A process for preparing alkylene glycol from particulate matter comprising hemicellulose, cellulose and lignin, which process comprises the steps of subjecting a reactor comprising such particulate matter to a two-stage hydrolysis in the presence of hydrochloric acid to hydrolase the hemicellulose and cellulose in the particulate matter to saccharides, followed by subjecting the obtained hydrolysates to a catalytic conversion with hydrogen and in the presence of a catalyst system to a product comprising one or more alkylene glycols.

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 precious metal-supported eggshell catalyst with a preparation method and an application are provided. The precious metal-supported eggshell catalyst includes a carrier, a precious metal and a promoter. As an active component, the precious metal and the promoter are evenly distributed on surface of the carrier, wherein the promoter includes one or more than two of a precious metal, an alkaline earth metal, a transition metal lanthanide series metal, an actinium series metal and/or a metal oxide thereof. With a highly utilization of the precious metal, the precious metal-supported eggshell catalyst showed high conversion, good selectivity and excellent stability, and the precious metal-supported eggshell catalyst is used more than 300 hours with no obvious loss of activity in preparing 1,3-propanediol through hydrogenation of 3-hydroxypropionaldehyde aqueous solution. Furthermore, with large particles the precious metal-supported eggshell catalyst is easily separated from reaction products.

A precious metal-supported eggshell catalyst with a preparation method and an application are provided. The precious metal-supported eggshell catalyst includes a carrier, a precious metal and a promoter. As an active component, the precious metal and the promoter are evenly distributed on surface of the carrier, wherein the promoter includes one or more than two of a precious metal, an alkaline earth metal, a transition metal lanthanide series metal, an actinium series metal and/or a metal oxide thereof. With a highly utilization of the precious metal, the precious metal-supported eggshell catalyst showed high conversion, good selectivity and excellent stability, and the precious metal-supported eggshell catalyst is used more than 300 hours with no obvious loss of activity in preparing 1,3-propanediol through hydrogenation of 3-hydroxypropionaldehyde aqueous solution. Furthermore, with large particles the precious metal-supported eggshell catalyst is easily separated from reaction products.

The present disclosure provides methods for producing a regenerated hydrogenation catalyst from a fouled hydrogenation catalyst having a total surface area and at least one associated impurity. The method can include maintaining contact between the fouled hydrogenation catalyst and a flushing medium that comprises water, oxygen, and an inert or diluent gas at a regeneration temperature and a regeneration pressure sufficient to remove at least a portion of the at least one impurity from the hydrogenation catalyst to produce the regenerated hydrogenation catalyst, where the regenerated hydrogenation catalyst is characterized as retaining at least 70% of the activity of the hydrogenation catalyst.

The present disclosure provides methods for producing a regenerated hydrogenation catalyst from a fouled hydrogenation catalyst having a total surface area and at least one associated impurity. The method can include maintaining contact between the fouled hydrogenation catalyst and a flushing medium that comprises water, oxygen, and an inert or diluent gas at a regeneration temperature and a regeneration pressure sufficient to remove at least a portion of the at least one impurity from the hydrogenation catalyst to produce the regenerated hydrogenation catalyst, where the regenerated hydrogenation catalyst is characterized as retaining at least 70% of the activity of the hydrogenation catalyst.

A method for recovering mono-propylene glycol from a mixture comprising bio-derived diols and an organic impurity is disclosed. The method may comprise: (ia) separating the organic impurity from mono-propylene glycol in a first distillation process, wherein the first distillation process is carried out at a temperature within the range of 140-200° C. and a pressure within the range of 0.3-1.0 bar; and (ii) recovering mono-propylene glycol. Further is disclosed mono-propylene glycol obtainable by the method.

A method for recovering mono-propylene glycol from a mixture comprising bio-derived diols and an organic impurity is disclosed. The method may comprise: (ia) separating the organic impurity from mono-propylene glycol in a first distillation process, wherein the first distillation process is carried out at a temperature within the range of 140-200° C. and a pressure within the range of 0.3-1.0 bar; and (ii) recovering mono-propylene glycol. Further is disclosed mono-propylene glycol obtainable by the method.

The invention provides a process for the separation of MEG from a glycol stream comprising MEG and 1,2-BDO, said process comprising the steps of: (a) providing the glycol stream and an azeotrope-forming agent to a distillation column, (b) subjecting the glycol stream and the azeotrope-forming agent to distillation at a distillation temperature and a distillation pressure; (c) obtaining a first overhead stream comprising an azeotrope of MEG and the azeotrope-forming agent and a first bottoms stream comprising 1,2-BDO; and (d) subjecting the first overhead stream to phase separation in the presence of water to obtain an MEG-rich aqueous stream and an azeotrope-forming agent rich stream, wherein the azeotrope-forming agent is an organic solvent that forms a homogeneous azeotrope with MEG and does not form an azeotrope with 1,2-BDO at the distillation temperature and pressure.