An integrated process for producing cumene and purifying isopropanol is described, in which a crude isopropanol stream containing in excess of 0.1 wt % water is separated into a dry isopropanol fraction containing no more than 0.1 wt % water and a wet isopropanol fraction containing the remainder of the water in said crude isopropanol stream. The dry isopropanol fraction is recovered and the wet isopropanol fraction is contacted with benzene in an alkylation zone under alkylation conditions such that at least part of the isopropanol reacts with the benzene to produce an effluent stream comprising cumene.

An integrated process for producing cumene and purifying isopropanol is described, in which a crude isopropanol stream containing in excess of 0.1 wt % water is separated into a dry isopropanol fraction containing no more than 0.1 wt % water and a wet isopropanol fraction containing the remainder of the water in said crude isopropanol stream. The dry isopropanol fraction is recovered and the wet isopropanol fraction is contacted with benzene in an alkylation zone under alkylation conditions such that at least part of the isopropanol reacts with the benzene to produce an effluent stream comprising cumene.

An integrated process for producing cumene and purifying isopropanol is described, in which a crude isopropanol stream containing in excess of 0.1 wt % water is separated into a dry isopropanol fraction containing no more than 0.1 wt % water and a wet isopropanol fraction containing the remainder of the water in said crude isopropanol stream. The dry isopropanol fraction is recovered and the wet isopropanol fraction is contacted with benzene in an alkylation zone under alkylation conditions such that at least part of the isopropanol reacts with the benzene to produce an effluent stream comprising cumene.

A methanol/MMA azeotrope is broken or avoided by a method comprising the steps of (1) raising the pressure within a first vessel, e.g., a distillation column, that contains a methanol/MMA azeotrope, (2) collecting the azeotrope as a liquid, and then in a second, separate vessel, e.g., another distillation column, (3) raising the pressure sufficiently to allow for the breaking of or avoidance of the azeotrope and the recovery of the methanol.

A methanol/MMA azeotrope is broken or avoided by a method comprising the steps of (1) raising the pressure within a first vessel, e.g., a distillation column, that contains a methanol/MMA azeotrope, (2) collecting the azeotrope as a liquid, and then in a second, separate vessel, e.g., another distillation column, (3) raising the pressure sufficiently to allow for the breaking of or avoidance of the azeotrope and the recovery of the methanol.

The purification method of isopropyl alcohol including: feeding a feed including isopropyl alcohol, water, and a byproduct comprising normal propyl alcohol to an azeotropic distillation purification tower; separating an azeotrope comprising isopropyl alcohol, normal-propyl alcohol, and water from the top of the azeotropic distillation purification tower and feeding the azeotrope to a dehydration tower; separating the isopropyl alcohol and the normal-propyl alcohol from the bottom of the dehydration tower and feeding the isopropyl alcohol and the normal-propyl alcohol to a normal-propyl alcohol purification tower; and separating the isopropyl alcohol from the top of the normal propyl alcohol purification tower.

The purification method of isopropyl alcohol including: feeding a feed including isopropyl alcohol, water, and a byproduct comprising normal propyl alcohol to an azeotropic distillation purification tower; separating an azeotrope comprising isopropyl alcohol, normal-propyl alcohol, and water from the top of the azeotropic distillation purification tower and feeding the azeotrope to a dehydration tower; separating the isopropyl alcohol and the normal-propyl alcohol from the bottom of the dehydration tower and feeding the isopropyl alcohol and the normal-propyl alcohol to a normal-propyl alcohol purification tower; and separating the isopropyl alcohol from the top of the normal propyl alcohol purification tower.

The purification method of isopropyl alcohol including: feeding a feed including isopropyl alcohol, water, and a byproduct comprising normal propyl alcohol to an azeotropic distillation purification tower; separating an azeotrope comprising isopropyl alcohol, normal-propyl alcohol, and water from the top of the azeotropic distillation purification tower and feeding the azeotrope to a dehydration tower; separating the isopropyl alcohol and the normal-propyl alcohol from the bottom of the dehydration tower and feeding the isopropyl alcohol and the normal-propyl alcohol to a normal-propyl alcohol purification tower; and separating the isopropyl alcohol from the top of the normal propyl alcohol purification tower.

The invention provides a process for refining bio-based propylene glycol, wherein impurities having boiling points close to that of propylene glycol are separated. In this process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic solvent together with the bio-based propylene glycol to obtain an azeotrope containing propylene glycol. Then the azeotropic solvent in the azeotrope is separated to obtain a crude propylene glycol which is further purified to obtain propylene glycol.

The invention provides a process for refining bio-based propylene glycol, wherein impurities having boiling points close to that of propylene glycol are separated. In this process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic solvent together with the bio-based propylene glycol to obtain an azeotrope containing propylene glycol. Then the azeotropic solvent in the azeotrope is separated to obtain a crude propylene glycol which is further purified to obtain propylene glycol.