Abstract: The present invention relates to a process for preparing cyclohexane by isomerizing a hydrocarbon mixture (HM1) comprising methylcyclopentane (MCP) in the presence of a catalyst. The catalyst is preferably an acidic ionic liquid. The starting material used is a stream (S1) which originates from a steamcracking process. The hydrocarbon mixture (HM1) obtained from this stream (S1) in an apparatus for aromatics removal has a reduced aromatics content compared to stream (S1), and (HM1) may optionally also be (virtually) free of aromatics. Depending on the type and amount of the aromatics remaining in the hydrocarbon mixture (HM1), especially in the case that benzene is present, the isomerization may additionally be preceded by performance of a hydrogenation of (HM1). In addition, depending on the presence of other components of (HM1), further purification steps may optionally be performed prior to or after the isomerization or hydrogenation.

Abstract: A process for the preparation of dintrotoluene which comprises (a) nitrating toluene with a nitrating acid, wherein said nitrating acid is a mixture of nitric acid and sulfuric acid, in one or more nitration steps, and separating the nitrating acid from the process stream thus formed, wherein a crude mixture comprising dinitrotoluene and a fraction of said nitrating acid dissolved therein is obtained, said crude mixture further comprising at least 50 ppm of HCN, and (b) washing the crude dinitrotoluene containing mixture in one or more washing steps, wherein, before the first washing step is carried out, the crude mixture is distilled and/or stripped to remove HCN therefrom, wherein a crude dinitrotoluene containing mixture which is essentially free of HCN is obtained.

Abstract: A process for the preparation of dintrotoluene which comprises (a) nitrating toluene with a nitrating acid, wherein said nitrating acid is a mixture of nitric acid and sulfuric acid, in one or more nitration steps, and separating the nitrating acid from the process stream thus formed, wherein a crude mixture comprising dinitrotoluene and a fraction of said nitrating acid dissolved therein is obtained, said crude mixture further comprising at least 50 ppm of HCN, and (b) washing the crude dinitrotoluene containing mixture in one or more washing steps, wherein, before the first washing step is carried out, the crude mixture is distilled and/or stripped to remove HCN therefrom, wherein a crude dinitrotoluene containing mixture which is essentially free of HCN is obtained.

Abstract: The present invention relates to a process for hydrocarbon conversion in the presence of an acidic ionic liquid. The hydrocarbon conversion is preferably an isomerization, especially an isomerization of methylcyclopentane (MOP) to cyclohexane. Prior to the hydrocarbon conversion, a hydrogenation is performed, preference being given to hydrogenating benzene to cyclohexane. The cyclohexane obtained in the hydrogenation and/or isomerization is preferably isolated from the process. In a preferred embodiment of the present invention, the hydrogenation is followed and the hydrocarbon conversion, especially the isomerization, is preceded by distillative removal of low boilers, especially C5-C6-alkanes such as cyclopentane or isohexanes, from the hydrocarbon mixture used for hydrocarbon conversion.

Abstract: The present invention relates to a process for preparing cyclohexane by isomerizing a hydrocarbon mixture (HM1) comprising methylcyclopentane (MCP) in the presence of a catalyst. The catalyst is preferably an acidic ionic liquid. The starting material used is a stream (S1) which originates from a steamcracking process. The hydrocarbon mixture (HM1) obtained from this stream (S1) in an apparatus for aromatics removal has a reduced aromatics content compared to stream (S1), and (HM1) may optionally also be (virtually) free of aromatics. Depending on the type and amount of the aromatics remaining in the hydrocarbon mixture (HM1), especially in the case that benzene is present, the isomerization may additionally be preceded by performance of a hydrogenation of (HM1). In addition, depending on the presence of other components of (HM1), further purification steps may optionally be performed prior to or after the isomerization or hydrogenation.

Abstract: The present invention relates to a process for preparing cyclohexane from benzene and/or methylcyclopentane (MCP) by hydrogenation or isomerization. Prior to the cyclohexane preparation, the dimethylpentanes (DMP) are removed in a distillation apparatus (D1) from a hydrocarbon mixture (HM1) comprising not only benzene and/or MCP but also DMP. If cyclohexane is already present in the hydrocarbon mixture (HM1), this cyclohexane is first removed together with DMP from benzene and/or MCP. This cyclohexane already present can be separated again from DMP in a downstream distillation step and recycled into the process for cyclohexane preparation.

Abstract: The present invention relates to a process for treating an output from a hydrocarbon conversion, wherein the hydrocarbon conversion is performed in the presence of an acidic ionic liquid. The hydrocarbon conversion is preferably an isomerization. First of all, the hydrogen halide is drawn off in an apparatus from a mixture which originates from the hydrocarbon conversion and comprises at least one hydrocarbon and at least one hydrogen halide, and then the mixture depleted of hydrogen halide is subjected to a wash.

Abstract: The present invention relates to a process for isomerizing at least one hydrocarbon in the presence of an acidic ionic liquid and at least one hydrogen halide (HX) in an apparatus (V1), wherein the hydrogen halide (HX) is removed in an apparatus (V2) in gaseous form from the isomerization product and is at least partly recycled into apparatus (V1).

Abstract: The present invention relates to a process for treating an output from a chemical reaction, wherein the chemical reaction is performed in the presence of an ionic liquid. The chemical reaction is preferably an isomerization. In a rectifying column with a partial condenser, the hydrogen halide is drawn off from a mixture which originates from the chemical reaction and comprises at least one organic compound, preferably at least one hydrocarbon, and at least one hydrogen halide.