A method for separating monoethylene glycol (MEG) from one or more oxygenates. The method includes providing a stream comprising MEG and one or more oxygenates to a distillation column, providing a water feed stream to a bottom of the distillation column, and removing a recovery stream comprising MEG from the distillation column. The distillation column is operated at higher temperatures than the thermal stability of MEG and the one or more oxygenates.

In a method and a system for decolorizing and deodorizing a polyhydric alcohol according to embodiments of the present invention, a mixture liquid containing a first polyhydric alcohol obtained by a separation process is prepared. The mixture liquid is subjected to a distillation treatment to preliminarily remove substances with different colors and odors to generate a pre-treatment liquid. The pre-treatment liquid is subjected to an adsorption treatment. Through a combination of the distillation treatment and the adsorption treatment, the removing efficiency of the substances with different colors and odors can be increased.

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.

An acid-resistant alloy catalyst, comprising nickel, one or more rare earth element, tin, aluminum and molybdenum. The catalyst is cheap and stable, does not need a carrier, can be stably applied in industrial continuous production, and can lower the production cost.

An acid-resistant alloy catalyst, comprising nickel, one or more rare earth element, tin, aluminum and molybdenum. The catalyst is cheap and stable, does not need a carrier, can be stably applied in industrial continuous production, and can lower the production cost.

By this invention processes are provided for the conversion of carbohydrate to ethylene glycol by retro-aldol catalysis and sequential hydrogenation using control methods having at least one of acetol (hydroxyacetone) and a tracer as inputs.

By this invention processes are provided for the conversion of carbohydrate to ethylene glycol by retro-aldol catalysis and sequential hydrogenation using control methods having at least one of acetol (hydroxyacetone) and a tracer as inputs.

A method for extracting polyol from a fermentation process is disclosed. The preparing method includes rectifying and purifying PDO (1,3-propanediol) from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is ≥99.5%. The preparing method meets the requirements of water resources recycling, reduces the production loss of PDO and BDO (2,3-butanediol) during the concentration, and greatly cuts down on the amount of wastewater.

A method for extracting polyol from a fermentation process is disclosed. The preparing method includes rectifying and purifying PDO (1,3-propanediol) from a polyol fermentation broth after concentration to form a steam condensate, wherein the concentration is a evaporative dehydration; and filtering the steam condensate through a reverse osmosis membrane to form a concentrated solution, wherein the retentate of the reverse osmosis flows back to the evaporative dehydration, and the penetrant of the reverse osmosis can be reused as a fermentation ingredient, as cleaning water or for sewage treatment; and the water content of the concentrated solution after the evaporative dehydration is 5-25 wt %; and the yield of PDO is ≥99.5%. The preparing method meets the requirements of water resources recycling, reduces the production loss of PDO and BDO (2,3-butanediol) during the concentration, and greatly cuts down on the amount of wastewater.