A process for the preparation of glycols from a glucose-containing feedstock in a reactor system, said process comprising: i) providing a first feed stream comprising said glucose-containing feedstock in a first solvent at a temperature of no more than 160°C; ii) providing a second feed stream comprising a tungsten-based retro-aldol catalytic species and an alkali metal containing species in a second solvent at a temperature in the range of from 150 to 250°C, wherein the alkali metal containing species is provided by one or more of the tungsten-based retro-aldol catalytic species and an alkali-metal buffer, wherein the alkali-metal buffer is selected from acetate buffers, phosphate buffers, lactate buffers, glycolate buffers, citrate buffers, and combinations thereof, and where the alkali metal containing species is provided by the tungsten-based retro-aldol catalytic species, the tungsten-based retro-aldol catalytic species is selected from the group consisting of tungstate compounds comprising at least one Group 1 element, metatungstate compounds comprising at least one Group 1 element, paratungstate compounds comprising at least one Group 1 element, heteropoly compounds of tungsten including group 1 phosphotungstates, and combinations thereof; iii) combining the first feed stream and the second feed stream, before they are provided to the reactor system, to form a combined feed stream; iv) providing the combined feed stream to the reactor system and operating the reactor at a temperature in the range of from 150°C to 250°C; and v) also contacting the combined feed stream with a hydrogenation catalytic species in the presence of hydrogen, wherein the molar ratio of alkali metal:tungsten in the combined feed stream is in the range of from 0.55 to 6. i) providing a first feed stream comprising said glucose-containing feedstock in a first solvent at a temperature of no more than 160°C; ii) providing a second feed stream comprising a tungsten-based retro-aldol catalytic species and an alkali metal containing species in a second solvent at a temperature in the range of from 150 to 250°C, wherein the alkali metal containing species is provided by one or more of the tungsten-based retro-aldol catalytic species and an alkali-metal buffer, wherein the alkali-metal buffer is selected from acetate buffers, phosphate buffers, lactate buffers, glycolate buffers, citrate buffers, and combinations thereof, and where the alkali metal containing species is provided by the tungsten-based retro-aldol catalytic species, the tungsten-based retro-aldol catalytic species is selected from the group consisting of tungstate compounds comprising at least one Group 1 element, metatungstate compounds comprising at least one Group 1 element, paratungstate compounds comprising at least one Group 1 element, heteropoly compounds of tungsten including group 1 phosphotungstates, and combinations thereof; wherein the alkali metal containing species is provided by one or more of the tungsten-based retro-aldol catalytic species and an alkali-metal buffer, wherein the alkali-metal buffer is selected from acetate buffers, phosphate buffers, lactate buffers, glycolate buffers, citrate buffers, and combinations thereof, and where the alkali metal containing species is provided by the tungsten-based retro-aldol catalytic species, the tungsten-based retro-aldol catalytic species is selected from the group consisting of tungstate compounds comprising at least one Group 1 element, metatungstate compounds comprising at least one Group 1 element, paratungstate compounds comprising at least one Group 1 element, heteropoly compounds of tungsten including group 1 phosphotungstates, and combinations thereof; iii) combining the first feed stream and the second feed stream, before they are provided to the reactor system, to form a combined feed stream; iv) providing the combined feed stream to the reactor system and operating the reactor at a temperature in the range of from 150°C to 250°C; and v) also contacting the combined feed stream with a hydrogenation catalytic species in the presence of hydrogen,