A method for preparing 1,2-propanediol involves continuously reacting propene with hydrogen peroxide in the presence of a catalyst mixture, containing a quaternary ammonium salt and a polytungstophosphate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase containing an alkylaromatic hydrocarbon solvent. The method then involves withdrawing the liquid reaction mixture from the reaction and adding a water-soluble sulfate salt or sulfuric acid to provide a mixture containing from 500 to 10,000 mg/kg of sulfate ions in the aqueous phase. The method further involves separating the mixture obtained into an aqueous phase (P.sub.a) containing 1,2-propanediol and an organic phase (P.sub.o), recycling at least a part of the organic phase (P.sub.o) to the reaction, and recovering 1,2-propanediol from the aqueous phase (P.sub.a). The method allows for extended operation of the reaction with little loss of tungsten and phase transfer catalyst.

A method for preparing 1,2-propanediol involves continuously reacting propene with hydrogen peroxide in the presence of a catalyst mixture, containing a quaternary ammonium salt and a polytungstophosphate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase containing an alkylaromatic hydrocarbon solvent. The method then involves withdrawing the liquid reaction mixture from the reaction and adding a water-soluble sulfate salt or sulfuric acid to provide a mixture containing from 500 to 10,000 mg/kg of sulfate ions in the aqueous phase. The method further involves separating the mixture obtained into an aqueous phase (P.sub.a) containing 1,2-propanediol and an organic phase (P.sub.o), recycling at least a part of the organic phase (P.sub.o) to the reaction, and recovering 1,2-propanediol from the aqueous phase (P.sub.a). The method allows for extended operation of the reaction with little loss of tungsten and phase transfer catalyst.

A method for preparing 1,2-propanediol involves reacting propene with hydrogen peroxide, in the presence of 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 containing a solvent having a solubility in water at 20° C. of less than 500 mg/kg. The method then involves separating the liquid reaction mixture into an aqueous phase containing 1,2-propanediol and an organic phase; recycling at least a part of the separated organic phase to the reaction; and extracting the separated aqueous phase with an extractant solution containing the same phase transfer catalyst and solvent as used in the reaction to provide an extracted aqueous phase and an extract phase. The method further involves recycling at least a part of the extract phase to the reaction and recovering 1,2-propanediol from the extracted aqueous phase.

A method for preparing 1,2-propanediol involves reacting propene with hydrogen peroxide, in the presence of 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 containing a solvent having a solubility in water at 20° C. of less than 500 mg/kg. The method then involves separating the liquid reaction mixture into an aqueous phase containing 1,2-propanediol and an organic phase; recycling at least a part of the separated organic phase to the reaction; and extracting the separated aqueous phase with an extractant solution containing the same phase transfer catalyst and solvent as used in the reaction to provide an extracted aqueous phase and an extract phase. The method further involves recycling at least a part of the extract phase to the reaction and recovering 1,2-propanediol from the extracted aqueous phase.

Systems and methods for processing crude methanol are disclosed. A crude methanol stream, comprising methanol and paraffin wax, is produced from syngas (carbon monoxide, carbon dioxide, and hydrogen). The crude methanol stream is cooled to form a partially condensed crude methanol stream, which is further separated in a vapor-liquid separator to form a liquid stream and a gas stream. The liquid stream is further cooled in a dewaxing unit to remove paraffin wax. The dewaxing unit includes two or more cooling units arranged in parallel such that when one of the cooling units is offline for cleaning, the methanol system does not need to be shut down.

Systems and methods for processing crude methanol are disclosed. A crude methanol stream, comprising methanol and paraffin wax, is produced from syngas (carbon monoxide, carbon dioxide, and hydrogen). The crude methanol stream is cooled to form a partially condensed crude methanol stream, which is further separated in a vapor-liquid separator to form a liquid stream and a gas stream. The liquid stream is further cooled in a dewaxing unit to remove paraffin wax. The dewaxing unit includes two or more cooling units arranged in parallel such that when one of the cooling units is offline for cleaning, the methanol system does not need to be shut down.

The present invention relates to a method of extracting at least one selected from carbonic acid, aliphatic acid, aliphatic acid ester and aliphatic alcohol from an aqueous medium, the method comprising the steps: (a) contacting the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol in the aqueous medium with an extracting medium containing at least one alkyl-phosphine oxide for a time sufficient to extract the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol from the aqueous medium into the extracting medium, and (b) separating the extracting medium with the extracted carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol from the aqueous medium, characterized in, that the at least one alkyl-phosphine oxide contains at least two different alkyl radicals per alkyl-phosphine oxide molecule and the aqueous medium in (a) contains a microorganism, preferably a living microorganism, producing the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol.

The present invention relates to a method of extracting at least one selected from carbonic acid, aliphatic acid, aliphatic acid ester and aliphatic alcohol from an aqueous medium, the method comprising the steps: (a) contacting the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol in the aqueous medium with an extracting medium containing at least one alkyl-phosphine oxide for a time sufficient to extract the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol from the aqueous medium into the extracting medium, and (b) separating the extracting medium with the extracted carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol from the aqueous medium, characterized in, that the at least one alkyl-phosphine oxide contains at least two different alkyl radicals per alkyl-phosphine oxide molecule and the aqueous medium in (a) contains a microorganism, preferably a living microorganism, producing the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol.

The present invention relates to a method of extracting at least one selected from carbonic acid, aliphatic acid, aliphatic acid ester and aliphatic alcohol from an aqueous medium, the method comprising the steps: (a) contacting the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol in the aqueous medium with an extracting medium containing at least one alkyl-phosphine oxide for a time sufficient to extract the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol from the aqueous medium into the extracting medium, and (b) separating the extracting medium with the extracted carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol from the aqueous medium, characterized in, that the at least one alkyl-phosphine oxide contains at least two different alkyl radicals per alkyl-phosphine oxide molecule and the aqueous medium in (a) contains a microorganism, preferably a living microorganism, producing the carbonic acid, aliphatic acid, aliphatic acid ester and/or aliphatic alcohol.

The present invention relates to a method of extracting an aliphatic alcohol, preferably containing 5 to 16 carbon atoms, from an aqueous medium, the method comprising: (a) contacting the aliphatic alcohol in the aqueous medium with at least one extracting medium for a time sufficient to extract the aliphatic alcohol from the aqueous medium into the extracting medium, (b) separating the extracting medium with the extracted aliphatic alcohol from the aqueous medium wherein the extracting medium comprises: at least one trialkyl-phosphine-oxide, preferably trioctyl-phosphine-oxide, and optionally at least one alkane, and wherein the aliphatic alcohol is produced from a carbon source by contacting the carbon source with at least one microorganism capable of converting the carbon source to the aliphatic alcohol.