CN106008201A - Method for extracting sodium glycollate from CMC wastewater - Google Patents

Abstract

The invention relates to a method for extracting sodium glycollate from CMC wastewater. The method specifically comprises the following steps of extracting a mother solution, evaporating CMC salt-containing wastewater by utilization of an MVR evaporator, and removing 80 percent of inorganic salt to obtain organic matters with 10 to 15 percent of salt and 35 to 55 percent of moisture, thus obtaining the mother solution, wherein for 35 to 50 percent of the organic matters in the mother solution, 90 percent of the organic matters is sodium glycollate; adjusting the PH value of the mother solution to 10 by utilization of sodium hydroxide, filtering at a temperature about 60 DEG C while the mother solution is hot, and extracting from the solution by utilization of an ethanol solvent so as to obtain a crude sodium glycollate solid product; acidizing by utilization of sulfuric acid, taking the sulfuric acid as a catalyst, performing esterification by utilization of methanol so as to obtain methyl glycolate, and finally hydrolyzing and converting the methyl glycolate into a glycolic acid solution with a purity of 70 percent. The method disclosed by the invention has the advantages that the design is complete, the use is convenient, salt contents are effectively removed and a part of recycled water reaching industrial reuse water standards is produced after the CMC wastewater is treated, and residual concentrated wastewater is prepared into chemical products with a higher economic value through further chemical treatment.

Description

Hydroxy acid sodium extracting method in CMC waste water

Technical field

The present invention relates to CMC field of waste water treatment, be specifically related to hydroxy acid sodium extracting method in a kind of CMC waste water.

Background technology

Sodium carboxymethyl cellulose, is called for short CMC, is the carboxyl methylation derivant of cellulose, has another name called cellulose gum, be main Ionic cellulose element glue.CMC is the most prepared by Germany in 1918, and patented in 1921 and be seen in generation, this After just Europe realize commercially produce.It is the most only thick product, as colloid and binding agent.1936-1941, to CMC The research of commercial Application is the most active, and has delivered and several have suggestive patent.During World War II, Germany will CMC is used for synthetic detergent.The industrialized production of CMC starts from nineteen thirties Germany IG Farbenindustrie AG.Hereafter, production technology, production efficiency and product quality have progressively had and have been significantly improved.1947 Year, U.S. FDA proves according to toxicological studies: CMC is to physiology nonhazardous effect, it is allowed to use it in food processing industry Make additive, play thickening power.CMC is because having many special natures: its moisture absorption degree has with atmospheric temperature and relative humidity Close, after arriving balance, the most no longer moisture absorption；

CMC aqueous solution have excellent bonding, thickening, emulsifying, suspension, film forming, protecting colloid, holding moisture, resistance to enzymolysis and The performances such as metabolism inertia；When CMC aqueous solution meets with stannum, silver, aluminum lead, ferrum, copper and some heavy metal, it may occur that precipitation, When CMC aqueous solution and calcium, magnesium, Sal coexist, precipitation will not be produced, but the viscosity of CMC aqueous solution can be reduced.CMC aqueous solution is met During to acid, acid CMC precipitation can be separated out.But anti-acid CMC has certain resistance to acid solution；CMC aqueous solution is with water-soluble Property the aqueous solution such as animal glue, glycerol ethylene glycol, sorbitol, arabic gum, pectin and soluble starch, all can mix the most molten mutually, CMC decorating film, benzene, acetate esters, carbon tetrachloride, Oleum Ricini, Semen Maydis oil, Oleum Arachidis hypogaeae semen, methanol, ethanol, ether, chloroform, three Ethyl chloride, thing such as thickening, bonding, film forming, water holding, emulsifying, the suspension etc. such as gasoline, butanone, toluene, dimethylbenzene, Oleum Terebinthinae, and It is used widely.In recent years, the CMC of different qualities is used in the different field of industry and people's life, extensively applies In oil, chemical industry, detergent, pottery, Medicated cigarette, print and dye, weave, the industry such as food, medicine, welding rod, have " industry monosodium glutamate " it Claim.The purposes of CMC widely, nontoxic, corrosion-free, harmless, free from environmental pollution, cohesive force by force, do not go mouldy, do not give birth to Worm, can be as emulsifying agent, thickening agent, stabilizer, sizing agent, film former, binding agent etc..

Unique pollutant that CMC industry produces are waste water, and feature is high salt, high COD (20000～40000mg/L).Often give birth to Produce 1 ton of CMC, will be about producing the waste liquid of 2.5～3 tons, CMC produce the process of waste water be always worldwide one important Problem, developed country particularly payes attention to.As Japan uses dioxygen water treatment technology, Germany to use exchange resin method, but still exist Respective shortcoming, fails to realize the zero-emission of surface water.China yet there are no the technical patent of maturation in this respect, with developed country Compare the gap still having increasing.At energy-saving and emission-reduction, protection environment, particularly protection aqueous systems has risen becomes the war of country of China Today slightly, solve this problem and seem extremely important.

The production technology of CMC uses solvent method, produces washes in washing process, and the processing cost of its great number allows state Inside and outside all of enterprise all cannot accept, and the processing mode of current industry is all to give waste-water treatment industry by waste water, is mixed in it His industrial wastewater further processes.Waste water in CMC production technology processes is badly in need of technique and the innovation of technical method.Its row Recovery and the comprehensive utilization of putting thing can bring considerable economic benefit to enterprise.

China is in the economic quickly rise period, and current CMC product is with higher annual rate of growth development.Anticipated China exists In nearly 5 years, demand can rise to 80～1,000,000 tons, and the growth in market is good, and therefore the recycling of CMC industry emission is convex Show the urgency and necessity implemented.

Summary of the invention

In order to solve the problems referred to above, the present invention proposes hydroxy acid sodium extracting method in a kind of CMC waste water, has designed Kind, easy to use, after treatment, salinity removed effectively, produce a part reaches industrial reuse water quality standard again to CMC waste liquid Unboiled water, remaining concentrating spent liquor is used for further chemical treatment, obtains the chemical products having higher economic worth.

In order to reach foregoing invention purpose, the present invention proposes techniques below scheme:

Hydroxy acid sodium extracting method in CMC waste water, is characterized in particular in following steps:

1) Extracting juice, CMC brine waste passes through MVR evaporator evaporation, removes the inorganic salt of 80%, and remaining is saliferous 10- 15%, moisture, at the Organic substance of 35-50%, obtains mother solution；In mother solution, the Organic substance of 35-50% 90% is wherein hydroxy acid sodium；

2) the pH value sodium hydroxide of mother solution is adjusted to 10, about 60 DEG C filtered while hot, extract from liquid with alcohol solvent, Obtain crude product hydroxy acid sodium solid；

3) it is acidified with sulphuric acid the most again and makees catalyst, being esterified with methanol (1 part of acidifying 3 parts of methanol of material), obtain hydroxyl second Acid methyl ester, last hydrolysis is the hydroxyacetic acid solution that purity reaches 70%.

Described the 3rd) reaction principle in step:

(1) 2HOCH2COONa+H2SO4 → 2HOCH2COOH+Na2SO4；

(2) HOCH2COOH+CH3OH → HOCH2COOCH3+H2O；

(3) HOCH2COOCH3 → HOCH2COOH+CH3OH.

It is an advantage of the invention that design is perfect, easy to use, after treatment, salinity is removed, is produced CMC waste liquid effectively A part reaches the recycled water of industrial reuse water quality standard, and remaining concentrating spent liquor is used for further chemical treatment, obtains having relatively The chemical products of high economic worth.

Detailed description of the invention

The method that CMC waste water processes, puts into kneader in proportion carry out cellulose (purified cotton), alkali, monoxone, ethanol Alkalization and etherification reaction, then wash with the ethanol solution of 50-75%, and material, through centrifugal squeezing, is divided into two parts: Gu Body drying materials, pulverize, be packaged into CMC finished product；Liquid material containing ethanol carries out ethanol recovery, and remaining is brine waste； It is characterized in particular in:

1) brine waste is evaporated by MVR, removes the inorganic salt (NaCl) of 80%, and remaining is saliferous (NaCl) 10-15%, moisture At the Organic substance of 40-50% and 35-50%, COD COD of this solution is up to 300,000 more than mg/L, is called for short mother solution；

2) mother liquor is become COD COD8000-1 ten thousand mg/L solution inside distribution reservoir, it is desirable to be COD:N:P= 300:7:1, sodium chloride content is less than 1%, and pH value is less than 7.2；Then the waste water prepared is taken out people's anaerobic pond；

3) waste water carries out 72 hours anaerobic treatment in anaerobic pond, it is desirable to temperature is more than 30 DEG C, and dissolved oxygen is less than 0.5mg/L, so Rear waste water outflow enters PACT pond；The anaerobic treatment method of described anaerobic pond is by (1) hydrolysis stage: macromolecule organic divides Solution becomes little molecule；Organic substance cellulose in waste water is resolved into cellobiose and glucose by cellulase；This after decomposition A little little molecules carry out next step decomposition；(2) souring stage: above-mentioned small organic molecule changes in entering into microbial body The simplest compound, the primary product in this stage is volatile fatty acid (VFA), also has the alcohols of part, breast simultaneously The products such as acid, carbon dioxide, hydrogen, ammonia, hydrogen sulfide produce；(3) produce the acetic acid stage: in this stage, the product of previous step enters one Step is converted to acetic acid, carbonic acid, hydrogen and new cellular material；(4) the methane phase stage: in this stage, acetic acid, hydrogen, Carbonic acid, formic acid and methanol are all converted to methane, carbon dioxide and new cellular material；

4) waste water stops in PACT pond and carries out Air Exposure in 60 hours, it is desirable to temperature is less than 40 DEG C, and pH value is less than 9, then gives up Water overflow enters contact-oxidation pool；The processing method in described PACT pond is: put into activated carbon in pond dirty with the carbon containing of backflow Mud aeration together, processes the poisonous and hazardous organic pollution that microorganism is difficult to degrade, and prevents the bounce-back of ammonia nitrogen index, improves difficulty Removal effect with degradation of organic substances.

5) waste water stops at contact-oxidation pool and carries out Air Exposure in 72 hours, it is desirable to temperature is at 30-40 DEG C, and pH value is less than 9； The processing method of described contact-oxidation pool is a kind of based on biofilm method, has the biological treatment device of activated sludge concurrently, passes through Oxygen source is provided, makes the Organic substance in sewage by microorganism adsorption, degraded, make waste water be purified；

6) waste water COD discharged from contact-oxidation pool is less than 500mg/L.

Hydroxy acid sodium extracting method in CMC waste water, is characterized in particular in following steps: Extracting juice, and CMC brine waste passes through MVR evaporator evaporation, removes the inorganic salt of 80%, and remaining is saliferous 10-15%, and moisture, at the Organic substance of 35-50%, obtains mother Liquid；In mother solution, the Organic substance of 35-50% 90% is wherein hydroxy acid sodium；The pH value sodium hydroxide of mother solution is adjusted to 10,60 Filtered while hot about DEG C, extracts from liquid with alcohol solvent, obtains crude product hydroxy acid sodium solid；It is acidified with sulphuric acid the most again And make catalyst, and it being esterified with methanol (1 part of acidifying 3 parts of methanol of material), obtain hydroxy methyl acetate, last hydrolysis is pure Degree reaches the hydroxyacetic acid solution of 70%.

MVR evaporation, ethanol, be acidified, be esterified, hydrolyze, brine waste → mother solution → crude product hydroxy acid sodium → hydroxyacetic acid Methyl ester → 70% hydroxyacetic acid solution；

Reaction principle:

(1) 2HOCH2COONa+H2SO4 → 2HOCH2COOH+Na2SO4；

(2) HOCH2COOH+CH3OH → HOCH2COOCH3+H2O；

(3) HOCH2COOCH3 → HOCH2COOH+CH3OH.

Claims (2)

1. Hydroxy acid sodium extracting method in 1.CMC waste water, it is characterised in that following steps:

   Extracting juice, CMC brine waste passes through MVR evaporator evaporation, removes the inorganic salt of 80%, and remaining is saliferous 10-15%, Moisture, at the Organic substance of 35-50%, obtains mother solution；In mother solution, the Organic substance of 35-50% 90% is wherein hydroxy acid sodium；

   The pH value sodium hydroxide of mother solution is adjusted to 10, about 60 DEG C filtered while hot, extract from liquid with alcohol solvent, To crude product hydroxy acid sodium solid；

   It is acidified with sulphuric acid the most again and makees catalyst, being esterified with methanol (1 part of acidifying 3 parts of methanol of material), obtain hydroxyacetic acid Methyl ester, last hydrolysis is the hydroxyacetic acid solution that purity reaches 70%.
2. Hydroxy acid sodium extracting method in CMC waste water the most according to claim 1, is characterized in that described the 3rd) anti-in step Answer principle:

   (1) 2HOCH2COONa+H2SO4 → 2HOCH2COOH+Na2SO4；

   (2) HOCH2COOH+CH3OH → HOCH2COOCH3+H2O；

   (3) HOCH2COOCH3 → HOCH2COOH+CH3OH.