A process for preparing 1,2-propanediol involves dehydrogenating propane to provide a product stream containing propane, propene, and hydrogen; and separating the product stream into a stream containing essentially hydrogen, a stream enriched in propane, and a stream enriched in propene. The process then involves reacting the stream containing essentially hydrogen with oxygen to provide a stream containing hydrogen peroxide; and reacting the stream enriched in propene with the stream containing hydrogen peroxide in the presence of a catalyst mixture, containing a phase transfer catalyst and a heteropolytungstate, in a reaction mixture with two liquid phases. The process further involves separating the reaction mixture of the propene oxidation into an aqueous phase and an organic phase, recycling the organic phase to the propene oxidation, and separating 1,2-propanediol from the aqueous phase.

A method for preparing 1,2-propanediol involves reacting propene with hydrogen peroxide in the presence of a catalyst mixture, containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase. The method then involves separating the reaction mixture into an aqueous phase (P.sub.a), containing 1,2-propanediol and phosphoric acid esters of 1,2-propanediol, and an organic phase (P.sub.o). The method further involves recycling at least part of the separated organic phase (P.sub.o) to the reaction; heating at least a part of the separated aqueous phase (P.sub.a) to a temperature of more than 140° C. at a pressure sufficient to maintain at least part of the aqueous phase as a liquid; and recovering 1,2-propanediol from the heated aqueous phase. The heating cleaves phosphoric acid esters of 1,2-propanediol into 1,2-propanediol and phosphoric acid.

A method for preparing 1,2-propanediol involves reacting propene with hydrogen peroxide in the presence of a catalyst mixture, containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase. The method then involves separating the reaction mixture into an aqueous phase (P.sub.a), containing 1,2-propanediol and phosphoric acid esters of 1,2-propanediol, and an organic phase (P.sub.o). The method further involves recycling at least part of the separated organic phase (P.sub.o) to the reaction; heating at least a part of the separated aqueous phase (P.sub.a) to a temperature of more than 140° C. at a pressure sufficient to maintain at least part of the aqueous phase as a liquid; and recovering 1,2-propanediol from the heated aqueous phase. The heating cleaves phosphoric acid esters of 1,2-propanediol into 1,2-propanediol and phosphoric acid.

A method can be used for preparing 1,2-propanediol, dipropylene glycol, and tripropylene glycol. The method involves reacting propene with hydrogen peroxide containing nitrate, in the presence of a catalyst mixture containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase. The method then involves separating the reaction mixture into an aqueous phase containing 1,2-propanediol, dipropylene glycol, tripropylene glycol, and nitrate and an organic phase. The method further involves recycling at least part of the separated organic phase to the reaction; hydrogenating the separated aqueous phase using a heterogeneous hydrogenation catalyst to provide a hydrogenated aqueous phase with a reduced nitrate content; and recovering 1,2-propanediol, dipropylene glycol, and tripropylene glycol from the hydrogenated aqueous phase by a sequential multiple-step distillation.

A method can be used for preparing 1,2-propanediol, dipropylene glycol, and tripropylene glycol. The method involves reacting propene with hydrogen peroxide containing nitrate, in the presence of a catalyst mixture containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase. The method then involves separating the reaction mixture into an aqueous phase containing 1,2-propanediol, dipropylene glycol, tripropylene glycol, and nitrate and an organic phase. The method further involves recycling at least part of the separated organic phase to the reaction; hydrogenating the separated aqueous phase using a heterogeneous hydrogenation catalyst to provide a hydrogenated aqueous phase with a reduced nitrate content; and recovering 1,2-propanediol, dipropylene glycol, and tripropylene glycol from the hydrogenated aqueous phase by a sequential multiple-step distillation.

Processes for converting ethanol and syngas (CO and H2) to isobutanol are disclosed. Syngas and ethanol are reacted Sin the first reaction zone in the presence of a first heterogeneous catalyst to produce a first reactor effluent comprising a first mixture of alcohols. The first reactor effluent is reacted a second reaction zone in the presence of a second heterogeneous catalyst to produce a second reactor effluent comprising a second mixture of alcohols. The second reactor effluent is separated into an overhead gas stream and a liquid bottom stream. The liquid bottom stream is separated into at least a C1-2 stream, a C3 stream, and a C4+ stream. The isobutanol is recovered from the C4+ stream.

Processes for converting ethanol and syngas (CO and H2) to isobutanol are disclosed. Syngas and ethanol are reacted Sin the first reaction zone in the presence of a first heterogeneous catalyst to produce a first reactor effluent comprising a first mixture of alcohols. The first reactor effluent is reacted a second reaction zone in the presence of a second heterogeneous catalyst to produce a second reactor effluent comprising a second mixture of alcohols. The second reactor effluent is separated into an overhead gas stream and a liquid bottom stream. The liquid bottom stream is separated into at least a C1-2 stream, a C3 stream, and a C4+ stream. The isobutanol is recovered from the C4+ stream.

The invention provides a process for the separation of a first C3 to C7 diol from a first mixture of C3 to C7 diols. The first mixture is provided to a first distillation column. An extractant is fed to the first distillation column above the first mixture. A stream comprising the first diol and the extractant is removed as a bottoms stream from the first distillation column and subjected to distillation in a second distillation column. A high purity first diol stream is removed from the top section of the second distillation column, while a used extractant stream is removed from the bottom section. The extractant is a C3 to C6 sugar alcohol or mixture thereof. The first diol is a close-boiler to and/or forms an azeotrope with one or more of the other C3 to C7 diols present in the first mixture.

The invention provides a process for the separation of a first C3 to C7 diol from a first mixture of C3 to C7 diols. The first mixture is provided to a first distillation column. An extractant is fed to the first distillation column above the first mixture. A stream comprising the first diol and the extractant is removed as a bottoms stream from the first distillation column and subjected to distillation in a second distillation column. A high purity first diol stream is removed from the top section of the second distillation column, while a used extractant stream is removed from the bottom section. The extractant is a C3 to C6 sugar alcohol or mixture thereof. The first diol is a close-boiler to and/or forms an azeotrope with one or more of the other C3 to C7 diols present in the first mixture.

The invention provides a process for the separation of a first C3 to C7 diol from a first mixture of C3 to C7 diols. The first mixture is provided to a first distillation column. An extractant is fed to the first distillation column above the first mixture. A stream comprising the first diol and the extractant is removed as a bottoms stream from the first distillation column and subjected to distillation in a second distillation column. A high purity first diol stream is removed from the top section of the second distillation column, while a used extractant stream is removed from the bottom section. The extractant is a C3 to C6 sugar alcohol or mixture thereof. The first diol is a close-boiler to and/or forms an azeotrope with one or more of the other C3 to C7 diols present in the first mixture.