Patent ID: 12221410

DETAILED DESCRIPTION OF EMBODIMENTS

The technical solutions of embodiments of this application will be clearly and fully illustrated with reference to the accompanying drawings. It is obvious that described herein are merely some embodiments of this application rather than all embodiments. Based on the embodiments of this application, other embodiments obtained by those of ordinary skill in the art without making creative effort shall fall within the scope of the present disclosure.

Sources of reagents of the embodiments are described as follows:2-methyl-2-butene: Zibo Liantan Chemical Co., Ltd;paraformaldehyde: Zibo Qixing Chemical Technology Co., Ltd;catalyst: Shandong Desheng New Material Co., Ltd; andhydrochloric acid is a by-product from other production lines, or is purchased.

The tar production in the following embodiments is measured as follows: the resulting reaction liquid is filtered and centrifuged, and the tar impurities are collected and weighed.

Example 1

The pinacolone preparation method of the present disclosure will be described in detail with reference toFIG.1.

500 kg of a 30 wt. % industrial hydrochloric acid was added into a reaction vessel, and was cooled to 0-10° C. 160 kg of 2-methyl-2-butene, which was pre-cooled to −5° C., was slowly dropwise added into the reaction vessel under stirring. The reaction mixture was reacted at 0-10° C. for 60-90 min, and then heated to 50° C. The reaction mixture was added with a catalyst, dropwise added with 140 kg of a paraformaldehyde hydrochloric acid solution, heated to 60-90° C., reacted for 1-6 h, and cooled to room temperature. After that, the reaction mixture was subjected to standing and layering, where an upper organic phase was subjected to single distillation to obtain a pinacolone product, and a bottom hydrochloric acid layer was extracted with dichloromethane or dichloroethane, supplemented with hydrogen chloride, and then recycled (in this example, the bottom hydrochloric acid layer was recycled for 40 times). Specific reaction principle and reaction process were detailedly shown inFIGS.1-2.

Example 2

According to the preparation method in Example 1, pinacolone was prepared respectively in the absence of a catalyst, and in the presence of a single lanthanide Lewis acid, compounded lanthanide Lewis acid, and other Lewis acid catalysts, where the catalyst (the total number of moles of ingredients for the compounded lanthanide Lewis acid) was 2% by mole of the 2-methyl-2-butene; the second reaction was performed at 83° C. for 4 h; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:5. Experimental results were shown in Table 1.

TABLE 1Experimental resultsTarTimeTemperatureproductionPurityYieldExampleCatalyst(h)(° C.)(%)(%)(%)2.1—48319.7594.5677.652.2Lanthanum chloride4838.2398.7689.382.3Cerium chloride4839.6598.6488.542.4Praseodymium chloride4839.5898.5186.622.5Neodymium chloride4838.6498.5887.542.6Erbium chloride4839.1498.5087.052.7Holmium chloride4839.5198.3885.522.8Dysprosium chloride4838.8298.5284.662.9Thulium chloride4839.2797.8184.972.10Lanthanum bromide48311.5397.3683.382.11Cerium bromide48311.1596.6181.542.12Praseodymium bromide48310.3898.2282.622.13n(Lanthanum4833.1798.6891.38chloride):n(Ceriumchloride) = 3:12.14n(Lanthanum4834.0598.5389.72chloride):n(Praseodymiumchloride) = 3:12.15n(Lanthanum4833.6498.6090.14chloride):n(Neodymiumchloride) = 3:12.16n(Lanthanum4834.5198.5688.31chloride):n(Erbiumchloride) = 3:12.17n(Cerium4835.1398.6388.26chloride):n(Praseodymiumchloride) = 3:12.18n(Cerium4834.7998.5789.15chloride):n(Neodymiumchloride) = 3:12.19n(Cerium4835.2798.5288.27chloride):n(Thuliumchloride) = 3:12.20n(Praseodymium4834.8298.6689.06chloride):n(Neodymiumchloride) = 3:12.21n(Praseodymium4835.5798.4988.54chloride):n(Erbiumchloride) = 3:12.22n(Praseodymium4835.9798.5187.63chloride):n(Holmiumchloride) = 3:12.23n(Cerium4834.8198.5289.43chloride):n(Holmiumchloride) = 3:12.24n(Lanthanum4835.0398.3987.94chloride):n(Thuliumchloride) = 3:12.25n(Dysprosium4839.2298.1785.96chloride):n(Neodymiumchloride) = 3:12.26n(Erbium4839.6998.4786.59chloride):n(Thuliumchloride) = 3:12.27n(Lanthanum4833.9398.7190.26chloride):n(Ceriumchloride):n(Praseodymiumchloride) = 3:1:12.28n(Lanthanum4833.5198.6791.67chloride):n(Ceriumchloride):n(Neodymiumchloride) = 3:1:12.29Zinc chloride48318.1097.6981.572.30Calcium chloride48316.6995.2278.982.31Aluminum chloride48325.2092.2175.672.32n(Zinc48318.5897.6080.22chloride):n(Calciumchloride) = 3:12.33n(Lanthanum48315.6993.6181.24chloride):n(Zincchloride) = 3:12.34n(Cerium48315.5292.1179.81chloride):n(Calciumchloride) = 3:1

Referring to Table 1, when the catalyst was absent, the tar production was as high as 19.75%. The reaction solution was partially taken out and subjected to standing in a separating flask, which was specifically shown inFIG.3. A large amount of tar was dissolved in the bottom hydrochloric acid layer, causing a difficulty of hydrochloric acid recycle, and a large amount of waste acid and waste water cannot be solved, resulting in high industrial environmental costs.

When a single lanthanide chloride was added as the catalyst, the tar production was greatly reduced, and the yield and purity of the pinacolone product were greatly improved. Considering the tar production and the yield of the pinacolone product, the single lanthanide chloride was preferably lanthanum chloride and cerium chloride.

When the compounded lanthanide Lewis acid was a combination of a first component and a second component, a molar ratio of the first component to the second component was 3:1, and when the compounded lanthanide Lewis acid was a combination of the first component and the second component, where the second component is a combination of two compounds, a molar ratio of the first component to one of the two compounds to the other of the two compounds was 3:1:1, which were better than the prior art. Referring to results of Table 1, when the first component was selected from the group consisting of lanthanum chloride, cerium chloride, praseodymium chloride and neodymium chloride, and the second component was selected from the group consisting of lanthanum chloride, cerium chloride, praseodymium chloride and neodymium chloride, erbium chloride, holmium chloride, dysprosium chloride, thulium chloride, and a combination thereof, but did not contain the compound selected as the first component, its effects were better than that of the single lanthanide chloride, showing that a combination of two or more lanthanide chlorides and its catalysis had a certain synergistic promoting effect. The tar contents in Examples 2.15, 2.20, 2.22, 2.25, 2.29 and 2.30 were all below 5%, and the whole reaction system was very clean, as shown inFIG.5.

When the catalyst was zinc chloride, calcium chloride, aluminum chloride, a mixture of zinc chloride and calcium chloride, or a mixture of zinc chloride, calcium chloride and the lanthanide chlorides, its effects were not ideal. The tar dissolved in hydrochloric acid, causing obstacles to recycling the hydrochloric acid, which cannot essentially realize the clean and green production of pinacolone.

A gas chromatogram of a pinacolone product in Example 2.15 (98.68% purity) was shown inFIG.5.

Example 3

The preparation process provided herein was basically the same as that in Example 1, where the catalyst was lanthanum chloride; the second reaction was performed at 83° C. for 4 h; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:5. Molar ratios of the lanthanum chloride to the 2-methyl-2-butene (e.g., 5:1000, 10:1000, 20:1000, 30:1000, 40:1000 and 50:1000) were employed for the preparation of pinacolone, and the results were shown in Table 2.

TABLE 2n(LanthanumTimeTemperatureTarPurityYieldExamplechloride):n(Isopentene)(h)(° C.)production (%)(%)(%)3.15:100048310.2898.5987.463.210:10004839.9198.5487.213.320:10004838.2398.7689.383.430:10004837.6598.5989.423.540:10004837.9398.6188.653.650:10004838.1498.7289.39

Referring to Table 2, the catalyst in this example was the lanthanum chloride. When n(Lanthanum chloride):n(2-methyl-2-butene)=20:1000, this example was performed at 83° C. for 4 h. The tar production was 8.23% (which decreased by 58.31%), the purity of the pinacolone production was above 98.50%, and the yield of the pinacolone was above 88%, showing significant improved effects.

Example 4

The preparation process provided herein was basically the same as that in Example 1, where the catalyst was a mixture of lanthanum chloride and cerium chloride; the second reaction was performed at 83° C. for 4 h; a molar ratio of the lanthanum chloride to the cerium chloride was 3:1; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:5. Molar ratios of the mixture of lanthanum chloride and cerium chloride to the 2-methyl-2-butene (e.g., 5:1000, 10:1000, 20:1000, 30:1000, 40:1000 and 50:1000) were employed for the preparation of pinacolone, and the results were shown in Table 3.

TABLE 3n(LanthanumTarchloride and CeriumTimeTemperatureproductionPurityYieldExamplechloride):n(Isopentene)(h)(° C.)(%)(%)(%)4.15:10004839.2898.5285.164.210:10004837.4898.5683.414.320:10004833.1798.6891.384.430:10004834.2598.6090.674.540:10004833.9198.5088.924.650:10004833.8498.6589.69

Referring to Table 3, the catalyst in this example was the mixture of lanthanum chloride and cerium chloride, and n(Lanthanum chloride):n(Cerium chloride)=3:1. When n(The mixture of lanthanum chloride and cerium chloride):n(2-methyl-2-butene)=20:1000, the second reaction was performed at 83° C. for 4 h. The tar production was 3.17% (which decreased by 83.94%), the purity of the pinacolone production was above 98.50%, and the yield of the pinacolone was above 91% (which increased by 17.70%).

Example 5

The preparation process provided herein was basically the same as that in Example 1, where the catalyst is a combination of lanthanum chloride and cerium chloride; a molar ratio of the compounded catalyst to 2-methyl-2-butene was 0.02:1; the second reaction was performed at 83° C. for 4 h; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:5. A series of lanthanum chloride-cerium chloride compounded catalysts varying in molar ratio (e.g., 1:10, 1:5, 1:3, 3:1, 5:1, 10:1, 1:20, 1:50, 20:1 and 50:1) were employed for the preparation of pinacolone, and the results were shown in Table 4.

TABLE 4n(LanthanumTarchloride):n(CeriumTimeTemperatureproductionPurityYieldExamplechloride)(h)(° C.)(%)(%)(%)5.11:104838.3497.8686.945.21:54835.6798.5388.615.31:34835.2898.5187.925.41:14834.9398.5989.475.53:14833.1798.6891.385.65:14835.6698.5288.955.710:14836.3498.5789.245.81:2068312.5695.8582.345.91:5068315.6995.5781.855.1020:168313.5396.4183.055.1150:168314.3997.2184.26

Referring to Table 4, the catalyst in this example was the combination of the lanthanum chloride and the cerium chloride. When n(Lanthanum chloride):n(Cerium chloride)=1:10-10:1, the tar productions were below 10%, the purities of the pinacolone production were above 98.50%, and the yields of the pinacolone were above 86.94%. When n(Lanthanum chloride):n(Cerium chloride) is outside the range of 1:10-10:1, the tar productions increased significantly, and the purities and the yields of the pinacolone products decreased.

Example 6

The preparation process provided herein was basically the same as that in Example 1, where the catalyst was a combination of lanthanum chloride, cerium chloride and praseodymium chloride; a molar ratio of the compounded catalyst to 2-methyl-2-butene was 0.02:1; the second reaction was performed at 83° C. for 4 h; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:5. A series of lanthanum chloride-cerium chloride-praseodymium chloride compounded catalysts varying in molar ratio (3:1:1, 5:1:1, 5:3:3, 5:2:2, 1:1:1, 6:1:1 and 5:4:4) were employed for the preparation of pinacolone, and the results were shown in Table 5.

TABLE 5n(Lanthanumchloride):n(CeriumTarchloride):n(PraseodymiumTimeTemperatureproductionPurityYieldExamplechloride)(h)(° C.)(%)(%)(%)6.13:1:14833.9398.7190.266.25:1:14836.6798.5388.616.35:3:34838.1698.5187.926.45:2:24838.9398.5987.476.51:1:14834.6698.6289.556.66:1:148312.6698.2085.956.75:4:448313.2298.2487.80

Referring to Table 5, when the catalyst was the combination of lanthanum chloride, cerium chloride and praseodymium chloride, a preferred range was 1-5:1-3:1-3, preferably 1-3:1:1 or 3:1:1.

Example 7

The preparation process provided herein was basically the same as that in Example 1, where the catalyst is a combination of lanthanum chloride and cerium chloride; a molar ratio of the lanthanum chloride to the cerium chloride was 3:1; a molar ratio of the compounded catalyst to 2-methyl-2-butene was 0.02:1; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:5. An addition of the paraformaldehyde hydrochloric acid solution lasted for 0.5 h, and the second reaction was performed at 60° C. for 1 h. The tar production, the purity and the yield (based on the 2-methyl-2-butene) of the pinacolone product were analyzed, and an experimental result was shown in Table 6.

Example 8

The preparation process provided herein was basically the same as that in Example 1, where the catalyst was the combination of lanthanum chloride and cerium chloride; a molar ratio of the lanthanum chloride to the cerium chloride was 3:1; a molar ratio of the compounded catalyst to 2-methyl-2-butene was 0.02:1; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:10. An addition of the paraformaldehyde hydrochloric acid solution lasted for 1 h, and the second reaction was performed at 70° C. for 3 h. The tar production, the purity and the yield (based on the 2-methyl-2-butene) of the pinacolone product were analyzed, and an experimental result was shown in Table 6.

Example 9

The preparation process provided herein was basically the same as that in Example 1, where the catalyst was the combination of lanthanum chloride and cerium chloride; the molar ratio of the lanthanum chloride to the cerium chloride was 3:1; the molar ratio of the compounded catalyst to 2-methyl-2-butene was 0.02:1; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:10. An addition of the paraformaldehyde hydrochloric acid solution lasted for 2 h, and the second reaction was performed at 83° C. for 4 h. The tar production, the purity and the yield (based on the 2-methyl-2-butene) of the pinacolone product were analyzed, and an experimental result was shown in Table 6.

Example 10

The preparation process provided herein was basically the same as that in Example 1, where the catalyst was the combination of lanthanum chloride and cerium chloride; the molar ratio of the lanthanum chloride to the cerium chloride was 3:1; the molar ratio of the compounded catalyst to 2-methyl-2-butene was 0.02:1; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:15. An addition of the paraformaldehyde hydrochloric acid solution lasted for 3 h, and the second reaction was performed at 90° C. for 6 h. The tar production, the purity and the yield (based on the 2-methyl-2-butene) of the pinacolone product were analyzed, and an experimental result was shown in Table 6.

Example 11

The preparation process provided herein was basically the same as that in Example 1, where the catalyst was the combination of lanthanum chloride and cerium chloride; the molar ratio of the lanthanum chloride to the cerium chloride was 3:1; the molar ratio of the compounded catalyst to 2-methyl-2-butene was 0.02:1; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:20. An addition of the paraformaldehyde hydrochloric acid solution lasted for 2 h, and the second reaction was performed at 80° C. for 5 h. The tar production, the purity and the yield (based on the 2-methyl-2-butene) of the pinacolone product were analyzed, and an experimental result was shown in Table 6.

Example 12

The preparation process provided herein was basically the same as that in Example 1, where the catalyst was the combination of lanthanum chloride and cerium chloride; the molar ratio of the lanthanum chloride to the cerium chloride was 3:1; a molar ratio of the compounded catalyst to 2-methyl-2-butene was 0.02:1; and a weight ratio of paraformaldehyde to hydrochloric acid in the paraformaldehyde hydrochloric acid solution was 1:5. An addition of the paraformaldehyde hydrochloric acid solution lasted for 2 h, and the second reaction was performed at 83° C. for 4 h. The tar production, the purity and the yield (based on the 2-methyl-2-butene) of the pinacolone product were analyzed, and an experimental result was shown in Table 6.

TABLE 6Weight ratio ofparaformaldehydeAdditionTarto hydrochlorictimeTimeTemperatureproductionPurityYieldExampleacid(h)(h)(° C.)(%)(%)(%)71:50.51609.7497.7385.6981:1013708.5898.4986.2391:1024834.2698.7192.08101:1536905.5996.3188.37111:2025808.6898.5687.89121:524833.1798.6891.38

Referring to Table 6, in the second reaction, reaction results were affected by weight ratios of paraformaldehyde to hydrochloric acid, the addition time of the paraformaldehyde hydrochloric acid solution and the reaction time. The weight ratio of paraformaldehyde to hydrochloric acid was preferably 1:5 or 1:10, the addition time of the paraformaldehyde hydrochloric acid solution was not less than 2 h, the reaction time was greater than 4 h, and the reaction temperature was about 83° C.

Example 13

In the industrial production, for the annual 8,000-ton pinacolone output, the preparation method provided herein can reduce the discharge of waste acid by 48,000 tons per year, and save more than 12 million yuan per year. This application facilitated the green and clean production of pinacolone, and greatly promoted the progress of pinacolone industrial production.

Described above are only preferred embodiments of the present disclosure, which are not intended to limit the disclosure. Any modifications and equivalent replacements made within the spirit and principle of the present disclosure shall fall within the scope of this application defined by the appended claims.