Removing impurities from sugar solutions
View Patent ↗Provided is a process for removing impurities from a solution (S1), wherein said solution (S1) comprises one or more sugar dissolved in an aqueous solvent, wherein said solution (S1) has conductivity at 25° C. of 500 μS/cm or higher, and wherein said process comprises (a) contacting said solution (S1) with a cation exchange resin (R1) to produce a solution (S2) in which 80% or more of the cations are all of the same element (E); and (b) then contacting said solution (S2) with a cation exchange resin (R2) in which, prior to said contacting, 90% or more of acid groups are in the salt form with said element (E). Also provided is a process for producing glycols comprising providing an extract solution by the process of claim 1 , and then contacting said solution (S3) with hydrogen and a metal catalyst.
1. A process for removing impurities from a solution (S1), wherein said solution (S1) comprises one or more sugar dissolved in an aqueous solvent, wherein said solution (S1) has conductivity at 25° C. of 500 μS/cm or higher, and wherein said process comprises
(a) contacting said solution (S1) with a cation exchange resin (R1) to produce a solution (S2) in which 80% or more of the cations are all of the same element (E), on a molar basis, based on the total moles of cations in resin (R1); and
(b) then contacting said solution (S2) with a cation exchange resin (R2) in which, prior to said contacting, 90% or more of acid groups are in the salt form with said element (E) as the cation, on a molar basis, based on the total moles of acid groups on resin (R2).
2. The process of claim 1 wherein said sugar comprises one or more monosaccharide.
3. The process of claim 1 wherein said solution (S1) has conductivity of 750 μS/cm.
4. The process of claim 1 wherein said solution (S1) has color of 500 IU.
5. The process of claim 1 wherein said process additionally comprises the steps:
after said step (b), separating said resin (R2) from the extract solution resulting from said step (b), and
bringing said extract solution into contact with a cation exchange resin (CR3) and with an anion exchange resin (AR3).
6. A process for producing glycols comprising steps
(A) providing an extract solution by the process of claim 1 , and
(B) then contacting said solution (S3) with hydrogen and a metal catalyst.