CN104262100A - Glycerine refining method - Google Patents

Glycerine refining method Download PDF

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Publication number
CN104262100A
CN104262100A CN201410548061.1A CN201410548061A CN104262100A CN 104262100 A CN104262100 A CN 104262100A CN 201410548061 A CN201410548061 A CN 201410548061A CN 104262100 A CN104262100 A CN 104262100A
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China
Prior art keywords
glycerine
phase splitter
acid
soap
raw
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CN201410548061.1A
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Chinese (zh)
Inventor
李彦峰
资燕
李嘉锡
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FOSHAN TIANSHENGLONG GREASE CHEMICAL Co Ltd
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FOSHAN TIANSHENGLONG GREASE CHEMICAL Co Ltd
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Priority to CN201410548061.1A priority Critical patent/CN104262100A/en
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    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/74Separation; Purification; Use of additives, e.g. for stabilisation
    • C07C29/94Use of additives, e.g. for stabilisation
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/74Separation; Purification; Use of additives, e.g. for stabilisation
    • C07C29/76Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/74Separation; Purification; Use of additives, e.g. for stabilisation
    • C07C29/76Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment
    • C07C29/80Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment by distillation
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C29/00Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
    • C07C29/74Separation; Purification; Use of additives, e.g. for stabilisation
    • C07C29/88Separation; Purification; Use of additives, e.g. for stabilisation by treatment giving rise to a chemical modification of at least one compound

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

The invention discloses a glycerine refining method which comprises the following steps: adding alcohol into crude glycerine for dilution, then adding an inorganic acid to form a fatty acid, first glycerine and an inorganic acid salt, then adding an alcohol auxiliary for separation, and separating the first glycerine by using a phase splitter; filtering the first glycerine, adding ferric trichloride into the separated first glycerine to form second glycerine, an iron soap and impurities, and separating the second glycerine by using the phase splitter; mixing the second glycerine and sodium hydroxide, regulating the pH value, neutralizing and settling the excessive ferric trichloride and the iron soap, improving the purity of the second glycerine, leaving the second glycerine to stand, clarifying, and filtering; distilling the second glycerine. According to the scheme, the crude glycerine is preprocessed and filtered by using different auxiliaries before the step of distilling the glycerine, the substances like the fatty acid, salt, soap and ester in the glycerine are removed, so that the distilling and the purifying lead the glycerine to a higher purity degree; in addition, the technological process in the scheme is simpler in comparison with an existing refining method, and is suitable for continuous commercialized batch production.

Description

A kind of glycerine method of refining
 
Technical field
The present invention relates to a kind of glycerine method of refining.
Background technology
In grease production, as oil splitting, saponification, grease alcoholysis, except can obtaining natural acid, soap, fatty acid methyl ester, also can produce the sugar water of about about 10%.Glycerine sugar water is the main source of natural glycerin, natural glycerin output more than 90% from oil and fat product.And for example, in biofuel volume production, produce 1 ton of biofuel and about produce 100 kg of glycerin.In many industrial production, glycerine often exists with by-product form, in such as soap production, produces glycerine when fat saponification produces soap (alkali soap).Therefore, reasonably develop these by products, meet environmental protection theory.
Pure glycerine is a kind of colourless pleasantly sweet glutinous shape liquid, can generate various derivative, as Biodegradable plastics material acid, produce raw material 1,3 propylene glycol of diesel oil antifreezing agent glyceryl ether and PTT.Because glycerine is nontoxic, therefore food, medicine, with chemical field all have important application.
Because glycerine viscosity is high and mobility is not good, in order to obtain the glycerine of high purity (more than 99.5% purity), traditional heating mode is infeasible by glycerine heating evaporation purifying, and in various purification technique, when glycerol source is from fermenter, raw glycerine contains olefin polymer, ketone, double key carbon compound and other insatiable hunger and closes organic pollution materials, use ion exchange method, membrane separation process, with vacuum distillation method purification of glycerol, first above-mentioned pollution substance must be removed, just can carry out glycerine refining.And when glycerol source is from biofuel, because of in production of biodiesel process, for improving reaction conversion ratio, often add excessive methyl alcohol and alkali catalyst, these alkali and methyl alcohol are all dissolved in byproduct glycerine, these raw glycerines from biofuel contain the materials such as soap, salt and ester, if use vacuum distillation method, thin film separation or ion exchange methods glycerine, glycerol polymerization is easily there is and Ion-exchange particles lost efficacy during production, glycerine purity is unstable, purification efficiency is not high, and production, maintenance and running cost are high.In sum, more easy pre-treating process is still needed to carry out refined glycerol to improve glycerine purity at present.
Summary of the invention
The object of this invention is to provide a kind of technique simple and be applicable to a large amount of quantity-produced glycerine method of refining, refining can go out highly purified glycerine by the method.
For achieving the above object, the technical solution used in the present invention is as follows:
A kind of glycerine method of refining, is characterized in that: comprise the steps:
(1) first, in the raw glycerine of the first phase splitter, add alcohols dilute, to improve its mobility; Secondly, in raw glycerine, add mineral acid, form lipid acid, the first glycerine and inorganic acid salt; Then, alcohol analog assistant is added in raw glycerine, to improve the separating effect of inorganic acid salt in the first phase splitter; Finally, the raw glycerine adding mineral acid and alcohols is isolated the first glycerine by the first phase splitter;
(2) the first glycerine is filtered by filtration unit, with filtering inorganic acid salt and saponified;
(3) in isolated described first glycerine, add iron trichloride, form the second glycerine, iron soap and impurity, and isolate described second glycerine with the second phase splitter;
(4) the second glycerine and sodium hydroxide are added static mixer, between pH value to 7.5 ~ 10 adjusting the second glycerine, middlely close the excessive iron trichloride of precipitation, iron soap improve the purity of the second glycerine;
(5) the second glycerine is left standstill, after clarifying, glycerine clear liquor is filtered by filtration unit;
(6) described second glycerine is distilled, form refined glycerol.
Further, described alcohols is methyl alcohol or ethanol.
Further, described mineral acid is phosphoric acid, hydrochloric acid or sulfuric acid.
Further, described first phase splitter and described second phase splitter are the liquid liquid/solid-liquor separation decanting vessel with baffle plate and tank level control, or plate separator.
Further, described filtration unit is the filter bag that supercentrifuge, plate filter or porosity are less than 10 microns.
Further, described distillation sequence comprises methanol stripper, moisture removal and glycerol distillation.
The beneficial effect of this programme is: this programme is before step (6) carries out glycerol distillation program, utilize different auxiliary agent that raw glycerine is carried out pre-treatment, and filtered by filtration unit, be stripped of the materials such as lipid acid in glycerine, salt, soap and ester class, therefore carry out distillation purifying program and glycerine can be refined to high purity grades, and the technical process of this programme to compare existing method of refining more simple and easy, and be applicable to commercialization and produce in a large number continuously.
Embodiment
A kind of glycerine method of refining, comprises the steps:
First stage:
(1) in raw glycerine, add alcohols to dilute.Inject the first phase splitter after using static mixer to be mixed with appropriate alcohols by raw glycerine, improve its mobility to dilute raw glycerine.
(2) in raw glycerine, add mineral acid, form lipid acid, the first glycerine and inorganic acid salt.Added by mineral acid in raw glycerine, with the alkali in neutralized crude glycerine, adjust the pH value of raw glycerine simultaneously, make the soap in raw glycerine or fat hydrolysis be lipid acid, wherein mineral acid is sulfuric acid, hydrochloric acid or commercial phosphoric acid; Must control the pH value of glycerine solution when adding mineral acid between 3.0 ~ 5.0, take pH4.0 as the best; If when pH value is too high, significantly can reduce glycerin purification usefulness, if when pH value is too low, its purity promote and not obvious and acid ion easily and Fe 2+in conjunction with formation iron dirt material.
(3) add in raw glycerine by appropriate alcohol analog assistant, the reason of adding alcohol analog assistant is that glycerine has partial solubility to inorganic acid salt, and alcohols has comparatively low solubility to inorganic acid salt, therefore can improve the separating effect of inorganic acid salt in phase splitter.
(4) with the first phase splitter, the raw glycerine adding mineral acid and alcohols is isolated the first glycerine.Due to lipid acid and glycerine mutual solubility low, the first phase splitter can be utilized to be separated into lipid acid upper strata, glycerine phase middle level and part insoluble inorganic acid salt and saponified lower floor.First phase splitter can be the liquid liquid/solid-liquor separation decanting vessel with baffle plate and tank level control, or plate separator.Lipid acid after separation separately stores, and the glycerine in middle level then continues to flow into next stage mutually.
In the first phase, alcohols is methyl alcohol or ethanol, and the part by weight of raw glycerine and the alcohol diluent added and auxiliary agent is between 1:0.50 to 1:2.00; If the addition of alcohols is lower than above-mentioned scope, then can reduce glycerin purification rate, though and the addition increasing alcohol can increase glycerin purification rate, then can increase energy consumption during alcohols distillation in back segment operation when ratio is too high.
The first stage is verified: get 100g raw glycerine with experimental data, select methyl alcohol respectively, ethanol is as the auxiliary agent of first stage, its addition is respectively 50ml, 100ml, 200ml, add phosphoric acid neutralization again and make pH=7.0, filter salt and saponified after, take out glycerin layer to reheat to 150 DEG C to remove alcohols, phosphoric acid, and moisture, finally pour separating funnel into, separation of fatty acids and glycerine, take out the glycerine after being separated and analyze glycerine purity, find along with methyl alcohol addition increases, glycerine purity also increases, respectively by 83.16% to 95.87%, and when changing methyl alcohol into ethanol, addition be 50 or 100 ml time, it is higher when glycerine purity all comparatively adds methyl alcohol, when ethanol addition is 100ml, glycerine purity is the highest by about 98.25%, but be 200 ml as increased ethanol addition again, then glycerine purity is down to 90.89% on the contrary.
Subordinate phase: by the inorganic acid salt in the first glycerine and saponifiedly to be filtered by filtration unit, filtration unit can adopt supercentrifuge, plate filter or porosity to be less than the filter bag of 10 microns.
Phase III: iron trichloride is added in the first glycerine after subordinate phase filtration, form impurity, the second glycerine and iron soap, and isolate the second glycerine with the second phase splitter.Specific as follows:
Due to the lipid acid of the first glycerine still containing residual soap, various different molecular weight, pigment and other organic impuritys after subordinate phase filtration, therefore iron trichloride need be added in the second phase splitter, residual soap in making glycerine mutually and lower molecular weight lipid acid generate insoluble iron soap, increase saponified removal efficiency; Because saponified (<0.1%) of trace easily causes distillation tower in back segment operation to bubble, cause distillation tower liquid level to rise instantaneously and cause system operation unstable.After adding iron trichloride, above-mentioned glycerine is met and is separated into three layers, is then separated upper strata black impurity, middle level glycerine phase and lower floor's part inorganic acid salt class and saponified with the second phase splitter.Wherein the part by weight of the iron trichloride of the first glycerine and interpolation is between 1:0.001 to 1:0.1; If the addition of iron trichloride is lower than above-mentioned scope, then can be unfavorable for hydrolysis and the precipitation of residual soap during glycerine mutually, if now in the second phase splitter, lipid acid removal effect is not good, then residual soap will make subsequent filter block by the second phase splitter, and very easily cause distillation tower in back segment operation to bubble; If the adding proportion of iron trichloride auxiliary agent is too high, then may there is scale formation in excessive iron ion in equipment, reduces equipment use usefulness.Wherein the second phase splitter can be the Liquid liquid Separation or solid-liquor separation decanting vessel with baffle plate and tank level control, or plate separator.
The phase III is verified: after getting the glycerine of purifying in 100mL previous experiments and the iron trichloride mixing of 5g, surveying its saponification value is 77.88mg KOH/g with experimental data; Get the glycerine of purifying in 100mL previous experiments, not adding iron trichloride, directly to survey its saponification value be 35.33mg KOH/g.In addition, due to the easy moisture absorption of iron trichloride, two hydrate (FeCl can be generated 3-2H 2and six hydrate (FeCl O) 3-6H 2o), the aqueous solution in acid, help hydrolysis glycerine mutually in residual soap, increase saponified removal efficiency, and can with glycerine mutually in lower molecular weight lipid acid is combined, grease molecular-weight average (i.e. saponification equivalent) increase in making glycerine mutually.
Fourth stage: the second glycerine and sodium hydroxide are added static mixer, between pH value to 7.5 ~ 10 adjusting the second glycerine, middlely closes the excessive iron trichloride of precipitation, iron soap improve the purity of the second glycerine.Specific as follows:
Through phase III isolated second glycerine, most soap, lipid acid and inorganic acid salt are removed.But before glycerine is sent into distillation sequence mutually, first isolated glycerine is injected static mixer, and mixed with the second glycerine by appropriate sodium hydroxide, the addition of the second glycerine and sodium hydroxide must control the pH value of glycerine solution between 7.5 ~ 10.0.If the addition of sodium hydroxide auxiliary agent is lower than above-mentioned scope, then iron soap formation efficiency is low, and low ph value will make the fatty acid content entering glycerol distillation tower higher excessively, then lipid acid is by the purity of the final glycerol product of impact, causes glycerine purity to be increased to more than 99.7%; If the adding proportion of sodium hydroxide auxiliary agent is higher than above-mentioned scope, then alkalescence is excessively strong, also can cause corrosion to equipment.This stage utilizes in sodium hydroxide and mineral acid, and controls the temperature of reaction of static mixer, can transfer ester class to soap and become sodium salt on the one hand, on the other hand excessive Iron trichloride hexahydrate is transformed into ironic hydroxide (Fe (OH) 3), make part unsegregated sodium salt transfer to molysite deposition be separated, and in the strainer of back segment filtering and removing.Be with removing the order of sodium salt effectively to improve the heavies viscosity at the bottom of back segment distillation sequence tower, make the tower bottom reboiler design of glycerine rectifying tower and operation more accurately easily, also can reduce cost of equipment.In addition, owing to adding sodium hydroxide, glycerine can be made mutually in slight alkalinity, contribute to preventing back segment equipment by acid attack, extend the work-ing life of back segment distillation tower tower group.
Five-stage: left standstill by the second glycerine, is filtered glycerine clear liquor by filtration unit after clarifying.Specific as follows:
Through isolated second glycerine of fourth stage, most soap, lipid acid and inorganic acid salt are removed.First the second glycerine is injected glycerine feed tower in advance, make it to leave standstill clarification, then filtered by the glycerine clear liquor injection filtration unit after clarification, filtration unit can adopt supercentrifuge, plate filter or porosity to be less than the filter bag of 10 microns.
In 6th stage: the second glycerine is carried out distillation sequence, the second glycerine is made to form refined glycerol.Specific as follows:
Conventional distillation sequence can be adopted to carry out purifying to glycerine.The object of distillation obtains refining glycerine, three road continuous still batterys are carried out through alcohols distillation tower, moisture distillation tower and glycerol distillation tower, sequentially remove or reclaim alcohols, moisture and other impurity, these impurity may comprise the fatty acid soaps dissolved in glycerine, polyglycerol, water and salt.Alcohols distillation tower can obtain purity more than 99.5% alcohols, and alcohols is recyclable; And the glycerine purity at the bottom of moisture distillation tower tower can be increased to more than 85%, through glycerol distillation tower, glycerol concentration can distillation and concentration further.In the design of glycerol distillation tower, because considering that the glycerine boiling point under normal pressure is 290 DEG C, but just start to decompose and polymerization reaction take place at 204 DEG C, therefore distillation must be carried out in below 15torr condition at vacuum level requirements and use thin-film evaporator as reboiler, to reduce glycerol polymerization and to go bad.The product that collection glycerol distillation tower distillates can obtain highly purified refined glycerol.
Above embodiment is merely illustrative and not limiting to the invention, therefore all equivalences done according to the method described in patent claim of the present invention change or modify, and are included in patent claim of the present invention.

Claims (6)

1. a glycerine method of refining, is characterized in that: comprise the steps:
(1) first, in the raw glycerine of the first phase splitter, add alcohols dilute, to improve its mobility; Secondly, in raw glycerine, add mineral acid, form lipid acid, the first glycerine and inorganic acid salt; Then, alcohol analog assistant is added in raw glycerine, to improve the separating effect of inorganic acid salt in the first phase splitter; Finally, the raw glycerine adding mineral acid and alcohols is isolated the first glycerine by the first phase splitter;
(2) the first glycerine is filtered by filtration unit, with filtering inorganic acid salt and saponified;
(3) in isolated described first glycerine, add iron trichloride, form the second glycerine, iron soap and impurity, and isolate described second glycerine with the second phase splitter;
(4) the second glycerine and sodium hydroxide are added static mixer, between pH value to 7.5 ~ 10 adjusting the second glycerine, middlely close the excessive iron trichloride of precipitation, iron soap improve the purity of the second glycerine;
(5) the second glycerine is left standstill, after clarifying, glycerine clear liquor is filtered by filtration unit;
(6) described second glycerine is distilled, form refined glycerol.
2. a kind of glycerine method of refining according to claim 1, is characterized in that: described alcohols is methyl alcohol or ethanol.
3. a kind of glycerine method of refining according to claim 1, is characterized in that: described mineral acid is phosphoric acid, hydrochloric acid or sulfuric acid.
?
4. a kind of glycerine method of refining according to claim 1, is characterized in that: described first phase splitter and described second phase splitter are the liquid liquid/solid-liquor separation decanting vessel with baffle plate and tank level control, or plate separator.
5. a kind of glycerine method of refining according to claim 1, is characterized in that: described filtration unit is the filter bag that supercentrifuge, plate filter or porosity are less than 10 microns.
6. a kind of glycerine method of refining according to claim 1, is characterized in that: described distillation sequence comprises methanol stripper, moisture removal and glycerol distillation.
CN201410548061.1A 2014-10-16 2014-10-16 Glycerine refining method Pending CN104262100A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109721471A (en) * 2017-10-27 2019-05-07 中国石油化工股份有限公司 A method of the Purifing of Glycerol from the by-product of production biodiesel

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1083531A (en) * 1992-08-29 1994-03-09 郭静峰 Utilize useless vinasse to produce the method for glycerine
CN101633605A (en) * 2008-07-23 2010-01-27 张伟民 Method for preparing glycerin from byproduct in manufacture procedure of biodiesel
TW201024254A (en) * 2008-12-17 2010-07-01 Ind Tech Res Inst Method for refining glycerin
KR101099367B1 (en) * 2010-08-06 2011-12-29 제이씨케미칼(주) Method for simultaneous refining of crude bio-diesel and crude glycerin in bio-diesel production process

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1083531A (en) * 1992-08-29 1994-03-09 郭静峰 Utilize useless vinasse to produce the method for glycerine
CN101633605A (en) * 2008-07-23 2010-01-27 张伟民 Method for preparing glycerin from byproduct in manufacture procedure of biodiesel
TW201024254A (en) * 2008-12-17 2010-07-01 Ind Tech Res Inst Method for refining glycerin
KR101099367B1 (en) * 2010-08-06 2011-12-29 제이씨케미칼(주) Method for simultaneous refining of crude bio-diesel and crude glycerin in bio-diesel production process

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109721471A (en) * 2017-10-27 2019-05-07 中国石油化工股份有限公司 A method of the Purifing of Glycerol from the by-product of production biodiesel
CN109721471B (en) * 2017-10-27 2021-08-06 中国石油化工股份有限公司 Method for purifying glycerin from by-product of biodiesel production

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Application publication date: 20150107