CN1003644B

CN1003644B - Catalytic synthesis of monoterpene ether from natural mordenite

Info

Publication number: CN1003644B
Application number: CN86105408.3A
Authority: CN
Inventors: 陈庆之; 李允隆; 罗金兰; 岑中杨; 沈奔
Original assignee: Guangzhou Institute of Chemistry of CAS
Current assignee: Guangzhou Institute of Chemistry of CAS
Priority date: 1986-08-26
Filing date: 1986-08-26
Publication date: 1989-03-22
Also published as: CN86105408A

Abstract

本发明是用天然丝光沸石催化剂固定床逆流式连续法直接催化单萜烯烃与醇生成单萜基醚的新工艺，所用的单萜烯烃是：α－蒎烯、β－蒎烯、莰烯、双戊烯（柠烯）、松油烯等，与萜烯加成的醇可以是甲醇、乙醇、丙醇、异丙醇、丙烯醇、丁醇、乙二醇、香茅酵以及苯甲醇等。反应获得的醚有α－松油基醚、龙脑基醚（冰片基醚）和异龙脑基醚等，反应醚化率可达９０～１００％，醚产率最高可达９０％以上，该法具有反应转化率高，异构化付反应产物少。产率高和成本低的优点。The present invention is a new process for directly catalyzing monoterpene hydrocarbons and alcohols to generate monoterpene ethers by using a natural mordenite catalyst fixed bed countercurrent continuous method. The monoterpene hydrocarbons used are: α-pinene, β-pinene, camphene, Dipentene (limonene), terpinene, etc. Alcohols added to terpenes can be methanol, ethanol, propanol, isopropanol, propenyl alcohol, butanol, ethylene glycol, citronella yeast, benzyl alcohol, etc. . The ethers obtained by the reaction include α-terpineyl ether, bornyl ether (bornyl ether) and isobornyl ether, etc. The reaction etherification rate can reach 90-100%, and the ether yield can reach more than 90%. The method has the advantages of high reaction conversion rate and less isomerization by-reaction products. The advantages of high yield and low cost.

Description

Catalytic synthesis of monoterpene ether by natural mordenite

The invention belongs to the synthesis of monoterpene ether.

Some monoterpene olefins can undergo addition reaction with alcohols under acid catalysis to generate various monoterpene ethers, and many monoterpene ethers can be used as perfumes, surfactants and the like. In the past, the technology of etherification of monoterpene hydrocarbon has been reported, and the catalyst used is various inorganic acids or cation exchange resins. For example Burczxk Bogdan [ C.A.7345613 (1970) ] with sulfuric acid as catalyst, with alpha-pinene with methanol, ethanol, propanol and isopropanol, respectively, the corresponding monoterpene ethers are obtained in the highest yields of 83.5%, 68%, 77% and 56%, respectively. As another example, mnssinan C.J. et al report [ U.S. patent4,131,687 (1978) ] that they use the reaction of alkene with BF ₃.Et₂ O in ethanol to produce 1.8-diethoxy-P-alkane, a terpene ether useful as a fragrance and pigment for foods, pharmaceuticals and cosmetics. The method for synthesizing the monoterpene ether has the problems of serious reaction isomerization, low yield, equipment corrosion and the like.

In 1981 and 1985 we reported the use of synthetic hydrogen mordenite, catalytic citronellol and alpha-pinene, camphene, olefins, and alcohols to produce methoxy, ethoxy citronellol and alpha-terpinyl, n-campholenyl, iso-campholenyl and various ethers, respectively (Guangdong society of chemistry paper (1981), chemical communications (86.4), which has the advantages of higher conversion and less isomerisation, but synthetic zeolites are expensive and only suitable for batch production, and therefore the production costs are still higher.

Aiming at the problems in the method, the invention adopts the cheap natural mordenite as the catalyst, uses a fixed bed countercurrent and flow-through reaction vessel to carry out continuous catalytic reaction, has high reaction conversion rate, less isomerization side reaction products, high product yield and low cost, and is a novel ideal process for producing the monoterpene ether. The core of the invention is that natural mordenite after special treatment is used as a catalyst, and a fixed bed countercurrent continuous reaction vessel is used for catalyzing the addition reaction of monoterpene olefin and alcohol to obtain monoterpene ether.

Suitable monoterpene olefins include alpha-pinene, beta-pinene, camphene, limonene (dipentene), terpinene and the like. The alcohol added with terpene can be methanol, ethanol, n-propanol, isopropanol, butanol, propenol, glycol, citronellol, benzyl alcohol, etc., and the etherification products are alpha-terpinyl ether, borneol (borneol) ether, isobornyl ether, etc. The reaction conversion rate varies according to different raw materials and reaction conditions (temperature, feeding speed and the like), and is generally 100-60%. The yield of the ether is 98-50%, the isomerization reaction is lower than 1-30%, and ideal results can be obtained by controlling the reaction conditions, changing the selectivity of the catalyst and the like.

Embodiments of the invention are as follows:

preparation of (one) catalyst

Natural mordenite (containing more than 50% of mordenite) of natural zeolite mineral products in Jinyun county, zhejiang province, china is taken as a raw material to be treated according to the following method:

① Crushing natural mordenite, sieving, taking 1-3 mm size as raw material, treating the zeolite with 0.5-6N hydrochloric acid or sulfuric acid at 90-100 deg.C, wherein the acid consumption is four times of zeolite (weight), and stirring while heating for one hour. Repeating the acid treatment process for 4-12 times, washing the mordenite subjected to the acid treatment with water until washing water is neutral, drying, heating to 400-600 ℃ in an electric furnace or other heating furnaces, roasting for 3-8 hours, and repeating the operation processes from the acid treatment to the roasting.

② Treating ① treated mordenite with ammonia water or ammonium bicarbonate solution with ammonia water concentration of 0.5-2% and ammonium bicarbonate solution concentration of 1-4%, stirring at room temperature for 1 hr, washing with water to neutral, oven drying, and roasting in electric furnace or other heating furnace at 350-450 deg.C (preferably 400 deg.C) for 3-8 hr to obtain monoterpene etherification catalyst. The catalyst has better stability and regeneration.

(II) fixed bed countercurrent reactor A schematic diagram of a fixed bed countercurrent reactor for carrying out etherification reaction of monoterpene olefins is shown in figure 1.

Description of fig. 1:

1. A feeder; 2, a charging pipe, 3, a reactor, 4, a heating jacket, 5, a catalyst bed, 6, a heat carrier inlet, 7, a heat carrier outlet, 8, a reflux condenser, 9, a condenser, 10, a reaction product receiver, 11, a heater and 12, a heat carrier circulating pipe.

The reactor is a glass tube (or stainless steel) with a heating jacket, the inner diameter is 25mm, the length of the tube is 1.2 m, the catalyst bed is 1 m, the reactor is filled with prepared catalyst with the length of 1-3 mm, a sieve plate is arranged at the bottom of the reactor to support the catalyst, reaction materials are added from the bottom and flow through the catalyst bed in a countercurrent way from bottom to top, the reaction materials flow out from the top of the reactor after cooling through a condenser, a reflux condenser is arranged at the top of the reactor for refluxing low-boiling-point alcohols, and the interlayer of the reactor can use water, oil or steam and the like as heat carriers according to different reaction temperature requirements through a continuously circulating heat carrier.

The olefin and the alcohol are prepared into reaction materials according to a certain proportion, different feeding speeds are adopted according to different raw materials, and the reaction temperature is maintained through a heat carrier in an interlayer of the reactor.

(III) regeneration of the catalyst

The catalyst is used for more than half a year, the activity is gradually reduced, the catalyst can be regenerated by washing the catalyst with water, then drying the catalyst slowly, placing the catalyst in an electric furnace, heating the catalyst to 550-600 ℃ slowly, keeping the temperature for 4-10 hours, repeating the acid treatment process in the first embodiment, then repeatedly treating the catalyst with ammonia water (0.5-2%) or ammonium bicarbonate (1-4%) under the same treatment condition as in the first embodiment), washing the catalyst with water to be neutral, drying the catalyst, placing the catalyst in the electric furnace or other heating furnaces, and roasting the catalyst for 3-8 hours at a roasting temperature of 350-450 ℃ and preferably 400 ℃. After regeneration, the original catalytic activity can be completely recovered.

Example one

And etherifying the alpha-pinene with ethanol to prepare alpha-terpinyl diethyl ether and campholyl diethyl ether.

The industrial alpha-pinene (containing 95% of alpha-pinene) and absolute ethyl alcohol are used as raw materials, the reaction materials are prepared according to the molar ratio of alpha-pinene to ethyl alcohol=1:10, the fixed bed countercurrent reactor is adopted for reaction, 550 g of the prepared catalyst in the embodiment (II) is filled in the reactor, the reaction temperature is 78 ℃ plus or minus 2 ℃, the feeding speed of the reaction materials is 0.4 g/h (weight airspeed, namely, 0.4 g of the reaction materials passing through each g of the catalyst per hour) is adopted, two products of alpha-terpinyl diethyl ether and borneol diethyl ether can be simultaneously obtained after fractionation, the conversion rate of the alpha-pinene is 100%, the yield of the alpha-terpinyl diethyl ether is 45%, 25% of borneol diethyl ether can be obtained at the same time, the continuous reaction is carried out according to the reaction conditions, and the service life of the catalyst can be kept for more than half a year without regeneration.

Example two

Preparation of isobornyl methyl ether by etherification of camphene and methanol

Industrial camphene (containing tricyclic terpene about 20%) and anhydrous methanol are used as raw materials, the raw materials are prepared according to the ratio of camphene to methanol=1:20 (molar ratio), the raw materials can be heated appropriately for dissolving camphene, an embodiment (II) is adopted, the fixed bed countercurrent reactor is filled with 550 g of the prepared catalyst in the embodiment (I), the reaction temperature is 65 ℃ plus or minus 2 ℃, the feeding speed of the raw materials is 0.2 g/h (weight airspeed, namely 0.2 g of raw materials are passed through each g of catalyst per hour), pure isobornyl methyl ether can be obtained after fractional distillation, the conversion rate of camphene is more than 98%, the yield of isobornyl methyl ether is 95%, the continuous reaction is carried out, and the catalyst can be used for more than half a year without regeneration.

Example three

Preparation of alpha-terpinyl diethyl ether by etherification of dipentene and ethanol

Industrial dipentene (the content of which is more than 90%) and absolute ethyl alcohol are taken as raw materials, the ratio of dipentene to ethyl alcohol is 1:10 (molar ratio), an implementation (II) is adopted in the fixed bed countercurrent reactor, 550 g of the catalyst prepared in the implementation (I) is filled in the reactor, the reaction temperature is 78 ℃ plus or minus 2 ℃, the feeding speed of reaction materials is 0.4 g/h (weight airspeed, namely 0.4 g of the reactant passes through each gram of the catalyst per hour), pure alpha-terpinyl diethyl ether can be obtained after fractionation, the conversion rate of the dipentene in the reaction is more than 95%, the yield of the alpha-terpinyl diethyl ether is more than 90%, and the activity of the continuous reaction catalyst can be maintained for more than half a year without regeneration.

Claims

1. A method for the direct synthesis of monoterpene ethers comprising the steps of:

① Preparing a catalyst for synthesizing monoterpene ether, treating natural mordenite with 0.5-6N acid at 90-100 ℃ for 1 hour, wherein the weight ratio of the acid to the zeolite is 4:1, repeating the treatment for 4-12 times, roasting at 400-600 ℃ for 3-8 hours, treating with 0.5-2% ammonia water or 1-4% ammonium bicarbonate solution, and roasting at 350-450 ℃ for 3-8 hours to obtain the catalyst.

② The method is characterized in that monoterpene olefin and alcohols are used as raw materials to carry out etherification reaction in a fixed bed countercurrent reactor, and the reactor is filled with the catalyst.

③ When the activity of the catalyst is reduced, the catalyst can be calcined at 550-600 ℃ for 4-10 hours, the acid treatment process for preparing the catalyst in claim 1 is repeated and then ammonia water (or ammonium bicarbonate) is used for treatment, and finally the catalyst is calcined at 350-450 ℃ for 3-8 hours to recover the activity.

2. The process for preparing a catalyst according to claim 1, wherein the acid used for acid treatment of the mordenite is hydrochloric acid or sulfuric acid.

3. The process for preparing a catalyst according to claim 1, wherein the aqueous ammonia (or ammonium bicarbonate) is used in an amount of four times that of zeolite when it is treated with aqueous ammonia or ammonium bicarbonate solution, and the treatment time is one hour.

4. The method for preparing a catalyst according to claim 1, wherein the calcination temperature is preferably controlled at 400 ℃ during the final calcination.

5. The etherification process according to claim 1, wherein the terpene hydrocarbon used as the raw material for the etherification is alpha-pinene, beta-pinene, camphene, limonene (dipentene), terpinene, methanol, ethanol, n-propanol, isopropanol, butanol, propenol, ethylene glycol, benzyl alcohol, citronellol.