JPS644814B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a surfactant. More specifically, coal is heated to high temperature and
A method for producing a surfactant that is particularly effective as a dispersant and a cement admixture, characterized in that the extract obtained by extraction under a pressure higher than the critical pressure of the solvent is converted into a sulfonate. It is.

Several techniques are already known for producing surfactants, such as cement admixtures, using coal as a raw material. For example,
Publication No. 4080 discloses an invention for producing a cement water reducing agent from humic-like substances contained in low-rank coal. Further, Japanese Patent Publication No. 47-39208 discloses an invention in which a cement water reducing agent is obtained by treating coal tar at a high temperature of 700-2000°C and then sulfonating it. However, when producing surfactants using these inventions, there are restrictions on the type of coal, or coal tar, which is a carbonized product of coal, must be treated at a high temperature of 700°C or higher. Surfactants obtained from such high-temperature treated coal tar do not necessarily exhibit sufficient surfactant action when used as a dispersant for cement or as a dispersant for slurry of coal and water. There are problems such as.

The present invention provides a method for efficiently producing a surfactant using coal as a raw material, but using a method completely different from the known methods for producing surfactants as described above.

In the present invention, coal is heated at a temperature of 200 to 500°C (preferably,
The coal extract obtained by extraction is carried out at an extraction temperature of 300 to 450 ° C., using an extraction solvent having a critical temperature lower than the extraction temperature, and under a pressure higher than the critical pressure of the extraction solvent. , a method for producing a surfactant characterized by sulfonation and then neutralization using an alkalizing agent.

Therefore, the present invention uses coal of any type as a raw material, utilizes a coal extract that can be obtained in good yield under relatively low temperature conditions, and converts the coal extract into a sulfonate. Since it is easy to obtain a surfactant with excellent performance, it is very advantageous in practical terms.

Next, the present invention will be explained in detail.

The coal extract used as the raw material for sulfonation of the present invention is obtained by extracting coal of any coal type at a temperature of 200 to 500°C using a solvent having a critical temperature lower than the extraction temperature.
Moreover, it is a coal extract obtained by extraction under a pressure higher than the critical pressure. There is already a technology to obtain a coal extract by extracting coal with aromatic hydrocarbons at a temperature higher than the critical temperature of the aromatic hydrocarbons and under a pressure higher than the critical pressure, that is, in a supercritical state. , for example, U.S. Patent No.
It is disclosed in No. 3558468 and is publicly known.

The coal extract used in the present invention is also obtained by the extraction method described above. The extraction solvent does not necessarily need to be limited to aromatic hydrocarbons; it must be a solvent that has a critical temperature lower than the temperature used for solvent extraction, is relatively stable at the extraction temperature, and does not have high reactivity. Any solvent can be used as long as it is suitable. However, if a solvent whose critical temperature is extremely low compared to the extraction temperature is used, the solvent's dissolving power will be small, making it disadvantageous for industrial extraction operations, so the critical temperature must be slightly lower than the extraction temperature. It is desirable to select a solvent such that the difference between the extraction temperature and the critical temperature is generally within 150°C. Examples of such solvents include benzene, toluene, o-xylene, m-xylene, p-xylene, xylene mixtures, aromatic hydrocarbons such as ethylbenzene and propylbenzene, and those having 5 or more carbon atoms such as cyclopentane and cyclohexane. Hydrocarbons such as alicyclic hydrocarbons, aliphatic hydrocarbons with 6 or more carbon atoms such as hexane, heptane, and nonane, aliphatic alkylamines such as methylamine, ethylamine, and dimethylamine, and heterocyclic compounds such as pyridine. can be mentioned. Particularly preferred solvents are aromatic hydrocarbons. Further, these solvents may be used alone or in combination of two or more.

There is no particular restriction on the type of coal to be subjected to solvent extraction, and any type of coal can be targeted.

The solvent extraction operation is carried out at a temperature of 200 to 500°C (preferably 300 to 450°C) as described above. However, the solvent extraction temperature is selected to be within the above range and above the critical temperature of the extraction solvent used. When the extraction temperature exceeds 500°C, thermal decomposition of the coal becomes more intense, resulting in the production of a large amount of low boiling point fractions, which are contained in large amounts in the solvent extract. The extract containing a large amount of such a low boiling point fraction is sulfonated by the method described below,
Even when neutralized as a sulfonate, it does not show any effective action as a surfactant, for example, as an admixture for cement or a dispersant for slurry of coal and water. On the other hand, when the extraction operation is performed at a temperature lower than 200°C, the extraction efficiency is poor and it is not possible to obtain an extract with an industrially effective yield.

Note that the extraction operation needs to be performed under a pressure higher than the critical pressure of the solvent used for extraction. The solvency power of a solvent is very low below the critical pressure, but increases sharply when the critical pressure is exceeded. Therefore, when the extraction operation is performed below the critical pressure, the yield of the extract is
This becomes extremely low, which is extremely disadvantageous for industrial extraction operations.

In addition, by performing the extraction operation to obtain the coal extract, which is the raw material for the surfactant of the present invention, in a supercritical state using a solvent with a critical temperature lower than the extraction temperature, it is possible to later convert it into a surfactant. This has the advantage that a large amount of coal components exhibiting excellent surfactant action can be easily extracted. Furthermore, the use of such an extraction solvent has advantages such as ease of separation of the coal extract and the solvent after the extraction operation. Therefore, in order to carry out the invention it is necessary to use a coal extract extracted under such conditions.

After going through the solvent extraction operation as described above,
The coal extract obtained by removing the solvent is solid at room temperature. This solid coal extract is composed of many components with complex chemical structures, and the details of each component are not clear.
This point is symmetrical to coal tar whose main component is a component with a relatively small number of condensed rings.

In other words, coal tar, which is a carbonized product of coal, is obtained by carbonizing coal at a high temperature of around 1000℃, and due to such high temperature treatment, the complex chemical structure that coal originally has is destroyed. Destroyed naphthalene, methylnaphthalene, anthorcene,
A large amount of low boiling point aromatic compounds such as benzpyrene are produced, resulting in large amounts of them being contained in coal tar. Coal tar is mainly composed of components with a relatively small number of these fused rings, so even if it is sulfonated, neutralized, and converted into a surfactant, it cannot be used as a cement water reducer, for example. It is thought that it does not exhibit satisfactory effects as a surfactant for uses such as cement admixtures or dispersants for dispersing fine coal powder in water.

However, the coal extract used in the production of the surfactant of the present invention mostly contains components with a relatively small number of fused rings of low boiling point, such as naphthalene and anthracene, which are the main components of coal tar as described above. Not yet. This is because the coal extract used in the present invention is obtained through an extraction operation at a relatively low temperature, so the decomposition of the complex chemical structure of coal does not progress very much, and therefore it is difficult to convert it into a surfactant later. very effective as a surfactant when derivatized, and especially as a surfactant for applications such as cement admixtures, such as cement water reducers, or dispersing agents for dispersing coal powder in water, etc. This is considered to indicate that

Next, the sulfonation method and the neutralization method using an alkalizing agent of the present invention will be described.

Sulfonation methods for aromatic compounds and condensed ring compounds are generally known, and the sulfonation of the coal extract of the present invention can also be carried out by a method similar to those known sulfonation methods.

As the sulfonating agent used for sulfonation, for example, sulfonating agents such as sulfuric acid, oleum, chlorosulfonic acid, or sulfuric anhydride are generally used, and these sulfonating agents are also used in the present invention. It is desirable to use Among these sulfonating agents, sulfuric anhydride is particularly preferred from the viewpoint of improving the workability of the sulfonation reaction, improving the yield of the sulfonation reaction, and reducing the amount of by-product inorganic substances produced.

The amount of the sulfonating agent used is preferably 0.1 to 5.0 times the weight of the coal extract. If the amount used is less than 0.1 times the amount, the amount of sulfonic acid groups added to the coal extract will be small, which will not only make it difficult for the obtained surfactant to have sufficient performance, but also reduce the amount of sulfonated products from the coal extract. There is a problem when the amount of produced decreases. On the other hand, even if the amount used exceeds 5.0 times the amount used, no increase in the amount of sulfonic acid groups added to the coal extract can be expected, and not only will the sulfonation yield not improve, but the unreacted sulfonated product will be converted into a reaction product. This cannot be said to be advantageous because of the economic disadvantage of leaving the unreacted sulfonating agent in the reaction product, ie, the need for a neutralizing agent and energy separately to remove the unreacted sulfonating agent from the reaction product.

There is no particular restriction on the reaction temperature for sulfonation, but
Generally, it is preferable to select from the range of 0-200°C. When the reaction temperature is lower than 0°C,
There are disadvantages such as the reaction rate of sulfonation is reduced and the sulfonating agent is solidified, making reaction operation difficult. On the other hand, if the reaction temperature is higher than 200°C, problems arise such as significant heat generation due to the sulfonation reaction, making it difficult to control the reaction temperature.

In addition, since the coal extract of the present invention is obtained in a solid state at room temperature as described above, the sulfonation reaction is preferably carried out as a solution by dissolving the coal extract in an appropriate solvent. The solvent for dissolving the coal extract of the present invention is not particularly limited as long as it dissolves the extract and does not react with the sulfonating agent, but for practical purposes, methylene chloride, chloroform, carbon tetrachloride, etc. It is preferable to use chlorinated hydrocarbons such as. These chlorinated hydrocarbon solvents not only dissolve the coal extract of the present invention well, but also have no reactivity with sulfonating agents such as sulfuric acid, oleum, chlorosulfonic acid, or sulfuric anhydride. Therefore, it is particularly preferable as a reaction solvent for the sulfonation reaction in the present invention.

The sulfonated coal extract by the method described above is then converted into a product useful as a surfactant by neutralization with an alkalizing agent.

In the production of surfactants, the technique of neutralizing a sulfonated substance with an alkalizing agent to form a sulfonate is already known, and neutralization methods using various alkalizing agents are known. Also in the present invention, it is preferable to use these neutralization methods. Therefore, the alkalizing agent and reaction conditions used in the neutralization reaction of the present invention may be selected according to known alkalizing agents and reaction conditions.

The surfactant obtained according to the present invention is a sulfonate (-SO ₃ M, where M is Na,
Alkali metals such as K, alkaline earth metals such as Mg, Ca, Ba, or -NH ₄ , -
_NH2CH2CH2OH , _{-NH ( CH2CH2OH} ) _{2 ,} -N
The main component is organic amines such as (C ₂ H ₅ OH) ₃ ). The surfactant obtained according to the present invention can be used as a dispersant for making an aqueous slurry from pulverized coal or other water-insoluble fine powder, or as an admixture for cement such as a water reducing agent. Useful.

Next, Examples and Comparative Examples of the present invention will be shown.

Example 1 Production of coal extract Domestic A coal (moisture 1.3%, ash content 20.4%, volatile content 37.7%,
Fixed carbon 39.0%) 30g and toluene (critical temperature:
(320°C) and 300 g of the autoclave were placed in an autoclave with an internal volume of 0.5 and equipped with a stirrer, the inside of the autoclave was purged with nitrogen gas, the air inside was sufficiently removed, and the autoclave was sealed. While stirring the contents, the autoclave was heated in an electric furnace, and the autoclave temperature was raised to 400°C over 1 hour. At this time, the pressure inside the autoclave was 220 Kg/cm ² . This temperature was further maintained for 1 hour while stirring was continued to extract coal.

Next, after cooling the autoclave to room temperature, the contents are taken out and filtered to extract the solid extraction residue and the extract (filtrate) in the form of a toluene solution.
It was separated into two parts. Next, toluene was evaporated from the filtrate under normal pressure using an evaporator, and then toluene was sufficiently evaporated and removed under reduced pressure to obtain a coal extract.

The extraction yield (=weight of extract (g)/weight of charged coal (g, converted to dry coal weight)) was 30% by weight. The obtained coal extract contained almost no low-boiling point aromatic hydrocarbons such as naphthalene, methylnaphthalene, anthracene, and benzpyrene.

Sulfonation and Neutralization 7.0 g of the coal extract obtained as described above was
It was dissolved in 50 g of carbon tetrachloride and placed in a 100 ml three-necked flask (equipped with a stirring device, a device for cooling evaporated matter, and a dropping funnel). While stirring the contents of the flask, sulfuric anhydride was slowly added dropwise from the dropping funnel. At this point, a total of 5.1 g of sulfuric anhydride was added dropwise over 30 minutes while maintaining the reaction temperature at 20°C. After the dropwise addition was completed, the temperature of the flask was raised and the reaction was carried out for 1 hour at a temperature at which carbon tetrachloride refluxed to effect sulfonation.

After the reflux was completed, a vacuum distillation device was attached to the flask, and carbon tetrachloride was distilled off. Water was added to the coal extract sulfonation reaction product remaining as a residue in the flask to make a homogeneous aqueous solution, which was then taken out from the flask.

The obtained sulfonation reaction product was dissolved in 200 g of water, and the aqueous solution was placed in a beaker with a capacity of 500 ml, and an aqueous solution of calcium hydroxide was added while stirring to neutralize the pH to 7.0. This neutralized solution was applied to a centrifuge and centrifuged at 2000 rpm for 10 minutes. The supernatant liquid of the centrifuged neutralized liquid was taken out, and water was removed by evaporation using a conventional method to obtain 3.1 g of calcium sulfonate as a coal extract.

Performance evaluation 80 g of the aqueous solution containing 1.0 g of calcium sulfonate of the coal extract obtained as described above was placed in the container of a high-speed homogenizer (manufactured by Tokushu Kakoki Co., Ltd.).
Add 100g of portland cement to this and make approx.
Kneaded for 10 seconds. Thereafter, the cement slurry adhering to the wall of the homogenizer container was scraped off, and the mixture was kneaded again for 1 minute and 30 seconds to prepare a cement slurry.

Separately, prepare a flow value measuring device in which a flow cone (inner volume 86 ml, upper end diameter 25 mm x lower end diameter 50 mm x height 75 mm) is placed on a flat glass plate, and the cement slurry after mixing is placed in this flow cone. I put it in immediately. Then, the flow cone was gently lifted and the spread diameter of the cement/water slurry spread on the glass plate was measured at two locations, and the average value of the diameters was taken as the flow value. Note that these kneading operations and flow value measurement operations were performed at room temperature of 25°C.

The flow value thus obtained was 199 mm.

Example 2 Production of coal extract In Example 1, the extraction temperature was changed to 350°C, and the amounts of domestic A charcoal and toluene charged into the autoclave were each increased by 10% (i.e., the amounts of domestic A charcoal and toluene charged were increased by 10%). A coal extract was obtained by performing the same operation except that the amounts were changed to 33 g and 330 g, respectively. Please note that the temperature of the autoclave is 350℃.
The pressure inside the autoclave when the temperature was raised to 220 Kg/cm ² was the same as in Example 1.

The extraction yield was 20% by weight. Similar to the coal extract obtained in Example 1, the obtained coal extract contained almost no low-boiling point aromatic hydrocarbons.

Sulfonation and Neutralization 6.0 g of the coal extract obtained as described above was
Coal extraction was performed in the same manner as in Example 1, except that a solution dissolved in 50 g of methylene chloride was used, the amount of sulfuric anhydride used for sulfonation was changed to 11.6 g, and reflux was performed under the reflux conditions of methylene chloride. 4.8 g of calcium sulfonate was obtained.

Performance Evaluation A cement flow test was conducted under the same conditions as in Example 1 using 1.0 g of calcium sulfonate from the coal extract obtained as described above.
The flow value obtained was 210 mm.

Comparative Example 1 A cement flow test was conducted under the same conditions as in Example 1 using a commercially available lignin sulfonate water reducing agent in place of the calcium sulfonate in the coal extract, and the flow value obtained was 133 mm. It was hot.

Example 3 Production of coal extract In Example 1, coal was changed from domestic coal A to Australian coal B.
The same procedure was used except that charcoal (moisture 3.1%, ash 14.4%, volatile content 31.8%, fixed carbon 50.8%) was used.
An extraction operation was performed at 400°C to obtain a coal extract.
Note that when the temperature of the autoclave was raised to 400° C., the pressure inside the autoclave was 220 Kg/cm ² as in Example 1.

The extraction yield was 20% by weight. Similar to the coal extract obtained in Example 1, the obtained coal extract contained almost no low-boiling point aromatic hydrocarbons.

Sulfonation and Neutralization 13.2 g of the coal extract obtained as described above was
Lime extraction was performed in the same manner as in Example 1, except that a solution dissolved in 50 g of methylene chloride was used, the amount of sulfuric anhydride used for sulfonation was changed to 9.6 g, and reflux was performed under the reflux conditions of methylene chloride. A sulfonated product of the product was obtained.

The obtained sulfonation reaction product was dissolved in 200 g of water, and the aqueous solution was placed in a beaker with a capacity of 500 ml, and an aqueous solution of calcium hydroxide was added while stirring to neutralize the pH to 7.0. This neutralized solution was filtered to remove insoluble inorganic substances. Furthermore, the filtrate was subjected to vacuum distillation to remove water, thereby obtaining 13.4 g of calcium sulfonate as a coal extract.

Next, the calcium sulfonate of the above coal extract was dissolved in water and sodated with sodium carbonate, and then water-insoluble inorganic substances and water were removed to obtain the sodium sulfonate of the coal extract. Ta.

Performance evaluation Australian C coal (moisture 3.5%, ash 10.5%, volatile content 33.7
%, fixed carbon 52.3%) to a specific gravity liquid (specific gravity
1.35), and the floating coal was pulverized in a ball mill to prepare pulverized coal of 200 mesh pass 80%.

Water was added to the above pulverized coal having a dry weight of 66.8 g to give a total weight of 100 g. To this was added 0.5 g of the above-mentioned sodium sulfonate of coal extract and mixed for 5 minutes using a high-speed homogenizer (manufactured by Tokushu Kakoki Co., Ltd.) to prepare a pulverized coal/water slurry. Immediately after mixing, the mixture was transferred to a container for viscosity measurement, and the viscosity was measured using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) at 27°C.
It was 1900 cp.

Comparative Example 2 A commercially available polycarboxylic acid type anionic surfactant was used instead of sodium sulfonate in the coal extract, and added to the pulverized coal/water slurry under the same conditions as in Example 3, and the viscosity of the mixture was measured. After aging, the viscosity was over 10,000 cp and there was no fluidity.

Comparative Example 3 Using a commercially available lignin sulfonate type surfactant instead of sodium sulfonate in the coal extract, it was added to the pulverized coal/water slurry under the same conditions as in Example 3, and the viscosity of the mixture was measured. After aging, the viscosity was over 10,000 cp and there was no fluidity.

Example 4 Production of coal extract Same as Example except that 250 g of cyclopentane (critical temperature: 239°C) was used instead of toluene, the extraction temperature was changed to 250°C, and the extraction pressure was changed to 210 Kg/cm ² 1.8 g of coal extract (extraction yield: 6% by weight) was obtained in the same manner as in 1.

Sulfonation and neutralization 3.0 g of coal extract obtained by performing the above extraction twice,
1.2 g of calcium sulfonate of coal extract was obtained in the same manner as in Example 1 except that 21.5 g of carbon tetrachloride and 2.2 g of anhydrous sulfuric acid were used.

Performance Evaluation Using the calcium sulfonate of the coal extract obtained above, a cement flow test was conducted under the same conditions as in Example 1. The flow value obtained was 192 mm.

Example 5 Production of coal extract The amount of domestic A coal was changed to 25g, and the amount of toluene was changed to 25g.
250g, the extraction temperature was changed to 450°C, and the extraction pressure was changed to 245Kg/cm ² , but the same procedure as in Example 1 was performed to obtain 6.4g of coal extract (extraction yield: 26% by weight). .

Sulfonation and Neutralization Calcium sulfonate of coal extract was prepared in the same manner as in Example 1 except that 6.0 g of the coal extract obtained by the above extraction, 43 g of carbon tetrachloride, and 4.5 g of sulfuric anhydride were used. 2.4g was obtained.

Performance Evaluation Using the calcium sulfonate of the coal extract obtained above, a cement flow test was conducted under the same conditions as in Example 1. The flow value obtained was 195 mm.

Example 6 Production of petroleum extract Coal extraction was carried out in the same manner as in Example 1 (extraction pressure 210 Kg/cm ² ) except that m-xylene (critical temperature: 346°C) was used instead of toluene. 8.3 g (extraction yield: 28% by weight) of the product was obtained.

Sulfonation and Neutralization 3.0 g of calcium sulfonate from a coal extract was obtained in the same manner as in Example 1, except that the coal extract obtained by the above extraction was used.

Performance Evaluation Using the calcium sulfonate of the coal extract obtained above, a cement flow test was conducted under the same conditions as in Example 1. The flow value obtained was 201 mm.

Comparative Example 4 Tar obtained by dry distilling coal at high temperature was distilled under reduced pressure to obtain a fraction with a temperature of 250° C. or higher in terms of normal pressure. 7.0 g of the obtained fraction was sulfonated in the same manner as in Example 1, neutralized with an aqueous calcium hydroxide solution,
Water was removed by evaporation to obtain 2.8 g of calcium sulfonate from the above fraction.

Example 1 Using this calcium sulfonate
Cement flow tests were conducted under the same conditions as in . The flow value obtained was 141 mm.

Comparative example 5 The extraction temperature was changed to 250℃ and the extraction pressure was 18Kg/cm ²
Coal was extracted in the same manner as in Example 1, except that . The extract of the toluene solution was evaporated using an evaporator to obtain a coal extract.

The extraction yield of the coal extract is less than 2% by weight,
It was very low and impractical.

Claims (1)

[Claims] 1 Coal is extracted at an extraction temperature of 200 to 500°C using an extraction solvent having a critical temperature lower than the extraction temperature and under a pressure higher than the critical pressure of the extraction solvent,
The coal extract obtained by extraction is sulfonated,
A method for producing a surfactant, which is then neutralized using an alkalizing agent.