The present invention relates to the integration of an alkylation unit for use in a hydrocarbon conversion process. More specifically, the present invention relates to the integration of a dehydrogenation unit and an alkylation unit and the placement of different isomerization units located off the deisobutanizer and the debutanizer.

The invention relates to a process for preparing 1,3-butadiene from n-butenes, comprising the steps of: A) providing an input gas stream a comprising butanes, 1-butene, 2-butene and isobutene, with or without 1,3-butadiene, from a fluid catalytic cracking plant; B) removing isobutene from the input gas stream a, giving a stream b comprising butanes, 1-butene and 2-butene, with or without 1,3-butadiene; C) feeding the stream b comprising butanes, 1-butene and 2-butene and optionally an, oxygenous gas and optionally water vapor into at least one dehydrogenating zone and dehydrogenating 1-butene and 2-butene to 1,3-butadiene, giving a product gas stream c comprising 1,3-butadiene, butanes, 2-butene and water vapor, with or without oxygen, with low-boiling hydrocarbons, with high-boiling secondary components, with or without carbon oxides and with or without inert gases; D) cooling and compressing the product gas stream c, giving at least one aqueous condensate stream d1 and a gas stream d2 comprising 1,3-butadiene, butanes, 2-butene and water vapor, with or without oxygen, with low-boiling hydrocarbons, with or without carbon oxides and with or without inert gases; Ea) removing uncondensable and low-boiling gas constituents comprising low-boiling hydrocarbons, with or without oxygen, with or without carbon oxides and with or without inert gases, as gas stream e2 from the gas stream d2 by absorbing the C.sub.4 hydrocarbons comprising 1,3-butadiene, butanes and 2-butene in an absorbent, giving an absorbent stream laden with C.sub.4 hydrocarbons and the gas stream e2, and Eb) subsequently desorbing the C.sub.4 hydrocarbons from the laden absorbent stream, giving a C.sub.4 hydrocarbon stream e1; F) separating the C.sub.4 hydrocarbon stream e1 by extractive distillation with a 1,3-butadiene-selective solvent into a stream f1 comprising 1,3-butadiene and the selective solvent and a stream f2 comprising butanes and 2-butene, wherein at least 90% of the 1-butene present in stream b is converted in step C) and a product stream f2 comprising butanes and 2-butene is obtained in step F.

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. High-purity (on-spec) cyclohexane is preferably isolated from the hydrocarbon mixture (HM2) obtained in the isomerization, the specifications being, for example, those applicable to the use of the cyclohexane for the preparation, known to those skilled in the art, of caprolactam.

A continuous mixing reactor has an outer shell having a cylindrical portion with a central section and two opposite conical end sections; a circulation tube within the shell so that an annular passage forms between the shell and the circulation tube; an impeller within and positioned adjacent to one end of the circulation tube; and heat exchange means penetrating the outer shell and extending into the end of the circulation tube opposite the impeller. The outer shell has a hydraulic head forming one end of the shell, a heat exchange medium header at the opposite end of the shell. The circulation tube nearer the heat exchange medium header terminates at or downstream from a tangential plane extending through the shell at the intersection of the central section and the conical end section of the cylindrical portion of shell. The reactor is useful in an alkylation process.

A continuous mixing reactor has an outer shell having a cylindrical portion with a central section and two opposite conical end sections; a circulation tube within the shell so that an annular passage forms between the shell and the circulation tube; an impeller within and positioned adjacent to one end of the circulation tube; and heat exchange means penetrating the outer shell and extending into the end of the circulation tube opposite the impeller. The outer shell has a hydraulic head forming one end of the shell, a heat exchange medium header at the opposite end of the shell. The circulation tube nearer the heat exchange medium header terminates at or downstream from a tangential plane extending through the shell at the intersection of the central section and the conical end section of the cylindrical portion of shell. The reactor is useful in an alkylation process.

A continuous mixing reactor has an outer shell having a cylindrical portion with a central section and two opposite conical end sections; a circulation tube within the shell so that an annular passage forms between the shell and the circulation tube; an impeller within and positioned adjacent to one end of the circulation tube; and heat exchange means penetrating the outer shell and extending into the end of the circulation tube opposite the impeller. The outer shell has a hydraulic head forming one end of the shell, a heat exchange medium header at the opposite end of the shell. The circulation tube nearer the heat exchange medium header terminates at or downstream from a tangential plane extending through the shell at the intersection of the central section and the conical end section of the cylindrical portion of shell. The reactor is useful in an alkylation process.