Sugar Solution Purification via Sequential Cation Exchange
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Solution Overview
Problem
Existing methods for purifying aqueous sugar solutions, such as those derived from cellulose hydrolysis, are inefficient due to the use of mineral acids and alkalis for ion exchange resin regeneration, and fail to effectively remove both salt and colored impurities, which are necessary for improved glycol production.
Innovation Solution
A process involving sequential cation exchange steps using cation exchange resins, where the first resin is contacted with a solution to replace cations with a single element, and the second resin has a high percentage of acid groups in the salt form, followed by ion exclusion chromatography to remove impurities, using a salt solution for regeneration and water as the eluent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If ion exchange methods are used to purify sugar solutions, then salt impurities are removed, but mineral acids and alkalis are required for resin regeneration which increases cost and operational difficulty
Solution Approach 1:
The patent changes the chemical form of the ion exchange resin from acid form to salt form (specifically sodium form), which eliminates the need for acid and alkali regeneration. The salt-form resin is regenerated using salt solutions instead of mineral acids, directly resolving the operational difficulty while maintaining salt removal efficiency
Solution Approach 2:
The patent employs disposable or easily regenerable salt-form ion exchange resins that can be regenerated with inexpensive salt solutions rather than expensive mineral acids. This approach treats the resin as a consumable or easily renewable component, reducing both operational complexity and cost
2Quantity of substance
If traditional ion exchange methods are used, then purification is achieved, but the process is inefficient and expensive due to acid and alkali consumption
Solution Approach 1:
The patent changes the regeneration chemistry from acid-based to salt-based regeneration. By using salt solutions (such as NaCl) instead of mineral acids (such as HCl) and alkalis (such as NaOH), the process eliminates the need for expensive and hazardous chemicals, directly reducing operational costs while maintaining purification effectiveness
Solution Approach 2:
The patent converts the typically harmful waste streams (acid and alkali) into benign salt solutions for regeneration. The salt-form resin approach transforms a hazardous chemical process into an environmentally friendly one, where common salt becomes the regeneration agent instead of corrosive acids and bases
3Device complexity
If single-step ion exchange is used, then process simplicity is maintained, but colored impurities are not effectively removed
Solution Approach 1:
The patent divides the purification process into two distinct sequential steps: first removing salt impurities through cation exchange, then removing colored impurities through chromatography. This segmentation allows each step to be optimized for its specific function, achieving comprehensive purification while maintaining reasonable process simplicity
Solution Approach 2:
The patent introduces an intermediate purification step between salt removal and final product. The chromatography step acts as an intermediary process that specifically targets colored impurities without interfering with the salt removal achieved in the first step, enabling selective removal of different impurity types
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process achieves a significant reduction in salt and colored impurities, resulting in a highly purified sugar solution suitable for improved glycol production with reduced operational costs and environmental impact.
Implementation Method 1
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)
Implementation Method 2
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
Data Source
AI summary
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.