplied by ion transport membranes. More particularly, the present technology relates in part to a process involving steam reforming and subsequent production of a synthetic product where carbon dioxide and/or hydrogen downstream of the process is reclaimed to generate the synthetic product. The present technology also relates in part to an ethylene formation process involving a viral-templated coupling catalyst in the presence of an ion transport membrane.

A process for the production of ammonia and urea in an ammonia-urea integrated plant comprising an ammonia section and a tied-in urea section, wherein a hydrocarbon is reformed to produce ammonia make-up synthesis gas; said make-up gas is purified by shift conversion and removal of carbon dioxide; carbon dioxide is removed from the make-up gas by a first and a second CO2 removal sections; the first section removes CO2 by absorption with a suitable medium, and the second section removes CO2 by washing with a carbamate solution taken from the urea section; the make-up gas is reacted to produce ammonia; the CO2 removed from the make-up gas and at least part of the ammonia are used to produce urea.

The invention relates to a method and to a plant for chemical looping oxidation-reduction combustion (CLC) of a gaseous hydrocarbon feed, for example natural gas essentially containing methane. According to the invention, catalytic steam reforming of the feed is performed between two successive feed combustion steps on contact with an oxidation-reduction active mass in form of particles. The reforming catalyst is arranged in a fixed bed in an intermediate reforming zone (130) between the two reduction zones (120, 140) where the two combustion steps are conducted.

FIG. 2 to be published.

A process for producing hydrocarbons is disclosed in which a first feed substream and a second feed substream are obtained from a hydrocarbonaceous feed stream, of which the first feed substream is converted by means of partial oxidation or autothermal reforming to a first synthesis gas stream and the second feed substream is converted by means of steam reforming to a second synthesis gas stream and subsequently combined with the first synthesis gas stream to give a third synthesis gas stream, of which at least a first portion is converted by Fischer-Tropsch synthesis to a crude product stream comprising hydrocarbons of different chain lengths, from which light hydrocarbons are separated in a tail gas, in order to recycle them and use them in the partial oxidation or autothermal reforming. The characteristic feature here is that unsaturated hydrocarbons are separated from at least a portion of the tail gas.

Disclosed are methods for accommodating changes in the conditions of partial oxidation of hydrocarbonaceous feedstock by changing characteristics of the hot oxygen used in the partial oxidation.

Disclosed is methodology for controlling the H2:CO ratio of the product produced in a partial oxidation reactor, by adjusting the properties of the product formed in the partial oxidation.