Abstract: A process for the recovery of a pure aromatics-containing product is disclosed. This product is obtained by extractive distillation of a gasoline rich in aromatics, in which olefins, diolefins and polyolefins are separated, and this extractive distillation is followed by a hydrogenation of the recovered aromatics-rich, olefin-lean product stream, in which the alkylated aromatics, especially toluene and xylene, are dealkylated and the paraffinic dealkylation products further converted into methane so that a significant portion of hydrogen can be saved by carrying out the hydrogenation subsequent to the extractive distillation, as the aromatics mixture is then free of olefins and no hydrogen is required for an olefin hydrogenation, with extractive distillation and recovery of the extracting solvent taking place in one column. An apparatus for carrying out the process described is also disclosed.

Abstract: A process for the separation of the aromatic compounds benzene, toluene and xylene from an aromatics-containing reformate gasoline and pyrolysis gasoline or a coke-oven light oil or an aromatics-containing refinery stream, in which the aromatics are separated by an extractive distillation uses a novel solvent combination made up of the compounds n,n?-diformyl piperazine or 2,2-bis-(cyanoethyl)ether in a combination with n-formyl morpholine as a second solvent for extractive distillation so that the solvent combination obtained shows a higher selectivity with regard to the aromatics to be extracted so that a lower solvent load is required. The aromatics-containing feed mixture is first submitted to a pre-distillation so that the obtained fraction has a narrow boiling point range. This fraction is then submitted to an extractive distillation in a first column, in which an aromatics-lean head product of predominantly paraffinic hydrocarbons is obtained as well as an aromatics-enriched bottom product.

Abstract: A process for the separation of the aromatic compounds benzene, toluene and xylene from an aromatics-containing reformate gasoline and pyrolysis gasoline or a coke-oven light oil or an aromatics-containing refinery stream, in which the aromatics are separated by an extractive distillation uses a novel solvent combination made up of the compounds n,n?-diformyl piperazine or 2,2?-bis-(cyanoethyl)ether in a combination with n-formyl morpholine as a second solvent for extractive distillation so that the solvent combination obtained shows a higher selectivity with regard to the aromatics to be extracted so that a lower solvent load is required. The aromatics-containing feed mixture is first submitted to a pre-distillation so that the obtained fraction has a narrow boiling point range. This fraction is then submitted to an extractive distillation in a first column, in which an aromatics-lean head product of predominantly paraffinic hydrocarbons is obtained as well as an aromatics-enriched bottom product.

Abstract: A process for the recovery of a pure aromatics-containing product is disclosed. This product is obtained by extractive distillation of a gasoline rich in aromatics, in which olefins, diolefins and polyolefins are separated, and this extractive distillation is followed by a hydrogenation of the recovered aromatics-rich, olefin-lean product stream, in which the alkylated aromatics, especially toluene and xylene, are dealkylated and the paraffinic dealkylation products further converted into methane so that a significant portion of hydrogen can be saved by carrying out the hydrogenation subsequent to the extractive distillation, as the aromatics mixture is then free of olefins and no hydrogen is required for an olefin hydrogenation, with extractive distillation and recovery of the extracting solvent taking place in one column. An apparatus for carrying out the process described is also disclosed.

Abstract: A process for the separation of the aromatic compounds benzene, toluene and xylene from an aromatics-containing reformate gasoline and pyrolysis gasoline or a coke-oven light oil or an aromatics-containing refinery stream, in which the aromatics are separated by an extractive distillation uses a novel solvent combination made up of the compounds n,n?-diformyl piperazine or 2,2?-bis-(cyanoethyl)ether in a combination with n-formyl morpholine as a second solvent for extractive distillation so that the solvent combination obtained shows a higher selectivity with regard to the aromatics to be extracted so that a lower solvent load is required. The aromatics-containing feed mixture is first submitted to a pre-distillation so that the obtained fraction has a narrow boiling point range. This fraction is then submitted to an extractive distillation in a first column, in which an aromatics-lean head product of predominantly paraffinic hydrocarbons is obtained as well as an aromatics-enriched bottom product.

Abstract: A process for enriching the content of oxygen in oxygen- and nitrogen-containing gases in a separation apparatus which has an interior which is divided into a substrate chamber and into a permeate chamber by an oxygen-conducting ceramic membrane is described. The process comprises the introduction of oxygen- and nitrogen-containing sweep gas into the permeate chamber and the establishment of a pressure in the substrate chamber so that the oxygen partial pressure in substrate chamber and sweep chamber results in the transfer of oxygen through the ceramic membrane. The process is distinguished by high operational safety.