WE CLAIM:
[Claim 1]
A method for producing a sugar alcohol from a cellulose-containing biomass as a raw material, comprising:
step (1): a step of filtering a sugar aqueous solution obtained by hydrolysis of the cellulose-containing biomass, through a separation membrane having a molecular weight cut-off of 300 to 800 to remove a catalyst poison to a non-permeation side and collecting a sugar solution from a permeation side; and
step (2): a step of subjecting the sugar solution obtained in the step (1) to a hydrogenation reaction in the presence of a metal catalyst. [Claim 2]
The method for producing a sugar alcohol according to claim 1, wherein the separation membrane in the step (1) is a separation membrane having a molecular weight cut-off of 300 to 500. [Claim 3]
The method for producing a sugar alcohol according to claim 1, wherein the separation membrane in the step (1) is a separation membrane having a molecular weight cut-off of 600 to 800. [Claim 4]
The method for producing a sugar alcohol according to any one of claims 1 to 3, wherein the metal catalyst in the step (2) is a ruthenium catalyst or a Raney nickel catalyst. [Claim 5]
The method for producing a sugar alcohol according to any one of claims 1 to 4, wherein the sugar alcohol comprises sorbitol and/or xylitol as a main component. [Claim 6]
A method for producing an anhydrous sugar alcohol, comprising a step of producing a sugar alcohol by the production method according to any one of claims 1 to 5, and a step of subjecting the sugar alcohol to a dehydration reaction. [Claim 7]
The method for producing an anhydrous sugar alcohol according to claim 6, wherein the anhydrous sugar alcohol comprises a sorbitan and/or a xylitan as a main component. [Claim 8]

A method for producing an anhydrous sugar alcohol ester, comprising a step of producing a sugar alcohol by the production method according to any one of claims 1 to 5, a step of producing an anhydrous sugar alcohol by the production method according to claim 6, and a step of subjecting the anhydrous sugar alcohol to a condensation reaction with a saturated or unsaturated fatty acid. [Claim 9]
The method for producing an anhydrous sugar alcohol ester according to claim 8, wherein the anhydrous sugar alcohol ester comprises a sorbitan ester and/or a xylitan ester as a main component.