A process for recovering and regenerating a tungsten compound suitable as co-catalyst in converting carbohydrates with hydrogen into alkylene glycols and polyols, from ash comprising one or more tungsten-oxygen components (e.g. comprising a tungstate and/or tungstic acid). Such ash is obtainable from burning a liquid mixture comprising alkylene glycols and/or polyols and sodium tungstate and/or tungstic acid.

The present invention relates to a process for the direct conversion of cellulose into glycols by using a non noble metal supported zeolite catalyst selected from Al—Ni—W/HY, Al—Ni—W/NaY and Al—Ni—W/Na-ZSM-5, wherein the ratio of the metal in the catalyst is in the range of 15%-12%-30% to 0%-3%-5%.

The present invention relates to a process for the direct conversion of cellulose into glycols by using a non noble metal supported zeolite catalyst selected from Al—Ni—W/HY, Al—Ni—W/NaY and Al—Ni—W/Na-ZSM-5, wherein the ratio of the metal in the catalyst is in the range of 15%-12%-30% to 0%-3%-5%.

The present invention relates to a process for the direct conversion of cellulose into glycols by using a non noble metal supported zeolite catalyst selected from Al—Ni—W/HY, Al—Ni—W/NaY and Al—Ni—W/Na-ZSM-5, wherein the ratio of the metal in the catalyst is in the range of 15%-12%-30% to 0%-3%-5%.

The present application provides a composite catalyst and use thereof in preparing propylene glycol, where the composite catalyst includes: a main catalyst; and an assistant catalyst, forming on the main catalyst; the assistant catalyst is a magnesium hydroxide shell with a cage-like shape forming on the surface of the main catalyst, and the main catalyst is located inside the magnesium hydroxide shell.

The present application provides a composite catalyst and use thereof in preparing propylene glycol, where the composite catalyst includes: a main catalyst; and an assistant catalyst, forming on the main catalyst; the assistant catalyst is a magnesium hydroxide shell with a cage-like shape forming on the surface of the main catalyst, and the main catalyst is located inside the magnesium hydroxide shell.

The present application provides a composite catalyst and use thereof in preparing propylene glycol, where the composite catalyst includes: a main catalyst; and an assistant catalyst, forming on the main catalyst; the assistant catalyst is a magnesium hydroxide shell with a cage-like shape forming on the surface of the main catalyst, and the main catalyst is located inside the magnesium hydroxide shell.

Provided is a method for preparing a diol. In the method, a saccharide and hydrogen as raw materials are contacted with a catalyst in water to prepare the diol. The employed catalyst is a composite catalyst comprised of a main catalyst and a cocatalyst, wherein the main catalyst is a water-insoluble acid-resistant alloy; and the cocatalyst is a soluble tungstate and/or soluble tungsten compound. The method uses an acid-resistant, inexpensive and stable alloy needless of a support as a main catalyst, and can guarantee a high yield of the diol in the case where the production cost is relatively low.

Provided is a method for preparing a diol. In the method, a saccharide and hydrogen as raw materials are contacted with a catalyst in water to prepare the diol. The employed catalyst is a composite catalyst comprised of a main catalyst and a cocatalyst, wherein the main catalyst is a water-insoluble acid-resistant alloy; and the cocatalyst is a soluble tungstate and/or soluble tungsten compound. The method uses an acid-resistant, inexpensive and stable alloy needless of a support as a main catalyst, and can guarantee a high yield of the diol in the case where the production cost is relatively low.

Provided is a method for preparing a diol. In the method, a saccharide and hydrogen as raw materials are contacted with a catalyst in water to prepare the diol. The employed catalyst is a composite catalyst comprised of a main catalyst and a cocatalyst, wherein the main catalyst is a water-insoluble acid-resistant alloy; and the cocatalyst is a soluble tungstate and/or soluble tungsten compound. The method uses an acid-resistant, inexpensive and stable alloy needless of a support as a main catalyst, and can guarantee a high yield of the diol in the case where the production cost is relatively low.