CN115124977A - Antifreezing solution prepared from products obtained after vacuum distillation of coal-to-ethylene glycol byproducts - Google Patents
Antifreezing solution prepared from products obtained after vacuum distillation of coal-to-ethylene glycol byproducts Download PDFInfo
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- CN115124977A CN115124977A CN202210166001.8A CN202210166001A CN115124977A CN 115124977 A CN115124977 A CN 115124977A CN 202210166001 A CN202210166001 A CN 202210166001A CN 115124977 A CN115124977 A CN 115124977A
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- C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
- C09K5/20—Antifreeze additives therefor, e.g. for radiator liquids
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Abstract
The invention relates to an antifreezing solution prepared from a product obtained by vacuum rectification of a coal-to-ethylene glycol byproduct. The antifreezing solution comprises the following components in percentage by mass: 38-60% of coal-made glycol by-product after vacuum rectification, triethanolamine, benzotriazole, sodium benzoate, sebacic acid, sodium phytate, phenol red and distilled water. The freezing point of the antifreeze reaches-56 ℃ at the lowest, and is 4 ℃ lower than that of glycol with the same alcohol content, wherein the freezing point of the antifreeze is-52 ℃. The boiling point reaches up to 115 ℃, which is far higher than the national standard requirement.
Description
Technical Field
The invention belongs to the field of antifreeze, and particularly relates to an antifreeze prepared by using dihydric alcohol extracted from a byproduct of coal-to-ethylene glycol.
Background
China has the resource characteristics of abundant coal resources and relatively lack of petroleum and natural gas, and the technology for preparing ethylene glycol from coal is widely popularized in China based on the development requirements of modern coal chemical industry. The device capable of producing 40 ten thousand tons of ethylene glycol per year can produce a byproduct mixture of ethylene glycol and 1, 2-butanediol with the content of 1, 2-butanediol of about 20 percent and the content of ethylene glycol of 60-70 percent. Currently, 30-40 million tons of such by-products will be produced each year, and are generally sold at low value or used as fuels.
The by-product mainly contains ethylene glycol, butanediol, a small amount of esters and other components, the physical properties of the by-product accord with the requirements of the antifreezing solution, the chemical properties of the by-product are stable, and the by-product has the advantage of being used as the antifreezing solution; because the freezing point of the contained 1, 2-butanediol is lower than that of the ethylene glycol, the separation of the ethylene glycol and the butanediol is not needed, the energy consumption can be saved, and the antifreeze solution can be converted into an antifreeze solution product with higher added value. Hou's Anxiang and the like (research on Hou's Anxiang and automobile antifreeze prepared from coal-to-ethylene-glycol process waste liquid [ D ] Beijing university of chemical industry, 2017.) have conducted researches on preparation of antifreeze from coal-to-ethylene-glycol waste liquid, but the material composition of the antifreeze has a large difference from the raw materials on the market, and firstly, the antifreeze contains a large amount of light components such as methanol, ethanol and water, secondly, the 1, 2-butanediol content is relatively low, and thirdly, the raw materials are treated by alkaline hydrolysis reaction, so that the pretreatment requirement on the raw materials is high.
Object of the Invention
The invention aims to provide a method for preparing an antifreezing solution by extracting dihydric alcohol from a coal-to-ethylene glycol byproduct, aiming at the defects in the prior art. The by-products of the coal-made glycol mainly contain glycol, butanediol, propanediol, esters and the like, firstly, the glycol raw material is obtained by removing methyl glycolate and the like through vacuum rectification, and the main components are glycol, butanediol and propanediol, then a certain amount of corrosion resistant agent is added, and additives with high toxicity such as phosphate and nitrate are not added, so that the engine antifreeze fluid which is safe and economical and has a lower freezing point is prepared.
In order to achieve the above purpose, the invention is realized by the following technical scheme:
an antifreeze fluid prepared from products of coal-to-ethylene glycol by-products after vacuum distillation comprises the following components in percentage by mass:
the components and the mass percentages of the products after the coal-to-ethylene glycol byproduct is subjected to vacuum rectification comprise: 65-75% of ethylene glycol, 16-28% of butanediol (1, 2-butanediol, 3-5% of 2, 3-butanediol) and 2-4% of 1, 2-propanediol, 0.1-0.4% of esters (gamma-butyrolactone, ethylene carbonate and the like), less than 0.1% of methyl glycolate and the balance of water;
the preparation method of the anti-freezing solution comprises the following steps:
according to the proportion, related components and distilled water are added into the vacuum rectification product solution and stirred for 10-20min at 40-60 ℃ to obtain the prepared antifreeze solution.
The vacuum rectification pretreatment process comprises the following steps: rectifying under reduced pressure at 15-30KPa (A) to remove methyl glycolate light component, and controlling methyl glycolate in the extract to be less than 0.1%.
The invention has the substantive characteristics that:
compared with the antifreezing solution which takes ethylene glycol or propylene glycol as a main component in the traditional antifreezing solution, the antifreezing solution is obtained by adding a small amount of anti-corrosion additive and part of distilled water, wherein the main components of the antifreezing solution are ethylene glycol, butanediol and propylene glycol. The phosphate and the nitrate are only corrosion inhibitors and do not influence the antifreezing performance of the antifreezing solution. The antifreezing property is mainly that substances with lower freezing point, such as glycol, and water are mixed in different proportions, so that the freezing point of water is lowered to different degrees to achieve the antifreezing property and the aim.
The invention selects organic and organic acid additives such as triethanolamine, sebacic acid, sodium phytate and other corrosion inhibitors. The sodium phytate is a pure natural green additive, has strong chelation with metal ions and strong oxidation resistance, is used as an anti-corrosion additive, and has strong safety performance. Phenol red is a dye, and a small amount of the phenol red is added to change the color of the antifreeze solution, so that the antifreeze solution has more obvious color and is convenient to distinguish from other solutions.
The beneficial effects of the invention are as follows:
according to the invention, the by-product of the coal-to-ethylene glycol is used for extracting the series of anti-freezing solutions prepared from the dihydric alcohol, and the by-product of the coal-to-ethylene glycol is pretreated to remove ester light components in the by-product of the coal-to-ethylene glycol, so that the anti-freezing solution mainly comprises ethylene glycol, butanediol and propylene glycol, and is not pure ethylene glycol in the traditional anti-freezing solution. And then the pretreated product, a small amount of additive and distilled water are simply heated and stirred to prepare the high-efficiency safe novel antifreezing solution. Meanwhile, through tests, the lowest freezing point of the antifreezing solution prepared by the formula reaches-56 ℃, and is 4 ℃ lower than the freezing point of-52 ℃ compared with that of glycol with the same alcohol content. The boiling point reaches up to 115 ℃, which is far higher than the national standard requirement. At present, most of the commercially available antifreeze solutions do not add inorganic salt corrosion inhibitors any more, but favor organic additives with higher safety, and organic acid corrosion inhibitors also become the development trend of future antifreeze solution additives due to the green and safe characteristics of the additives. The invention also selects a plurality of organic corrosion inhibitors and organic acid corrosion inhibitors, does not add additives with higher toxicity such as phosphate, nitrate and the like, and adds natural green additives such as sodium phytate and the like, thereby having stronger safety performance and lower freezing point.
The invention uses the byproduct of the coal-made glycol with the selling price of 3000-.
Detailed Description
The prior rectification process for preparing ethylene glycol from coal is generally divided into two types, one type is that crude ethylene glycol sequentially passes through a methanol removal tower, a deesterification tower, a light component removal tower (removing butanediol) and a product tower to obtain an ethylene glycol product, and the other type is that the crude ethylene glycol sequentially passes through the methanol removal tower, the dehydration tower/the light component removal tower (removing butanediol, methyl glycolate and dimethyl oxalate) and the product tower to obtain the ethylene glycol product.
The invention adopts the coal-to-ethylene glycol byproduct obtained by the second process (the components and the mass percentage of the byproduct are 60 to 70 percent of ethylene glycol, 15 to 20 percent of 1, 2-butanediol, 2 to 4 percent of 2, 3-butanediol, 1.5 to 3.5 percent of esters (methyl glycolate, ethylene carbonate, gamma-butyrolactone and the like), 1 to 3 percent of 1, 2-propylene glycol, 0.2 to 0.5 percent of water and other components)
Because the by-product of the coal-based glycol contains more lipid substances (methyl glycolate, ethylene carbonate, gamma-butyrolactone and the like) 1.5-3.5%, the ester substances can be hydrolyzed to generate substances such as oxalic acid, glycolic acid and the like, and have certain corrosivity, and meanwhile, the low-boiling-point alcohol substances generated by ester hydrolysis and the low-boiling-point substances contained in the raw materials can reduce the boiling point of the product, so that the boiling point does not reach the standard and the performance of the antifreeze liquid product is influenced, the invention carries out reduced-pressure rectification pretreatment on the by-product of the coal-based glycol to remove the ester substances influencing the performance of the product.
Performing pretreatment, namely performing reduced pressure rectification to remove methyl glycolate light components under 15-30KPa (A), and controlling the content of methyl glycolate in the extract to be less than 0.1%, removing light component ester impurities to obtain a main antifreezing solution raw material, wherein the main components of the antifreezing solution raw material are 65% of ethylene glycol, 28% of butanediol (1, 2-butanediol, 3.5% of 2, 3-butanediol) and 3% of 1, 2-propanediol, 0.4% of esters (gamma-butyrolactone, ethylene carbonate and the like), and the content of methyl glycolate is less than 0.1%.
The properties of the present invention are further illustrated below with reference to specific examples:
example 1
Carrying out reduced pressure rectification under 15-30KPa (A) to remove the light components of methyl glycolate to obtain mixed dihydric alcohol as a preparation raw material, adding the mixed dihydric alcohol into a beaker, adding triethanolamine, benzotriazole, sodium benzoate, sebacic acid, sodium phytate, phenol red and distilled water into the beaker, and stirring for 15min at 55 ℃ to obtain the novel efficient and safe antifreezing solution.
A novel efficient and safe antifreezing solution comprises the following components in percentage by mass: 60% of vacuum rectification product, 0.4% of triethanolamine, 0.2% of benzotriazole, 0.1% of sebacic acid, 0.2% of sodium phytate, 0.5% of sodium benzoate, 0.01% of phenol red and 38.59% of distilled water.
Performance testing
Ice boiling point test:
referring to the national petrochemical industry standard SH/T0090 engine coolant freezing point determination method, the test method comprises the following steps: measuring 075-100mL of antifreeze solution, adding the antifreeze solution into a cooling pipe of a stirring device with up-and-down motion, cooling the sample by adopting a refrigerant or other methods, wherein the cooling speed is within 1 ℃/min, and the stirring speed is adjusted to be 60-80 times per minute. Carefully observing, recording the temperature of the sample per minute, drawing a temperature curve graph, drawing the intersection point of a crystallization curve and a cooling curve of the reagent, wherein the ordinate of the intersection point is the freezing point of the sample. When the supercooling phenomenon occurs in the test, the highest temperature to which the reagent is raised after supercooling is the freezing point.
Referring to the national petrochemical industry standard SH/T0089 engine coolant boiling point determination method, the test method comprises the following steps: a60 mL sample was weighed into a 100mL flask, a few grains of zeolite were added, a calibrated thermometer was placed in the side port of the flask to a depth of 6.5nm from the center of the bottom of the beaker, and the side port of the beaker and the thermometer were sealed with an appropriate material to prevent gas leakage. Clean, dry condenser tubes were inserted vertically into the flask and placed on an electric heating mantle. The upper part of the condensation pipe is fixed on the iron bracket by a clamp. When the preparation is completed, heating is started. The heating speed of the electric heating sleeve is adjusted to ensure that the sample to be tested reaches boiling within 10 min. After boiling, the knob is slowly adjusted to reduce the heating intensity, so that the reflux speed of the kettle reaches 1-2 drops per second within 10 min. Carefully observe the reflux rate, and read the temperature 2min after reaching the specified reflux rate. The observed temperature and the atmospheric pressure at the time of the test were recorded, and correction of the temperature was performed.
Test samples: example 1, control 1
Control 1 is the current basic glycol-type antifreeze: contains 60% of glycol, 0.4% of corrosion inhibitor triethanolamine, 0.25% of sodium benzoate, 0.15% of sodium metasilicate and the balance of distilled water.
The freezing points of example 1 were-56 deg.C and control 1 was-52 deg.C as a result of the test. Therefore, compared with pure glycol type antifreeze, when the alcohol content is the same, the antifreeze prepared by the formula has a lower freezing point which reaches-56 ℃ and a boiling point which also reaches 115 ℃.
The corrosion resistance of the organic corrosion inhibitor mainly added in the invention meets the national standard requirement.
Example 2
A novel efficient and safe antifreezing solution comprises the following components in percentage by mass: 40% of vacuum distillation product, 0.4% of triethanolamine, 0.2% of benzotriazole, 0.1% of sebacic acid, 0.2% of sodium phytate, 0.5% of sodium benzoate, 0.01% of phenol red and 58.59% of distilled water. The freezing point is-24.6 ℃, and is 0.6 ℃ lower than that of the pure glycol type antifreeze solution with the glycol content of 40 percent at-24 ℃.
Example 3
A novel efficient and safe antifreezing solution comprises the following components in percentage by mass: 44% of vacuum rectification product, 0.4% of triethanolamine, 0.2% of benzotriazole, 0.1% of sebacic acid, 0.2% of sodium phytate, 0.5% of sodium benzoate, 0.01% of phenol red and 54.59% of distilled water. The freezing point is-28.7 ℃, which is 0.7 ℃ lower than that of the pure glycol type antifreeze solution with the content of 44 percent of glycol at-28 ℃.
Example 4
A novel efficient and safe antifreezing solution comprises the following components in parts by mass: 48% of vacuum rectification product, 0.4% of triethanolamine, 0.2% of benzotriazole, 0.1% of sebacic acid, 0.2% of sodium phytate, 0.5% of sodium benzoate, 0.01% of phenol red and 50.59% of distilled water. The freezing point is-35.6 ℃, and is 2.6 ℃ lower than that of pure glycol type antifreeze with 48 percent of glycol at-33 ℃.
Example 5
A novel efficient and safe antifreezing solution comprises the following components in percentage by mass: 52% of vacuum rectification product, 0.4% of triethanolamine, 0.2% of benzotriazole, 0.1% of sebacic acid, 0.2% of sodium phytate, 0.5% of sodium benzoate, 0.01% of phenol red and 46.59% of distilled water. The freezing point is-40.7 ℃, and is 2.7 ℃ lower than that of pure glycol antifreeze with the content of glycol of 52 percent at-38 ℃.
As can be seen from the above examples, the starting material of the present invention contains a certain amount of propylene glycol in addition to a large amount of 1, 2-butanediol. The raw materials are decompressed and rectified to remove light components such as methyl glycolate and the like, so that a purer raw material of dihydric alcohol is obtained, and a series of antifreeze with freezing point is prepared. The raw materials do not contain light components such as methanol, ethanol and the like, and simultaneously, a large amount of organic salts generated by alkaline hydrolysis are avoided, so that the energy consumption for processing the raw materials can be greatly reduced, and the dihydric alcohol with higher purity can be obtained. Therefore, the antifreeze with excellent freezing point performance and low production energy consumption can be obtained, and a foundation is laid for efficient resource utilization of the coal-to-ethylene glycol byproduct.
The above description is only for the specific embodiments of the present invention, and the present invention is not limited to the above examples, and any modification, replacement, improvement, etc. made by those skilled in the art without departing from the scope of the present invention shall be within the protection scope of the present invention.
The invention is not the best known technology.
Claims (4)
1. An antifreeze fluid prepared from products obtained by vacuum distillation of coal-to-ethylene glycol byproducts is characterized by comprising the following components in percentage by mass:
2. the antifreeze fluid prepared from products of vacuum distillation of ethylene glycol byproduct prepared from coal as claimed in claim 1, wherein the antifreeze fluid comprises
The product obtained by vacuum distillation of the coal-to-ethylene glycol byproduct comprises the following components in percentage by mass: 65-75% of ethylene glycol, 16-28% of butanediol (1, 2-butanediol, 3-5% of 2, 3-butanediol) and 2-4% of 1, 2-propanediol, 0.1-0.4% of esters (gamma-butyrolactone and ethylene carbonate), less than 0.1% of methyl glycolate and the balance of water.
3. The method for preparing the antifreeze solution prepared from the products of the vacuum rectification of the byproducts of the ethylene glycol prepared from coal as claimed in claim 1, which comprises the following steps:
according to the proportion, related components and distilled water are added into the vacuum rectification product solution and stirred for 10-20min at 40-60 ℃ to obtain the prepared antifreeze solution.
4. The method according to claim 3, wherein the vacuum distillation process comprises: rectifying under reduced pressure at 15-30KPa (A) to remove methyl glycolate light component, and controlling methyl glycolate in the extract to be less than 0.1%.
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2022
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| CN110699047A (en) * | 2018-07-09 | 2020-01-17 | 中国石油化工股份有限公司 | Propylene glycol type cold carrier liquid |
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