Propagation of Yeast for Removal of Sugars From Spent Sulfite Liquor
AssigneeDomtar Paper Company, LLC
InventorNeelakantam NARENDRANATH
Life of this patent
Estimating the term…
Abstract
Methods for production of yeast biomass and removal of sugar from red liquor by propagating yeast on sugars in red liquor byproduct of the sulfite pulping process are disclosed. Yeast are propagated using the sugars in red liquor as a carbon source, thereby consuming the sugars and producing a composition of lignosulfonates that has a reduced sugar content. Disclosed methods allow for separation of sugars from lignosulfonates in red liquor without costly ultrafiltration or nanofiltration processes and also produce valuable yeast biomass.
Claims15
A method of propagating yeast comprising:
- (a) combining an aqueous red liquor byproduct from a sulfite pulping process and a first cell mass of yeast to form a liquid culture, wherein the red liquor comprises monosaccharides and lignosulfonates;
- and
- (b) incubating the liquid culture for sufficient time period to form a second cell mass of yeast that has a higher dry cell weight than the first cell mass of yeast;
- wherein no more than 0.1 g/L of ethanol is produced in the liquid culture during step (b).
A method of removing monosaccharides from a lignosulfonate composition, the method comprising:
- (a) obtaining an aqueous red liquor byproduct of a sulfite pulping process, wherein the red liquor comprises monosaccharides and lignosulfonates;
- (b) propagating yeast in the red liquor, wherein the yeast metabolize the monosaccharides;
- and
- (c) removing the yeast from the red liquor, thereby producing a lignosulfonate composition comprising lignosulfonates, wherein the concentration of monosaccharides in the lignosulfonate composition is no more than 0.1 g/L.
Dependencies are inferred from the claim text.