CN1743303A - Low-concentration acetic acid recovery method - Google Patents
Low-concentration acetic acid recovery method Download PDFInfo
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- CN1743303A CN1743303A CN 200410041884 CN200410041884A CN1743303A CN 1743303 A CN1743303 A CN 1743303A CN 200410041884 CN200410041884 CN 200410041884 CN 200410041884 A CN200410041884 A CN 200410041884A CN 1743303 A CN1743303 A CN 1743303A
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Abstract
This invention relates to a method to recycle acetic acid from fluid containing low-concentration acetic acid. First, directly introduce the vapor containing low-concentration acetic acid into reactor and simultaneously feed complexing agent gas into the reactor to make the acetic acid in the steam and the complexing agent conduct complexation to generate an acetic acid complex whose boiling point is higher than that of acetic acid. Then, after gas liquid separation, the acetic acid complex is discharged from the bottom of the reactor, which is then conducted regeneration and separation to obtained the acetic acid and complexing agent, the acetic acid is recovered and the complexing agent is feedback to the reactor for circulation use. Or, make the acetic acid complex conduct to obtain the other acetic complex which can be directly used .Advantages: short technological process, low apparatus investment, low energy consumption, high acetic acid recovery rate and low acetic acid content in wastewater after recovering process.
Description
Technical field:
The present invention relates to a kind of method that reclaims acetic acid, relate in particular to a kind of method that from the fluid that contains low-concentration acetic acid, reclaims acetic acid.
Background technology:
Acetic acid is a kind of important chemical product or raw material, and many chemical processes all relate to acetic acid utilization and recovery.The reclaimer operation of Dichlorodiphenyl Acetate is comparatively easy under the high density situation, still, how could reclaim acetic acid better from low-concentration acetic acid solution, remains an important topic in the Chemical Manufacture so far.It is reported, there are a considerable amount of acetic acid to discharge not thorough industrial every year because reclaim with waste water, for example, the acetic acid amount that be discharged national every year in furfural production has about 10,000 tons approximately, pure terephthalic acid (PTA) production equipment that one cover annual production is about 350,000 tons, contain more than 3000 ton of acetic acid in the waste water of annual discharging, this has not only lost a large amount of useful resources, but also has polluted environment.Therefore, from dilute acetic acid aqueous solution, reclaim acetic acid, great economic benefit is not only arranged, and be that environment protection institute is essential.
At present, the method for recovery acetic acid has methods such as solvent extration, esterification process, azeotropic distillation substantially from contain acetic acid containing waste water.Chinese patent CN1342637 discloses " a kind of integrated technology process and system that reclaims dilute acetic acid ", this method is that 20%～80% tributyl phosphate mixes with kerosene with volume content, the organic solution that forms is as extraction agent, reclaim dilute acetic acid by operation stepss such as extraction, vacuum distilling, solvent reclamation, oil washes, applicable to acetic acid content is 1%～15% acetum, and the acetic acid rate of recovery of a whole set of technology is 92%.Other has and reports: the trialkylphosphine oxide extraction agent of Beijing Inst. of Chemical Metallurgy, Ministry of Nuclear Industry's development can be used for reclaiming acetic acid from dilute acetic acid waste water; Janet A.Tamada has studied the extraction ability of all kinds of amine extractants, finds that low-molecular-weight tertiary amine loading capacity is big, Heat stability is good, and thinks that trioctylamine (TOA) is the maximum extraction agent of research.
The method of above-mentioned recovery acetic acid all is to extract acetic acid from the waste water that contains acetic acid, and in many chemical processs, these waste water that contain acetic acid all are by the water vapor condensation that contains acetic acid, therefore, in the removal process of acetic acid, aforesaid method all exists defectives such as energy consumption height, extraction process complexity, investment is big, organic efficiency is low to some extent, particularly at the processing of low-concentration acetic acid wastewater, its recovering effect is more undesirable, and economic benefit is relatively poor.
Summary of the invention:
The object of the present invention is to provide a kind of recovery method of low-concentration acetic acid, this method and chemical process are combined closely, and directly reclaim acetic acid from the water vapour that contains acetic acid, reclaim technical process thereby shorten acetic acid, play energy-saving and cost-reducing effect.
For realizing purpose of the present invention, a kind of recovery method of low-concentration acetic acid, the steam that will contain low-concentration acetic acid is directly introduced reactor, simultaneously, in this reactor, feed complexing agent with gas form, make acetic acid and complexing agent generation complex reaction in the steam, generate the boiling point acetic acid complex compound higher than acetic acid, pass through gas-liquid separation then, with water vapour is the top effusion of the gas of major ingredient from reactor, forming waste water after the condensation, is that the liquid of major ingredient is then discharged from reactor bottom with the acetic acid complex compound; Described acetic acid complex compound separates through regeneration, obtains acetic acid and complexing agent respectively, and acetic acid is recovered, and complexing agent is sent back to reactor cycles and used; Perhaps, the acetic acid complex compound is carried out chemical reaction, obtain another acetic acid compound that can directly use and corresponding by product, thereby make acetic acid obtain efficient recovery.
In the recovery method of above-mentioned low-concentration acetic acid, the preferred organic amine compound of complexing agent, more preferably triethylamine or trioctylamine or primary amine compounds, entering the acetic acid of complex reactor and the mol ratio of complexing agent is 10: 1～1: 2.
When complexing agent is triethylamine or trioctylamine, enter preferred 6: 1～3: 1 of the mol ratio of the acetic acid of complex reactor and complexing agent.
In the recovery method of above-mentioned low-concentration acetic acid, the weight concentration of acetic acid is advisable with 1%～10% in the steam that is recovered.During recovery, what discharge from reactor bottom is the liquid of major ingredient with the acetic acid complex compound, can implement regeneration by the mode of underpressure distillation and separate; Perhaps itself and alcohol compound are carried out chemical reaction, obtain acetic ester and organic amine, used alcohol compound preferred alcohol or propyl alcohol.
Outstanding substantive distinguishing features of the present invention and obvious improvement are embodied in following several respects:
The present invention changes traditional way that reclaims acetic acid from trade effluent, but the reclaimer operation of acetic acid and main production technique are combined closely, the water vapour that will contain low-concentration acetic acid directly causes the recovery reactor, make the acetic acid in the water vapour generate high boiling complex compound by complex reaction, and then realize gas-liquid separation automatically, reach the purpose that reclaims acetic acid.This method has been avoided a large amount of evaporations that solvent in the removal process was reclaimed or extracted in rectifying in the prior art, has technical process weak point, equipment less investment, low, the organic efficiency advantages of higher of energy expenditure.
In the technical solution of the present invention, the acetic acid complex compound that complex reaction generates can realize that complexing agent separates with the regeneration of acetic acid by underpressure distillation, because the concentration of acetic acid is lower, the amount of this acetic acid complex compound is less relatively, the isolating operation of regenerating is easier, the complexing agent that obtains can turn back to complex reactor and recycle, and the cost recovery of acetic acid is further reduced.Perhaps, directly carry out chemical reaction with alcohol compounds such as ethanol, propyl alcohol and the acetic acid complex compound that obtains, generate acetic ester and corresponding by product, this acetic ester can directly use in other chemical process, is a kind of good chemical feedstocks.
Description of drawings:
Fig. 1 is a process flow diagram of the present invention;
Fig. 2 is the variation relation figure between " boiling point of the complex compound that acetic acid and triethylamine form " and " molar weight of triethylamine accounts for the percentage ratio of the mole total amount of acetic acid and triethylamine ";
Fig. 3 is the simulation test device synoptic diagram of present method invention.Among the figure, 1,2 is well heater, and 3,4 is three-necked bottle, and 5 is complex reactor, 6,7 is the phlegma receiving flask, and 8 is condenser, the 31st, and the solution that contains acetic acid enters the mouth, the 41st, the complexing agent inlet, the 32, the 42nd, nitrogen inlet, 81,82 are respectively the import and the outlet of heat-eliminating medium.
Embodiment:
As Fig. 1, the invention provides a kind of recovery method of low-concentration acetic acid, the steam that contains low-concentration acetic acid in the chemical processs such as PTA is directly introduced reactor, simultaneously, in this reactor, feed complexing agent with gas form, make acetic acid and complexing agent generation complex reaction in the steam, generate the boiling point acetic acid complex compound higher than acetic acid.Passing through gas-liquid separation then, is that the gas of major ingredient is overflowed from the top of reactor with water vapour, forms waste water after the condensation.And be that the liquid of major ingredient is discharged from reactor bottom with the acetic acid complex compound, separate through regeneration, obtain acetic acid and complexing agent respectively, acetic acid is recovered, and complexing agent is sent back to reactor cycles and is used; Perhaps, the acetic acid complex compound is carried out chemical reaction, obtain another acetic acid compound that can directly use and corresponding by product, thereby make acetic acid obtain efficient recovery.
This method can form the high boiling point complex compound by hydrogen bond based on acetic acid and many amine substances, and this complex compound can be condensed into liquid under comparatively high temps, thereby realizes separating of acetic acid and water vapour.Fig. 2 has represented the variation relation between " boiling point of the complex compound that acetic acid and triethylamine form " and " molar weight of triethylamine accounts for the percentage ratio of the mole total amount of acetic acid and triethylamine ".The boiling point of acetic acid is 118 ℃, and the boiling point of triethylamine is 89 ℃, and 4 acetic acid molecule and 1 triethylamine molecular complex can form boiling point and be 165 ℃ complex compound.Therefore, the product of the complex reaction of carrying out in the gas phase can be condensed under comparatively high temps, and the water molecules that has neither part nor lot in reaction still is gaseous phase, and gas-liquid is separated automatically, thereby realizes the purpose of Separation and Recovery acetic acid from the water vapour that contains low-concentration acetic acid.
Key of the present invention is to select suitable complexing agent kind and consumption, with guarantee gas phase condition down with water vapour in the low-concentration acetic acid generation complex reaction that contains, the separation of the liquid complex compound of generation, regeneration or chemical treating process are relatively easily realized.Therefore, the contriver catches technological difficulties, has designed the testing apparatus of a cover simulation commercial run, as shown in Figure 3, by testing repeatedly and studying, has confirmed the feasibility of technical solution of the present invention.
In Fig. 3, two three- necked bottles 3 and 4 are placed respectively in the middle of two place's well heaters 1 and 2, be used to generate low-concentration acetic acid steam and complex compound steam, the acetic acid dilute solution is from the 31 adding three-necked bottles 3 that enter the mouth, complexing agent is from the 41 adding three-necked bottles 4 that enter the mouth, and inlet 32 and 42 is used for logical nitrogen in two bottles, makes device inside be inert atmosphere when beginning to heat up, three-necked bottle 3 is connected with complex reactor 5 with pipeline respectively with 4 remaining separately place outlets, and pipeline is provided with the flow control valve.Granular weighting material is equipped with in the inside of complex reactor 5, fully effectively carries out to guarantee complex reaction, and its below is connected with receiving flask 6, is used to accept the acetic acid complex compound liquid that complex reaction generates; Its top is a pneumatic outlet, and pipeline is provided with condenser 8, heat-eliminating medium from enter the mouth 81, outlet 82 turnover condensers 8, the gas of finishing after the complex reaction is cooled off, the wastewater collection that condensation is got off is in the middle of receiving flask 7.
During device work, earlier in two three-necked bottles, add acetum and complexing agent respectively, the sealing inlet 31 and 41 then, from entering the mouth 32 and 42 to the inner logical nitrogen of device, keep the nitrogen micrometeor after displacement finishes, simultaneously, open the terminal valve of condenser 8 used heat-eliminating mediums, the controlled chilling rate-of flow remains within the specialized range condenser temperature; Then, the heater switch of opening well heater 1 and 2 heats up three- necked bottle 3 and 4 simultaneously, the control heat-up rate, treat behind the liquid boiling by the control valve on the control steam connection tube road, make three-necked bottle 3 and the 4 inner steam that produce in the identical time, all be evaporated to the inside of complex reactor 5, the acetic acid complex compound that reaction generates is collected in the middle of the receiving flask 6, and the wastewater collection that condensation is got off is in the middle of receiving flask 7.
Because the concentration of acetic acid is lower in the starting soln, the amount of the acetic acid complex compound that reaction generates is less relatively, can be by multiple modes such as underpressure distillation to its separation of regenerating, to operate easylier, and the complexing agent that obtains can be for next testing campaign use.On the other hand, measure and analyze, the rate of recovery that acetic acid consumption before and after the contrast reaction and content can calculate acetic acid by the waste water that receiving flask 7 is collected.
Result of study shows, technical solution of the present invention has advantages such as technical process weak point, equipment less investment, energy expenditure are low, and the content of acetic acid is very low in the middle of the rate of recovery height of acetic acid, the waste water after the recovery, well below emission standard, satisfies environmental requirement.
This scheme is applicable to the multiple chemical process that relates to acetic acid, for the factory based on acetic acid (assisting) product, can improve the output of acetic acid, increases the performance of enterprises; For for the factory of acetic acid (assisting) raw material, as the PTA production equipment, then can effectively reduce acetic acid consumption, reduce production cost.
The present invention is fine for the recovering effect of the low-concentration acetic acid solution of concentration expressed in percentage by weight in 1%～10% scope, when acetate concentration is higher, operations such as technical solution of the present invention and rectifying can be combined, the recovery of Dichlorodiphenyl Acetate will be more thorough, and economic benefit is also more remarkable.
Below in conjunction with accompanying drawing 3, be example with triethylamine and these two kinds of typical complexing agents of trioctylamine, specify process and the effect of using technical solution of the present invention.These embodiment only provide as example, can not limit rights protection scope of the presently claimed invention.
Embodiment 1
Adding 100ml weight concentration is 3% aqueous acetic acid in three-necked bottle 3, in three-necked bottle 4, add the 5ml triethylamine, control heater 1 and 2 rate of heating all are evaporated in the middle of the reactor 5 both in the identical time, accept acetic acid complex compound and waste water respectively in receiving flask 6 and 7.Analyze the waste water of collecting in the receiving flask 7, the weight concentration of acetic acid is 0.29%, and the rate of recovery that calculates acetic acid is about 90%.The acetic acid complex compound that receiving flask 6 is collected gets acetic acid and triethylamine through underpressure distillation.
Adding 100ml weight concentration is 3% aqueous acetic acid in three-necked bottle 3, in three-necked bottle 4, add the 8ml trioctylamine, control heater 1 and 2 rate of heating all are evaporated in the middle of the reactor 5 both in the identical time, accept acetic acid complex compound and waste water respectively in receiving flask 6 and 7.Analyze the waste water of collecting in the receiving flask 7, the weight concentration of acetic acid is 0.68%, and the rate of recovery that calculates acetic acid is about 77%.The acetic acid complex compound that receiving flask 6 is collected gets acetic acid and trioctylamine through underpressure distillation.
Adding 100ml weight concentration is 8% aqueous acetic acid in three-necked bottle 3, in three-necked bottle 4, add the 12ml triethylamine, control heater 1 and 2 rate of heating all are evaporated in the middle of the reactor 5 both in the identical time, accept acetic acid complex compound and waste water respectively in receiving flask 6 and 7.Analyze the waste water of collecting in the receiving flask 7, the weight concentration of acetic acid is 0.78%, and the rate of recovery that calculates acetic acid is about 90%.The acetic acid complex compound that receiving flask 6 is collected gets acetic acid and triethylamine through underpressure distillation.
Adding 100ml weight concentration is 8% aqueous acetic acid in three-necked bottle 3, in three-necked bottle 4, add the 12ml trioctylamine, control heater 1 and 2 rate of heating all are evaporated in the middle of the reactor 5 both in the identical time, accept acetic acid complex compound and waste water respectively in receiving flask 6 and 7.Analyze the waste water of collecting in the receiving flask 7, the weight concentration of acetic acid is 1.5%, and the rate of recovery that calculates acetic acid is about 82%.The acetic acid complex compound that receiving flask 6 is collected gets acetic acid and trioctylamine through underpressure distillation.
Adding 500ml weight concentration is 3% aqueous acetic acid in three-necked bottle 3, in three-necked bottle 4, add the 20ml triethylamine, control heater 1 and 2 rate of heating all are evaporated in the middle of the reactor 5 both in the identical time, accept acetic acid complex compound and waste water respectively in receiving flask 6 and 7.Analyze the waste water of collecting in the receiving flask 7, the weight concentration of acetic acid is 0.28%, and the rate of recovery that calculates acetic acid is about 91%.The acetic acid complex compound that receiving flask 6 is collected gets acetic acid and triethylamine through underpressure distillation.
Adding 500ml weight concentration is 5% aqueous acetic acid in three-necked bottle 3, in three-necked bottle 4, add the 35ml trioctylamine, control heater 1 and 2 rate of heating all are evaporated in the middle of the reactor 5 both in the identical time, accept acetic acid complex compound and waste water respectively in receiving flask 6 and 7.Analyze the waste water of collecting in the receiving flask 7, the weight concentration of acetic acid is 0.42%, and the rate of recovery that calculates acetic acid is about 92%.The acetic acid complex compound that receiving flask 6 is collected with ethanol synthesis, gets vinyl acetic monomer and diethylamine under the effect of resin catalyst.
Claims (8)
1, a kind of recovery method of low-concentration acetic acid, it is characterized in that: the steam that will contain low-concentration acetic acid is directly introduced reactor, simultaneously, in this reactor, feed complexing agent with gas form, make acetic acid and complexing agent generation complex reaction in the steam, generate the boiling point acetic acid complex compound higher than acetic acid, pass through gas-liquid separation then, the gas that with water vapour is major ingredient is overflowed from the top of reactor, forms waste water after the condensation, is that the liquid of major ingredient is then discharged from reactor bottom with the acetic acid complex compound, the acetic acid complex compound that generates separates through regeneration, obtain acetic acid and complexing agent respectively, acetic acid is recovered, and complexing agent is sent back to reactor cycles and used;
2, the recovery method of a kind of low-concentration acetic acid according to claim 1, it is characterized in that: also the acetic acid complex compound that generates can be carried out chemical reaction, obtain another acetic acid compound that can directly use and corresponding by product, thereby make acetic acid obtain efficient recovery.
3, the recovery method of a kind of low-concentration acetic acid according to claim 1 and 2, it is characterized in that: described complexing agent can adopt organic amine compounds such as triethylamine, trioctylamine or primary amine compounds, and entering the acetic acid of complex reactor and the mol ratio of complexing agent is 10: 1～1: 2.
4, the recovery method of a kind of low-concentration acetic acid according to claim 3 is characterized in that: described complexing agent can be triethylamine or trioctylamine, and entering the acetic acid of complex reactor and the mol ratio of complexing agent is 6: 1～3: 1.
5, the recovery method of a kind of low-concentration acetic acid according to claim 4 is characterized in that: underpressure distillation is adopted in the regeneration sepn process of described acetic acid complex compound.
6, the recovery method of a kind of low-concentration acetic acid according to claim 2 is characterized in that: described acetic acid complex compound and alcohol compound are carried out chemical reaction, obtain acetic ester and organic amine.
7, the recovery method of a kind of low-concentration acetic acid according to claim 6 is characterized in that: described alcohol compound can adopt ethanol or propyl alcohol.
8, the recovery method of a kind of low-concentration acetic acid according to claim 1 is characterized in that: in the described low-concentration acetic acid steam, the weight concentration of acetic acid is 1%～10%.
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| CN 200410041884 CN1743303A (en) | 2004-09-04 | 2004-09-04 | Low-concentration acetic acid recovery method |
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| CN 200410041884 CN1743303A (en) | 2004-09-04 | 2004-09-04 | Low-concentration acetic acid recovery method |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102824880A (en) * | 2011-06-15 | 2012-12-19 | 逸盛大化石化有限公司 | Acetic acid spray improvement method |
| CN104844445A (en) * | 2015-03-27 | 2015-08-19 | 中国昆仑工程公司 | Method for recycling acetic acid from blanking residues of PTA (purified terephthalic acid) film evaporator |
| CN116606204A (en) * | 2023-07-17 | 2023-08-18 | 成都普什医药塑料包装有限公司 | Recovered acetic acid for low-chroma acetic anhydride and cellulose acetate, and recovery method and application thereof |
-
2004
- 2004-09-04 CN CN 200410041884 patent/CN1743303A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102824880A (en) * | 2011-06-15 | 2012-12-19 | 逸盛大化石化有限公司 | Acetic acid spray improvement method |
| CN104844445A (en) * | 2015-03-27 | 2015-08-19 | 中国昆仑工程公司 | Method for recycling acetic acid from blanking residues of PTA (purified terephthalic acid) film evaporator |
| CN104844445B (en) * | 2015-03-27 | 2017-06-20 | 中国昆仑工程有限公司 | The method of recovery of acetic acid from PTA thin film evaporator blanking residues |
| CN116606204A (en) * | 2023-07-17 | 2023-08-18 | 成都普什医药塑料包装有限公司 | Recovered acetic acid for low-chroma acetic anhydride and cellulose acetate, and recovery method and application thereof |
| CN116606204B (en) * | 2023-07-17 | 2023-10-20 | 成都普什医药塑料包装有限公司 | Recovered acetic acid for low-chroma acetic anhydride and cellulose acetate, and recovery method and application thereof |
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