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.

In a process for the separation of a gas rich in carbon dioxide and containing at least one component lighter than carbon dioxide, the feed gas rich in carbon dioxide is cooled in a first heat exchanger, partially condensed and separated to form a gaseous portion and a liquid, sending the liquid portion to the top of a distillation column, removing a liquid stream richer in carbon dioxide than the feed gas from the bottom of the distillation column, removing a gaseous stream less rich in carbon dioxide than the feed gas from the top of the distillation column and warming the gaseous stream in the first heat exchanger, sending the gaseous portion to a shell and tube heat exchanger having tubes in a bath of triple point carbon dioxide, in which it condenses at least partially to form a liquid fraction, sending the liquid fraction to the top of the distillation column, vaporizing a liquid stream from the bottom of the distillation column outside or within the distillation column to form a gas which is subsequently separated in the distillation column, expanding a liquid stream from the bottom of the distillation column, vaporizing at least part of the expanded liquid stream in the shell and tube heat exchanger to form a vapor and warming the vapor formed in the first heat exchanger.

A process and apparatus for producing a hydrogen-enriched product and recovering CO.sub.2 from an effluent stream from a hydrogen production process unit are described. The process utilizes a CO.sub.2 recovery system integrated with a PSA system that produces at least two product streams to recover additional hydrogen and CO.sub.2 from the tail gas stream of a hydrogen PSA unit in the hydrogen production process.

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.

A process and a plant for the continuous conversion of a hydrocarbonaceous feed gas into a synthesis gas comprising carbon monoxide and hydrogen, wherein the H.sub.2/CO molar ratio of the product gases can be varied within a wide range. This is achieved in that at least a part of a methane-rich gas obtained during the fractionation of the raw synthesis gas is admixed to the feed gas mixture, and that in the alternative at least a part of the H.sub.2 product gas and/or a fraction of a hydrogen-rich gas increased with respect to the normal operation of the process is admixed to the heating gas mixture, in order to lower the H.sub.2/CO ratio, or at least a part of the CO product gas and/or a fraction of a carbon monoxide-rich gas increased with respect to the normal operation of the process is admixed to the heating gas mixture, in order to increase the H.sub.2/CO ratio.

The invention relates to mixtures comprising molecular hydrogen, hydrocarbons, and nitrogen oxides; to processes for removing at least a portion of the nitrogen oxides therefrom; to equipment useful in such processes; and to the use of such hydrocarbons for, e.g., chemical manufacturing.

A system and method for argon and nitrogen extraction from a feed stream comprising hydrogen, methane, nitrogen and argon, such as tail gas of an ammonia production plant is provided. The disclosed system and method provides for nitrogen-argon rectification and the methane rejection within a column system comprised of at least one distillation column. Nitrogen and argon are further separated and to produce liquid products. An argon stripping column arrangement is disclosed where residual argon is further removed from the methane-rich fuel gas and recycled back to the feed stream.

A method of integrating a fuel cell with a steam methane reformer is provided. The system includes at least one fuel cell including an anode and a cathode, and a steam methane reformer including a syngas stream, and a flue gas stream. The method includes introducing at least a portion of the flue gas stream to the cathode, thereby producing a CO2 depleted flue gas stream and introducing a hydrocarbon containing stream to the anode, thereby producing an electrical energy output and a carbon dioxide and hydrogen containing stream from the fuel cell.

A process for preparing methanol by a methanol synthesis reaction of carbon dioxide with hydrogen may involve a distillation step and a condensation step following the synthesis of a crude methanol. A volatile component and water may be separated off from a methanol-containing product stream, and a gas stream containing a volatile component that has been separated off may be discharged at least partially as offgas. At least part of the gas stream that has been separated off may be recirculated into the methanol synthesis reaction. A plant for preparing methanol can store or utilize electric power generated from renewable energy sources and provide facilities for discharging the offgas stream, which can be purified by catalytic after-combustion. Alternatively, the plant can be configured without discharge of an offgas substream, or the offgas streams are so small that they can be released without treatment into the environment at a suitable position.