CN106238051A - Catalyst for ethyl acetate preparation of ethanol by hydrogenating and its preparation method and application - Google Patents

Abstract

The invention discloses a catalyst for hydrogenation of ethyl acetate to produce ethanol and its preparation method and application. The catalyst comprises: 10%-60% of active components, 3%-40% of auxiliary agents, in terms of mass percentage, The balance is carrier; the active component is at least one of Cu, Co, and Ni, and the additive is at least one of Fe ₂ O ₃ , MgO, MnO, GeO ₂ , ZnO, MoO ₃ , and CdO. One, the carrier is SiO ₂ . The catalyst of the present invention is a non-precious metal catalyst with low production cost, good stability, environmental friendliness and high catalytic activity. When used for hydrogenation of ethyl acetate to produce ethanol, the conversion rate of ethyl acetate is high and the selectivity of product ethanol is high. .

Description

Catalyst for hydrogenation of ethyl acetate to ethanol, preparation method and application thereof

technical field

The invention relates to the field of catalyst preparation, in particular to a catalyst for hydrogenating ethyl acetate to produce ethanol, a preparation method and application thereof.

Background technique

Ethanol, commonly known as alcohol, with a molecular formula of C ₂ H ₅ OH, is a colorless, transparent liquid with a special aroma and pungent taste, and has a wide range of uses. Ethanol is a raw material for organic chemical products such as rubber, plastics, detergents, extractants, and artificial fibers. It can also be used to produce chloroethanol, ethyl chloride, acetaldehyde, ether, acetic acid, ethyl acetate, etc., and is also an important organic chemical. solvent.

At present, the contradiction between energy supply and demand in the world has become increasingly prominent, and environmental problems have become increasingly serious. The development and utilization of biomass energy has received more and more attention and attention. In the 1970s, the United States and Brazil took the lead in vigorously promoting fuel ethanol policies, followed by France, Canada, Spain and other countries, and fuel ethanol gradually developed worldwide. my country also began to vigorously advocate biomass energy in 2016 and promulgated the "Renewable Energy Law", and fuel ethanol has also become a key target of government support as a renewable energy source, resulting in a gradual increase in the demand for fuel ethanol.

At present, the industrial methods for synthesizing ethanol mainly include ethylene hydration, fermentation, acetaldehyde hydrogenation, and synthesis gas to ethanol. There are two main categories of large-scale industrial production: ethylene hydration and fermentation. Fermentation mainly refers to the production of ethanol through microbial fermentation using biomass raw materials such as starch, sugar or fiber. At present, the main method of ethanol production in my country is the fermentation method using sugar and starch as raw materials. Due to rising raw material prices and national food security issues, the fermentation method is facing a huge test. Ethylene hydration method directly synthesizes ethanol from ethylene and water, but because the value of ethylene is much higher than that of ethanol, this method has little application value.

More coal, less oil, and less gas are the basic situation of my country's energy resources. In recent years, with the development of coal chemical industry, the synthesis gas to acetic acid route has gradually matured, and the price of acetic acid has been falling continuously. also gradually increased. Therefore, using acetic acid as a raw material, first producing ethyl acetate, and then hydrogenating and reducing ethyl acetate to produce ethanol has a greater economic value. However, the process of producing ethyl acetate from acetic acid is quite mature, so it is necessary to develop the process of hydrogenating ethyl acetate to produce ethanol, so as to achieve the purpose of producing ethanol with acetic acid and hydrogen as raw materials.

Contents of the invention

The invention provides a catalyst for hydrogenation of ethyl acetate to ethanol and its preparation method, and also discloses the application of the catalyst in the hydrogenation of ethyl acetate to ethanol. The catalyst has high catalytic activity and low production cost , good stability and environmental friendliness.

A catalyst for ethyl acetate hydrogenation to ethanol, in mass percent, comprising:

Active ingredient 10%～60%

Auxiliary 3%～40%

The remainder is the carrier;

The active component is at least one of Cu, Co and Ni, the additive is at least one of Fe ₂ O ₃ , MgO, MnO, GeO ₂ , ZnO, MoO ₃ , and CdO, and the The carrier is SiO ₂ .

The catalyst of the invention is a non-precious metal catalyst with high catalytic activity. When used for hydrogenation of ethyl acetate to produce ethanol, the conversion rate of ethyl acetate is as high as 97%, and the selectivity of product ethanol is as high as 95%.

Preferably, the active component is at least one of Cu, Co and Ni, the additive is MgO, and the carrier is SiO ₂ .

Magnesium is an alkali metal element. When MgO is used as an additive, the microstructure of the catalyst is different from when transition metal oxides are used as an additive. The addition of an appropriate amount of MgO increases the dispersion and surface area of the active component Cu, effectively reducing the The grain size of Cu greatly improves the catalytic activity of the catalyst. Moreover, MgO changes the concentration of basic active centers on the surface of the catalyst and improves the stability of the catalyst.

The microstructure of the catalyst when MgO is used as a promoter makes the catalyst have a better catalytic effect on the reaction of ethyl acetate hydrogenation to ethanol, and the reaction conditions are relatively mild.

The Cu content of the catalyst active component has a great influence on the performance of the catalyst. When the Cu content is low and the MgO content is relatively high, the dispersion of Cu is high, the interaction force between Cu and the support is strong, and CuO is not easy to be absorbed. It is reduced to zero-valent Cu as the active component, and when the content of Cu is high and the content of MgO is low, the interaction force between Cu and the support is weak, and CuO is easily reduced to zero-valent Cu as the active component. However, when the Cu content is too high, it is easy to cause the agglomeration between Cu species, thereby reducing the catalytic efficiency.

As preferably, the catalyst for the hydrogenation of ethyl acetate to ethanol, in mass percent, includes:

Active ingredient 25%～50%

Auxiliary 3%～30%

The remainder is the carrier;

The active component is Cu, the auxiliary agent is MgO, and the carrier is SiO ₂ .

The present invention also discloses a preparation method of the above-mentioned catalyst, comprising:

(1) Dissolve the precursor of the active component and the precursor of the auxiliary agent in water according to the proportion to obtain solution A, dissolve sodium silicate in water according to the proportion to obtain solution B, add solution A dropwise to solution B to react and produce precipitation ;

(2) Filtrating the precipitate, washing with water, aging, drying, roasting, and reducing to obtain the catalyst for hydrogenating ethyl acetate to produce ethanol.

In the present invention, the above-mentioned catalyst is prepared by the chemical co-precipitation method, and the precursor of the active component and the precursor of the auxiliary agent are reacted with sodium silicate to produce a precipitate, and then the precipitate is filtered and washed, aged, dried, roasted, and reduced. After the operation, the catalyst of the present invention is obtained. Compared with the common physical co-precipitation method, the interaction between the active component and the carrier in the catalyst prepared by the present invention is stronger, the dispersibility of the active component is better, and the particle size of the active component is smaller. small, thereby improving the catalytic performance of the catalyst.

Preferably, the precursor of the active component is copper acetate, copper oxalate or copper nitrate, and the precursor of the auxiliary agent is magnesium acetate, magnesium oxalate or magnesium nitrate.

Preferably, in step (2), the drying temperature is 100°C-200°C, and the drying time is 5h-12h; the calcination temperature is 200°C-600°C, and the calcination time is 2h-6h.

The active component in the catalyst of the present invention is zero-valent Cu, and the reduction step in the preparation process reduces the Cu element in the catalyst to be the active component zero-valent Cu, so the reduction process is an important step that affects the activity of the catalyst. As a preference, the present invention In step (2) of the preparation method, the reduction temperature is 250°C-550°C, the reduction pressure is 0.5MPa-2.5MPa, the reduction time is 2h-5h, and the hydrogen space velocity is 500h ^-1 -2000h ^-1 .

The invention also discloses the application of the above-mentioned catalyst in the hydrogenation of ethyl acetate to ethanol. The reaction is carried out in a tubular fixed-bed reactor with a reaction temperature of 200°C to 300°C and a reaction pressure of 0.8MPa to 3.4MPa. The liquid hourly space velocity is 0.6h ^-1 ~ 1.2h ^-1 , and the molar ratio of H ₂ to ethyl acetate is 10 ~ 50:1.

Compared with prior art, the beneficial effect of the present invention is:

(1) The catalyst of the present invention is a non-precious metal catalyst, with low production cost, good stability, environmental friendliness, and high catalytic activity. When used for the hydrogenation of ethyl acetate to ethanol, the conversion rate of ethyl acetate is as high as 97%, and the product The selectivity of ethanol is as high as 95%;

(2) in the catalyst of the present invention, compared with when transition metal oxide is used as a promoter, when the promoter is MgO, the microstructure of the catalyst is different, and now the microstructure of the catalyst makes the catalytic activity of the catalyst better;

(3) the preparation method of catalyst of the present invention is simple, adopts sodium silicate precipitation method, compares with common physical co-precipitation method, active component dispersibility is better in the catalyst prepared by the present invention, and the particle diameter of active component is smaller, and then The catalytic performance of the catalyst is improved, and the preparation method has good repeatability.

detailed description

Example 1

(1) Add 7.248g copper nitrate trihydrate and 2.564g magnesium nitrate hexahydrate to 100ml deionized water, stir at room temperature for 1h to obtain a mixed solution of copper nitrate and magnesium nitrate; add 11.368g sodium silicate nonahydrate to 120ml deionized water water, stirred at room temperature for 1 h to obtain an aqueous solution of sodium silicate;

(2) Slowly add the mixed solution of copper nitrate and magnesium nitrate into the sodium silicate aqueous solution dropwise, keep stirring at a constant speed during the dropwise addition, continue to stir for 2 hours after the dropwise addition is completed, then filter the liquid to obtain a filter cake, use a certain amount of Wash with deionized water to remove sodium ions, and place the filter cake in air at room temperature for aging for 12 hours;

(3) Dry the aged filter cake in an oven at 120°C for 12 hours, then grind it and place it in a muffle furnace, and bake it for 5 hours at 500°C in air;

(4) Fill 2.4ml of the calcined filter cake into a fixed-bed tubular reactor, and reduce it at 450°C for 3h in an _H2 atmosphere of 0.1Mpa and a space velocity of 1000h ^-1 to obtain a catalyst.

In terms of mass percentage, in the obtained catalyst: Cu40.67%, MgO8.47%.

Application example 1

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 260°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 30:1, the ethyl acetate conversion rate is 88.6%, and the ethanol selectivity is 92.3%.

Application example 2

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 280°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 30:1, the ethyl acetate conversion rate is 96.6%, and the ethanol selectivity is 93.3%.

Application example 3

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 300°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 30:1, the ethyl acetate conversion rate is 98.6%, and the ethanol selectivity is 91.3%.

Application example 4

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 280°C, a reaction pressure of 1.6MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition that the molar ratio of ester is 30:1, the conversion rate of ethyl acetate is 78.6%, and the selectivity of ethanol is 90.3%.

Application example 5

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 280°C, a reaction pressure of 2.4MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition that the molar ratio of ester is 30:1, the conversion rate of ethyl acetate is 96.2%, and the selectivity of ethanol is 92.5%.

Application example 6

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 280°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.4h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 30:1, the ethyl acetate conversion rate is 75.8%, and the ethanol selectivity is 95.2%.

Application example 7

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 280°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 0.6h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 30:1, the conversion rate of ethyl acetate is 100%, and the selectivity of ethanol is 69.8%.

Application example 8

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 280°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 10:1, the ethyl acetate conversion rate is 56.1%, and the ethanol selectivity is 90.1%.

Application example 9

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 1, at a reaction temperature of 280°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 50:1, the ethyl acetate conversion rate is 96.5%, and the ethanol selectivity is 91.1%.

Example 2

(1) Add 7.248g copper nitrate trihydrate and 4.462g zinc nitrate hexahydrate to 120ml deionized water, stir at room temperature for 1h to obtain a mixed solution of copper nitrate and zinc nitrate; add 12.780g sodium silicate nonahydrate to 130ml deionized water water, stirred at room temperature for 1 h to obtain an aqueous solution of sodium silicate;

(2) Slowly add the mixed solution of copper nitrate and zinc nitrate into the sodium silicate aqueous solution dropwise, keep stirring at a constant speed during the dropwise addition, and continue stirring for 2 hours after the dropwise addition is completed, then filter the liquid to obtain a filter cake, and use a certain amount of Wash with deionized water to remove sodium ions, and place the filter cake in air at room temperature for aging for 12 hours;

(3) Dry the aged filter cake in an oven at 120°C for 12 hours, then grind it and place it in a muffle furnace, and bake it for 5 hours at 500°C in air;

(4) Fill 2.4ml of the calcined filter cake into a fixed-bed tubular reactor, and reduce it at 450°C for 3h in an _H2 atmosphere of 0.1Mpa and a space velocity of 1000h ^-1 to obtain a catalyst.

In terms of mass percentage, in the obtained catalyst: Cu 32.90% ZnO 20.82%.

Application Example 10

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 2, at a reaction temperature of 280°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 30:1, the ethyl acetate conversion rate is 85.4%, and the ethanol selectivity is 80.6%.

Example 3

(1) Add 3.02g of copper nitrate trihydrate and 2.525g of ferric nitrate hexahydrate into 50ml of deionized water, stir at room temperature for 1h to obtain a mixed solution of copper nitrate and ferric nitrate; add 6.213g of sodium silicate nonahydrate into 60ml of deionized water water, stirred at room temperature for 1 h to obtain an aqueous solution of sodium silicate;

(2) Slowly add the mixed solution of copper nitrate and ferric nitrate into the aqueous solution of sodium silicate, keep stirring at a constant speed during the dropping process, and continue stirring for 2 hours after the addition is completed, then filter the liquid to obtain a filter cake, and use a certain amount of Wash with deionized water to remove sodium ions, and place the filter cake in air at room temperature for aging for 12 hours;

(3) Dry the aged filter cake in an oven at 120°C for 12 hours, then grind it and place it in a muffle furnace, and bake it for 5 hours at 500°C in air;

(4) Fill 2.4ml of the calcined filter cake into a fixed-bed tubular reactor, and reduce it at 450°C for 3h in an _H2 atmosphere of 0.1Mpa and a space velocity of 1000h ^-1 to obtain a catalyst.

In terms of mass percentage, in the obtained catalyst: Cu 32.98% Fe ₂ O ₃ 20.61%.

Application Example 11

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 3, at a reaction temperature of 280°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 30:1, the ethyl acetate conversion rate is 86.7%, and the ethanol selectivity is 83.5%.

Example 4

(1) Add 7.248g copper nitrate trihydrate and 5.395g manganese nitrate solution with a mass fraction of 50% to 120ml deionized water, stir at room temperature for 1h to obtain a mixed solution of copper nitrate and manganese nitrate; 12.780g sodium silicate nonahydrate Add to 130ml deionized water, stir at room temperature for 1h to obtain sodium silicate aqueous solution;

(2) Slowly add the mixed solution of copper nitrate and manganese nitrate into the aqueous solution of sodium silicate, keep stirring at a constant speed during the dropping process, and continue stirring for 2 hours after the addition is completed, then filter the liquid to obtain a filter cake, and use a certain amount of Wash with deionized water to remove sodium ions, and place the filter cake in air at room temperature for aging for 12 hours;

(3) Dry the aged filter cake in an oven at 120°C for 12 hours, then grind it and place it in a muffle furnace, and bake it for 5 hours at 500°C in air;

(4) Fill 2.4ml of the calcined filter cake into a fixed-bed tubular reactor, and reduce it at 450°C for 3h in an _H2 atmosphere of 0.1Mpa and a space velocity of 1000h ^-1 to obtain a catalyst.

In terms of mass percentage, in the obtained catalyst: Cu 33.77% MnO 18.73%.

Application example 12

In a fixed-bed tubular reactor filled with 2.4ml of the catalyst prepared in Example 4, at a reaction temperature of 280°C, a reaction pressure of 2MPa, and an ethyl acetate liquid hourly space velocity of 1.0h ^-1 , H ₂ and ethyl acetate Under the condition of the molar ratio of 30:1, the conversion rate of ethyl acetate is 75.3%, and the selectivity of ethanol is 86.0%.

The embodiments described above have described the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. All within the scope of the principles of the present invention Any modifications, supplements and equivalent replacements should be included within the protection scope of the present invention.

Claims (8)

1. the catalyst for ethyl acetate preparation of ethanol by hydrogenating, it is characterised in that by percentage to the quality, including:

Active component 10%～60%

Auxiliary agent 3%～40%

Surplus is carrier；

Described active component is at least one in Cu, Co, Ni, and described auxiliary agent is Fe₂O₃、MgO、MnO、GeO₂、ZnO、 MoO₃, at least one in CdO, described carrier is SiO₂。

Catalyst for ethyl acetate preparation of ethanol by hydrogenating the most according to claim 1, it is characterised in that described activity Component is at least one in Cu, Co, Ni, and described auxiliary agent is MgO, and described carrier is SiO₂。

Catalyst for ethyl acetate preparation of ethanol by hydrogenating the most according to claim 1, it is characterised in that with percent mass Than counting, including:

Active component 25%～50%

Auxiliary agent 3%～30%

Surplus is carrier；

Described active component is Cu, and described auxiliary agent is MgO, and described carrier is SiO₂。

4. the preparation side of the catalyst agent for ethyl acetate preparation of ethanol by hydrogenating according to claims 1 to 3 Method, it is characterised in that including:

(1) according to ratio, the presoma of active component and the presoma of auxiliary agent are dissolved in water and obtain solution A, according to ratio by sodium silicate It is dissolved in water and obtains solution B, solution A is added drop-wise in solution B reaction and produces precipitation；

(2) precipitation is filtered, washing, aging, dry, roasting, reduction, obtain described for ethyl acetate preparation of ethanol by hydrogenating Catalyst.

Preparation method the most according to claim 4, it is characterised in that the presoma of described active component be Schweinfurt green, Cupric oxalate or copper nitrate, the presoma of described auxiliary agent is magnesium acetate, magnesium oxalate or magnesium nitrate.

Preparation method the most according to claim 4, it is characterised in that in step (2), baking temperature is 100 DEG C～200 DEG C, drying time is 5h～12h；Sintering temperature is 200 DEG C～600 DEG C, and roasting time is 2h～6h.

Preparation method the most according to claim 4, it is characterised in that in step (2), reduction temperature is 250 DEG C～550 DEG C, reduction pressure is 0.5MPa～2.5MPa, and the recovery time is 2h～5h, and hydrogen gas space velocity is 500h^-1～2000h^-1。

8. a catalyst according to claims 1 to 3 application in ethyl acetate preparation of ethanol by hydrogenating, its feature exists In, use tubular fixed-bed reactor to react, reaction temperature is 200 DEG C～300 DEG C, reaction pressure is 0.8MPa～ 3.4MPa, ethyl acetate liquid hourly space velocity (LHSV) 0.6h^-1～1.2h^-1、H₂Mol ratio 10～50: 1 with ethyl acetate.