SYNTHESIS METHOD FOR HIGHLY SELECTIVE 2-METHYLALLYL CHLORIDE AND SYNTHESIS REACTOR THEREOF

Abstract

The present invention relates to a synthesis method and synthesis reactor of high-selectivity 2-methylallyl chloride by taking isobutylene and chlorine gas as raw materials and performing a gas-phase chlorination reaction in a microchannel reactor with a cooling surface. The isobutylene and the chlorine gas are reacted in a T-shaped microchannel reactor, and the mixing speed is extremely fast. Meanwhile, the huge heat exchange area per unit volume can ensure that the reaction proceeds stably at a substantially constant temperature and has good controllability. Therefore, side reactions caused by excessive local temperature can be effectively suppressed, the reaction selectivity is high, and no coking phenomenon occurs.

Claims

1. A method for synthesizing high-selectivity 2-methyl-3-chloroallyl, which is used for synthesizing 2-methyl-3-chloroallyl comprising: taking isobutylene and chlorine gas as raw materials, and performing a chlorination reaction in a synthesis reactor with a cooling surface, the synthesis reactor is a synthesis reaction tube with an isobutylene inlet tube and a chlorine gas inlet tube; the isobutylene and the chlorine gas form a mixed raw material and enter the synthesis reaction tube for a gas-phase chlorination reaction; the isobutene inlet tube, the chlorine gas inlet tube and the synthesis reaction tube have a diameter of 0.2˜0.5 mm, respectively; and the cooling surface of the synthesis reactor has a heat exchange area of 8000˜20000 m.sup.2/m.sup.3 based on the actual reaction volume.

2. The synthesis method according to claim 1, wherein a slightly excessive amount of isobutylene is added in the chlorination reaction.

3. The synthesis method according to claim 2, wherein a molar ratio of the isobutylene to the chlorine gas is preferably 1.005˜1.02:1.

4. The synthesis method according to claim 1, wherein the chlorination reaction temperature is 0˜30° C.; the chlorination reaction residence time is 0.1˜1 second.

5. A synthesis reactor of high-selectivity 2-methyl-3-chloroallyl, a synthesis reaction tube with an isobutylene inlet tube and a chlorine gas inlet tube; and a cooling jacket wrapped around the synthesis reaction tube, wherein the isobutylene inlet tube, the chlorine gas inlet tube, and the synthesis reaction tube are connected in a tee form.

6. The synthesis reactor according to claim 5, wherein the isobutylene inlet tube, the chlorine gas inlet tube, and the synthesis reaction tube are connected in a T-shape or a Y-shape.

7. The synthesis reactor according to claim 5, wherein the isobutene inlet tube and the chlorine gas inlet tube are connected in a U-shape, and the upper end of the synthesis reaction tube is connected to the U-shaped outer bottom.

8. The synthesis reactor according to claim 5, wherein the isobutene inlet tube, the chlorine gas inlet tube and the synthesis reaction tube have a diameter of 0.2˜0.5 mm, respectively; and the cooling surface of the synthesis reactor has a heat exchange area of 8000˜20000 m.sup.2/m.sup.3 based on the actual reaction volume.

9. A synthesis reactor assembly for high-selectivity 2-methyl-3-chloroallyl, comprising a plurality of synthesis reactors according to claim 5, wherein the cooling jackets of the plurality of synthesis reactors are communicated with each other.

10. The synthesis reactor assembly according to claim 9, wherein the several synthesis reactors are fixed side by side in the same cooling jacket.

11. A synthesis reactor assembly for high-selectivity 2-methyl-3-chloroallyl, comprising a plurality of synthesis reactors according to claim 6, wherein the cooling jackets of the plurality of synthesis reactors are communicated with each other.

12. The synthesis reactor assembly according to claim 11, wherein the several synthesis reactors are fixed side by side in the same cooling jacket.

13. A synthesis reactor assembly for high-selectivity 2-methyl-3-chloroallyl, comprising a plurality of synthesis reactors according to claim 7, wherein the cooling jackets of the plurality of synthesis reactors are communicated with each other.

14. The synthesis reactor assembly according to claim 13, wherein the several synthesis reactors are fixed side by side in the same cooling jacket.

15. A synthesis reactor assembly for high-selectivity 2-methyl-3-chloroallyl, comprising a plurality of synthesis reactors according to claim 8, wherein the cooling jackets of the plurality of synthesis reactors are communicated with each other.

16. The synthesis reactor assembly according to claim 15, wherein the several synthesis reactors are fixed side by side in the same cooling jacket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a schematic structural diagram of a synthesis reactor according to the present invention; and

[0028] FIG. 2 is a schematic structural diagram of a synthesis reactor assembly of the present invention.

[0029] Reference symbols represent the following components: 1-cooling jacket; 2-chlorine gas inlet tube; 3-isobutylene inlet tube; 4-reaction tube; 5-reaction product outlet tube.

DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below with reference to the drawings and examples.

[0031] As shown in FIG. 1, the present invention relates to a synthesis reactor with a cooling jacket 1. The reactor is an elongated reaction tube 4. A raw chlorine gas inlet tube 2 and an isobutylene inlet tube 3 are connected to an upper port of the reaction tube 4, and a reaction product outlet tube 5 is connected to a lower port of the reaction tube 4. According to the present invention, the chlorine gas inlet tube 2, the isobutylene inlet tube 3 and the reaction tube 4 are connected (e.g., connected in a tee shape) just by ensuring that the two raw materials enter the one end of the reaction tube 4 at the same time for a mixed reaction. A product outlet is formed in the other end of the reaction tube 4. Preferably, the chlorine gas inlet tube 2, the isobutylene inlet tube 3 and the reaction tube 4 are T-shaped or Y-shaped.

[0032] As shown in FIG. 2, a plurality of synthesis reactors of the present invention are connected in a combined manner. Each reactor is an independent reaction tube 4, with an independent chlorine gas inlet tube 2, isobutene inlet tube 3 and reaction product outlet tube 5. A plurality of reactors share the same cooling jacket 1, which is equivalent that a plurality of synthesis reactors of the present invention are fixed side by side in the same cooling jacket, thereby effectively using the space and energy, and improving the reaction efficiency.

EXAMPLE 1

[0033] Isobutene and chlorine gas are introduced respectively into the microchannel reactor shown in FIG. 1 (the channel diameter is 0.2 mm, and the heat exchange area calculated based on the actual reaction volume is 20000 m.sup.2/m.sup.3). By adjusting and controlling the flows of isobutene and chlorine gas, the reaction residence time reaches 1 second. A molar ratio of the isobutylene to the chlorine gas is 1.005:1, and the reaction temperature is controlled to 0° C. by freezed brine. After 30 minutes of stable operation, a liquid product is sampled from an outlet of the reactor, and the composition of the liquid product is analyzed as the following mass content: 89.6% of 2-methylallyl chloride, 2.3% of chloro-tert-butane, 1.3% of isobutenyl chloride, 5.6% of dichloro-tert-butane, and 1.2% of dichloro-isobutene. Therefore, the selectivity of the calculated 2-methylallyl chloride is calculated as 91.4%.

EXAMPLE 2

[0034] Isobutene and chlorine gas are introduced respectively into the microchannel reactor shown in FIG. 1 (the channel diameter is 0.5 mm, and the heat exchange area calculated based on the actual reaction volume is 8000 m.sup.2/m.sup.3). By adjusting and controlling the flows of isobutene and chlorine gas, the reaction residence time reaches 0.1 second. A molar ratio of the isobutylene to the chlorine gas is 1.02:1, and the reaction temperature is controlled to 30° C. by low-temperature water. After 30 minutes of stable operation, a liquid product is sampled from the outlet of the reactor, and the composition of the liquid product is analyzed as the following mass content: 88.7% of 2-methylallyl chloride, 2.1% of chloro-tert-butane, 1.5% of isobutenyl chloride, 6.0% of dichloro-tert-butane, and 1.5% of dichloro-isobutene. Therefore, the selectivity of the calculated 2-methylallyl chloride is calculated as 90.5%.

EXAMPLE 3

[0035] Isobutene and chlorine gas are introduced respectively into the microchannel reactor shown in FIG. 1 (the channel diameter is 0.4 mm, and the heat exchange area calculated based on the actual reaction volume is 10000 m.sup.2/m.sup.3). By adjusting and controlling the flows of isobutene and chlorine gas, the reaction residence time reaches 0.5 second. A molar ratio of the isobutylene to the chlorine gas is 1.01:1, and the reaction temperature is controlled to 10° C. by freezed brine. After 30 minutes of stable operation, a liquid product is sampled from the outlet of the reactor, and the composition of the liquid product is analyzed as the following mass content: 89.3% of 2-methylallyl chloride, 2.3% of chloro-tert-butane, 1.4% of isobutenyl chloride, 5.7% of dichloro-tert-butane, and 1.3% of dichloro-isobutene. Therefore, the selectivity of the calculated 2-methylallyl chloride is calculated as 91.1%.

EXAMPLE 4

[0036] Isobutene and chlorine gas are introduced respectively into the microchannel reactor shown in FIG. 2 (the channel diameter is 0.3 mm, and the heat exchange area calculated based on the actual reaction volume is 13330 m.sup.2/m.sup.3). By adjusting and controlling the flows of isobutene and chlorine gas, the reaction residence time reaches 0.3 second. A molar ratio of the isobutylene to the chlorine gas is 1.01:1, and the reaction temperature is controlled to 20° C. with low-temperature water. After 30 minutes of stable operation, a liquid product is sampled from the outlet of the reactor, and the composition of the liquid product is analyzed as the following mass content: 89.1% of 2-methylallyl chloride, 2.2% of chloro-tert-butane, 1.5% of isobutenyl chloride, 5.8% of dichloro-tert-butane, and 1.4% of dichloro-isobutene. Therefore, the selectivity of the calculated 2-methylallyl chloride is calculated as 90.9%.