RU2108316C1 - METHOD FOR PRODUCTION OF α-PINENE OF SULFATE TURPENTINE - Google Patents

Abstract

FIELD: organic chemistry. SUBSTANCE: α-pinene is prepared by treatment of sulfate turpentine with air, the process is carried out within 1.5-3.0 h at 45-55 C in the presence of organic peroxide compounds. Then alkaline washing of reaction mass and rectification of oxidate are carried out. Thus prepared α-pinene has low sulfur content. EFFECT: improved efficiency of the method. 2 cl, 1 tbl

Description

 The invention relates to methods for producing α-pinene with a low sulfur content from sulfate turpentine and can be used in enterprises of the chemical and pulp and paper industry.

 Known methods for producing α-pinene by distillation of various types of turpentine: gum, extraction, sulfate. The most affordable and cheapest raw material for producing α-pinene is currently sulfate turpentine.

 Despite the fact that the content of α-pinene in this type of turpentine is at the level of gum (60 - 75%), its isolation by rectification does not allow to obtain a high-quality product: a distinctive feature of sulfate turpentine is the presence of sulfur-containing compounds in it, which is due to the method of its preparation . The presence of these compounds gives a sharp, unpleasant odor to sulfate turpentine and products based on it. The same circumstance makes it impossible to use α-pinene obtained from it by rectification as a raw material for a number of deep chemical transformations due to the poisoning of the catalysts used in this process. Practice has shown that α-pinene satisfies the requirements of consumers and does not have limitations in its application areas only if the mass fraction of total sulfur in it does not exceed 50 ppm (0.005%).

Usually produced, including in Russia, sulfate turpentine contains at best 0.02% sulfur, which makes it almost impossible to obtain α-pinene of the required quality from it
Known methods for cleaning and deodorizing sulfate turpentine using various oxidizing agents: nitrogen oxides; hydrogen peroxide; hypochlorites; oxygen of the air. The use of these reagents leads to the oxidation of mercaptans and sulfides present in turpentine to sulfonic acids, sulfoxides and sulfones. During the oxidation of disulfides, thiolsulfites, thiolsulfonates, sulfonic acids can be obtained (Chemistry and physicochemistry of organic compounds of petroleum distillates M .: Nauka, 1984, p. 119).

Благодаря окислению серасодержащих соединений, входящих в состав сульфатного скипидара, происходит образование высококипящих окисленных серасодержащших соединений, что дает возможность их отделения от летучих терпенов методом ректификации.

Due to the oxidation of sulfur-containing compounds that are part of sulfate turpentine, the formation of high-boiling oxidized sulfur-containing compounds occurs, which makes it possible to separate them from volatile terpenes by distillation.

A known method of purification of sulfate turpentine by treating with a mixture of a solution of sodium hypochlorite (with a concentration of active chlorine of 150 - 240 g / l and sodium hydroxide (12 g / l) in an acidic environment (pH 3.5 - 5.0) at 10 - 40 ^o C within 20-60 minutes After settling and removing the acidic layer, turpentine is neutralized with an alkali solution, washed with water and dried by filtration through a layer of table salt. however using it impossible as a chemical raw material due to the still rather high sulfur content (SU N 332116, class C 09 G 1/10, 1972).

 In another method, bleach is used to purify sulfate turpentine. However, in the processing of raw turpentine with this reagent, concomitant reactions occur, in particular, the oxidation and polymerization of terpenes, which leads to a low yield of commodity terpene fraction - about 30%. To reduce terpene losses, it was proposed to remove the bulk of sulfur compounds by distillation, then turpentine is treated with a weak solution of bleach. This allows you to reduce the loss of terpenes during processing, but they are still quite high: the total loss of terpenes is 17%, and the yield of α-pinene is reduced by 10%. The mass fraction of sulfur in turpentine purified by this method is 0.03% (Scientific and technical abstract collection Lesokhimiya and podsochka 1973, N 2, p. 5-6).

A known method of purification of sulfate turpentine using hydroperoxides of terpene compounds: p-mentane, pinan, metapinan (PL N 124833, class C 09 F 3/00, 1985). The advantage of such hydroperoxides is that after the reaction they remain as terpene alcohols without reducing the consumer properties of turpentine. The process is carried out at a temperature of about 100 ^o C, the consumption of hydroperoxide 3 - 10 g per 10 g of turpentine, followed by distillation of the fractions boiling at 100 - 160 ^o C, washing with distilled water (20 - 25 g). After decantation, the organic phase is used as the finished product. The degree of purification of the finished product from sulfur-containing compounds is not indicated. The disadvantages of the method include: the lack of industrial production of hydroperoxides used, their high consumption, high process temperature, which leads to the oxidation of terpenes contained in turpentine, and a decrease in the mass fraction of α-pinene.

 Closest to the proposed is a method of deodorizing turpentine by treating it with air or oxygen with an activating additive, in particular ozone.

 The oxidation process is carried out continuously or batchwise. Isolation of the product by known methods (PL N 136717, class C 09 F 3/00, 1986).

The process is conducted in two stages:
a) the oxidation of turpentine by passing oxygen containing 0.5 to 3.0% ozone at a speed of 30 l / h for 35 min 20 ^o C;
b) allocation of turpentine fraction (P $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ 1.4720) from the oxidate obtained in step a) by steam distillation.

In this case, a terpene fraction is obtained with a yield of 93%, which does not have a sharp unpleasant odor characteristic of sulfur-containing compounds. The product contains 58% α-pinene and 36% Δ ³ - -karen (GLC).

 The main disadvantage of this method, taken as a prototype, is the high consumption (0.5 - 3.0%) of expensive ozone and significant technological difficulties in implementing the method.

 The purpose of the invention is to obtain purified from sulfur α-pinene with a mass fraction of total sulfur of not more than 0.005% by deep purification of sulfate turpentine and its subsequent distillation.

The goal is achieved by the fact that sulfate turpentine is subjected to air treatment at 45 - 55 ^o C in the presence of peroxide compounds active in the specified temperature range. In addition, carrying out the reaction at this temperature does not lead to chemical transformations of terpenes, which are part of turpentine.

 Oxidation is carried out for 1.5 - 3.0 hours, the consumption of peroxide compounds (cyclohexine peroxydicarbonate, isopropylbenzene hydroperoxide, lauryl peroxide, benzoyl peroxide) 0.05-0.1% by weight of turpentine taken for oxidation.

After completion of the oxidation reaction of sulfate turpentine, the reaction mixture is treated with a 10-15% alkali solution at 75 - 80 ^o C. This is necessary for further safe rectification process.

After separation of the alkaline solution, the oxidate is rectified under reduced pressure. The resulting target product - α-pinene - has the following quality indicators: mass fraction of α-pinene - not less than 94%; P $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ 1.4654-1.4656; mass fraction of total sulfur not more than 0.005%. The yield of the target product is not less than 80% of the α-pinene contained in the starting turpentine.

Example 1. In the reactor load 100 g of sulfate turpentine (mass fraction of sulfur 0.1244%) and 0.1 g of cyclohexine peroxydicarbonate (CPA). The contents of the reactor are heated to 50 ^° C. and air is supplied through a bubbler at a speed of 30 dm ³ / h. within 3.0 hours. After completion of the reaction, 10 g of a 15% sodium hydroxide solution is poured onto the obtained oxidate, the mixture is heated to 75 - 80 ^° C and kept at this temperature for 1.0 hour with stirring. Then the mass is cooled to room temperature, the organic fraction is separated and it is rectified on a distillation column under reduced pressure (0.06 MPa), isolating the fraction boiling at 115 - 118 ^o C.

The resulting product has the following physico-chemical characteristics:
density at 20 ^o C - 0.865 g / cm;
refractive index at 20 ^o C - 1,4654;
mass fraction of total sulfur - 0.0027%;
mass fraction of the residue from evaporation - 0.1%;
mass fraction of α-pinene - 92%.

 The yield of 60 g of the target product with a mass fraction of α-pinene in the original turpentine 75%.

 To obtain comparative data, experiments were carried out with various peroxides active in a given temperature range; the temperature and duration of the reaction and the mass fraction of peroxide used were changed. The data are tabulated.

 Pinene obtained using these peroxides has the properties of the product obtained according to example 1.

 The advantage of the proposed method is that the use of peroxide compounds in the processing of sulfate turpentine air allows you to get pinene with a low sulfur content (less than 0.005%). Used peroxide compounds are not deficient, are produced by domestic industry, their consumption is low. The use of peroxide compounds practically does not change the chemical composition of sulfate turpentine, the mass fraction of α-pinene in it does not decrease. The proposed method for producing α-pinene can be easily implemented in an industrial environment using standard equipment.

 Obtained by this method, purified pinene sulfate is characterized by a low sulfur content, which allows it to be used as a chemical raw material for various syntheses along with pinene obtained from gum turpentine.

 Currently, domestic industry product of this quality is not produced. Mass fraction of sulfur in pinene produced at Ust-Ilimsky PPM is 0.03%.

Claims (2)

1. A method of producing α-pinene from sulfate turpentine, including treating sulfate turpentine with air in the presence of an activating additive and rectification of the oxidate, characterized in that the treatment is carried out at a temperature of 45 - 55 ^o C for 1.5 to 3.0 hours, followed by alkaline washing the oxidate and using organic peroxides active in the temperature range of processing turpentine as an activating additive.  2. The method according to claim 1, characterized in that the use of peroxide compounds in an amount of 0.05 - 0.1%.

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