SU1109380A1 - Process for preparing h-butyric aldehyde - Google Patents

Abstract

1. METHOD OF OBTAINING N-OIL ALDEHYDE by catalytic hydrogenation of crotonic aldehyde in the presence of a nickel-containing catalyst at a temperature of 130-170 ° C With and isolating the target product, characterized in that, in order to increase the productivity of the process, improve the quality of the target product, the nickel-chromium catalyst suspended in a high boiling alcohol-containing solvent is used as the nickel-containing catalyst, and the process is carried out in the liquid phase at a pressure of 0.3- 1 ati by continuous distillation of the resulting / desired product. 2. The method according to claim 1, is also distinguished by the fact that 2-ethylhexanol or (L high-boiling by-products: s obtained by synthesizing 2-ethylhexanol or a mixture of aliphatic primary alcohols) is used as a high-boiling alcohol-containing solvent.

Description

with

00 00 1 The invention relates to a process for the preparation of H-butyraldehyde, which is widely used as an intermediate for the production of n-butanol, 2-ethylhexanol, polyvinyl butyral. A known method of producing α-butyraldehyde by hydrogenation of crotonaldehyde at 210 ° C in the presence of a nickel – copper catalyst on silica gel with a nickel content of 6–8% and copper 6–8%. The crotonaldehyde conversion is 90%, the productivity is 1200 g of crotonaldehyde per liter of catalyst per hour, the selectivity is 91.8 .98% Cu. The disadvantage of this method is low selectivity and productivity of the process. The closest technical solution to the invention is a method of producing and-butyric aldehyde, catalytic hydrogenation of crotonic aldehyde in the presence of a stationary nickel catalyst containing elemental sulfur, sulfides, sulfur compounds, at 140-250 With and atmospheric pressure in the vapor phase. Process selectivity 82.5-96.5% of the prostate capacity 0.12 kg of crotonic aldehyde per 1 liter of catalyst per hour Sulfur content in target The product is 0.001-0.005 wt.% 2. The disadvantage of the known method is the relatively low productivity of the process and the quality of the target product due to the content of sulfur compounds in the latter, which is unacceptable because k-oil al degvd is mainly used in as a raw material for the synthesis of 2-ethylhexanol, which is the initial product for the preparation of plasticizers plastic masses. The presence of sulfur compounds in the plasticizer as impurities, even in ppm, is not allowed, since sulfur compounds increase the aging rate of plastics, contributes to the destruction of polymer chains under the action of light and oxygen. The presence of impurities of sulfurous compounds in the oil-aldehyde is unacceptable, too, because sulfurous compounds poison the copper and nickel catalysts used in 802 stages of hydrogenation of 2-ethylhexenap. in 2-ethylhexanol and purification of raw 2-ethylhexanol. The aim of the invention is to increase the productivity of the process and improve the quality of the target product. This goal is achieved by the fact that according to the method of obtaining M-oil aldehyde by catalytic hydrogenation of crotonic aldehyde in the presence of a nickel-chromium catalyst suspended in a high boiling alcohol-containing solvent, the process is carried out in the liquid phase at 130170 s and 0.3-1-1 pressure by continuous distillation of the resulting target product As a high-boiling alcohol-containing solvent, 2-ethylhexanol or high-boiling by-products obtained during the synthesis of 2-ethyl 1 hexanol, or a mixture of alif In the proposed method, an industrial NW catalyst is used. The following composition, wt.%: Nickel nickel48-51 Chromium oxide 26-29 Moisture, not more than 3.0 Sulfide sulfur, not more than 0.02 Iron, not more than 0.5 High-boiling point The by-product used in the proposed method as a solvent consists of a complex mixture of oxygen-containing compounds and is a colorless or light yellow liquid with an average molecular weight of about 260, a density of 0.35-0.95 g / cm and a temperature boiling at 50 mm Hg 150-200 ° C. The main components of the mixture are 2-ethylenehexanol, 2-ethylhexanoic and 2-ethylhexenoic esters and esters, n-butanol acetal, isooctanol and 2-ethylhexanal or 2-ethylhexenal, C-alcohols. and C. Hydrogen fed to the lower part of the reactor provides mixing of the catalytic fluid and the products entering the reactor, as well as maintaining the catalyst in suspended form. The consumption of hydrogen for hydrogenation is made up by supplying it to a constant pressure of 0.3-1.0 at. The method is carried out as follows. A nickel-chromium catalyst is used to hydrogenate in the form of a suspension, called a catalytic liquid. For preparing a catalytic liquid, a plasticized nickel-chromium pelletized catalyst is crushed and mixed with a portion of the solvent. The catalytic liquid is pumped into the reactor, which is an apparatus equipped in the lower part with a sparger for supplying hydrogen and connected in the upper part with a distillation column. Then the rest of the solvent is pumped in, hydrogen is supplied and the required pressure is established. After heating the reactor to the operating temperature, crotonaldehyde is fed there. Through the top of the reactor, the resulting H-aldehyde is removed as vapor. The vapors enter the column, where the n-butyraldehyde is separated from the impurities of crotonic aldehyde and high boiling solvent entrained in vapors of oily dehydrated oil. H-aldehyde is from the column for further purification and processing, and crotonaldehyde and solvent are returned to the reactor. Nickel-chromium catalysts are widely used to hydrogenate aldehydes in alcohols AZ, and they exhibit very high activity in this reaction. Therefore, the possibility of using a nickel-chromium catalyst for the selective hydrogenation of crotonaldehyde to n-butyric aldehyde with practically no formation of alcohol was unexpected. A combination of techniques such as carrying out the reaction in the liquid phase in a high-boiling solvent medium suspended in a non-nickel-chromium catalyst with Henphe blunt deduction from the reaction zone of n-buty aldehyde, forming an intermediate product, will make it possible to stop the crotonic hydrogenation reaction aldehyde at the stage of formation of n-butyric aldehyde and prevent further conversion of n-butyric aldehyde into n-butanol. Example 1. 300 g of a nickel-chromium catalyst with a bulk weight of 1.1 kg / l are crushed, mixed with 0.5 l of 2-ethylhexanol, a catalytic liquid is obtained and pumped into the reactor. There also serves 15 liters of 2-1H hexanol, hydrogen and set the pressure to 0.3 MPa. Then the reactor is heated to 130 ° C and crotonaldehyde is fed to the bottom in the amount of 1.8 kg / h (density 0.8 kg / l). From the top of the distillation column, 1.85 kg / h of product containing, in wt.%, Are taken: H-butyric aldehyde 96.3 Butanol2.5 Crotonic aldehyde1.2 Hydrogenation is carried out continuously with a bulk feed rate of crotonaldehyde of 8.2 h The degree of crotonaldehyde conversion is 98.8% with a selectivity of hydrogenation to i-aldehyde of 97.5%. The productivity of the process in terms of n-aldehyde is 5.94 kg per 1 kg of catalyst per hour (6.5 kg / l of catalyst per hour). The resulting n-butyric aldehyde dyscine is purified by known methods to obtain n-butyric aldehyde. Example 2. 250 g of a nickel-chromium catalyst are ground and mixed with 0.4 l of 2-ethylhexanol. 14 liters of high boiling point by-products of the synthesis of 2-ethylhexanol are pumped into the reactor, the resulting catalytic liquid is added thereto, hydrogen is introduced and the pressure is set to 1.0 MPa. Then the reactor is heated to 170 ° C and crotonaldehyde is fed to the bottom in an amount of 1 kg / h. From the top of the distillation column, 1.02 kg / h of product containing, in wt.%, Is taken: h-butyric aldehyde 96.0 Butanol3.7 Crotonic aldehyde0.3 Hydrogenation is carried out continuously with a volumetric feed rate of crotonaldehyde 5.5 h . The conversion of crotonaldehyde is 99.7% with a selectivity of hydrogenation to n-butyric aldehyde of 96.3%. The productivity of the process in terms of H-butyraldehyde is 3.9 kg per catalyst per hour (4.3 kg / l of catalyst per hour). Example 3. The method is carried out analogously to example 1 with the only difference that the temperature in the reactor is maintained at 145 ° C and the pressure is 0.6 at. 1.6 kg / h of crotonaldehyde is fed to the reactor, and 1.64 kg / h of product containing wt.% Is taken from the top of the column: tH-butyric aldehyde98, 0 Butanol1.0 Crotonic aldehyde 1.0 Hydrogenation is carried out They are fed continuously with a volumetric feed rate of crotonaldehyde 7.3. The degree of crotonaldehyde conversion is 99.0% with a hydrogenation selectivity of 99.0%. The productivity of the process in terms of aldehyde and oil is 5.3 kg per kg of catalyst per hour (5.8 kg / l per talizer per hour). Example 4. The method is carried out analogously to example 1 with the only difference that the temperature in the reactor is maintained at 115 ° C, high boiling by-products of the synthesis of 2-ethylhexanol are used as a solvent, crotonaldehyde is fed in an amount of 0.7 kg / h. From the top of the distillation column, 0.72 kg / h of product containing in its composition, wt.%; c-Oil aldehyde 87.5 Butanol 10 Crotonaldehyde 2.5 Hydrogenation is carried out continuously with a bulk feed rate of 3.2 h. The degree of crotonaldehyde conversion is 97.5% with a hydrogenation selectivity of 90% and an Andaldehyde production rate of 2.1 kg of aldehyde per kg of catalyst per hour (2.3 kg / l of catalyst per hour). Example 5. The method is carried out analogously to example 1 with the only difference that a mixture of aliphatic, primary alcohols Ci.,. At the same time, from the top of the distillation column, 1.8 kg / h of a product containing in its composition, wt.%: N-butyric aldehyde, 96.1 Butanol2.6 Crotonic aldehyde1,3 are taken. The process is carried out continuously with a volumetric feed rate of 8 , 2 ch1. The degree of crotonaldehyde conversion is 98.7% with a hydrogenation selectivity of 97.4%. The productivity of the process with respect to n-butyraldehyde is 5.7 kg per 1 kg of catalyst per hour (6.2 kg / l of catalyst per hour). The indicators of the process according to the proposed and known methods are presented in the table. The proposed method allows to increase the productivity of the process to 4.3-6.5 kg / l of catalyst per hour versus 0.127 kg / l of catalyst per hour in a known method, as well as to improve the quality of the target product due to the absence of sulfur in the target product.

Temperature, C

200 200

130 Volumetric feed rate of crotonaldehyde, H-1 0.150.15 Output of n-butyraldehyde. 96.096.5 96, Selectivity, 97.597.5 97, Sulfur content in n oil aldegy 10-5010-50 Ots de, ppm Production capacity for aldehy n and oil, du, kg / l catalys, 127 0.127 congestion per hour

145,115

170

130 7.3 3.2 6.0 98.0 87.5 96.1 6.3 99.0 90 Missing t 2.3 6.2

Claims (2)

1. METHOD FOR PRODUCING N-OIL Η 0ΓΌ ALDEHYDE by catalytic hydrogenation of crotonic aldehyde in the presence of a nickel-containing catalyst at a temperature of 130-170 ° C and isolating the target product, characterized in that, in order to increase the productivity of the process, improve the quality of the target product, use nickel-containing catalyst as nickel-chromium catalyst suspended in a high-boiling alcohol-containing solvent, and the process is carried out in the liquid phase at a pressure of 0.3-1 atm and continuous distillation of the resulting evogo product. 2. The method of pop. 1, characterized in that as high _a solubility in the alcohol-containing kokipyaschego of Tell is 2-ethylhexanol or high-boiling byproducts obtained in the synthesis of 2-ethylhexanol, or mixture of aliphatic primary alcohols, C ₁₂ -C _17.