JP2006327987A - Method for re-converting waste containing organochlorine compound into resource - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method with which nearly all of wastes containing organochlorine compounds can be re-converted into resources and utilized without carrying out an incineration treatment of the wastes containing the organochlorine compounds. <P>SOLUTION: The problems can be solved by the method for re-converting the wastes containing the organochlorine compounds into the resources comprising carrying out dechlorination of the wastes containing the organochlorine compounds by a hot water treatment, recovering the organochlorine compounds as an alcohol and/or organic acids and an inorganic salt for utilization and recovering the residual wastes in which the organochlorine compounds are removed as a fuel for utilization. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for recycling waste containing an organic chlorine compound. More specifically, the present invention includes an organic chlorine compound without incinerating waste containing an organic chlorine compound that has been conventionally incinerated. It relates to a method for recycling and using almost all waste.

Conventionally, chlorinated organic compounds are harmful to living organisms, but due to their properties of dissolving organic compounds well, they have been used in large amounts in degreasing cleaning of machinery and electronic parts, dry cleaning of clothing, and solvents in the chemical industry. Yes.
Waste containing organic chlorine compounds discharged from processes such as degreasing, chemical reaction and extraction is not only organic chlorine compounds, but also organic substances such as water, lubricating oil, rust preventive oil, oil and fat, and resin. It contains one or more components of inorganic substances such as mud and sand.
At present, waste containing organic chlorine compounds is incinerated as industrial waste.

  However, when incinerated, the generated hydrochloric acid corrodes the equipment and is severely worn, and dioxins are generated by the chlorine contained in the organic chlorine compounds, so removal measures must be taken, resulting in a very high processing cost. ing. For this reason, there is a demand for the development of treatment technology and recycling technology other than incineration of waste containing organic chlorine compounds.

In order to meet this demand, many technologies as shown in the following (1) to (9) have been proposed as treatment or resource recycling technologies for waste containing an organic chlorine compound.
(1) A method of decomposing an organic chlorine compound into carbon dioxide, water, etc. by hydrothermal reaction in the presence of sodium carbonate (see Patent Document 1).
(2) A reactor for oxidatively decomposing organochlorine compounds such as PCB using supercritical water (see Patent Document 2).
(3) An organochlorine compound such as PCB is decomposed by a hydrothermal reaction using sodium ethoxide as a catalyst (see Patent Document 3).
(4) An organic chlorine compound such as PCB or agricultural chemical is decomposed by a subcritical water reaction using acetic acid, zinc, platinum or the like as a catalyst (see Patent Document 4).
(5) Thermal plasma is generated by microwaves to decompose the organic chlorine compound (see Patent Document 5).
(6) The organic chlorine compound is decomposed by ultraviolet rays (see Patent Document 6).
(7) It relates to a method and an apparatus for performing a desalting reaction by heating and pressurizing using an alkaline methanol solution. The organic chlorine compound is decomposed into carbon monoxide and hydrogen gas, and the produced sodium formate and sodium carbonate are used as an alkaline agent. It utilizes for dechlorination reaction (refer patent document 7).
(8) The organic solvent mixed with the organic chlorine compound is dechlorinated using a metal hydrogen compound, and the organic solvent is recovered (see Patent Document 8). Organochlorine compounds after dechlorination are not recovered because they become gases such as methane and ethane.
(9) Halogenated organic waste is desalted by hydrothermal reaction, and energy is recovered by subjecting the product to methane fermentation (see Patent Document 9).
JP 2003-81883 A JP 2001-300290 A Japanese Patent Laid-Open No. 11-309367 Japanese Patent Laid-Open No. 10-28951 JP 2003-175332 A JP 2000-218157 A JP 2001-261583 A JP 2000-239189 A JP 2002-138057 A

  However, these conventional technologies are mainly used to completely decompose and detoxify chlorinated organic compounds, or to detoxify chlorinated organic compounds and collect and reuse part of waste. However, a technology for reusing most of the waste containing organochlorine compounds has not been established.

  The purpose of the present invention is to solve the conventional problems, and when incineration is performed, equipment is corroded and severely worn by the generated hydrochloric acid, and dioxins are generated by the chlorine contained in the organic chlorine compounds, so removal measures must be taken. Providing a method that can recycle and use almost all of the waste containing organic chlorine compounds without incineration treatment of waste containing organic chlorine compounds, which has been extremely expensive. That is.

  The invention according to claim 1 of the present invention for solving the above-mentioned problems is to dechlorinate waste containing an organic chlorine compound by hot water treatment, and to convert the organic chlorine compound into an alcohol and / or an organic acid and an inorganic substance. This is a method for recycling waste containing an organic chlorine compound, which is recovered and used as a salt, and the remaining waste from which the organic chlorine compound has been removed is recovered and used as a fuel.

  Invention of Claim 2 of this invention is the recycling method of the waste containing the organochlorine compound of Claim 1, The reaction temperature of hydrothermal treatment is 80-300 degreeC, Reaction pressure is the said reaction temperature. The saturated vapor pressure is 15 MPa or less.

  The invention according to claim 3 of the present invention is a method for recycling waste containing an organic chlorine compound according to claim 1 or claim 2 when performing hot water treatment of waste oil containing an organic chlorine compound. An alkaline agent is used.

  According to a fourth aspect of the present invention, in the method for recycling waste containing an organochlorine compound according to any one of the first to third aspects, the amount of the alkaline agent used is in the waste. The amount of chlorine contained in the contained organic chlorine compound is 1.0 to 2 times equivalent.

  Invention of Claim 5 of this invention is a recycling method of the waste containing the organochlorine compound in any one of Claims 1-4. WHEREIN: The said organochlorine compound is dichloromethane, chloroform, trichloroethylene, It is at least one compound selected from tetrachloroethylene and carbon tetrachloride.

In the method for recycling waste containing an organic chlorine compound according to claim 1 of the present invention, the waste containing the organic chlorine compound is dechlorinated by hot water treatment to convert the organic chlorine compound into alcohol and / or Since organic acids and inorganic salts are recovered and used, and the remaining waste from which the organic chlorine compounds have been removed is recovered and used as fuel,
When incinerated, the equipment is corroded and worn out by hydrochloric acid, and dioxins are generated by the chlorine contained in the organic chlorine compounds, so removal measures have to be taken, resulting in very high processing costs. Waste containing organic chlorinated compounds is not incinerated, organic chlorinated compounds contained in the waste are not completely decomposed, and dechlorinated by hydrothermal treatment to remove alcohol, organic acid or organic acid salts, etc. Organic acids can be recovered and used by ordinary methods, and the generated inorganic salts can also be recovered and used by ordinary methods. The remaining waste from which the organic chlorine compounds have been removed is liquid fuel, As with solid oil and heavy oil, as well as coal, it can be effectively used as boiler fuel. A marked effect that can be used by recycling.

  Invention of Claim 2 of this invention is the recycling method of the waste containing the organochlorine compound of Claim 1, The reaction temperature of hydrothermal treatment is 80-300 degreeC, Reaction pressure is the said reaction temperature. Since the saturated vapor pressure is 15 MPa or less, the reaction is easily controlled, the organic chlorine compound contained in the waste is not completely decomposed, and the generated alcohol and organic acid are not decomposed efficiently. Dechlorination is often performed by hot water treatment to produce alcohols and organic acids. These yields are high, and it is not necessary to use expensive high corrosion resistance materials as equipment materials. As a result, there is a further remarkable effect that the apparatus cost is reduced.

The invention according to claim 3 of the present invention is a method for recycling waste containing an organic chlorine compound according to claim 1 or claim 2 when performing hot water treatment of waste oil containing an organic chlorine compound. Because alkaline agents such as sodium hydroxide and sodium carbonate are used,
At the same time as the desalting reaction is promoted, the decomposition of the alcohol and organic acids produced is prevented and suppressed, and dechlorination can be performed more efficiently by hydrothermal treatment to produce alcohol and organic acids. The resulting hydrochloric acid can be neutralized.

According to a fourth aspect of the present invention, in the method for recycling waste containing an organochlorine compound according to any one of the first to third aspects, the amount of the alkaline agent used is in the waste. Since it is 1.0 to 2 times equivalent of the amount of chlorine contained in the organic chlorine compound contained,
Without completely decomposing the organic chlorine compound contained in the waste, it is possible to efficiently dechlorinate by hot water treatment to produce alcohol and organic acids economically.

  Invention of Claim 5 of this invention is a recycling method of the waste containing the organochlorine compound in any one of Claims 1-4. WHEREIN: The said organochlorine compound is dichloromethane, chloroform, trichloroethylene, It is characterized by being at least one compound selected from tetrachloroethylene and carbon tetrachloride, and is used in large amounts in degreasing cleaning of machinery and electronic parts, dry cleaning of clothing, and solvents in the chemical industry. Further, it is possible to recycle and use almost all of the waste containing these organochlorine compounds.

Next, embodiments of the present invention will be described in detail.
In the present invention, when a waste containing an organic chlorine compound is treated with hot water, water and an alkali agent are added to the waste containing the organic chlorine compound as necessary, and the reaction is performed at a predetermined temperature and pressure for a predetermined time. .
Waste oil, water, and alkali agents containing organic chlorine compounds may be mixed and then reacted by heating and pressurization, or each of them may be used alone or in combination of two or more to perform heating and pressurization. After that, the reaction may be carried out by mixing all of them.

An example of a reaction in which an organic chlorine compound is dechlorinated by hydrothermal treatment is shown below.
It is considered that dichloromethane, which is an organic chlorine compound, proceeds as shown in the following formulas (1) and (2) to produce alcohols, organic acids, and inorganic salts. Dechlorination of 90% or more within 30 minutes of reaction time under subcritical water conditions using sodium hydroxide equivalent to 1.2 times the amount of chlorine contained in dichloromethane and reaction temperature of 100 to 230 ° C. and reaction pressure of 2 to 5 MPa. Rate was achieved.

CH2Cl2 + 2NaOH → CH2 (OH) 2 + 2NaCl Formula (1)
2CH2 (OH) 2 → CH3OH + HCOOH + H2O Formula (2)

The nucleophilic substitution reaction represented by the formula (1) is considered to be a two-step sequential reaction represented by the following formulas (1-1) and (1-2).
CH2Cl2 + -OH-> CH2Cl (OH) +-Cl Formula (1-1)
CH2Cl (OH) +-OH-> 2CH2 (OH) 2 + -Cl Formula (1-2)

  The k1 and k2 were obtained from the experimental results at a reaction temperature of 180 ° C., where k1 and k2 represented by the following equations are the first-order reaction rate constants, and k1 = 0.0041 [sec−1], k2 = 0. 0013 [sec-1].

k1 = -d [CH2Cl2] / dt
k2 = -d [CH2Cl (OH)] / dt

  The dechlorination reaction under the subcritical water condition has been conventionally considered to be an SN2 reaction, but from this result, it was found that it can be treated as a pseudo primary reaction (SN1 reaction). This is because, in subcritical water in which a sufficient amount of water is present, the -OH concentration becomes excessively large, so even if the SN2 reaction, which is a secondary reaction, is the main reaction, the apparent reaction is doubtful. It is thought that it proceeds as a primary reaction (SN1 reaction).

  The reaction temperature varies depending on the organochlorine compound to be decomposed, but is preferably 80 to 300 ° C. When the reaction temperature is less than 80 ° C., it varies depending on the organic chlorine compound and the alkali agent used, but this is not preferable because the reaction does not proceed or becomes extremely slow. If the reaction temperature exceeds 300 ° C., it is difficult to control the reaction, the decomposition of the generated alcohol and organic acid proceeds, and the yield is deteriorated. Furthermore, when the reaction temperature exceeds 300 ° C., the corrosion of the apparatus becomes severe, and an expensive high corrosion resistance material must be used as the apparatus material, which is not preferable because the apparatus cost increases.

  The reaction pressure is preferably between the saturated vapor pressure at the reaction temperature and 15 MPa. Even if the reaction pressure is increased, the reaction rate does not change so much. If the reaction pressure exceeds 15 MPa, it is not preferable because a high pressure resistance is required for the apparatus and the apparatus cost is increased.

  The reaction apparatus may be a batch type, a continuous type or a combination of these, but a continuous type reaction apparatus having a high production rate is preferable.

  The reaction temperature may be controlled by any method of an electric heater, a direct heating method such as induction heating, an indirect heating method using a heat medium oil, or a combination thereof.

  To increase the reaction pressure, a pressurizing pump is used. Regardless of the type of pump, any type of pump can be used as long as it can pressurize to a predetermined pressure.

  In the present invention, it is preferable to use an alkaline agent when performing the hydrothermal treatment. The reason for this is that the use of an alkaline agent accelerates the desalting reaction and at the same time prevents and suppresses the decomposition of the alcohol and organic acid produced. This is because it is prevented.

  Examples of the alkali agent used in the present invention include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate, carbonates and calcium hydroxide, calcium carbonate, calcium oxide, aluminum hydroxide and aluminum carbonate. And oxides, hydroxides, and carbonates of alkaline earth metals such as aluminum oxide, magnesium hydroxide, magnesium carbonate, and magnesium oxide.

  The addition amount of the alkaline agent is preferably 1.0 to 2 times equivalent, more preferably 1 to 1.4 times equivalent to the chlorine content of the organic chlorine compound contained in the waste oil. If the amount is less than 1.0 times equivalent, the added effect is small, and if the amount exceeds 2 times equivalent, the effect does not change, which is uneconomical.

  The alkali agent may be used alone or in combination of two or more types, but also when used in combination of two or more types, the alkali agent is necessary for generating all the chlorine and alkali salts contained in the organic chlorine compound. It is preferable to adjust so that it may become 1.0-2 times equivalent of a sufficient amount.

The reaction time varies depending on the kind of the organic chlorine compound and the alkali agent used, but is preferably about 5 minutes to 2 hours.
If the reaction time is too long, once generated alcohol, organic acid and the like are further decomposed to form water and carbon dioxide, which is not preferable because the yield is reduced.
After the reaction for a predetermined time, the reaction product is separated into moisture, oil and solid after cooling.

  The solid content includes solid organic matter, mud, crystals of inorganic salts, etc., but is separated by centrifugation or filtration. The inorganic salt contained in the solid content is purified by a method such as recrystallization.

  Some alcohol, organic acids and inorganic salts are dissolved in the water. Alcohol and organic acid are recovered by general methods such as distillation and solvent extraction. Inorganic salts are purified and recovered by methods such as ion exchange, membrane separation, and recrystallization.

  The oil contains a small amount of unreacted organic chlorine compounds, organic substances other than organic chlorine compounds contained in waste, some alcohols, and organic acids. Alcohol and organic acid are recovered by methods such as distillation and solvent extraction.

In order to increase recovery efficiency such as distillation for alcohols and organic acids having a relatively low boiling point, the reaction product may be cooled to about 80 ° C. to 100 ° C., flushed, and recovered by a condenser.
When the reaction product is flushed at about 80 ° C., most of the alcohol having a boiling point of 80 ° C. or less is vaporized and is recovered by cooling and condensing in a condenser.

  When the reaction product is flushed at about 100 ° C., most of the alcohol having a boiling point of 100 ° C. or less is vaporized, and the organic acid and water near 100 ° C. are azeotropically recovered by cooling and condensing in a condenser. Since water is vaporized by azeotropic distillation, the dissolved inorganic salt can be crystallized and separated, which is preferable.

  Although it is difficult to separate and recover alcohol and organic acid only by flash operation, it can be separated from high-boiling point waste oil and inorganic salt dissolved in moisture, and the separation and recovery cost can be reduced.

  Most of waste oil having a boiling point of 100 ° C. or higher is stored in a flash tank as a liquid and separated into oil and water.

  The recovered alcohol, organic acid, and inorganic salt are used as industrial raw materials, and oily and solid organic substances are used as boiler fuel.

Next, an example of usage will be specifically described.
The obtained desalted oil can be used as a fuel for boilers, a heating fuel for buildings, a diesel fuel, a fuel for house cultivation, etc., in the same manner as light oil and heavy oil, depending on its properties.

  For example, desalted oil whose properties correspond to light oil can be used as fuel for diesel engines such as buses and trucks, fuel for gas turbines, fuel for power generation, and fuel for boilers.

  Desalinated oil whose properties correspond to heavy oil can be used as fuel for small and large diesel engines, fuel for power generation, fuel for ships, fuel for boilers, and the like.

  The obtained solid organic matter can be used as a boiler fuel for electric power generation or a fuel for iron making as well as coal.

  The obtained inorganic salt sodium chloride can be used as soda and other chemical industrial raw materials, mine refining raw materials and the like. Calcium chloride can be used as a snow melting agent for roads.

  The obtained methanol can be used as a raw material for formalin, acetic acid, methyl methacrylate, methylamine, fragrance and the like.

  Further, the formic acid of the obtained organic acid can be used as a dyeing assistant, an epoxy plasticizer, a pharmaceutical, a plating assistant, a bactericide raw material, and the like.

  Glycolic acid can be used as a boiler cleaning agent, an electropolishing agent, a dyeing aid, a scale removing agent, and the like.

  The description of the above embodiment is for explaining the present invention, and does not limit the invention described in the claims or reduce the scope. Moreover, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

EXAMPLES Next, although an Example and a comparative example demonstrate this invention in detail, unless it deviates from the main point of this invention, it is not limited to these Examples.
Example 1
As a simulated waste oil containing an organic chlorine compound, 12.00 g of dichloromethane (reagent special grade) was placed in a 100 ml volumetric flask, and machine oil was added to make the total amount 100 ml.
As the reaction vessel, a cylindrical pressure resistant reactor in which a swage lock was attached to both ends of a stainless steel (SUSTP 10A sch10S) tube having an inner diameter of 14 mm, a thickness of 1.65 mm, and an internal volume of 30 ml was used.
As the reaction operation, 8.0 g of simulated waste oil and 14.52 g of distilled water in which 1.1 g of sodium hydroxide was dissolved in a reaction vessel closed at one end with Swagelok (water equivalent to 1.2 times the amount of chlorine contained in dichloromethane). (Including sodium oxide), the air in the space was replaced with argon gas, the reaction vessel was closed with Swagelok, and the oil bath set at 230 ° C. was charged for a predetermined time (5, 10, 40, 60 minutes) ( The reaction pressure was 2.8 MPa because it was the saturated vapor pressure of water), and then taken out, put into a water tank and rapidly cooled to stop the reaction.
After the reaction vessel has cooled sufficiently, the reaction product is taken out, divided into an oil layer and an aqueous layer, the amount of chlorine ions contained in the aqueous layer is measured according to JIS K0101, the desalting rate is calculated, and the pH of the aqueous layer is shown in Table 1. Shown with value.

(Example 2)
The same operation as in Example 1 was carried out except that 1.0 g of calcium hydroxide (including 1.2 times the amount of chlorine contained in dichloromethane) was added instead of 1.1 g of sodium hydroxide. The salt rejection was calculated and shown in Table 1 together with the pH value.

(Comparative Example 1)
The desalting rate was calculated in the same manner as in Example 1 except that 1.1 g of sodium hydroxide was not added, and is shown in Table 1 together with the pH value.

  As shown in Table 1, when dichloromethane used sodium hydroxide and calcium hydroxide as alkaline agents (Examples 1 and 2), the desalting rate was about 98% after a reaction time of 10 minutes, and the pH was 7 On the other hand, in the case of no addition (Comparative Example 1), the desalination rate was 10% even at a reaction time of 60 minutes, the pH was very low at 1.6, and corrosion of the reaction vessel was observed. From the above results, it can be seen that the use of an alkaline agent is effective.

(Example 3)
As a simulated waste oil containing an organic chlorine compound, 8.0 g of chloroform, trichlorethylene, tetrachloroethylene (each reagent special grade), 12.00 g each, was added to a 100 ml volumetric flask, and machine oil was added to make a total volume of 100 ml. Alkaline agent is sodium hydroxide used as a 10% aqueous solution in an amount equivalent to 1.2 times the amount of organic chlorine compound contained in simulated waste oil, and is placed in an oil bath set at 80 to 250 ° C. for a predetermined time (5-90 Min) It was taken out in the same manner as in Example 1 except that it was taken out, put into a water tank, quenched to stop the reaction, and the desalting rate was calculated. The reaction pressure is a saturated water vapor pressure at the reaction temperature.
The test results are shown in FIG. 1 (a graph showing the relationship between the desalination rate of chloroform and time when simulated waste oil containing chloroform at the temperature shown in the figure is treated with hot water), and FIG. 2 (simulation containing trichlorethylene at the temperature shown in the figure). Deposition rate and time of tetrachlorethylene when hydrothermal treatment of simulated waste oil containing tetrachlorethylene at the temperature shown in the figure is a graph showing the relationship between time and desalination rate of trichlorethylene when waste oil is hydrothermally treated Graph showing the relationship between

From FIG. 1, it can be seen that chloroform has a desalting rate of 95% or more at a reaction temperature of 120 ° C., a reaction pressure of 0.20 MPa, and a reaction time of 10 minutes.
From FIG. 2, it can be seen that trichlorethylene has a desalination rate of 95% or more at a reaction temperature of 230 ° C., a reaction pressure of 2.80 MPa, and a reaction time of 10 minutes.
FIG. 3 shows that the desalination rate of tetrachlorethylene becomes 95% or more at a reaction temperature of 250 ° C., a reaction pressure of 3.98 MPa, and a reaction time of 30 minutes.

Example 4
Waste oil-1 shown in Table 2 (synthetic reaction waste oil mainly containing a high boiling point solvent, containing 43.6% dichloromethane) was used as the waste oil containing the organic chlorinated compound, and the reaction vessel was used as an autoclave with a stirrer with a capacity of 100 ml ( The reaction was carried out using a high pressure microreactor MMJ-100 manufactured by OM Labotech Co., Ltd.
Waste oil-1 30 g and distilled water 30 g dissolved in sodium hydroxide 14.78 g were placed in an autoclave, and the air in the reaction vessel space was replaced with argon gas, hot water at a reaction temperature of 220 ° C. and a reaction pressure of 2.32 MPa for 15 minutes. After carrying out the treatment reaction, the reaction vessel portion of the autoclave was immersed in a water tank to stop the reaction. This operation was repeated 10 times to obtain 580 g of a reaction product.
When the reaction product was put into a beaker and allowed to stand, it separated into an oil layer and an aqueous layer, and sodium chloride crystals were precipitated in the lower part of the aqueous layer.

When the oil layer floating above was separated, 154 g of desalted oil was obtained.
Next, the sodium chloride crystals contained in the aqueous layer were filtered and dried to obtain 7.6 g of sodium chloride. The purity of the obtained sodium chloride was 87%.
23.5 g of methanol was separated from the filtrate from which sodium chloride had been removed by atmospheric distillation. The obtained methanol contained 10% by mass of water.
7. Formic acid, which is a reaction product contained in the aqueous layer from which methanol has been removed, is a sodium salt, so that hydrochloric acid is added to adjust pH = 2 to form formic acid, and then formic acid and water are removed by distillation. 9 g of sodium chloride was obtained. The purity of the obtained sodium chloride was 92%.
The obtained methanol and sodium chloride are sufficiently usable as industrial raw materials, and are used after further purification depending on the application.
Since the amount of dichloromethane contained in the desalted oil is very small at 3200 ppm and its main component is a high boiling point solvent, it can be used as a boiler fuel corresponding to A heavy oil.
The formic acid concentration of the formic acid aqueous solution recovered by distillation is about 8% by mass, which is a composition suitable for methane fermentation.

(Example 5)
Using the same autoclave as in Example 4, waste oil-2 shown in Table 2 (metal washing waste oil mainly containing rust preventive oil, containing 41.3% tetrachloroethylene) 20 g and 9.56 g of sodium hydroxide dissolved in 40 g of distillation Water is put into an autoclave, the air in the reaction vessel space is replaced with argon gas, a hydrothermal treatment reaction is performed at a reaction temperature of 250 ° C. and a reaction pressure of 4.01 MPa for 30 minutes, and then the autoclave reaction vessel is immersed in a water tank. The reaction was stopped. This operation was repeated 10 times to obtain 585 g of a reaction product.
When the reaction product was put into a beaker and allowed to stand, it was divided into two layers, an oil layer and an aqueous layer, and the upper oil layer was taken out to obtain 10.8 g of desalted oil.
Next, since glycolic acid contained in the aqueous layer is a sodium salt, hydrochloric acid was added to adjust pH = 2 to obtain glycolic acid, and then water was removed by distillation to obtain a mixture of glycolic acid and sodium chloride crystals.
Isopropyl alcohol was added to this mixture to dissolve glycolic acid, and crystalline sodium chloride was separated by filtration and dried to obtain 102 g of sodium chloride. The purity of sodium chloride was 87.4%.
Isopropyl alcohol was removed by distillation of the isopropyl alcohol glycolate solution from which the sodium chloride crystals had been separated to obtain 33 g of glycolic acid. The purity of glycolic acid was 86.9%.

The obtained sodium chloride and glycolic acid can be sufficiently used as industrial raw materials, and are used after further purification depending on their use.
The concentration of tetrachlorethylene contained in the obtained desalted oil is very low at 2200 ppm. Since the main component of the desalted oil is a rust preventive oil, it can be used as a boiler fuel corresponding to A heavy oil.

(Example 6)
Using the same autoclave as in Example 4, waste oil-3 shown in Table 2 (metal washing waste oil mainly containing water, containing 96.2% trichlorethylene) 20 g, 40 g of distilled / dissolved sodium hydroxide of 20.09 g Water is put into an autoclave, the air in the reaction vessel space is replaced with argon gas, a hydrothermal treatment reaction is performed at a reaction temperature of 250 ° C. and a reaction pressure of 4.01 MPa for 30 minutes, and then the autoclave reaction vessel is immersed in a water tank. The reaction was stopped. This operation was repeated 10 times to obtain 570 g of a reaction product.
When the reaction product was put into a beaker, no oil layer was observed, and only an aqueous layer in which sodium chloride crystals were deposited at the bottom.
Sodium chloride crystals contained in the aqueous layer were filtered and dried to obtain 13.1 g of sodium chloride. The purity of sodium chloride was 85.3%.
Next, since glycolic acid contained in the aqueous layer is a sodium salt, hydrochloric acid was added to obtain pH = 2 to obtain glycolic acid, and then water was removed by distillation to obtain a mixture of glycolic acid and sodium chloride crystals.

Isopropyl alcohol was added to the mixture to dissolve glycolic acid, and sodium chloride crystals not dissolved in isopropyl alcohol were filtered and dried to obtain 8.9 g of sodium chloride. The purity of sodium chloride was 83.7%.
Isopropyl alcohol was removed from the isopropyl alcohol glycolate solution from which sodium chloride had been removed by distillation to obtain 103 g of glycolic acid. The purity of glycolic acid was 92.5%.
The obtained sodium chloride and glycolic acid can be sufficiently used as industrial raw materials, and are used after further purification depending on their use.

In the present invention, waste containing an organic chlorine compound is dechlorinated by hydrothermal treatment, and the organic chlorine compound is recovered and used as an alcohol and / or an organic acid and an inorganic salt. Since the remaining waste removed is recovered and used as fuel,
When incinerated, the equipment is corroded and worn out by hydrochloric acid, and dioxins are generated by the chlorine contained in the organic chlorine compounds, so removal measures have to be taken, resulting in very high processing costs. Waste containing organic chlorinated compounds is not incinerated, organic chlorinated compounds contained in the waste are not completely decomposed, and dechlorinated by hydrothermal treatment to remove alcohol, organic acid or organic acid salts, etc. Organic acids can be recovered and used in a normal manner, and the generated inorganic salt can be recovered and used in a normal manner. The remaining waste from which the organic chlorine compound has been removed is liquid fuel, As a solid fuel, it can be effectively used as boiler fuel, as well as heavy oil, coal, etc. Since a marked effect that can be used by recycling, high industrial value.

It is a graph which shows the relationship between the desalination rate (%) of chloroform at the time of dechlorinating the simulated waste oil containing chloroform at the temperature shown in a figure, and time (minutes). It is a graph which shows the relationship between the desalination rate (%) of trichlorethylene at the time of dechlorinating the simulation waste oil containing a trichlorethylene at the temperature shown in a figure, and time (minutes). It is a graph which shows the relationship between the desalination rate (%) of tetrachlorethylene at the time which dechlorinates the simulated waste oil containing tetrachloroethylene at the temperature shown in a figure, and time (minutes).

Claims (5)

  Waste containing an organic chlorine compound is dechlorinated by hydrothermal treatment, the organic chlorine compound is recovered and used as an alcohol and / or an organic acid and an inorganic salt, and the remaining organic chlorine compound is removed. A method for recycling waste containing organic chlorinated compounds, characterized in that the waste is collected and used as fuel.   2. Recycling of waste containing organochlorine compound according to claim 1, wherein the reaction temperature of the hydrothermal treatment is 80 to 300 ° C. and the reaction pressure is not less than the saturated vapor pressure at the reaction temperature and not more than 15 MPa. Method.   The method for recycling waste containing an organic chlorine compound according to claim 1 or 2, wherein an alkaline agent is used when the hot oil treatment of the waste oil containing the organic chlorine compound is performed.   The organic material according to any one of claims 1 to 3, wherein the amount of the alkali agent used is 1.0 to 2 times the amount of chlorine contained in the organic chlorine compound contained in the waste. A method for recycling waste oil containing chlorine compounds.   The organic chlorine compound-containing waste according to any one of claims 1 to 4, wherein the organic chlorine compound is at least one compound selected from dichloromethane, chloroform, trichloroethylene, tetrachloroethylene, and carbon tetrachloride. How to recycle things.

Images