Gas phase aldehyde hydrogenation process for butanol and octanol device

Abstract

The invention relates to the technical field of chemical engineering, in particular to a gas-phase aldehyde hydrogenation process for a butanol-octanol device. The technical scheme adopted by the invention is as follows: the method comprises the following steps: raw material preparation: mixing mixed butyraldehyde and hydrogen in a butyraldehyde gas phase hydrogenation evaporator to form uniform raw material gas flow; and gas-phase reaction: introducing the raw material gas flow into a fixed bed tubular reactor filled with a catalyst, carrying out gas-phase aldehyde hydrogenation reaction at the reaction temperature of 160-220 DEG C and the pressure of 0.4-0.5 MPaG at the air speed of more than or equal to 0.1 h <-1 >, the hydrogen-aldehyde ratio (mass) of 1.0-1.4 and the butyraldehyde / octene conversion rate of more than or equal to 95% to generate corresponding alcohol products. The method has the advantages that the method has the characteristic of lower energy consumption, the production cost can be effectively reduced, the environmental protection requirement can be met, the product yield can be improved, the subsequent purification process can be simplified, the requirements of high-quality fine chemical production, quality improvement and value increase can be met, and the method has the characteristics of good catalytic activity, high selectivity, good stability, strong liquid resistance and the like.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering technology, and particularly to a gas-phase aldehyde hydrogenation process for a butanol and octanol plant. Background Art

[0002] In the existing butanol and octanol production processes, the aldehyde hydrogenation reaction is a crucial step. This reaction directly affects the quality and production efficiency of the final product. Although the traditional liquid-phase aldehyde hydrogenation process has become a mature and reliable method through long-term development and technological accumulation, it has exposed many problems in practical applications.

[0003] Firstly, the reaction time of the liquid-phase aldehyde hydrogenation process is relatively long, which leads to an extended production cycle and reduces the overall efficiency of the production line. Secondly, this process requires a large amount of equipment investment, including reaction kettles, heating systems, and complex separation equipment, etc., which undoubtedly increases the financial burden on enterprises. In addition, the energy consumption problem is also very prominent. High energy consumption not only raises the production cost but also does not meet the current society's requirements for energy conservation and environmental protection. More critically, the liquid-phase aldehyde hydrogenation process produces more by-products during the reaction. These by-products not only reduce the yield of the target product but also increase the difficulty and cost of subsequent product purification. Some by-products may even pose potential hazards to the environment and human health, thus bringing challenges to the sustainable development of enterprises.

[0004] Therefore, it is particularly important to develop a highly efficient, low-energy-consuming, and environmentally friendly gas-phase aldehyde hydrogenation process. The gas-phase aldehyde hydrogenation process is expected to solve the main problems existing in the liquid-phase process. Summary of the Invention

[0005] The object of the present invention is to provide a gas-phase aldehyde hydrogenation process for a butanol and octanol plant. Through gas-phase reaction, this process can significantly increase the reaction rate, shorten the reaction time, and thus improve the production efficiency. At the same time, the gas-phase process has a relatively low dependence on equipment, can reduce the equipment investment cost. In terms of energy consumption, it has lower energy consumption characteristics, can effectively reduce the production cost and meet the environmental protection requirements, can improve the product yield and simplify the subsequent purification process, can meet the needs of high-quality fine chemical production and quality improvement and value addition, has characteristics such as good catalytic activity, high selectivity, good stability, strong anti-liquid ability, etc., and has excellent compressive and wear-resistant strength, convenient loading and unloading, etc.

[0006] The technical solution of the present invention is as follows: A gas-phase aldehyde hydrogenation process for a butanol and octanol plant, characterized by the following steps: Raw material preparation: Mix mixed butyraldehyde and hydrogen in a butyraldehyde gas-phase hydrogenation evaporator to form a uniform raw material gas stream; Gas-phase reaction: Introduce the raw material gas stream into a fixed-bed tubular reactor filled with a catalyst, with a reaction temperature of 160-220°C, a pressure of 0.4-0.5 MPaG, perform gas-phase aldehyde hydrogenation reaction, the space velocity ≥ 0.1 h-1, the hydrogen-to-aldehyde ratio (by mass) is 1.0-1.4, and the conversion rate of butyraldehyde / octene ≥ 95% to produce the corresponding alcohol products; Product separation: Cool and separate the reacted mixed gas to obtain the target alcohol products; Catalyst regeneration: Regularly regenerate the used catalyst to restore its catalytic activity; The catalyst is a JHK-2 type hydrogenation catalyst, and the JHK-2 type hydrogenation catalyst is a black bar, with a diameter of 6.5 mm and a length of 6.2-6.6 mm, the active component is CuO-ZnO-Al2O3, the bulk density is 1.25-1.55 kg / L, the specific surface area ≥ 30 m2 / g, the pore volume ≥ 0.15 ml / g, and the strength ≥ 100 N / cm.

[0007] Advantages of the present invention: 1) Compared with the traditional liquid-phase aldehyde hydrogenation process, the gas-phase aldehyde hydrogenation process of the present invention has the following advantages: 2) Short reaction time: The gas-phase reaction is faster than the liquid-phase reaction, greatly shortening the reaction time and improving production efficiency.

[0008] 3) Relatively low operating pressure: The operating pressure of the gas-phase reaction is lower than that of the liquid-phase reaction, improving operating safety.

[0009] 4) Less equipment investment: Due to mild reaction conditions, the equipment requirements are reduced, and the overall investment cost is reduced.

[0010] 5) Low energy consumption: The energy consumption of the gas-phase reaction is significantly lower than that of the liquid-phase reaction, with obvious energy-saving effects.

[0011] 6) Few by-products: The gas-phase reaction conditions are easier to control, and the generation amount of by-products is greatly reduced, improving product purity.

[0012] 7) Environmental protection: No waste water or waste residue is generated during the whole process, meeting environmental protection requirements. Description of the drawings

[0013] Figure 1 is a flow chart of the gas-phase aldehyde hydrogenation process of the present invention; In the figure: 1, butyraldehyde; 2, butyraldehyde gas-phase hydrogenation evaporator; 3, hydrogenation system recycle gas; 4, gas-phase raw material gas; 5, first heat exchanger; 6, second heat exchanger; 7, third heat exchanger; 8, gas-phase hydrogenation reactor; 9, compressor; 10, demister; 11, separation tank; 12, hydrogen; 13, crude butanol. Detailed implementation mode

[0014] As Figure 1 shown, a gas-phase aldehyde hydrogenation process for a butanol and octanol plant is characterized by the following steps: Raw material preparation: Mix mixed butyraldehyde and hydrogen in a butyraldehyde gas-phase hydrogenation evaporator to form a uniform raw material gas stream; Gas-phase reaction: Introduce the raw material gas stream into a fixed-bed tubular reactor filled with a catalyst, with a reaction temperature of 160-220 °C, a pressure of 0.4-0.5 MPaG, carry out gas-phase aldehyde hydrogenation reaction, the space velocity ≥ 0.1 h-1, the hydrogen-aldehyde ratio (mass) is 1.0-1.4, and the conversion rate of butyraldehyde / octene ≥ 95% to produce the corresponding alcohol products; Product separation: Cool and separate the reaction mixture gas to obtain the target alcohol products; Catalyst regeneration: Regularly regenerate the used catalyst to restore its catalytic activity; The catalyst is a JHK-2 type hydrogenation catalyst, and the JHK-2 type hydrogenation catalyst is a black strip, with a diameter of 6.5 mm and a length of 6.2-6.6 mm, the active component is CuO-ZnO-Al2O3, the bulk density is 1.25-1.55 kg / L, the specific surface area ≥ 30 m2 / g, the pore volume ≥ 0.15 ml / g, and the strength ≥ 100 N / cm.

[0015] In a specific embodiment, the mixed butyraldehyde from the storage tank and the recycled hydrogen from the hydrogenation system are mixed and evaporated into the gas phase in a gas-phase hydrogenation evaporator in a certain proportion, and the proportion is modified accordingly with the operation time of the device. The mixed raw material gas is heated to 160 °C by a heating system and introduced into the tube side of a tubular fixed-bed reactor filled with JHK-2 type hydrogenation catalyst from bottom to top. Circulating water is introduced into the shell side to take away the generated reaction heat.

[0016] The raw material gas undergoes gas-phase aldehyde hydrogenation reaction under the conditions of 160-220 °C and 0.4-0.5 MPaG. During the reaction process, it is necessary to ensure the uniformity and stability of the raw material gas stream to avoid uneven reaction and the generation of by-products. The reaction mixture gas after reaction is condensed and separated to obtain a mixture of n-butanol and isobutanol. The catalyst is regenerated every 1 year of operation to ensure its catalytic activity. The regeneration time is 1 day, the temperature is 200-350 °C, and the pressure is 0.4 MPa. The catalyst can be first subjected to high-temperature calcination to remove the carbon deposition and impurities on the surface, and then reduced with hydrogen to restore its catalytic activity. Regarding the production of octanol, since butanol and octanol can be produced through the same hydrogenation reactor by switching the process, the scheme is the same as above.

[0017] The JHK-2 hydrogenation catalyst can be applied to the deep hydrogenation treatment of raw materials such as gaseous aldehydes, meeting the requirements for the production of high-quality fine chemicals and quality improvement and value addition. The overall performance of the catalyst reaches the international advanced level and can completely replace imported catalysts. The production technology of this catalyst is the first in China. Compared with similar foreign catalysts, it has the characteristics of good catalytic activity, high selectivity, good stability, strong anti-liquid ability, etc., and has excellent compressive and abrasion resistance strength and convenient loading and unloading. It is mainly used for the gas-phase hydrogenation of butyraldehyde and octenal to produce butanol and octanol.

[0018] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements or substitutions can be made, and these improvements or substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A gas-phase aldehyde hydrogenation process for a butanol and octanol plant, characterized in that, It includes the following steps: Raw material preparation: Mix mixed butyraldehyde and hydrogen in a butyraldehyde gas-phase hydrogenation evaporator to form a uniform raw material gas stream; Gas-phase reaction: Introduce the raw material gas stream into a fixed-bed tubular reactor filled with a catalyst. The reaction temperature is 160~220°C, the pressure is 0.4~0.5 MPaG, carry out gas-phase aldehyde hydrogenation reaction, the space velocity ≥0.1 h-1, the hydrogen-to-aldehyde ratio (mass) is 1.0~1.4, and the butyraldehyde / octene conversion rate ≥95% to produce the corresponding alcohol products; Product separation: Cool and separate the reacted mixed gas to obtain the target alcohol products; Catalyst regeneration: Regularly regenerate the used catalyst to restore its catalytic activity; The catalyst is a JHK-2 type hydrogenation catalyst. The JHK-2 type hydrogenation catalyst is a black bar with a diameter of 6.5 mm and a length of 6.2~6.6 mm. The active component is CuO-ZnO-Al2O3, the bulk density is 1.25~1.55 kg / L, the specific surface area ≥30 m2 / g, the pore volume ≥0.15 ml / g, and the strength ≥100 N / cm.

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