Deodorization method of sulfurized isobutylene

Abstract

The invention discloses a sulfurized isobutylene deodorization method, which specifically comprises the following steps: mixing sulfurized isobutylene with isocyanate, carrying out stirring reaction, standing, and carrying out reduced pressure distillation to obtain a deodorized sulfurized isobutylene product. According to the method, very active isocyanate substances react with the mercaptan to eliminate or reduce the content of the mercaptan in the sulfurized isobutylene, so that the odor of the sulfurized isobutylene is effectively reduced, the removal rate of the mercaptan can reach 96% or above, the odor of the sulfurized isobutylene can be reduced by three grades to 1 grade according to an odor evaluation method, and the odor of the sulfurized isobutylene can be reduced by three grades to 1 grade. Meanwhile, the PB, PD, ZMZ, wear scar diameter and other properties of the sulfurized isobutylene are not greatly changed. The method can greatly improve the industrial production and use environment of sulfurized isobutylene, and has important application value in the field of extreme pressure wear resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricant addition, and particularly relates to a method for deodorizing sulfided isobutylene. Background Art

[0002] In the traditional production process of isobutylene sulfide, a large amount of H 2 S, NaCl, Na 2 S and other waste gases and wastewater. Every ton of isobutylene sulfide produced generates about 6 tons of sulfur-containing alkaline wastewater and 136 kg H 2 S waste gas. In particular, the mass concentration of COD in wastewater is as high as 20,000 mg / L, and the mass concentration of suspended solids is about 10,000 mg / L, which contains extremely difficult-to-treat substances such as mercaptans and sulfides, has a strong odor, is not easy to desorb, and causes serious corrosion to equipment and pollution to the environment.

[0003] The Chinese patent (application number: 201310387600.3, publication number: CN103408531A) discloses a method for synthesizing isobutylene sulfide, and its main features are: the reaction equipment and containers in the production process are fully enclosed and their exhaust gases are classified and concentrated, and are discharged in an orderly manner into an absorption tower system with sufficient absorption capacity; strict management of its tail gas is achieved through the design and layout of the absorption tower and the mechanism and operation control of the absorption liquid; the combined wastewater of the dechlorination process is acidified, oxidized, flocculated and treated to recover sodium sulfide and discharge colorless, transparent and odorless wastewater; after the absorption liquid reaches the end point, the corresponding solid sodium sulfide is obtained and enters the production circulation system, thereby achieving the recycling of resources, reducing production costs and improving economic benefits.

[0004] A Chinese patent (application number: 202210982556.X, publication number: CN115340480A) discloses a method for removing mercaptans from sulfided olefins. The sulfided isobutylene is treated with an alkali and a catalyst to effectively reduce the content of mercaptans in sulfided butane, and the mercaptan sulfur content in the sulfided isobutylene sample can be reduced by up to 95.5%; the treated isobutylene sulfide not only has a low odor, but also has low corrosion to copper sheets; however, this method uses more chemical reagents, the processing steps are cumbersome, and there is a lot of waste of raw materials in the processing process.

[0005] As an extreme pressure and anti-wear agent with excellent performance, isobutylene sulfide has important applications in industrial processing, ship fuel, load transportation and other fields. However, isobutylene sulfide has a strong odor during use, which not only affects the extreme pressure and anti-wear properties of isobutylene sulfide, but also endangers the health of personnel and pollutes the air. Although certain treatments have been made to the odor of isobutylene sulfide in its production and post-processing, there is still no simple and effective method to remove the odor of isobutylene sulfide. In order to effectively reduce the odor of isobutylene sulfide, the components of isobutylene sulfide are analyzed by nuclear magnetic resonance (NMR), mass spectrometry (MS), gas chromatography-mass spectrometry (GCMS) and infrared spectrometer (IR). It is found that isobutylene sulfide is a mixture system with complex components and a large number of substances. Further analysis and detection show that isobutylene sulfide contains a small amount of short-chain olefins, isobutyl sulfide, isobutyl mercaptan, isobutyl polysulfide and cyclic alkyl sulfide. The content of isobutyl mercaptan and other alkyl mercaptan is 0.5-4%. The verification experiment shows that the source of the odor is volatile short-chain small molecule mercaptan. Therefore, reducing the content of mercaptan in isobutylene sulfide will greatly reduce the odor of isobutylene sulfide. Summary of the invention

[0006] The object of the present invention is to provide a method for deodorizing isobutylene sulfide, so as to reduce the content of mercaptan in isobutylene sulfide, thereby greatly reducing the odor of isobutylene sulfide.

[0007] The technical scheme adopted by the present invention is a method for deodorizing isobutylene sulfide, which specifically comprises: mixing isobutylene sulfide with isocyanate, carrying out stirring reaction, standing and performing reduced pressure distillation to obtain a deodorized isobutylene sulfide product.

[0008] The present invention is also characterized in that:

[0009] The isocyanate is any one of tolylene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone isocyanate.

[0010] The mass ratio of sulfided isobutylene to isocyanate is 1:0.05-0.1.

[0011] The stirring reaction temperature is 25-35°C, and the stirring reaction time is 10-15h.

[0012] The reduced pressure distillation temperature is 60-80°C, the vacuum degree is 10-15 mmHg, the reduced pressure distillation time is 1-2 h; the standing time is 24 h.

[0013] The beneficial effects of the present invention are as follows: the present invention adopts a very active isocyanate substance to react with mercaptan to eliminate or reduce the content of mercaptan in sulfided isobutylene, thereby effectively reducing the odor of sulfided isobutylene, and the removal rate of mercaptan can reach more than 96%. The odor of sulfided isobutylene can be reduced by 3 levels to level 1 according to the odor evaluation method, and at the same time, the performances of sulfided isobutylene, such as PB, PD, ZMZ and wear spot diameter, do not change much. The method can greatly improve the environment for industrial production and use of sulfided isobutylene, and has important application value in the field of extreme pressure and anti-wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the GC detection spectrum of the standard sample sulfided isobutylene;

[0015] Figure 2 This is the GC detection spectrum of the sample in Example 1;

[0016] Figure 3 This is the GC detection spectrum of the sample in Example 2;

[0017] Figure 4 This is the GC detection spectrum of the sample in Example 3;

[0018] Figure 5 This is the GC detection spectrum of the sample in Example 4;

[0019] Figure 6 This is the GC detection spectrum of the sample in Example 5. DETAILED DESCRIPTION

[0020] The present invention is described in detail below in conjunction with specific implementation modes and accompanying drawings.

[0021] The present invention provides a method for deodorizing sulfided isobutylene, which is specifically:

[0022] The isobutylene sulfide is mixed with the isocyanate, stirred for reaction, left to stand for 24 hours and then distilled under reduced pressure to obtain the deodorized isobutylene sulfide product.

[0023] The isocyanate is any one of tolylene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone isocyanate.

[0024] The mass ratio of sulfided isobutylene to isocyanate is 1:0.05-0.1;

[0025] The stirring reaction temperature is 25-35°C, and the stirring reaction time is 10-15h;

[0026] The vacuum distillation temperature is 60-80℃, the vacuum degree is 10-15mmHg, and the vacuum distillation time is 1-2h;

[0027] In order to reduce and remove isobutyl mercaptan and alkyl mercaptan in isobutylene sulfide, the present invention adopts a chemical reaction method to make isobutyl mercaptan and alkyl mercaptan in isobutylene sulfide form macromolecular sulfide compounds through rapid organic chemical reaction, and the substances forming sulfide can reduce volatility and reduce odor, and also do not affect the extreme pressure and anti-wear properties of isobutylene sulfide. In order to enable the mercaptan in isobutylene sulfide to react quickly, isocyanate is selected as a reactant and added to isobutylene sulfide for reaction. Isocyanate is an important intermediate in organic synthesis, which can be made into a series of carbamate insecticides, bactericides, herbicides, and is also used to improve the waterproofness of plastics, fabrics, leather, etc. Therefore, as a low-cost industrial product, isocyanate is more suitable as a reaction reagent, which can form sulfide substances with mercaptan to reduce volatility and reduce odor, and can also form sulfide without affecting the extreme pressure and anti-wear properties of isobutylene sulfide. The present invention uses a very active isocyanate substance to react with mercaptan to eliminate or reduce the content of mercaptan in sulfided isobutylene, thereby effectively reducing the odor of sulfided isobutylene, the removal rate of mercaptan can reach more than 96%, the odor of sulfided isobutylene can be reduced by 3 levels to level 1 according to the odor evaluation method, and at the same time, the performances of sulfided isobutylene, such as PB, PD, ZMZ and wear spot diameter, do not change much. The present invention uses low-cost isocyanate as a reaction reagent, provides a new path and method for removing mercaptan, and the method can greatly improve the environment for industrial production and use of sulfided isobutylene, and has important application value in the field of extreme pressure and anti-wear.

[0028] Select isobutylene sulfide as the treatment object, control the room temperature at 25±2°C, take 100 mL of isobutylene sulfide, add isocyanate to it for treatment, stir it thoroughly at different temperatures and let it stand for 24 hours.

[0029] The odor of treated sulfided isobutylene is evaluated subjectively. The subjective evaluation method of odor refers to the description of the characteristics or words of the concentration, intensity, persistence, pleasantness-unpleasantness, odor quality, taste and feeling of the odor through the human sense of smell. During the evaluation process, the tester should wear clean gloves on both hands and quickly put the odor sample treated by the deodorization cleaning procedure into a 500mL odorless sealed stoppered conical flask, let it stand for 30 minutes, then open the stoppered conical flask, take out the sample with a sample paper and bring it close to the nostrils, smell the odor on the sample carefully, refer to ISO 17299-2014, evaluate the sample according to the odor concentration, and record the odor concentration level. The higher the level, the stronger the odor concentration. The subjective evaluation process should be carried out in a room with suitable temperature and humidity and no odor, and rated by 3 trained testers respectively. During the olfactory measurement, the tester shall not communicate with others about the results of the selection. If the rating results of more than two testers are the same, the majority rating result will be used as the odor concentration level; if the rating results of the three testers are different, retest. The consistent evaluation results of at least two testers will be used as the final result of the odor detection.

[0030] Table 1 Subjective evaluation rating table of odor concentration

[0031]

[0032] Take 0.2 mL of isocyanate-treated isobutylene sulfide and # The white oil was diluted 400 times as a whole and recorded as A, which was evaluated by three odorists using a subjective evaluation method.

[0033] Evaluation method for extreme pressure and anti-wear of treated sulfurized isobutylene:

[0034] The friction performance was tested using a MS-10J four-ball machine, Class I base oil MVI500 and medium-high carbon chromium bearing steel balls that meet GB / T 308.1-2013. The test conditions were 75°C and 1200 rpm for 1 hour. The values ​​of PB / N, PD / N, ZMZ and wear spot diameter were obtained by taking the average value of two tests according to GB / T3142 standards.

[0035] Example 1

[0036] Take 100 mL of the sulfided isobutylene product, add 0.5 mL of toluene diisocyanate (TDI) for 5 min, stir thoroughly for 5 h, and then let it stand for 24 h for odor evaluation and performance evaluation. Figure 1 This is the gas chromatogram of mercaptan content in sulfided isobutylene before treatment. Figure 2 The figure is a gas chromatogram of the mercaptan content in the treated sulfided isobutylene. The mercaptan removal rate detected by gas chromatography is 96.5%.

[0037] Table 2 Odor evaluation

[0038] Sniffer No. Untreated sample rating Rating of processed samples Downgrade 1 5 1 4 2 5 2 3 3 5 1 4

[0039] Table 3 Performance evaluation

[0040] serial number PB / N PD / N ZZ Wear spot diameter / mm Untreated samples 785 3924 543 0.52 Sample of Example 1 792 3970 550 0.50

[0041] As shown in Table 2, the pungent odor of the sulfided isobutylene product treated with toluene diisocyanate (TDI) decreased by 3-4 levels, which is consistent with the removal rate obtained by gas chromatography and meets the human sensory standards and production environment requirements. As shown in Table 3, the four parameter indicators of the sulfided isobutylene product treated with the isocyanate did not fluctuate much, among which the no-seizure load decreased slightly, while the sintering load and the comprehensive wear value increased slightly, and the wear spot diameter remained basically unchanged, only decreasing by 0.02 mm. All parameters were qualified, so the product treated with the isocyanate met the requirements.

[0042] Example 2

[0043] Take 100 mL of the sulfided isobutylene product, add 1.0 mL of diphenylmethane diisocyanate dropwise for 15 min, stir thoroughly at room temperature for 5 h, and let stand for 24 h before evaluating the performance and odor. Figure 3 The figure is a gas chromatogram of the mercaptan content in the treated sulfided isobutylene. The mercaptan removal rate detected by gas chromatography is 97.3%.

[0044] Table 4 Odor evaluation

[0045]

[0046]

[0047] Table 5 Performance evaluation

[0048] serial number PB / N PD / N ZZ Wear spot diameter / mm Untreated samples 785 3924 543 0.52 Sample of Example 2 788 3945 544 0.50

[0049] As shown in Table 4, the pungent odor of the sulfided isobutylene product treated with diphenylmethane diisocyanate (MDI) decreased by 4-5 levels, and the mercaptan removal effect was excellent, meeting the human sensory standards and production environment requirements. As shown in Table 5, the four parameter indicators of the sulfided isobutylene product treated with the isocyanate did not fluctuate much, the no-seizure load, sintering load, and comprehensive wear value increased slightly, and the wear spot diameter decreased by 0.04 mm. All parameters were qualified, so the product treated with the isocyanate met the requirements.

[0050] Example 3

[0051] Take 100 mL of the sulfided isobutylene product, add 2.0 mL of hexamethylene diisocyanate dropwise for 5 min, stir thoroughly for 5 h at room temperature, and let stand for 24 h for performance and odor evaluation. Figure 4 The figure is a gas chromatogram of the mercaptan content in the treated sulfided isobutylene. The mercaptan removal rate detected by gas chromatography is 98.4%.

[0052] Table 6 Odor evaluation

[0053] Sniffer No. Untreated sample rating Rating of processed samples Downgrade 1 5 2 3 2 5 2 3 3 5 2 3

[0054] Table 7 Performance evaluation

[0055]

[0056]

[0057] As shown in Table 6, the pungent odor of the isobutylene sulfide product treated with hexamethylene diisocyanate (HDI) decreased by 3 levels, and the mercaptan removal effect was poor, failing to meet the human sensory standards and production environment requirements. As shown in Table 7, the four parameter indicators of the isobutylene sulfide product treated with the isocyanate fluctuated greatly, among which the sintering load and the comprehensive wear value deviated greatly from the standard value, the wear spot diameter deviated by 0.08 mm, and the parameters except the no-seizure load changed greatly. Therefore, the performance of the product treated with the isocyanate was unstable and did not meet the requirements.

[0058] Example 4

[0059] Take 100 mL of the sulfided isobutylene product, add 0.5 mL of isophorone isocyanate dropwise for 5 min, stir thoroughly for 5 h at 40 °C, and let stand for 24 h for performance and odor evaluation. Figure 5 The figure is a gas chromatogram of the mercaptan content in the treated sulfided isobutylene. The mercaptan removal rate detected by gas chromatography is 96.1%.

[0060] Table 8 Odor evaluation

[0061] Sniffer No. Untreated sample rating Rating of processed samples Downgrade 1 5 2 3 2 5 2 3 3 5 2 3

[0062] Table 9 Performance evaluation

[0063] serial number PB / N PD / N ZZ Wear spot diameter / mm Untreated samples 785 3924 543 0.52 Sample of Example 4 786 3934 551 0.55

[0064] As shown in Table 8, the pungent odor of the isobutylene sulfide product treated with isophorone isocyanate (IPDI) decreased by 3-4 levels, and the mercaptan removal effect was not ideal, but it still met the human sensory standards and production environment requirements. As shown in Table 9, among the four parameter indicators of the isobutylene sulfide product treated with the isocyanate, the non-seizure load, comprehensive wear value, and wear spot diameter did not deviate from the standard values ​​by much, but the sintering load changed greatly, so the overall performance of the product treated with the isocyanate met the requirements.

[0065] Example 5

[0066] Take 100 mL of the sulfided isobutylene product, add 0.5 mL of dicyclohexylmethane diisocyanate to react for 15 min. After stirring for 5 h, let it stand for 24 h for performance evaluation and odor evaluation. Figure 6 The figure is a gas chromatogram of the mercaptan content in the treated sulfided isobutylene. The mercaptan removal rate detected by gas chromatography is 97.0%.

[0067] Table 10 Odor evaluation

[0068] Sniffer No. Untreated sample rating Rating of processed samples Downgrade 1 5 0 5 2 5 1 4 3 5 1 4

[0069] Table 11 Performance evaluation

[0070] serial number PB / N PD / N ZZ Wear spot diameter / mm Untreated samples 785 3924 543 0.52 Sample of Example 5 795 3958 550 0.48

[0071] As shown in Table 10, the pungent odor of the sulfided isobutylene product treated with dicyclohexylmethane diisocyanate (HMDI) is reduced by 3 levels. As shown in Table 11, the four parameter indicators of the sulfided isobutylene product treated with the isocyanate do not deviate from the standard values ​​by much, so the performance of the product treated with the isocyanate meets the requirements as a whole.

[0072] According to the above experimental results, in terms of deodorization, the removal rate of each isocyanate on mercaptan observed by gas chromatography can reach more than 90%, and the removal rate after treatment with diphenylmethane diisocyanate (MDI) and dicyclohexylmethane diisocyanate (HMDI) can reach 97%. In terms of product performance, the overall performance indicators of isocyanate treatment products do not fluctuate much and all meet the requirements.

Claims

1. A method for deodorizing by sulfiding isobutylene, characterized in that: Specifically, isobutylene sulfide is mixed with isocyanate, stirred for reaction, and left to stand for reduced pressure distillation to obtain a deodorized isobutylene sulfide product.

2. The method for deodorizing sulfided isobutylene according to claim 1, characterized in that: The isocyanate is any one of toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and isophorone isocyanate.

3. The method for deodorizing sulfided isobutylene according to claim 1, characterized in that: The mass ratio of the sulfided isobutylene to the isocyanate is 1:0.05-0.

1.

4. The method for deodorizing sulfided isobutylene according to claim 1, characterized in that: The stirring reaction temperature is 25-35°C, and the stirring reaction time is 10-15h.

5. The method for deodorizing sulfided isobutylene according to claim 1, characterized in that: The reduced pressure distillation temperature is 60-80°C, the vacuum degree is 10-15 mmHg, the reduced pressure distillation time is 1-2 h; the standing time is 24 h.

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