Method for preparing tert-dodecyl mercaptan by using byproduct of high-boiling residue of nonene device

Abstract

The invention belongs to the field of fine chemical engineering, and particularly discloses a method for preparing tert-dodecyl mercaptan by using a high-boiling residue byproduct of a nonene device, which comprises the following steps: purifying and refining the high-boiling residue byproduct of the nonene device as a raw material through vacuum rectification, collecting fractions at 70-90 DEG C under the conditions that the vacuum degree is 95-98kPa and the reflux ratio is 3-5 as a dodecene raw material for synthesizing the tert-dodecyl mercaptan, in an absorption tower type reactor, under the catalytic action of a tubular acidic resin catalyst, tert-dodecanethiol is subjected to reverse contact and chemical absorption with hydrogen sulfide, tert-dodecanethiol is continuously synthesized, the highest conversion per pass can reach 87%, and the selectivity is close to 100%. Due to the adoption of the packed tower type structure, the difficulty in designing, manufacturing and operating the reactor is greatly reduced, and the temperature rise can be controlled through the circulation of materials after the reaction. The method not only solves the problem of raw material source of tert-dodecanethiol, but also makes full use of the high-boiling residue byproduct of the nonene device, and greatly improves the economic benefit and market core competitiveness of the nonene device.

Description

Technical Field

[0001] The invention relates to the field of fine chemicals, in particular to a method for preparing tert-dodecyl mercaptan by using high-boiling by-products of a nonene device. Background Art

[0002] Tert-dodecyl mercaptan (also known as tert-dodecyl mercaptan, trade name TDM) is mainly used as a molecular weight regulator in the synthesis process of polymer materials such as ABS resin and styrene-butadiene rubber (SBR), reducing the branching degree of the polymer chain and making the relative molecular mass distribution uniform. The main raw material dodecene of tert-dodecyl mercaptan includes two types of trimerized isobutylene and tetrapropylene, which are complex mixtures. Among them, tetrapropylene has become the most important raw material source of commodity tert-dodecyl mercaptan with its high stability in the reaction process and the product tert-dodecyl mercaptan performance is more excellent. Although many research institutions and enterprises at home and abroad have made major breakthroughs in the synthesis of tert-dodecyl mercaptan from tetrapropylene and trimerized isobutylene, including aspects such as catalysts and synthesis processes, there is no special production device for tetrapropylene and trimerized isobutylene in China, and the industrial raw materials of domestic synthesis of tert-dodecyl mercaptan products are in urgent need of solution. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for preparing tert-dodecyl mercaptan using high-boiling by-products of a nonene device.

[0004] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0005] A method for preparing tert-dodecyl mercaptan from high-boiling by-products of a nonene device comprises the following steps:

[0006] S1. Purify the high-boiling by-product of the nonene unit by vacuum distillation, and collect the fraction at 70-90° C. under the conditions of vacuum degree of 95-98 kPa and reflux ratio of 3-5 as dodecene raw material for synthesizing tert-dodecyl mercaptan, wherein the dodecene raw material contains the following components in weight percentage: 90%-92% dodecene, 3%-4% decadecene, 4%-6% undecene, and less than 1.0% tridecene and above;

[0007] S2. An absorption tower reactor filled with a tubular acid resin catalyst is used. The dodecene raw material entering from the upper part of the reactor is in reverse contact with the hydrogen sulfide entering from the lower part of the reactor to cause a chemical absorption process. The reaction conditions are: the feed temperature of the dodecene raw material is 50-100°C, the spray density of the dodecene raw material is 5.0-20.0 mL / cm 2h, the molar ratio of the dodecene raw material to the hydrogen sulfide is 1:1-5, and the reaction pressure is 0.5-3.0 MPa; tert-dodecyl mercaptan product is continuously generated, and the tert-dodecyl mercaptan product is circulated and input into the absorption tower reactor, and the tert-dodecyl mercaptan product finally obtained is desorbed under reduced pressure to obtain a crude tert-dodecyl mercaptan product.

[0008] Preferably, the catalyst is a tubular acid resin catalyst or a solid acid catalyst with a filling porosity greater than 40%.

[0009] Preferably, the catalyst has a height-to-diameter ratio of 8-20.

[0010] Preferably, the tubular acid resin catalyst is LXC-503 cation exchange resin, and the solid acid catalyst with a filling porosity greater than 40% is HND-33 solid acid catalyst.

[0011] Preferably, the circulation recovery ratio of the tert-dodecyl mercaptan product is 0-5.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The present invention can make full use of the high-boiling by-products of the nonene unit as the starting raw material for synthesizing tert-dodecyl mercaptan, which not only solves the problem of the raw material source of tert-dodecyl mercaptan, but also can greatly improve the economic benefits and market core competitiveness of the nonene unit, and at the same time provides the possibility and opportunity for the localization of tert-dodecyl mercaptan.

[0014] 2. The present invention develops an absorption tower reactor with simple structure, easy design and manufacture, and convenient operation, and a chemical absorption reaction process adapted thereto, which simplifies the process flow and operation steps.

[0015] 3. The present invention adopts a tubular resin catalyst or a solid acid catalyst with a relatively large filling porosity, which greatly increases the gas-liquid contact specific surface area, making the diffusion process of gaseous hydrogen sulfide to the liquid phase body faster, thereby increasing the concentration of hydrogen sulfide in the liquid phase body in disguised form, making the addition reaction of dodecene and hydrogen sulfide faster. At the same time, since the flow rate of hydrogen sulfide in the absorption tower reactor mainly depends on the absorption rate, the hydrogen sulfide that needs to be recycled is greatly reduced, greatly reducing the process energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a simplified experimental flow chart of preparing tert-dodecyl mercaptan from dodecene obtained by purifying and refining high-boiling by-products of a nonene device. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.

[0018] The high-boiling byproducts of the nonene unit used in the following examples were sourced from Daqing Zhonglan Petrochemical Co., Ltd. Hydrogen sulfide gas was purchased from Shandong Zibo Dijia Special Gas Co., Ltd. with a purity greater than 99%. High-purity nitrogen was purchased from Daqing Xuelong Petrochemical Technology Development Co., Ltd. with a purity greater than 99%. LXC-503 cationic ion exchange resin catalyst was purchased from Xi'an Lanxiao Technology Co., Ltd.; HND-33 solid acid catalyst was purchased from Jiangyin Nanda Synthetic Chemical Co., Ltd.

[0019] The dodecene conversion and tert-dodecyl mercaptan selectivity used in the following examples were measured by Agilent 7890B gas chromatography, capillary column: RTX-5, 50m×0.25mm×0.25μm; column temperature: initial temperature 50°C, maintained for 5min, and increased at 10°C / min to a final temperature of 280°C; FID detector detection, nitrogen as carrier gas, and feed amount of 0.5μL.

[0020] The batch distillation tower and absorption tower reactor used in the following examples were manufactured by Beijing Huafan Technology Co., Ltd. The batch distillation tower has an inner diameter of 35 mm and is filled with 1300 mm of φ2.5×2.5 mm θ mesh ring filler, which is equivalent to 47 theoretical plates. The absorption tower reactor has an inner diameter of 32 mm, a maximum catalyst loading height of 600 mm, and is divided into two sections with heights of 200 mm and 400 mm, respectively.

[0021] Example 1

[0022] like Figure 1 As shown, the high-boiling byproduct of the nonene unit is purified by vacuum distillation. Under the condition of vacuum degree 95-98kPa and reflux ratio of 3-5, the fraction of 70-90°C is collected as the dodecene raw material for synthesizing tert-dodecyl mercaptan, which contains 90%-92% dodecene, 3%-4% decadecene, 4%-6% undecene, and less than 1.0% tridecene and above; an absorption tower reactor filled with a tubular acid resin catalyst is used, the LXC-503 filling height is 300mm, only one section is filled, and there is no reaction product circulation; the dodecene raw material entering from the upper part of the reactor is in reverse contact with the hydrogen sulfide entering from the lower part of the reactor to undergo a chemical absorption process, and the tert-dodecyl mercaptan product is continuously generated. The obtained tert-dodecyl mercaptan product is desorbed under reduced pressure to obtain a crude tert-dodecyl mercaptan product. The reaction conditions are as follows: the feed temperature of the dodecene raw material is 60°C, the spray density of the dodecene raw material is 6.0mL / cm 2·h, the molar ratio of dodecene raw material to hydrogen sulfide is 1:1, the reaction pressure is 1.0Mpa, the product after the reaction enters the desorption tank for decompression analysis to obtain the crude product of tert-dodecyl mercaptan, and the desorbed hydrogen sulfide is subjected to alkali absorption treatment.

[0023] Example 2

[0024] The only difference from Example 1 is that the molar ratio of dodecene raw material to hydrogen sulfide is 1:2.

[0025] Example 3

[0026] The only difference from Example 1 is that the molar ratio of dodecene raw material to hydrogen sulfide is 1:3.

[0027] Example 4

[0028] The only difference from Example 1 is that the molar ratio of dodecene raw material to hydrogen sulfide is 1:4.

[0029] Example 5

[0030] The only difference from Example 1 is that the molar ratio of dodecene raw material to hydrogen sulfide is 1:5.

[0031] The reaction results of Examples 1 to 5 are shown in Table 1.

[0032] Table 1 Reaction results of Examples 1 to 5

[0033]

[0034] Example 6

[0035] The high-boiling byproduct of the nonene unit is purified by vacuum distillation. Under the conditions of vacuum degree of 95-98kPa and reflux ratio of 3-5, the fraction of 70-90°C is collected as the dodecene raw material for synthesizing tert-dodecyl mercaptan, which contains 90%-92% dodecene, 3%-4% decadecene, 4%-6% undecene, and less than 1.0% tridecene and above; an absorption tower reactor filled with a tubular acid resin catalyst is used, the LXC-503 filling height is 300mm, only one section is filled, and there is no reaction product circulation; the dodecene raw material entering from the upper part of the reactor is in reverse contact with the hydrogen sulfide entering from the lower part of the reactor to undergo a chemical absorption process, and the tert-dodecyl mercaptan product is continuously generated. The obtained tert-dodecyl mercaptan product is desorbed under reduced pressure to obtain a crude tert-dodecyl mercaptan product. The reaction conditions are as follows: the feed temperature of the dodecene raw material is 70°C, the spray density of the dodecene raw material is 6.0mL / cm 2 ·h, the molar ratio of dodecene raw material to hydrogen sulfide is 1:3, the reaction pressure is 1.0Mpa, the product after the reaction enters the desorption tank for decompression analysis to obtain the crude product of tert-dodecyl mercaptan, and the desorbed hydrogen sulfide is subjected to alkali absorption treatment.

[0036] Example 7

[0037] The only difference from Example 6 is that the feed temperature of the dodecene raw material is 80°C.

[0038] Example 8

[0039] The only difference from Example 6 is that the feed temperature of the dodecene raw material is 90°C.

[0040] Example 9

[0041] The only difference from Example 6 is that the feed temperature of the dodecene raw material is 100°C.

[0042] The reaction results of Examples 6 to 9 are shown in Table 2.

[0043] Table 2 Reaction results of Examples 6 to 9

[0044]

[0045] Example 10

[0046] The high-boiling byproduct of the nonene unit is purified by vacuum distillation. Under the conditions of vacuum degree of 95-98kPa and reflux ratio of 3-5, the fraction of 70-90°C is collected as the dodecene raw material for synthesizing tert-dodecyl mercaptan, which contains 90%-92% dodecene, 3%-4% decadecene, 4%-6% undecene, and less than 1.0% tridecene and above; an absorption tower reactor filled with a tubular acid resin catalyst is used, the LXC-503 filling height is 300mm, only one section is filled, and there is no reaction product circulation; the dodecene raw material entering from the upper part of the reactor is in reverse contact with the hydrogen sulfide entering from the lower part of the reactor to undergo a chemical absorption process, and the tert-dodecyl mercaptan product is continuously generated. The obtained tert-dodecyl mercaptan product is desorbed under reduced pressure to obtain a crude tert-dodecyl mercaptan product. The reaction conditions are as follows: the feed temperature of the dodecene raw material is 70°C, the spray density of the dodecene raw material is 6.0mL / cm 2 ·h, the molar ratio of dodecene raw material to hydrogen sulfide is 1:3, the reaction pressure is 1.5Mpa, the product after the reaction enters the desorption tank for decompression analysis to obtain the crude product of tert-dodecyl mercaptan, and the desorbed hydrogen sulfide is subjected to alkali absorption treatment.

[0047] Embodiment 11

[0048] The only difference from Example 10 is that the reaction pressure is 2.0 MPa.

[0049] Example 12

[0050] The only difference from Example 10 is that the reaction pressure is 2.5 MPa.

[0051] Example 13

[0052] The only difference from Example 10 is that the reaction pressure is 3.0 MPa.

[0053] The reaction results of Examples 10 to 13 are shown in Table 3.

[0054] Table 3 Reaction results of Examples 10 to 13

[0055]

[0056] Embodiment 14

[0057] The high-boiling byproduct of the nonene unit is purified by vacuum distillation. Under the conditions of vacuum degree of 95-98kPa and reflux ratio of 3-5, the fraction of 70-90°C is collected as the dodecene raw material for synthesizing tert-dodecyl mercaptan, which contains 90%-92% dodecene, 3%-4% decadecene, 4%-6% undecene, and less than 1.0% tridecene and above; an absorption tower reactor filled with a tubular acid resin catalyst is used, the LXC-503 filling height is 300mm, only one section is filled, and there is no reaction product circulation; the dodecene raw material entering from the upper part of the reactor is in reverse contact with the hydrogen sulfide entering from the lower part of the reactor to undergo a chemical absorption process, and the tert-dodecyl mercaptan product is continuously generated. The obtained tert-dodecyl mercaptan product is desorbed under reduced pressure to obtain a crude tert-dodecyl mercaptan product. The reaction conditions are as follows: the feed temperature of the dodecene raw material is 70°C, the spray density of the dodecene raw material is 10.0mL / cm 2 ·h, the molar ratio of dodecene raw material to hydrogen sulfide is 1:3, the reaction pressure is 1.5Mpa, the product after the reaction enters the desorption tank for decompression analysis to obtain the crude product of tert-dodecyl mercaptan, and the desorbed hydrogen sulfide is subjected to alkali absorption treatment.

[0058] Embodiment 15

[0059] The only difference from Example 14 is that the spray density of dodecene raw material is 15.0 mL / cm 2 ·h.

[0060] Example 16

[0061] The only difference from Example 14 is that the spray density of dodecene raw material is 20.0 mL / cm 2 ·h.

[0062] The reaction results of Examples 14 to 16 are shown in Table 4.

[0063] Table 4 Reaction results of Examples 14 to 16

[0064]

[0065] Embodiment 17

[0066] The high-boiling byproduct of the nonene unit is purified by vacuum distillation. Under the conditions of vacuum degree of 95-98kPa and reflux ratio of 3-5, the fraction of 70-90°C is collected as the dodecene raw material for synthesizing tert-dodecyl mercaptan, which contains 90%-92% dodecene, 3%-4% decadecene, 4%-6% undecene, and less than 1.0% tridecene and above; an absorption tower reactor filled with a tubular acid resin catalyst is used, the LXC-503 filling height is 300mm, only one section is filled, and there is no reaction product circulation; the dodecene raw material entering from the upper part of the reactor is in reverse contact with the hydrogen sulfide entering from the lower part of the reactor to undergo a chemical absorption process, and the tert-dodecyl mercaptan product is continuously generated. The obtained tert-dodecyl mercaptan product is desorbed under reduced pressure to obtain a crude tert-dodecyl mercaptan product. The reaction conditions are as follows: the feed temperature of the dodecene raw material is 70°C, the spray density of the dodecene raw material is 10.0mL / cm 2 h, the molar ratio of dodecene raw material to hydrogen sulfide is 1:3, the reaction pressure is 1.5 MPa, the circulation temperature of tert-dodecyl mercaptan product is 65°C, and the tert-dodecyl mercaptan product circulation: withdrawal ratio is 1; the product after the reaction enters the desorption tank for decompression analysis to obtain a crude tert-dodecyl mercaptan product, and the desorbed hydrogen sulfide is subjected to alkali absorption treatment.

[0067] Embodiment 18

[0068] The only difference from Example 17 is that the product recycle and withdrawal ratios of tert-dodecyl mercaptan are 3 respectively.

[0069] Embodiment 19

[0070] The only difference from Example 17 is that the product recycle and withdrawal ratios of tert-dodecyl mercaptan are 5 respectively.

[0071] The reaction results of Examples 17 to 19 are shown in Table 5.

[0072] Table 5 Reaction results of Examples 17 to 19

[0073]

[0074] Comparative Example 1

[0075] The operating conditions and process were the same as those in Example 18, except that the catalyst was HND33. The reaction results were: reactor temperature rise of 16.8° C., dodecene conversion of 62.08%, and mercaptan selectivity close to 100%.

[0076] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing tert-dodecyl mercaptan from high-boiling by-products of a nonene device, characterized in that: The following steps are involved: S1. Purify the high-boiling by-product of the nonene unit by vacuum distillation, and collect the fraction at 70-90° C. under the conditions of vacuum degree of 95-98 kPa and reflux ratio of 3-5 as dodecene raw material for synthesizing tert-dodecyl mercaptan, wherein the dodecene raw material contains the following components in weight percentage: 90%-92% dodecene, 3%-4% decadecene, 4%-6% undecene, and less than 1.0% tridecene and above; S2. An absorption tower reactor filled with a tubular acid resin catalyst is used. The dodecene raw material entering from the upper part of the reactor is in reverse contact with the hydrogen sulfide entering from the lower part of the reactor to cause a chemical absorption process. The reaction conditions are: the feed temperature of the dodecene raw material is 50-100°C, the spray density of the dodecene raw material is 5.0-20.0 mL / cm 2 h, the molar ratio of the dodecene raw material to the hydrogen sulfide is 1:1-5, and the reaction pressure is 0.5-3.0 MPa; the crude tert-dodecyl mercaptan product is continuously generated, and the tert-dodecyl mercaptan product is circulated and input into the absorption tower reactor, and finally the obtained tert-dodecyl mercaptan product is desorbed under reduced pressure to obtain a crude tert-dodecyl mercaptan product.

2. The method for preparing tert-dodecyl mercaptan from high-boiling by-products of a nonene device according to claim 1, characterized in that: The catalyst is a tubular acid resin catalyst or a solid acid catalyst with a filling porosity greater than 40%.

3. The method for preparing tert-dodecyl mercaptan from high-boiling by-products of a nonene device according to claim 1 or 2, characterized in that: The catalyst has a height-to-diameter ratio of 8-20.

4. The method for preparing tert-dodecyl mercaptan from high-boiling by-products of a nonene device according to claim 2, characterized in that: The tubular acid resin catalyst is LXC-503 cation exchange resin, and the solid acid catalyst with a filling porosity greater than 40% is HND-33 solid acid catalyst.

5. The method for preparing tert-dodecyl mercaptan from high-boiling by-products of a nonene device according to claim 1, characterized in that: The circulation recovery ratio of the tert-dodecyl mercaptan product is 0-5.

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