HU208847B - Prfocess for removing by molecule separation impurities and colouring agents of raw sugar solution obtained by saccharification of biomass originating from high lignine-containing wastes, particularly from wood chips, reed, sedge, corn-cob, etc. - Google Patents

Abstract

Contaminating and colouring agents are removed by molecular sepn. from raw sugar solns. prepd. by saccharification high lignium contg. biomasses. These biomasses are derived from ligneous waste ie., wood, sedge, reeds, corncols etc. The solns. are ultrafiltered, on membranes (1000-5000 Dalton cut) during a single continuous or batchwise operation The filtrate is treated with 5-15g/l adsorbent pref. active charcoal.

Description

The present invention relates to a process for the production of high lignin waste, preferably wood chips, reeds, sedges, corn cobs, etc. for the removal of impurities and dyes from the pre-filtered sugar solution obtained by the saccharification of the biomass originating from the product by ultrafiltration and treatment with activated carbon.

Most sugar-containing solutions are formed during the processing of sugar cane or beet. However, a sugar solution can be prepared from a variety of sugar-containing raw materials or raw materials containing sugars.

Currently, biomass from high lignin waste is being processed and sugared in several countries around the world. The purpose of saccharification is to extract valuable substances from plant material in the form of sugar (eg xylose). Xylose, along with cellulose, is found in a number of deciduous and coniferous trees, straw, corn cobs, bran, peanut and cotton seeds, apricot kernels, salt, and various industrial wastes such as. waste from the pulp industry, etc. and is obtained by hydrolysis with dilute sulfuric acid.

Industrially, xylose is obtained from the saccharification of wood and waste from the pulp manufacturing process. with the added benefit of not causing tooth decay.

In various sugar production processes, after leaching from the appropriate raw material, after dissolution, the sugar-containing juice is usually a brown, cloudy solution containing proteins, dissolved organic acids, lignin compounds, mineral salts, various coloring agents, pectins, floating and colloidal substances, resins, contain. These substances inhibit the economical extraction of sugar, so the raw juice must be purified. The first step in the traditional sugar juice purification process is clarification, in which lime milk is added to the raw juice. Lime milk binds organic acids, dyes and denatures proteins, so these substances are precipitated from the sugar solution. The excess lime milk is removed by introducing CO gas, a so-called saturation, the second step of conventional purification.

Thus, one of the most important and most costly steps in sugar production is the purification of the raw sugar solution. In addition to the above-mentioned conventional process, several processes are known in which the crude sugar solution is adsorbed on an adsorbent, usually activated carbon, and / or on the same. is passed through an ion exchange system for complete or partial decolorization and purification. Membrane separation techniques such as ultrafiltration, reverse osmosis and electrodialysis are also suitable for removing contaminants, coloring agents and purifying sugar solutions.

No. 2022,135. The English patent for the removal of cationic and / or coloring agents from sugar juice. pass through anion exchange bed with addition of filtration aids.

No. 102256. European patent relates to the purification of raw sugar solutions. The crude sugar solution is passed through a cation exchanger and a microporous adsorbent, activated carbon, is used to protect the anion exchanger, which is used to bind weak organic acids. The patent deals with the processing of sugar solutions of various origins: e.g. high fructose corn syrup, sugar cane, sugar beet syrup, dextrose and fructose syrup.

No. 4502890. U.S. Pat. The activated carbon used has an iodine number of at least 1200 and a size range of 0.4 to 4.0 mm. Total decolorization of the sugar solution with activated charcoal requires a large amount of high-quality activated charcoal, which makes the treatment very expensive.

No. 1350261. British Patent No. 4,121,198, provides a solution for removing contaminants and colorings in sugar juice extracted from sugar-containing raw materials. Following the conventional continuous carbonation process, the decolorization of the juice is accomplished by adsorption on activated carbon, and the remaining impurities and dyes are further removed by ion exchange resin and ion exchange membrane dialysis.

No. 4,523,577. U.S. Pat.

No. 2113247. An English patent purifies the raw material extracted from sugar cane by ultrafiltration, utilizing it as a soft drink. Ultrafiltration removes components that cause haze in the raw juice (resins), as well as taste disruptors and harmful bacteria. The ultrafiltration is done with sheet membranes with a cut-off value of 25,000-70000. The process is carried out at a pressure of 2-10 bar at 60-100 ° C. 100 ° C here also means sterilization. Operating at such high temperatures significantly reduces the life of the membranes.

No. 1361674. An English patent for ultrasound filtration of sugar cane and sugar beet juice. Instead of conventional lime clarification, it concentrates or ultra-filtrates high molecular weight materials, colloids, resins, color bodies. the resulting sugar permeate is further treated with one or a combination of the following treatment steps: chemical treatment, filtration, ion exchange, electrodialysis, reverse osmosis. The ultrafiltration is carried out at a pressure of 220 bar (0.2-2 MPa), the membrane being made of cellulose acetate. The ultrafiltration temperature is 25-35 ° C. The cellulose acetate membrane is relatively sensitive to pH, such as in the pH range above neutral, or to the pH. strongly acidic pH η should not be used.

The above patents do not mention the cost of decolorization by adsorption processes, the issue of the regenerability of adsorbents, the problem of the placement and disposal of non-regenerable adsorbents. Decolorization with pure activated carbon,

The treatment costs for cleaning are very high as only high quality charcoal can be used for decolorization. It is problematic to accurately measure capacity when operating because the quantity and quality of dyes and impurities also depend on the quality of the raw material to be processed. In general, the known processes require from 50 to 100 g / l of activated carbon. Activated charcoal regeneration is difficult or impossible to solve, and when depleted, large and expensive charcoal becomes waste, and special care must be taken to dispose of it.

Our process is based on the discovery of partially replacing pure activated carbon clarification with membrane separation, thus combining the benefits of ultrafiltration and activated carbon clarification, i.e. removing most of the impurities and dyes in an energy-efficient, environmentally friendly ultrafiltration, non-falling contaminants can now be removed with minimal activated carbon.

The process consists in subjecting the crude sugar solution obtained by the saccharification of the biomass from the high lignin waste to a membrane separation process (ultrafiltration) to remove impurities and dyes of the sugar solution after suitable pre-treatment (pre-filtration) and further filtration of the membrane process. High lignin waste can be wood chips, reeds, sedges, corn cobs, etc. The biomass derived from these, preferably corn cobs, is saccharified by acid hydrolysis.

In our procedure, a two-stage (coarse and fine) pre-filtration system is used for pre-filtration. The first stage of the pre-filtration consists of a coarse filter suitable for filtering fibers and lumps above 250 µm, and the filtered sugar solution is passed through a pressure drum filter, where the material above 50 µm is filtered.

The membrane process involves ultrafiltration. Ultrafiltration removes a large amount (70-80%) of the dyes and impurities from the valuable sugar fraction, so that the purified sugar solution as permeate ultrafiltration no longer contains floating and colloidal substances. This extends the lifetime of the additional treatment steps after the ultrafiltration (activated carbon clarifier, ion exchange).

In our proposed ultrafiltration apparatus, a large tube or capillary is used per membrane, the cut-off of the membrane being 1000 to 5000 Daltons. The pressure range of the ultrafiltration is 0.11.0 MPa, preferably 0.2-0.3 MPa. The ultrafiltration is carried out at 20-60 ° C, preferably at 30-50 ° C.

Filter the sugar solution for final decolorization

5-15 kg / m ^{3 of} activated carbon. This amount is 1 / 5-1 / 10 of the amount of activated carbon used in conventional activated carbon treatments.

The invention is illustrated by the following non-limiting example.

/. example

The process of the invention is treatment with activated charcoal after ultrafiltration

Starting material: 100 liters of solution obtained by pulverizing the biomass by filtration from fragments of solids. Producer of candied biomass from corn cobs is PÉTI NIM.

Analytical data:

Total reducing sugar: 2.7 g / 100 ml

Total sugar within the total reducing agent: 2.32 g / 100 ml

Furfural: 0.58 g / 100 mL pH: 4.33

Partial acid, H ₃ PO ₄ : 0.66 g / 100 ml

Dry matter content: 4.48 g / 100 ml

Color: Dark brown

Ultraszíírés

The ultrafiltration equipment:

m ² active area. The membrane is a capillary membrane of polysulfone.

Membrane Type: UFTA PSF-5-1.2 Cut-Off Value:

5000 Dalton operating parameters:

pressure: 0.2 MPa temperature: 34 ° C treatment time: 5 h

The 100 L of pre-filtered sugar solution is passed through an ultrafiltration apparatus equipped with a 5000 D cutoff ultrafiltration membrane with the above parameters for 5 hours continuously. The concentrate is recirculated and the permeate (the purified sugar solution) is continuously discharged. To avoid temperature increase due to pumping energy, a cold-water cooled snake was placed in the concentrate tank.

Analytical data of the obtained permeate:

Quantity: 701

Total sugar: 2.32 g / 100 ml

Furfural: 0.16 g / 100 mL pH: 4.35

Dry matter: 3.0 g / 100 ml

Partic acid in H-PO ₄ : 0.66 g / 100 ml

For complete decolorization: 1.18 g / 100 ml activated carbon

Activated carbon clearing:

Purifier: Activated carbon quality of tank with 100 liter mixer: a.t. (Reanal) Bulk density: 40 g / 100 ml particle size: approx. 1.5 mm

To the resulting 70 L ultrafiltrated permeate was added 0.83 kg of activated carbon of the above quality at room temperature (the amount of activated carbon needed was determined by laboratory experiments).

The slurry was stirred for 1/2 hour and after 1 hour the sugar solution, which had been decanted from the activated carbon, was filtered through filter paper.

HU 208,847 Β

Comparative Example 2

Starting material: 100 liters of solution obtained by pulverizing the biomass by filtration from fragments of solids.

Sugarized biomass is produced from corn cobs by Péti NIM.

Analytical data:

Divide by reducing sugar: 2.7 g / 100 ml Total sugar is the total reducing agent within material: 2.32 g / 100 ml furfural: 0.58 g / 100 ml pH: 4.33 Total acid, H ₃ PO ₄ in: 0.66 g / 100 ml Dry matter content: 4.48 g / 100 mL color: dark brown Active for complete decolorization amount of carbon: 6 g / 100 ml In this case cleaning 100 liters of sugar solution- to 6 kg of activated carbon necessary, this is approx. five times that

of the ultrafiltrated solution.

Our method, compared to conventional methods, results in a significant reduction in investment and operating costs, since membrane filtration can be achieved with minimal pumping energy.

A further advantage is the reduction in the use of activated carbon, with only 10-20% of the amount of activated carbon being decolorized with conventional activated carbon only. Because ultrafiltration membranes remove floating and colloidal particles from the sugar solution during ultrafiltration, they no longer burden the next treatment steps (activated carbon, ion exchanger), thus significantly increasing the capacity of these treatment units, while significantly reducing the amount of the amount of carbon and the volume of eluates from regeneration of the ion exchanger.

Claims (2)

L Method for removing impurities and colorants from a pre-filtered sugar solution obtained by saccharification of biomass from high lignin wastes, mainly from corn cobs, characterized in that the solution is filtered through ultrafiltration membranes with a cutoff of 1000-5000 Dalton at a pressure of 0.1-1.0 MPa. The reaction solution is treated with 5 to 15 kg / m ^{3 of} activated carbon. The process according to claim 1, wherein the ultrafiltration membrane is preferably a size tube or capillary.