Xylose Separation from Sulfite Spent Liquor via Long Resin Bed Chromatography

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Solution Overview

Problem

Current methods for extracting xylose from sulfite spent liquor in the paper industry are inefficient in terms of yield and purity, and require complex multi-step processes, leading to environmental concerns due to sulfur pollution.

Innovation Solution

A single-pass chromatographic separation process using a batch-type long resin bed chromatography column with a strong acid cation exchange resin, optimizing the bed length to mean resin bead diameter ratio, followed by crystallization to produce a high-purity xylose-rich fraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multi-step chromatographic separation processes are used to extract xylose from sulfite spent liquor, then xylose purity can be improved, but process complexity and the number of processing steps increase

Engineering Contradiction:
Improvexylose purityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention segments the chromatographic separation process into distinct operational phases within a single column: (i) loading the spent liquor onto the column, (ii) washing to remove lignosulfonates, (iii) eluting xylose with acid, and (iv) regenerating the resin with base. This segmentation allows each phase to be optimized independently while maintaining overall process simplicity and achieving high xylose purity in a single pass.

Inventive Principle:
Principle #1Segmentation

2Productivity

If conventional chromatographic separation methods are used, then xylose can be separated from sulfite spent liquor, but xylose yield and column capacity are limited

Engineering Contradiction:
Improvexylose yieldVSAvoidseparation efficiency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention optimizes critical parameters including using a specific strong acid cation exchange resin in Ca or Mg form, maintaining the resin in Ca/Mg form throughout the process, using controlled acid concentrations (0.1-2.0 M) for elution, and maintaining controlled base concentrations (0.1-2.0 M) for regeneration. These parameter optimizations collectively enhance xylose yield and column capacity while maintaining reliable separation.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If simplified single-pass chromatographic separation is used, then process complexity is reduced, but xylose purity and yield may decrease

Engineering Contradiction:
Improveprocess simplicityVSAvoidxylose purity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The invention implements continuous operation where the resin is regenerated in-situ within the same column without removal or replacement. The cycle of loading, washing, eluting, and regenerating continues uninterrupted, allowing the column to process multiple batches of spent liquor continuously. This maintains high xylose purity and yield while simplifying the overall process by eliminating the need for multiple columns or complex regeneration procedures.

Inventive Principle:
Principle #20Continuity of useful action

4Loss of substance

If traditional disposal methods for sulfite spent liquor are used, then environmental pollution is caused, but no valuable xylose is recovered

Engineering Contradiction:
Improvexylose recoveryVSAvoidenvironmental pollution
Core Design Contradiction:
Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The invention converts the harmful spent liquor, which was previously disposed of as waste, into a valuable resource by recovering high-purity xylose through chromatographic separation. The process transforms the environmental liability of sulfur-containing waste into a beneficial product (xylose) that can be used to produce xylitol and other valuable chemicals, thereby eliminating pollution while creating economic value.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 significantly increases xylose yield and purity, simplifies the separation process, and enhances chromatography column capacity, allowing for the direct crystallization of xylose without further processing, thus reducing environmental impact.

Implementation Method 1

chromatographic separation using a batch-type long resin bed chromatography column having a strong acid cation exchange resin

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Implementation Method 2

chromatographic separation of the Ca- or Mg-sulfite spent liquor using a single pass through a batch-type long resin bed chromatography column

Methodology Applied
Scientific EffectChromatography: Chromatography

Implementation Method 3

crystallizing xylose from said first xylose-rich fraction by using a crystallization method comprising (i) boiling crystallization; (ii) cooling crystallization or (iii) a combination of (i) and (ii)

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 4

maintaining the resin in Ca2+ or Mg2+ form and regenerating the resin with base

Methodology Applied
Scientific EffectResin regeneration: Ion Exchange

Data Source

PatentUS9109265B2Process for separation of Ca- or Mg-sulfite spent liquor to yield crystalline xylose
Publication Date: 2015.08.18 INT N&H DENMARK APS

AI summary

A process for the separation of a xylose-containing, lignosulphonate-containing Ca-sulfite spent liquor is provided. The process comprises a first step of: (A) chromatographic separation of the Ca- or Mg-sulfite spent liquor using a single pass through a batch-type long resin bed chromatography column having a strong acid cation exchange resin as a separation medium. The ratio of the bed length:mean resin bead diameter of the column is 10,000-40,000. This step yields •a first xylose-rich fraction having a xylose content 50-70 wt. % based on dry solids and • a lignosulphonate-rich fraction. The process further comprises a step of: (B) crystallizing xylose from the first xylose rich fraction by using a crystallization method comprising (i) boiling crystallization; (ii) cooling crystallization or (iii) a combination of (i) and (ii) to obtain a first batch of crystalline xylose and a first xylose run-off. The process provides a simplification of existing methods, and at the same time allows advantages such as improved xylose yield and improved xylose purity.