WO2016119140A1 - Preparation method for solid metal oxide catalyst and application thereof in transesterification and interesterification - Google Patents

Abstract

A preparation of a solid metal oxide catalyst and an application thereof in transesterification and interesterification. The solid metal oxide catalyst is a bi-metal oxide catalyst with the metals being manganese/copper/magnesium and aluminum, and continuous production of a fatty acid alkyl ester and high-price chemicals is carried out using a fixed packed bed reactor. The solid metal oxide catalyst can tolerate feeding of materials having high free fatty acid and water contents, and can subject to esterification and transesterification simultaneously to produce a fatty acid alkyl ester (for example, biodiesel). A developed solid metal oxide catalyst can also subject to interesterification and meanwhile has high catalytic activity.

Description

Preparation method of solid metal oxidation catalyst and its application in transesterification and exchange esterification Technical field

The invention relates to a preparation method of a solid metal oxidation catalyst, and can be applied to a continuous production process technology of a fatty acid alkyl ester (such as biodiesel) and a high monovalent biomass chemical.

Background technique

A fatty acid alkyl ester is a biofuel produced by transesterification of an alcohol with an animal or vegetable oil ester or a waste oil ester; usually a reaction with methanol, and a fatty acid methyl ester (FAME) produced therefrom. It is biodiesel. At present, the most commonly used in the industry is the homogeneous catalyst transesterification process technology, using alkaline catalysts such as sodium methoxide, sodium hydroxide and potassium hydroxide. If the free fatty acid in the feed oil is high, the acid catalyst is used first. The esterification reaction is carried out, followed by a basic catalyst transesterification process. Although the production process of homogeneous catalyst transesterification is simple, the disadvantage is that the quality of the feed oil is severe, especially the content of water and free acid, and complicated post-treatment procedures such as washing and neutralization are required, which will occur during the process. Salts and large amounts of wastewater, even if water is recovered, their thermal energy costs are not low; in addition, the formation of saponification will reduce product recovery and increase separation costs.

In order to omit the washing and neutralization unit and improve the defects of the process on equipment corrosion, product discoloration, and waste water, many researches have begun to invest in heterogeneous catalyst process development. In the transesterification reaction, the activity of the basic catalyst is much larger than that of the acidic catalyst. The activity of the metal compound is: alkali metal > alkaline earth metal > transition metal, but the alkali metal oxide is easily dissolved by the acid, and the catalyst is easily deactivated. Shortcomings such as short cycle. In alkaline earth metals, the activity of SrO and CaO is close to that of alkali metal, and the reaction temperature is 65 °C, but it takes a long reaction time; while the activity of MgO and transition metal oxide is low, the reaction temperature should exceed 200 °C. In order to obtain a higher yield of biodiesel.

Although the industry produces high-quality diesel fuel using traditional homogeneous alkali catalyst process, solid-state catalyst transesterification technology is still optimistic, among which Axens Esterfit-P process has successfully used this technology to commercialize the production of quality diesel (such as US patent US 5908946, US 6147196, US 6878837), the catalyst developed by the company is ZnO / Al ₂ O ₃ ; in addition, a number of manufacturers have developed different solid-state catalysts and processes with commercial potential (such as US patent US 2007/0083056, The verification phase of the trial production is carried out in US 7790651, US 2009/0112007, US 7563915, US 2011/0185625, US 8026381.

In addition to the reaction of alcohols with alcohols to produce fatty acid alkyl esters, other feeds can be used instead of alcohols to produce high-quality biomass chemicals. Professor Saka of Japan proposed to replace methanol with methyl acetate or dimethyl carbonate, exchange esterification reaction by supercritical fluid method, and prepare biochemicals such as triacetin.

It can be seen that there are still many shortcomings in the above existing methods, which is not a good design and needs to be improved.

Summary of the invention

The invention provides a preparation method of a solid metal oxidation catalyst, wherein the prepared solid metal oxide catalyst can be simultaneously subjected to transesterification and exchange esterification reaction, and can be applied to a continuous form of a fatty acid alkyl ester and a high monovalent raw material chemical. Production process technology.

The preparation method of the solid metal oxidation catalyst is as follows: the catalyst raw material contains two or more kinds of metal compounds, one of which is an aluminum-containing compound (pseudo-boehmite), and the other is an oxide, a hydroxide of manganese, copper, magnesium, Chloride or nitrate. The catalyst raw materials are uniformly mixed according to different weight ratios, and then uniformly stirred by adding appropriate proportion of deionized water, and the catalyst embryos can be obtained through the catalyst extrusion molding machine, and the catalyst shape (cylindrical, three-lobed, four-lobed, etc.) Can be obtained through different mold production. The catalyst green embryo is dried at room temperature for more than 24 hours, and then subjected to a high-temperature sintering process to obtain a solid metal oxide catalyst. The crystal phase structure of the solid metal oxide catalyst is identified by X-ray Diffratometer (XRD) analysis, and the specific surface area and porosity of the solid metal oxide catalyst are estimated by a surface area and porosity analyzer. Table 1 lists the physical properties of several prepared solid metal oxide catalysts, and analyzes the characteristics of the prepared solid metal oxide catalyst crystal phase structure, specific surface area and porosity.

Table I

In the first to fifth embodiments, the solid metal oxidation catalyst of the present invention is filled in a fixed bed reactor, and esterification and transesterification can be simultaneously carried out to produce fatty acid methyl ester (biodiesel). As shown in Figure 1, methanol and grease enter the reactor from bottom to top, and the reaction is carried out under high temperature and high pressure. The system pressure is controlled by a back pressure valve, and finally the liquid product is collected by heat exchanger cooling, including biodiesel. , glycerol and excess unreacted methanol. The reaction conversion rate and product composition were obtained by gas chromatography mass spectrometry (GC-MS) and high temperature gas chromatography (HTGC) analysis.

The process technique for the exchange of esterification of solid metal oxide catalysts is similar to that of the transesterification process, except that methanol is replaced with other feeds. In the sixth embodiment, methyl acetate is used in place of methanol, and after exchange esterification, fatty acid methyl ester (biodiesel) and high monovalent triacetin can be produced. The solid metal oxidation catalyst of the present invention can also be substituted with methanol using a polyhydric alcohol (for example, glycerin), and a transesterification reaction can produce a high monovalent mono-glyceride and di-glyceride. . The conversion and product composition of the reaction can be obtained by gas chromatography mass spectrometry (GC-MS) and high temperature gas chromatography (HTGC) analysis.

The detailed description above is a detailed description of a possible embodiment of the present invention, and is not intended to limit the scope of the present invention. In the scope of the patent in this case.

In summary, this case is not only innovative in terms of space type, but also can enhance the above-mentioned multiple functions compared with the customary items. It should fully comply with the statutory invention patent requirements of novelty and progressiveness, and apply for it according to law. Approved this invention patent application, in order to invent invention, to the sense of virtue.

DRAWINGS

1 is a schematic view of a solid state metal oxide catalyst fixed bed transesterification reaction apparatus of the present invention.

Figure 2 is the operating temperature and biodiesel yield of different solid metal oxide catalysts of the present invention Diagram.

Figure 3 is a graph showing the relationship between the operating temperature of different solid metal oxide catalysts and the yield of biodiesel in the present invention.

Figure 4 is a graph showing the relationship between the pre-activation treatment of solid metal oxide catalyst and the yield of biodiesel according to the present invention.

Fig. 5 is a graph showing the relationship between the operating temperature of the manganese-aluminum double metal oxide catalyst of the present invention for the exchange esterification reaction and the yield of the biomass diesel.

Description of the reference signs:

1 methanol

2 grease

3 high pressure pump

4 safety valve

5 tubular reactor

6 temperature controller

7 thermocouple

8 back pressure valve

9 heat exchanger

10 product collection tank

detailed description

In order to understand the technical features, contents and advantages of the present invention and the efficiencies thereof, the present invention will be described in detail with reference to the accompanying drawings, and the drawings used therein, The subject matter is only for the purpose of illustration and description. It is not necessarily the true proportion and precise configuration after the implementation of the present invention. Therefore, the scope and configuration relationship of the attached drawings should not be interpreted or limited. , first and foremost.

It is to be noted herein that the term "transesterification reaction" in the present invention is defined as "a process in which an oil and a fat react with an alcohol to form a fatty acid ester and another alcohol"; the term "exchange esterification reaction" is defined as "fat and oil" The process in which a lower ester is reacted to form a fatty acid ester and another ester."

As shown in FIG. 1 , it is a schematic diagram of a solid metal oxidation catalyst fixed bed transesterification reaction device of the present invention, wherein methanol 1 and grease 2 are passed from bottom to top via a high pressure pump 3, and flow rate is controlled by a safety valve 4 to enter a tubular reactor. 5. The tubular reactor 5 is provided with a plurality of temperature controllers 6 and is coupled with a thermocouple 7, and the reaction is maintained under high temperature and high pressure. The system pressure is controlled by the back pressure valve 8, and finally the liquid is collected by the heat exchanger 9 to collect the liquid. The product is in product collection tank 10 and contains biodiesel, glycerin and excess unreacted methanol.

Example 1: It is a test for comparing the conversion of different solid metal oxide catalysts to produce diesel fuel by transesterification. The operating conditions of the reactor are 90 bar, the molar ratio of alcohol to oil is 23, and the residence time is 18 minutes. The yield of biodiesel at different operating temperatures is shown in Figure 2. The activity of the catalyst under long-term operation is shown in Figure 3. . The results show that the manganese-aluminum double metal oxide catalyst has the best activity, and the yield of biodiesel can reach 98.6% at 220 °C. After 120 hours at 200 °C, the yield of biodiesel is increased from 87% to 98. %.

Example 2: Different grease transesterification tests were carried out using a manganese-aluminum double metal oxide catalyst, wherein the operating conditions of the reactor were 190 ° C, 90 bar, the molar ratio of alcohol to oil was 23, and the residence time was 18 minutes. The results are shown in Table 2. For the yield of biodiesel using different fats, the yield can exceed 96%.

Table II

Example 3: The transesterification reaction was carried out using a manganese-aluminum double metal oxide catalyst having different manganese oxide contents, wherein the operating conditions of the reactor were 190 ° C, 90 bar, the molar ratio of alcohol to oil was 23, and the residence time was 18 minutes. . The results are shown in Table 3. The yield of biodiesel after transesterification of manganese-aluminum double metal oxide catalysts representing different manganese oxide contents, wherein the weight percentage of manganese oxide exceeds 10%, and the yield of biodiesel can exceed More than 99%.

Table 3

Manganese oxide content (wt%)	67%	30%	10%	0%
					Biodiesel yield (%)	99.4	>99.5	>99.5	75.1

Example 4: The manganese-aluminum double metal oxide catalyst was activated by glycerol pretreatment and then subjected to a transesterification reaction, wherein the operating conditions of the reactor were 170 ° C, 70 bar, and the molar ratio of alcohol to oil was 23, and the residence time was 23 minutes. The results are shown in Fig. 4. It shows that the solid metal oxide catalyst which is not activated by glycerol in the initial stage of the reaction has a biodiesel yield of only 42.4%. It is usually necessary to increase the reaction temperature to 200 ° C and react for 24 hours. In order to increase to more than 98%; but after glycerol pretreatment activation, the catalyst activity can be rapidly increased at low temperature (170 ° C), and the yield of biodiesel can exceed 97% after 12 hours.

Example 5: The transesterification reaction was carried out using a manganese-aluminum double metal oxide catalyst under different feed conditions (changing the water content and the free fatty acid content), wherein the operating conditions of the reactor were 190 ° C, 90 bar, and the molars of the alcohol The ratio is 23 and the residence time is 18 minutes. The results are shown in Table 4, representing the yield of biodiesel after transesterification under different feed conditions. Table 4 shows that the methanol feed water content is 10 wt%, and the yield of biodiesel is over 99%. The best biodiesel yield (97.9%) was obtained when the free fatty acid content of the feed oil was 30 wt%, but the yield of biodiesel decreased slightly to 91.9% when the free fatty acid content was increased to 70 wt%.

Table 4

Example 6: Substituting methanol with methyl acetate, biodiesel and triacetin can be formed by exchange esterification reaction. Filling a manganese-aluminum double metal oxide catalyst in a fixed bed reactor for exchange The esterification reaction was tested in which the operating conditions of the reactor were 90 bar, the molar ratio of methyl acetate to soybean oil was 2:1, and the residence time was 36 minutes. The results are shown in Figure 5. It is shown that the conversion of soybean oil or the yield of biodiesel at 330 ° C can reach 99.5% or more, that is, the product contains high monovalent triacetin, which can be obtained by a subsequent purification procedure.

The detailed description of the present invention is intended to be illustrative of a preferred embodiment of the present invention, and is not intended to limit the scope of the invention. In the scope of the patent in this case.

To sum up, this case is not only innovative in terms of technical thinking, but also has many of the above-mentioned functions that are not in the traditional methods of the past. It has fully complied with the statutory invention patent requirements of novelty and progress, and applied for it according to law. The bureau approved the application for the invention patent, in order to invent the invention, to the sense of virtue.

Claims (15)

1. A method for preparing a solid metal oxidation catalyst, wherein two or more metal compounds are mixed in proportion, and extruded to form a solid metal oxide catalyst after sintering at a high temperature.
2. The method for preparing a solid metal oxidation catalyst according to claim 1, wherein the metal compound comprises at least a first metal compound and a second metal compound, wherein the first metal compound is an aluminum-containing metal compound (pseudo-boehmite), The second metal compound is a metal compound containing a manganese oxide, a copper oxide, a magnesium oxide, a hydroxide, a chloride or a nitrate.
3. The method for preparing a solid metal oxidation catalyst according to claim 2, wherein the weight percentage of the manganese-containing oxide, copper oxide and magnesium oxide is between 2 and 70%.
4. The method for preparing a solid metal oxidation catalyst according to claim 1, wherein the solid metal oxide catalyst is a ball, a cylinder, a threelobe, a quadlolobe, and a half ring. (Semi-ring), the solid metal oxidation catalyst has an outer diameter of between 1 and 3 mm.
5. The method for preparing a solid metal oxidation catalyst according to claim 1, wherein the temperature of the high temperature sintering is between 350 and 800 ° C and the temperature is maintained for more than 1 hour, wherein the volume of the solid metal oxide catalyst is between 0.1 and 0.5. Between cm ³ /g, the specific surface area is between 50 and 300 m ² /g.
6. The use of a solid metal oxidation catalyst prepared by the method for producing a solid metal oxidation catalyst according to any one of claims 1 to 5 in a transesterification and exchange esterification reaction, wherein a solid metal oxidation catalyst is filled in In a fixed bed reactor, transesterification and exchange esterification are carried out to produce a fatty acid alkyl ester, and the transesterification and exchange esterification reactant comprises an alcohol and a fat or oil, wherein the alcohol is methanol, ethanol, propanol or Butanol, the oils and fats are soybean oil, jatropha seed oil, castor oil, tung oil, palm oil, coconut oil, oleic acid, lard, butter, algae oil, waste cooking oil or waste acid oil .
7. The use of the solid metal oxidation catalyst according to claim 6 in a transesterification and exchange esterification reaction, wherein the fixed bed reactor has a pressure of between 1 and 100 bars and a temperature of between 100 and 300 ° C. The ratio of alcohols to oils and fats is between 5 and 46, and the residence time is between 1 and 60 minutes.
8. The use of the solid metal oxidation catalyst according to claim 6 in the transesterification and exchange esterification reaction, wherein the solid metal oxidation catalyst can be modified by activation with glycerol, wherein the pressure of activation Between 15 and 40 bars, the temperature is between 170 and 210 ° C, and the time is between 30 and 120 minutes.
9. The use of the solid metal oxidation catalyst according to claim 6 in the transesterification and exchange esterification reaction, wherein the methanol has a water content of 10% by weight, and the weight percentage of the free fatty acid content in the oil or fat is More than 50%.
10. The use of a solid metal oxidation catalyst according to claim 6 in a transesterification and exchange esterification reaction, wherein the solid metal oxidation catalyst is a manganese-aluminum solid metal oxidation catalyst, wherein the fixed bed reactor pressure is between 15 and 40 bars Between the temperature, the temperature is between 170 and 210 ° C, the ratio of the alcohol and the oil and fat is between 23 and 35, the residence time is between 5 and 30 minutes, and the operation time is 1000 hours. The yield is 99% or more.
11. The use of a solid metal oxidation catalyst prepared by the method for producing a solid metal oxidation catalyst according to any one of claims 1 to 5 in a transesterification and exchange esterification reaction, wherein a solid metal oxidation catalyst is filled in In a fixed bed reactor, transesterification and exchange esterification are carried out to produce a fatty acid alkyl ester and a glycerin-containing compound, and the transesterification and exchange esterification reactants comprise oils and fats, and the esters are methyl acetate, Ethyl acetate, methyl formate or dimethyl carbonate.
12. The use of a solid oxidation catalyst prepared by the method for producing a solid metal oxidation catalyst according to any one of claims 1 to 5 in a transesterification and exchange esterification reaction, wherein a solid metal oxidation catalyst is filled in In a fixed bed reactor, transesterification and exchange esterification are carried out to produce fatty acid methyl esters and triacetin, and the transesterification and exchange esterification reactants comprise oils and fats and methyl acetate, and the fixed bed is reacted. The pressure of the device is between 10 and 150 bars, the temperature is between 200 and 350 ° C, and the residence time is between 5 and 80 minutes.
13. A method for preparing a solid oxidation catalyst prepared by the method for preparing a solid metal oxidation catalyst according to claim 2, wherein the manganese-aluminum solid metal oxidation catalyst is filled in a fixed bed reactor Transesterification and exchange esterification to produce fatty acid methyl esters and triacetin, the transesterification and exchange esterification reactants comprise oils and fats and methyl acetate, and the pressure of the fixed bed reactor is between Between 50 and 90 bars, the temperature is between 300 and 330 ° C. The ratio of the oils and the methyl acetate is between 0.5 and 4. The residence time is between 20 and 40 minutes, and the conversion rate is above 90%. .
14. The use of a solid metal oxidation catalyst prepared by the method for producing a solid metal oxidation catalyst according to any one of claims 1 to 5 in a transesterification and exchange esterification reaction, wherein a solid metal oxidation catalyst is filled in In a fixed bed reactor, transesterification and exchange esterification are carried out to produce mono-glyceride and di-glyceride, and the transesterification and exchange esterification reactants comprise oils and fats. Polyols, which are glycerin, ethylene glycol, or butylene glycol.
15. The use of a solid metal oxidation catalyst according to claim 14 in a transesterification and exchange esterification reaction, wherein the fixed bed reactor has a pressure of between 10 and 150 bar and a temperature of between 150 and 270 ° C, and is retained. The time is between 10 and 90 minutes.

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