The invention provides a start-up method for a process for the preparation of glycols from a starting material comprising one or more saccharides in the presence of hydrogen and a catalyst system comprising one or more retro-aldol catalysts comprising tungsten and one or more catalytic species suitable for hydrogenation in a reactor, said method comprising introducing the one or more retro-aldol catalysts to the reactor whilst also in the presence of one or more agents suitable to suppress tungsten precipitation.

A continuous process for converting carbohydrates to ethylene and propylene glycol. The carbohydrates are mixed with water and passed through a reactor at a temperature that hydrolyzes the carbohydrate mixture at least partially to monosaccharides. The reactor has a first zone comprising a retro-aldol catalyst and a second zone comprising a reducing catalyst. The aldose is converted in the first zone into glycolaldehyde by the retro-aldol catalyst and the glycolaldehyde, in the presence of hydrogen, is converted to ethylene glycol in the second zone of the reactor. The reaction products are removed from the reactor and the ethylene glycol is recovered. The selectivity to propylene glycol can be enhanced via feeding ketose as the carbohydrate.

A continuous process for converting carbohydrates to ethylene and propylene glycol. The carbohydrates are mixed with water and passed through a reactor at a temperature that hydrolyzes the carbohydrate mixture at least partially to monosaccharides. The reactor has a first zone comprising a retro-aldol catalyst and a second zone comprising a reducing catalyst. The aldose is converted in the first zone into glycolaldehyde by the retro-aldol catalyst and the glycolaldehyde, in the presence of hydrogen, is converted to ethylene glycol in the second zone of the reactor. The reaction products are removed from the reactor and the ethylene glycol is recovered. The selectivity to propylene glycol can be enhanced via feeding ketose as the carbohydrate.

The invention provides a start-up method for a process for the preparation of glycols from a starting material comprising one or more saccharides in the presence of hydrogen and a catalyst system comprising one or more retro-aldol catalysts comprising tungsten and one or more catalytic species suitable for hydrogenation in a reactor, said method comprising introducing the one or more retro-aldol catalysts to the reactor whilst also in the presence of one or more agents suitable to suppress tungsten precipitation

The invention provides a start-up method for a process for the preparation of glycols from a starting material comprising one or more saccharides in the presence of hydrogen and a catalyst system comprising one or more retro-aldol catalysts comprising tungsten and one or more catalytic species suitable for hydrogenation in a reactor, said method comprising introducing the one or more retro-aldol catalysts to the reactor whilst also in the presence of one or more agents suitable to suppress tungsten precipitation

The invention provides a start-up method for a process for the preparation of glycols from a starting material comprising one or more saccharides in the presence of hydrogen and a catalyst system comprising one or more retro-aldol catalysts comprising tungsten and one or more catalytic species suitable for hydrogenation in a reactor, said method comprising introducing the one or more retro-aldol catalysts to the reactor whilst also in the presence of one or more agents suitable to suppress tungsten precipitation

The invention provides a process for the preparation of ethylene glycol and 1, 2-propylene glycol from starting material comprising one or more saccharides, wherein the process comprises the steps of i) providing the starting material and hydrogen to a first reactor, which first reactor operates with mixing; ii) reacting said starting material and hydrogen in the first reactor in the presence of solvent and a catalyst system; iii) continuously removing a first reactor product stream from the first reactor; iv) supplying at least a portion of the first reactor product stream to a second reactor, which reactor operates essentially in a plug flow manner; and v) further reacting the first reactor product stream with hydrogen in the presence of a solvent and optionally a catalyst system in the second reactor.

The invention provides a process for the preparation of ethylene glycol and 1, 2-propylene glycol from starting material comprising one or more saccharides, wherein the process comprises the steps of i) providing the starting material and hydrogen to a first reactor, which first reactor operates with mixing; ii) reacting said starting material and hydrogen in the first reactor in the presence of solvent and a catalyst system; iii) continuously removing a first reactor product stream from the first reactor; iv) supplying at least a portion of the first reactor product stream to a second reactor, which reactor operates essentially in a plug flow manner; and v) further reacting the first reactor product stream with hydrogen in the presence of a solvent and optionally a catalyst system in the second reactor.

The invention provides a process for the preparation of ethylene glycol and 1, 2-propylene glycol from starting material comprising one or more saccharides, wherein the process comprises the steps of i) providing the starting material and hydrogen to a first reactor, which first reactor operates with mixing; ii) reacting said starting material and hydrogen in the first reactor in the presence of solvent and a catalyst system; iii) continuously removing a first reactor product stream from the first reactor; iv) supplying at least a portion of the first reactor product stream to a second reactor, which reactor operates essentially in a plug flow manner; and v) further reacting the first reactor product stream with hydrogen in the presence of a solvent and optionally a catalyst system in the second reactor.

The invention provides a process for the catalytic conversion of a saccharide-containing feedstock in a reactor, wherein saccharide-containing feedstock is provided to the reactor as a feed stream through a feed pipe and is contacted with a catalyst system in the reactor and wherein, as the saccharide-containing feedstock is fed through the feed pipe, a solvent stream, initially comprising essentially no saccharide, is fed along the internal walls of the feed pipe.