A process for the stepwise separation of accompanying gases from a raw synthesis gas stream by a liquid absorbent countercurrently guided through all process steps and circulated via regeneration plants, wherein either the accompanying gases H.sub.2S, COS and CO.sub.2 are separated in a common absorption step or, in one of the selective absorption steps chiefly H.sub.2S and COS are separated and in the next step in flow direction of the gas chiefly CO.sub.2 is separated, and in the last step a separation of accompanying gas residues (fine wash) is effected, wherein before the separation of H.sub.2S and COS an absorption step chiefly for the separation of aromatics and subsequently an absorption step chiefly for the separation of methyl mercaptan is carried out.

The present disclosure provides a process for cleaning raw product gas. The process includes contacting the raw product gas with a flow of catalyst to reform organic contaminants and inorganic contaminants in the raw product gas and to remove particulates. Further, the process includes cooling the resulting product gas via heat exchange with a heat exchange medium in the presence of char or a solid adsorbent medium to condense remaining organic contaminants and inorganic contaminants on the char or solid adsorbent medium and to filter out fine particulates.

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.

A method is provided for removing tar from a gas by contacting a first gas containing tar with a second gas containing oxygen for time period sufficient to effect oxidation of at least a portion of the tar in the first gas, thus producing an oxidized product gas that contains less tar than the first gas. The method can also include heating a fluidized particulate material in a combustor, introducing the heated fluidized particulate material from the combustor and a biomass feedstock into a gasifier, such that heat from the heated fluidized particulate material causes the gasification of at least a portion of the biomass feedstock to form a tar-containing product gas, the first gas may contain at least a portion of the tar-containing gas, and the tar-containing gas may be extracted from the gasifier prior to contacting the first gas with the second gas.

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.

Processes for conversion of methane and ethane into syngas and ethylene are provided. An exemplary process can include providing a reaction mixture of methane, ethane, oxygen, and carbon dioxide and contacting the reaction mixture with a catalyst that includes at least one metal oxide. The processes can be combined processes in which oxidative dry reforming of methane and dehydrogenation of ethane to ethylene with carbon dioxide and oxygen occur concurrently.

Described is a plant and process for biomass treatment, where the plant is configured to actuate said process which comprises: —a step A of thermochemical treatment of transformation of a biomass into a carbonaceous solid, where this transformation involves treating the biomass at a treatment temperature of between 150° C. and 300° C. and at a treatment pressure of between 10 atm and 50 atm for 0.5-8 hours, in the presence of water, with accessory production of a treatment gas; —a step B of mixing the treatment gas with an auxiliary gas, to obtain operating gas; —a step C of thermochemical decomposition of the carbonaceous solid in an atmosphere consisting of the operating gas, where the thermochemical decomposition is suitable to obtain a combustible synthesis gas. step

A process and system for treating a hydroprocessing unit effluent gas stream for recycling includes introducing the effluent gas stream into a hydrogen purification zone and recovering a hydrogen-rich gas stream and a liquid stream containing a mixture that includes C1 to C4 hydrocarbons and H.sub.2S which is then mixed with an oxidant and fed to an oxidation unit containing catalyst for conversion of the H.sub.2S to elemental sulfur vapors that is separated for recovery of the elemental sulfur, and recovering a sweetened mixture that includes C1 to C4 hydrocarbons. Alternatively, the hydroprocessing unit effluent gas stream containing H.sub.2S is cooled, contacted with a solvent to absorb the C1 to C4 hydrocarbons and H.sub.2S, with the hydrogen-rich stream being recovered for recycling to the hydroprocessing unit, and the rich liquid solvent being flashed to produce a lean solvent stream for recycling to the adsorption zone and a mixed gas stream that includes the C1 to C4 hydrocarbons and H.sub.2S that is passed to an oxidation zone and is reacted with an oxidant in the presence of a catalyst to complete the process as described above for the recovery of elemental sulfur and a mixture that includes the sweetened C1 to C4 hydrocarbons.

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.

An apparatus and method for producing hydrocarbons including aromatic hydrocarbons and lower olefins including propylene from CH.sub.4 and CO.sub.2 through CO and H.sub.2 with high activity and high selectivity. The apparatus is provided with: a synthetic gas production unit to which a gas containing CH.sub.4 and CO.sub.2 is supplied from a first supply unit, and which generates a synthetic gas containing CO and H.sub.2 while heating a first catalyst structure; a production unit to which the synthetic gas is supplied and which generates hydrocarbons including aromatic hydrocarbons having 6-10 carbon atoms and lower olefins including propylene while heating a second catalyst structure; and a detection unit which detects propylene and the aromatic hydrocarbons discharged from the production unit, in which the first catalyst structure includes first supports having a porous structure and a first metal fine particle in the first supports, the first supports have a first channels, the first metal fine particle is present in the first channels, the second catalyst structure includes second supports having a porous structure and a second metal fine particle in the second supports, the second supports have a second channels, and a portion of the second channels have an average inner diameter of 0.95 nm or less.