Recovery of xylose
AssigneeDanisco Sweeteners Oy
InventorsHeikki Heikkila, Mika Manttari, Mirja Lindroos, Marianne Nystrom
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Abstract
The invention relates to a process of producing a xylose solution from a biomass hydrolysate by subjecting the biomass hydrolysate to nanofiltration and recovering as the nanofiltration permeate a solution enriched in xylose. The biomass hydrolysate used as starting material is typically a spent liquor obtained from a pulping process.
Claims42
A process of producing a xylose solution from a biomass hydrolysate or a part thereof, characterized by subjecting said biomass hydrolysate to nanofiltration and recovering as the nanofiltration permeate a solution enriched in xylose.
A process as claimed in any one of the preceding claims, characterized in that the dry substance content of the starting biomass hydrolysate is 3 to 50% by weight, preferably 8 to 25% by weight.
A process as claimed in any one of the preceding claims, characterized in that the dry substance content of the starting biomass hydrolysate used as the nanofiltration feed is less than 30% by weight.
A process as claimed in any one of the prededing claims, characterized in that the biomass hydrolysate has a xylose content of 5 to 95%, preferably 15 to 55%, more preferably 15 to 40% and especially 8 to 27% by weight, based on the dry substance content.
A process as claimed in any one of the preceding claims, characterized in that the biomass hydrolysate is a spent liquor obtained from a pulping process.
A process as claimed in any one of the preceding claims, characterized in that the biomass hydrolysate has been subjected to one or more pretreatment steps.
A process as claimed in any one of the preceding claims, characterized in that the nanofiltration is carried out a pH of 1 to 7, preferably 3 to 6.5, most preferably 5 to 6.5.
A process as claimed in any one of the preceding claims, characterized in that the nanofiltration is carried out at a pressure of 10 to 50 bar, preferably 15 to 35 bar.
A process as claimed in any one of the preceding claims, characterized in that the nanofiltration is carried out at a temperature of 5-95° C., preferably 30 to 60° C.
A process as claimed in any one of the preceding claims, characterized in that the nanofiltration is carried out with a flux of 10 to 100 liters/m2h.
A process as claimed in any one of the preceding claims, characterized in that the nanofiltration is carried out using a nanofiltration membrane selected from polymeric and inorganic membranes having a cut-off size of 100 to 2500 g/mol.
A process as claimed in any one of the preceding claims, characterized in that the nanofiltration process is repeated at least once.
A process as claimed in any one of the preceding claims, characterized in that the process is carried out batchwise or continuously.
A process as claimed in any one of the preceding claims, characterized in that the process is carried out using a nanofiltration equipment including several nanofiltration elements arranged in parallel or series.
A process as claimed in any one of the preceding claims, characterized in that the process also comprises one or more pretreatment steps.
A process as claimed in any one of the preceding claims, characterized in that the process also comprises one or more post-treatment steps.
A process as claimed in any one of the preceding claims, characterized in that the solution enriched in xylose and recovered as the nanofiltration permeate also includes other pentose sugars.
Dependencies are inferred from the claim text.