Abstract: A method of processing an aqueous hemicellulosic stream containing lignin, comprising: (a) contacting an aqueous hemicellulosic stream containing lignin with a C3-8 alkyl alcohol at elevated temperature and acidic pH; (b) separating the reaction mixture obtained from step (a) into an aqueous phase containing hemicellulose-derived monosaccharide and an organic phase containing C3-8 alkyl alcohol; (c) concentrating the organic phase obtained from step (b) to remove at least some C3-8 alkyl alcohol; (d) treating the residue from step (c) with water or an aqueous medium having an alkaline pH; and (e) recovering C3-8 alkyl alcohol from the product of step (d).

Abstract: A method of processing an aqueous hemicellulosic stream containing lignin, comprising: (a) contacting an aqueous hemicellulosic stream containing lignin with a C3-8 alkyl alcohol at elevated temperature and acidic pH; (b) separating the reaction mixture obtained from step (a) into an aqueous phase containing hemicellulose-derived monosaccharide and an organic phase containing C3-8 alkyl alcohol; (c) concentrating the organic phase obtained from step (b) to remove at least some C3-8 alkyl alcohol; (d) treating the residue from step (c) with water or an aqueous medium having an alkaline pH; and (e) recovering C3-8 alkyl alcohol from the product of step (d).

Abstract: A process for producing alkyl R-lactate from an initial compound comprising substructure (I) is provided. The process involves producing an intermediate comprising R,R- and S,S-lactide from the initial compound, wherein the initial compound is subjected to stereoisomerisation conditions; and reacting at least a portion of the intermediate with an alkyl alcohol to produce a product comprising alkyl R-lactate, wherein alkyl R-lactate is produced in the presence of an enzyme. Also provided are processes for the production of R-lactic acid, oligomeric R-lactic acid, R,R-lactide, poly-R-lactic acid and stereocomplex lactic acid.

Abstract: A process for producing lactic acid is provided. The process comprises (a) reacting a stream rich in saccharide with sodium hydroxide in the presence of water to produce a reaction mixture comprising sodium lactate; (b) reacting at least a portion of the sodium lactate with HCl to produce lactic acid and sodium chloride; (c) converting at least a portion of the sodium chloride to chlorine and sodium hydroxide; and (d) recycling at least a portion of the sodium hydroxide produced in step (c) to step (a). Also provided are processes for the production of alkyl lactate, oligomeric lactic acid, lactide, alkyl lactyllactate, poly-lactic acid, propylene glycol and acrylic acid.

Abstract: A process for producing lactic acid is provided. The process comprises (a) reacting a stream rich in saccharide with sodium hydroxide in the presence of water to produce a reaction mixture comprising sodium lactate; (b) reacting at least a portion of the sodium lactate with HCl to produce lactic acid and sodium chloride; (c) converting at least a portion of the sodium chloride to chlorine and sodium hydroxide; and (d) recycling at least a portion of the sodium hydroxide produced in step (c) to step (a). Also provided are processes for the production of alkyl lactate, oligomeric lactic acid, lactide, alkyl lactyllactate, poly-lactic acid, propylene glycol and acrylic acid.

Abstract: A process for producing alkyl R-lactate from an initial compound comprising substructure (I) is provided. The process involves producing an intermediate comprising R,R- and S,S-lactide from the initial compound, wherein the initial compound is subjected to stereoisomerisation conditions; and reacting at least a portion of the intermediate with an alkyl alcohol to produce a product comprising alkyl R-lactate, wherein alkyl R-lactate is produced in the presence of an enzyme. Also provided are processes for the production of R-lactic acid, oligomeric R-lactic acid, R,R-lactide, poly-R-lactic acid and stereocomplex lactic acid.

Abstract: A process for treating a mixture of R,R- and S,S-lactide is provided. The process involves contacting the lactide mixture with an aliphatic alcohol and/or an alkoxide to produce a mixture of R,R- and S,S-aliphatic ester of lactyllactic acid, subsequently contacting the mixture of R,R- and S,S-aliphatic ester of lactyllactic acid with an enzyme to produce a mixture comprising aliphatic ester of lactic acid corresponding to one lactide enantiomer and the aliphatic ester of lactyllactic acid corresponding to the other lactide enantiomer, and recovering the product. Also provided are processes for the production of S-lactic acid, S,S-lactide, poly-S-lactic acid, R-lactic acid, R,R-lactide, poly-R-lactic acid and stereocomplex polylactic acid.

Abstract: A process for treating a mixture of R,R- and S,S-lactide is provided. The process involves contacting the mixture with an aliphatic alcohol and an enzyme in the presence of a ketone solvent to produce a mixture comprising aliphatic ester of lactic acid corresponding to one lactide enantiomer, and the aliphatic ester of lactyllactic acid corresponding to the other lactide enantiomer. Also provided are processes for the production of S-lactic acid, S,S-lactide, poly-S-lactic acid, R-lactic acid, R,R-lactide, poly-R-lactic acid and stereocomplex polylactic acid.

Abstract: A process for treating a mixture of R,R- and S,S-lactide is provided. The process involves contacting the mixture with an aliphatic alcohol and an enzyme to produce a mixture comprising aliphatic ester of lactic acid corresponding to one lactide enantiomer and the aliphatic ester of lactyllactic acid corresponding to the other lactide enantiomer; separating the mixture from the enzyme, and recycling the enzyme to the process; and separating the aliphatic ester of lactic acid from the aliphatic ester of lactyl-lactic acid by fractional distillation. Also provided are processes for the production of S-lactic acid, S,S-lactide, poly-S-lactic acid, R-lactic acid, R,R-lactide, poly-R-lactic acid and stereocomplex polylactic acid.

Abstract: A process for treating a mixture of R,R- and S,S-lactide is provided. The process involves contacting the lactide mixture with an aliphatic alcohol and/or an alkoxide to produce a mixture of R,R- and S,S-aliphatic ester of lactyllactic acid, subsequently contacting the mixture of R,R- and S,S-aliphatic ester of lactyllactic acid with an enzyme to produce a mixture comprising aliphatic ester of lactic acid corresponding to one lactide enantiomer and the aliphatic ester of lactyllactic acid corresponding to the other lactide enantiomer, and recovering the product. Also provided are processes for the production of S-lactic acid, S,S-lactide, poly-S-lactic acid, R-lactic acid, R,R-lactide, poly-R-lactic acid and stereocomplex polylactic acid.

Abstract: A process for treating a mixture of R,R- and S,S-lactide is provided. The process involves contacting the mixture with an aliphatic alcohol and an enzyme to produce a mixture comprising aliphatic ester of lactic acid corresponding to one lactide enantiomer and the aliphatic ester of lactyllactic acid corresponding to the other lactide enantiomer; separating the mixture from the enzyme, and recycling the enzyme to the process; and separating the aliphatic ester of lactic acid from the aliphatic ester of lactyl-lactic acid by fractional distillation. Also provided are processes for the production of S-lactic acid, S,S-lactide, poly-S-lactic acid, R-lactic acid, R,R-lactide, poly-R-lactic acid and stereocomplex polylactic acid.

Abstract: A process for treating a mixture of R,R- and S,S-lactide is provided. The process involves contacting the mixture with an aliphatic alcohol and an enzyme in the presence of a ketone solvent to produce a mixture comprising aliphatic ester of lactic acid corresponding to one lactide enantiomer, and the aliphatic ester of lactyllactic acid corresponding to the other lactide enantiomer. Also provided are processes for the production of S-lactic acid, S,S-lactide, poly-S-lactic acid, R-lactic acid, R,R-lactide, poly-R-lactic acid and stereocomplex polylactic acid.

Abstract: A process for the production of a complex of lactic acid and either ammonia or an amine, comprising reacting one or more saccharides with barium hydroxide to produce a first reaction mixture comprising barium lactate, and contacting at least part of the first reaction mixture with ammonia or an amine and with carbon dioxide, or with the carbonate and/or bicarbonate salt of ammonia or an amine, to produce a second reaction mixture comprising said complex and barium carbonate.

Abstract: The present invention relates to a complex having the formula (I) wherein M is selected from Sn(II), Sn(IV), Al(III) and Mg(II); each of R1 and R2 is independently hydrocarbyl; R3 is H or hydrocarbyl; and X is a linker group. A further aspect of the invention relates to the use of said complex as a polymerisation initiator, particularly in the polymerisation of lactides.