SU695997A1 - Method of preparing methylcyclopentene isomers - Google Patents

Description

I

The invention relates to the field of the preparation of 101 alicyclic unsaturated hydrocarbons, in particular methyl diclopentenes. The methyl diclopentene isomers are the feedstock for the production of the effective monomer-methyl diclopentadiene.

A known method of producing cyclopengen and its alkyl derivatives by hydrating w-cyclopentadiene in the presence of a complex catalytic system based on complex compounds of the Vill metal of the group at a temperature of from -20 to 200 ° C 1,

The disadvantage of the method is the complexity of the technology.

The closest to the technical essence to the left is the method of producing isomers of methyl diclopentene by dehydratadium of ilclohexanol in the presence of aluminum oxide at 420-460 ° C.

The disadvantage of this method is the low selectivity of the process at the maximum yield of the product - a mixture of methyl diclopentenes. For example, at 450 ° С, the space velocity is 0.3 and the duration of the experiment is 1 h.

5-6% comes from methyl chloride, which is formed due to the redistribution of hydrogen with the simultaneous formation of a large amount of coke on the catalyst. The latter circumstance negatively affects the process technology and reduces the duration of the experiment with a simultaneous increase in the catalyst regeneration time.

The aim of the invention is to increase the selectivity of the process.

Delivered Del is achieved by the described method of producing methylcyclopentene isomers, concluding that diclohexanol is subjected to dehydratadium in the presence of a catalyst — clinoptilo-shta — at elevated temperature.

The difference of this method is the use of ksh1 smoke as a catalyst.

Preferably, the process is carried out at 350-450 ° C.

Clinoptilolite is a natural zeolite of the Heylandite group.

Natural zeolite-KLINOPTILOLIT - 70-80% of Azerbaijan’s deposits consist of an active mass - a crystalline form with an obieu formula (K, Na) 4Ca (AfgSi3o072) 20H20. The quartz constitutes 14-16%, calcium i-2.5%, biotite 2-2.5%, other 2-3%. The water adsorption capacity is 3.07 °. Alalysis of this zeolite showed that, in its composition, Ln.a t, wt.%: SiO2 65.9; AfjOs 12.2; FejOa, 1.0; TiOj 0.09; FeO 0.18; MgO 0.57; CaO 4.05 5.25; NajO 2.55; 1.18; HgO 6.2; COj 1.0. Clinoptilolite is used in the form of granules with a size of 3-4 mm, without any additional processing, in its natural form. j The process is carried out in a flow system. The reactor is a glass tube of the brand; an Irrex with an internal diameter of 20 mm, is centered in an electric tube furnace. The initial product, daclohexanol, is supplied from a drip burette at a temperature of 350-450 ° C and a space velocity of 0.25-0.5, and the reaction products, water and hydrocarbon, are collected in a serpentine trap cooled with ice and salt. After the release of the reaction water and drying, the products of the reaction are distilled on a column with a separating capacity of 15–20 theoretical plates in the temperature range of 62–85 ° C and analyzed using a GDG method using an PAHV-05 apparatus. As a stationary phase, a TEGNM deposited on Tripoli of the Zikeevsky open pit was used. Under the conditions of methylcyclopentene formation, the cyclohexanol rehydration reaction proceeds almost quantitatively. The reaction products were a mixture of cyclohexene and metalcyclopetene isomers. The mixture of metspdgklopentenov separated from the isomerizate by distillation, the selection fraction 69-75 ° C, and the fraction 76-85 ° C mainly consists of cyclohexene (boiling point 3-methylcyclopentene 63-64 ° C, l-met: "ltsiklopentena 74-75 ° C, diclohexene 82-83 ° C) Due to the reversibility of the isomerization reaction of cyclohexene and isomers of methylcyclopentene, the 76-85 ° C fraction can be used (and as risykl to convert the intermediate hydrocarbon - daclohexene - into the target product - methylcyclopentene - pa same catalyst with the same conditions. Example. Take something to the reaction: hexanol 19 g (20 ml); catalyst k; schioptilolite 40 ml. Experimental conditions: reaction temperature 350 ° C; volumetric feed velocity of the mouth 0.5 experience duration I h. Degree of alcohol dehydration. Formed: catalyzed - mixture of hydrocarbons 15.2 g (80%, 97.5% of theory); water 3.4 g (18%); coke on the catalyst and loss of 0.4 g (20%). The product boils in the temperature range 60-8: 5 С remaining catalyzate, wt.%: 3-Methp dklopenten 3.0 l Methylcyclopentec 5,9 Cyclohexene91,1. Example 2. Put into the reaction: cyclohexaol 19 g (20 ml); yupshoplolit catalyst 0 ml. Conditions of the experiment; temperature is 400 °; the volumetric flow rate of the alcohol, 5 hours, the duration of the experiment is 1 h. The heat of dehydration of the alcohol is 100%. brazuyuts; catalyzate - a mixture of hydrocarbons 5.0 g (79%; 96.2% of theory); water 3.4 g (18%); coke on catalyst and loss of 0.6 g (3%). A mixture of hydrocarbons boils at 60-85 ° C. Catalystate remaining, wt.%: 3-Methylpicoplopenten7.5 1-Methylcyclopenten17.3 Cyclohexene75.2. Example 3. Into the reaction: nt} 1-cohexaol 19 g (20 ml); Clinoptilolite 40 L-1L catalyst. Conditions of the experiment; reaction temperature 450 C; bulk alcohol feed rate 0.5 test duration 1 hour. Formed: catalyzate — 15.0 g of hydrocarbon mixture (79%, 92.6% of theory); water 3.4 g (18%); coke on catalyst and loss of 0.6 g (3%). 3-Methylcyclopenten 1 - Methyde clopenten Cyclohexene Example 4. In response: cyclohexanol 19 g (20 ml); Clinoptilolitol catalyst 40 ml. Conditions for conducting a grant; reaction temperature is 450 ° C; alcohol flow rate 0.5 h; test duration 1 hour. Formed; catalyzate - a mixture of hydrocarbons 15.0 g (79%, 92.6% of theory); water 3.4 g (18%); coke on the catalyst and loss-0.6 g (3%). Composition of catalyzate, wt.%: 3-Methylcyclopentene 16.0 1-Methylcyclopenten41.0 Cyclohexene43 Example 5. Extraction and reaction; adlohexanol 19 g (20 ml); clinopalolite catalyst 65 ml. Conditions of the experiment; temperature experience 450 ° C; bulk feed rate 0.3 test run time 1 hour. Formed: a mixture of hydrocarbons 14.5 g (76.3%, 93.1% of theory); water 3.4 g (18%); coke and loss of 1.1 g (5.7%).

Composition of catalyzate, wt.

Example 6. Put into reaction: cyclohexanol 19 g (20 ml); Clinoptilolitol catalyst 40 ml.

Test conditions: test temperature 450 ° C; bulk alcohol feed rate: 0.25 test duration: 2 hours. Formed: catalyzate-mixture of hydrogen chloride 14.5 g (76.3%, 93.1% of theory); water 3.4 g (18%); coke on catalyst and loss of 1.1 g (5.7%). The composition of catalyzate, wt.%;

B Methylcyclopemten 60,3

3-methylcyclopenten25,1

Cyclohexene14,0

Methylcyclopentane 0.6.

11rimer | 7. Take it into the reaction: cyclohexanol 95 g (100 ml); Clinoptilolitol catalyst 40 ml.

Test conditions: test temperature 450 ° C; alcohol flow rate 0.5 h; test duration 5 hours. The degree of alcohol dehydration is 100%. Obtained: catalyzate - a mixture of hydrocarbons 76.5 g (96.9% of theory).

The composition of catalyzate,

38.9 1-Methyl cyclopentene 17.0 3- Methyl hccclopenten Cyclohexene 44.1.

The isomerizate from example 7 is subjected to a clear

rectification on a separating column of 80 theoretical plates with sampling of 10 MP / h.

In selected fractions {x4b2-64 ° C = 73.5-75 ° C, the content of 3-methylcyclopentene and 1-methylcyclopentene is not less than 97-98%:

fraction 62-64 ° C, p 1.42001 d 0.7620 (for 3-methylcyclopentene);

fraction 73.5-75 ° C, 1.4330; d 0.7806 (for methylcyclopentene). The residue during distillation above 75 ° C consists mainly of cyclohexene and can be reused to produce methylcyclopentenes by an isomerization reaction on the same catalyst and identical conditions. In the hydrocarbon portion of the catalyzate from all the experiments, the corresponding Hometffle 3-megylcyclopente to 1-methylcyclopentene is 1: 3.

The table shows the composition of the hydrocarbon fraction of catalyzate of the product of the conversion of cyclohexanol to alumina and clinoptilolite under optamal conditions: a space velocity of 0.3 and a test run of 1 hour.

Claims (2)

From the analysis of the data obtained according to the invention and the prototype, it can be seen that the selectivity of the process in the first case is higher. The possibility of recycling cyclohexene (an intermediate product) provides quantitative conversion of cyclohexanol (from theory) to the target product, methylcyclopentenes. At the same time, under identical conditions, the duration of burning coke from spent aluminum oxide is 120 minutes, and of natural zeolite only 80 minutes. Claim 1. Method for producing methylcyclopentene isomers by dehydrating cyclohexanol in the presence of an oxide catalyst at elevated temperature, characterized in that, in order to increase the selectivity of the process, clinoptilolite is used as a catalyst. 2. A method according to claim 1, characterized in that the process is carried out at 35p-450C. Sources of information taken into account in the examination 1.Patent of France No. 2086699, cl. From 07 to 5/00, published 1971. 2. USSR Author's Certificate No. -350735, cl. C 07 C 13/14, 1969 (prototype).