US-20260125337-A1 - METHOD FOR PREPARATION OF ALDEHYDE

US20260125337A1US 20260125337 A1US20260125337 A1US 20260125337A1US-20260125337-A1

Abstract

A method for preparing an aldehyde including: reacting reactants in a reactor to obtain a reaction product; supplying the reaction product to a first flash drum, performing gas-liquid separation, and supplying a liquid separated product to a vaporization part including a vaporizer; vaporizing the liquid from the vaporization part separate-into a vapor stream and a liquid stream; supplying the vapor stream to a second flash drum to separate an upper discharge stream and a lower discharge stream from the second flash drum; and supplying the upper discharge stream from the second flash drum to one or more flash drums, and supplying the lower discharge stream from the second flash drum to a distillation tower and performing distillation to obtain the aldehyde from a lower discharge stream from the distillation tower, wherein a ratio of an operating temperature of the vaporizer to a reaction temperature of the reactor is controlled.

Inventors

Jae Hun Jeong
SUNG KYU LEE
Sung Kyun Kim
Min Suk Kang

Assignees

LG CHEM, LTD.

Dates

Publication Date: 20260507
Application Date: 20240709
Priority Date: 20231016

Claims (11)

1 . A method for preparing an aldehyde, comprising: supplying a reactant comprising a syngas and an olefin to a reactor and reacting them in the presence of a catalyst to obtain a reaction product comprising an aldehyde; supplying the reaction product to a first flash drum, performing gas-liquid separation, and supplying a liquid separated product comprising an unreacted olefin, the catalyst, and the aldehyde to a vaporization part comprising a vaporizer; vaporizing the liquid separated product in the vaporization part to separate a vapor stream comprising the unreacted olefin and the aldehyde, and a liquid stream comprising the catalyst; supplying the vapor stream to a second flash drum to separate an upper discharge stream from the second flash drum comprising the unreacted olefin, and a lower discharge stream from the second flash drum comprising the aldehyde; and supplying the upper discharge stream from the second flash drum to one or more flash drums, and supplying the lower discharge stream from the second flash drum to a distillation tower and performing distillation to obtain the aldehyde from a lower discharge stream from the distillation tower, wherein a ratio of an operating temperature (° C.) of the vaporizer to a reaction temperature (° C.) of the reactor is 1.1 to 1.9.
2 . The method of claim 1 , wherein before supplying the upper discharge stream from the second flash drum to one or more flash drums, the upper discharge stream from the second flash drum is supplied to the one or more flash drums through a vacuum pump.
3 . The method of claim 2 , wherein an internal pressure of the vaporizer is reduced by the vacuum pump.
4 . The method of claim 1 , wherein the one or more flash drums comprise a third flash drum.
5 . The method of claim 4 , wherein a condenser is provided upstream of the second flash drum and the third flash drum, respectively.
6 . The method of claim 4 , wherein the upper discharge stream from the second flash drum is supplied to the third flash drum to obtain an upper discharge stream from the third flash drum and a lower discharge stream from the third flash drum, and the lower discharge stream from the third flash drum is supplied to the second flash drum, and the upper discharge stream from the third flash drum is supplied to the reactor.
7 . The method of claim 6 , wherein the upper discharge stream from the third flash drum comprises the unreacted olefin, and the lower discharge stream from the third flash drum comprises the aldehyde.
8 . The method of claim 1 , wherein an internal pressure of the vaporizer is −0.7 to 1.0 kg/cm 2 .G.
9 . The method of claim 1 , wherein the ratio of the operating temperature (° C.) of the vaporizer to the reaction temperature (° C.) of the reactor is 1.3 to 1.7.
10 . The method of claim 1 , wherein the syngas is a mixed gas comprising carbon monoxide and hydrogen.
11 . The method of claim 1 , wherein the olefin is an alpha olefin having 3 to 20 carbon atoms.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a National Stage Application of International Application No. PCT/KR2024/009722 filed on Jul. 9, 2024, which claims the benefit of and priority to Korean Patent Application No. 10-2023-0137652 filed on Oct. 16, 2023 and Korean Patent Application No. 10-2024-0087889 filed on Jul. 4, 2024, the entire contents of which are incorporated herein as a part of the specification. TECHNICAL FIELD The present disclosure relates to a method for preparing an aldehyde, and more particularly, to a method for preparing an aldehyde by controlling a ratio of an operating temperature of a vaporizer to a reaction temperature of a reactor. BACKGROUND ART A hydroformylation reaction, which is also known as an oxo reaction, is a reaction in which various olefin-based compounds are reacted with a syngas (carbon monoxide (CO) and hydrogen (H2)) in the presence of a catalyst to produce a linear (normal) aldehyde and a non-linear (iso) aldehyde having the number of carbon atoms increased by 1. An aldehyde produced by the oxo reaction may be oxidized or hydrogenated, and converted into acid and alcohol which are aldehyde derivatives, or after a condensation reaction of aldol and the like, may be oxidized or hydrogenated, and converted into various acids and alcohols including a long alkyl group. A hydrogenated alcohol of the aldehyde by the oxo reaction is referred to as an oxo alcohol, and is widely used industrially as various solvents, additives, plasticizer raw materials, synthetic lubricants, and the like. In the preparation of the aldehyde, high-boiling point by-products such as aldehyde dimers or trimers are produced during the hydroformylation reaction. When these are produced in a large amount and accumulate in the process as impurities, the hydroformylation reaction may be reduced, and process stability is also reduced. Therefore, a method which may activate the hydroformylation reaction while decreasing accumulation of the high-boiling point by-products is needed. DISCLOSURE Technical Problem In order to solve the problems mentioned in the Background Art, an object of the present disclosure is to provide an effect of decreasing accumulation of high-boiling point by-products and activating the hydroformylation reaction. However, the object to be solved in the present application is not limited to the object mentioned above, and other objects which are not mentioned may be clearly understood by a person skilled in the art from the following descriptions. Technical Solution In one general aspect, provided is a method for preparing an aldehyde that includes: supplying reactants including a syngas and an olefin to a reactor and reacting them in the presence of a catalyst to obtain a reaction product including an aldehyde; supplying the reaction product to a first flash drum, performing gas-liquid separation, and supplying a liquid separated product including an unreacted olefin, the catalyst, and the aldehyde to a vaporization part including a vaporizer; vaporizing the liquid separated product in the vaporization part to separate a vapor stream including the unreacted olefin and the aldehyde, and a liquid stream including the catalyst; supplying the vapor stream to a second flash drum to separate an upper discharge stream from the second flash drum including the unreacted olefin, and a lower discharge stream from the second flash drum including the aldehyde; and supplying the upper discharge stream from the second flash drum to one or more flash drums, and supplying the lower discharge stream from the second flash drum to a distillation tower and performing distillation to obtain the aldehyde from a lower discharge stream from the distillation tower, wherein a ratio of an operating temperature (° C.) of the vaporizer to a reaction temperature (° C.) of the reactor is 1.1 to 1.9. Advantageous Effects According to the method for preparing an aldehyde of the present disclosure, by controlling the ratio of the operating temperature (° C.) of the vaporizer to the reaction temperature (° C.) of the reactor to 1.1 to 1.9, the amount of the high-boiling point by-products produced during the hydroformylation reaction performed in the reactor and the amount of the high-boiling point by-products further produced in the process may be decreased. Thus, the amount of the high-boiling point by-products included in the liquid stream separated from the vaporization part flash drum circulated to the reactor may be decreased, and a side reaction may be decreased during the hydroformylation reaction. In addition, since the high-boiling point by-products accumulate in a large amount and are circulated in the process, an increase in the operating temperature in the vaporizer and process instability may be suppressed. Furthermore, since the upper discharge stream from the second flash drum passes through a vacuum pump, internal pressure of the vaporizer is reduced by the vacuum pump, so that