Process for producing isooctanol and application thereof

Abstract

The invention discloses a process for producing isooctanol and application thereof, and belongs to the technical field of isooctanol production. Comprising the following steps: 1) first-stage reaction: preheating isooctenal; then taking isooctenal and hydrogen as raw materials, and carrying out liquid-phase hydrogenation reaction and gas-liquid separation under the catalysis of a first catalyst to obtain isooctanal; and 2) second-stage reaction: taking isooctanal and hydrogen as raw materials, and carrying out liquid-phase hydrogenation reaction and gas-liquid separation under the catalysis of a second catalyst to obtain the isooctanol. According to the process for producing the isooctanol, the isooctanal is prepared through liquid phase hydrogenation of the isooctenal, then the isooctanol is prepared through liquid phase hydrogenation of the isooctenal, the conversion rate and the selectivity of the isooctanal both reach 98% or above, and the conversion rate and the selectivity of the isooctanol both reach 98% or above. According to the application of the process for producing the isooctanol, unsaturated olefine aldehyde containing C = C bonds can be used as a raw material, and aldehyde and alcohol can be produced through a liquid-phase hydrogenation reaction.

Description

Technical Field

[0001] The invention discloses a process for producing isooctyl alcohol and application thereof, belonging to the technical field of isooctyl alcohol production. Background Art

[0002] 2-ethyl hexanol is an important chemical product with a wide range of uses. It can be mainly used to produce: dioctyl phthalate (DOP), dioctyl oxalate (DOA), trioctyl trimellitate (TOTM), other plasticizers, octyl acrylate, surfactants, lubricant additives, mining, diesel fuel additives, solvents and preparations, rust inhibitor esters, or other chemicals.

[0003] In the prior art, the industrial large-scale production of isooctyl alcohol is carried out by using gas phase propylene and synthesis gas as raw materials, using rhodium as a catalyst, generating mixed butyraldehyde, separating the products, condensing n-butyraldehyde to obtain isooctylaldehyde, hydrogenating the isooctylaldehyde to obtain crude isooctyl alcohol, and then refining it through distillation, rectification and other processes; that is, using gas phase hydrogenation as the first step and liquid phase fine hydrogenation as the second step.

[0004] The applicant found in the research that the existing isooctyl alcohol production process has the following problems: First, in the current production process of butyl isooctanol, the gas phase hydrogenation process of DAVY is widely used in my country. It uses a copper-based catalyst. After isooctenal is subjected to heterogeneous hydrogenation, the product obtained is mainly isooctanol. The reaction temperature of gas phase hydrogenation is usually 180°C or above. For example, the Second Fertilizer Plant of Sinopec Qilu Branch uses the DAVY process, which uses a copper-based catalyst to produce crude isooctanol by gas phase hydrogenation at 0.44-0.45MPa, 200-220°C, and 220-240°C hot spot temperature. In this process, the gasification of aldehyde raw materials consumes a lot of energy, and the reaction temperature is high, resulting in high production costs. At present, in China, the catalysts used in this process step are usually provided by Johnson Matthey Company of the United Kingdom, Clariant Company of Switzerland, Sinopec Nanjing Chemical Industry Co., Ltd. Research Institute, and Beijing Sanju Environmental Protection New Materials Co., Ltd. The hydrogenation conversion rate of isooctenal and the selectivity of isooctanol are usually 98% or above.

[0005] Secondly, in addition to the defects of energy consumption and cost, the existing gas phase hydrogenation also has the problem of product quality: in the existing production process, after gas phase hydrogenation, the obtained material usually contains a small amount of unsaturated residues such as isooctyl aldehyde, isooctyl aldehyde, and octenol, which affects the sulfuric acid color of the product isooctyl alcohol and reduces the product grade. Therefore, the existing gas phase hydrogenation technology requires an additional process to further hydrogenate the product isooctyl alcohol; that is, the first step is gas phase hydrogenation, and the second step is liquid phase fine hydrogenation to obtain impurity-containing isooctyl alcohol, which is hydrogenated again. At present, in China, the catalyst used for the process step of hydrogenation again usually adopts a nickel-based catalyst developed by the Research Institute of Sinopec Qilu Branch, such as the catalysts of patents CN 1217899C and CN 1268595C, which are designed for hydrogenation again. The existing technology must be refined by means of re-hydrogenation to achieve the purpose of increasing the yield of isooctyl alcohol and improving product quality; however, the existing re-hydrogenation method undoubtedly increases the complexity of the process, and the investment in catalysts and equipment will increase the production cost, and the process becomes complicated, and the production efficiency will inevitably decrease.

[0006] Thirdly, the applicant found in the study that when the activity and selectivity of the gas-phase hydrogenation catalyst are good (usually in the initial 24-28 months of catalyst use), the unsaturated content of the product is very low (total ≤0.5%), and the price of the fine hydrogenation reactor equipment is high. Enterprises usually do not invest in fine hydrogenation reactors to reduce production costs; after the activity and selectivity of the gas-phase hydrogenation catalyst decrease, enterprises invest in liquid-phase fine hydrogenation reactors and their catalysts. Some enterprises, considering investment and operation, only design and build one gas-phase hydrogenation reactor and operate it in a way that shortens the use cycle of the gas-phase hydrogenation catalyst.

[0007] Obviously, the existing isooctyl alcohol production process and method has the disadvantages of high energy consumption, low conversion rate, high operating cost, and low utilization rate of related equipment and catalysts after they are put into use.

[0008] Developing a method for preparing isooctyl alcohol by liquid-phase hydrogenation of isooctyl aldehyde with simple process and low operating cost is a technical problem that urgently needs to be solved. Summary of the invention

[0009] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a process for producing isooctyl alcohol and its application. The process adopts liquid phase hydrogenation of isooctyl aldehyde to produce isooctyl aldehyde, and then adopts liquid phase hydrogenation of isooctyl aldehyde to produce isooctyl alcohol, the conversion rate and selectivity of isooctyl aldehyde both reach more than 98%, and the conversion rate and selectivity of isooctyl alcohol both reach more than 98%.

[0010] The technical solution of the method adopted by the present invention to solve the technical problem is: the process for producing isooctyl alcohol is characterized by comprising the following steps: 1) One-stage reaction: preheat isooctenal first; then, isooctenal and hydrogen are used as raw materials, and are subjected to liquid phase hydrogenation reaction and gas-liquid separation under the catalysis of the first catalyst to obtain isooctenal; 2) Second stage reaction: using isooctyl aldehyde and hydrogen as raw materials, under the catalysis of the second catalyst, liquid phase hydrogenation reaction and gas-liquid separation are carried out to obtain isooctyl alcohol.

[0011] The specific operation of step 1) is as follows: first preheating isooctyl aldehyde to 70-150°C; then using isooctyl aldehyde and hydrogen as raw materials, under the catalysis of the first catalyst, undergoing liquid phase hydrogenation reaction and gas-liquid separation to obtain isooctyl aldehyde, wherein the reaction temperature of the liquid phase hydrogenation reaction is 70-160°C, the reaction pressure is 1.6-2.7MPa, and the liquid space velocity is 0.3-6.0h -1 , the molar ratio of hydrogen to isooctene aldehyde is 1.8-5.0:1.

[0012] Preferably, the specific operation of step 1) is: first preheating isooctyl aldehyde to 80-130°C; then using isooctyl aldehyde and hydrogen as raw materials, under the catalysis of a first catalyst, undergoing liquid phase hydrogenation reaction and gas-liquid separation to obtain isooctyl aldehyde, wherein the reaction temperature of the liquid phase hydrogenation reaction is 90-155°C, the reaction pressure is 1.6-1.8MPa, and the liquid space velocity is 0.6-5.0h -1 , the molar ratio of hydrogen to isooctene aldehyde is 2.0-4.0:1.

[0013] The specific operation of step 2) is as follows: using isooctyl aldehyde and hydrogen as raw materials, under the catalysis of the second catalyst, undergoing liquid phase hydrogenation reaction and gas-liquid separation to obtain isooctyl alcohol, wherein the reaction temperature of the liquid phase hydrogenation reaction is 90-180°C, the reaction pressure is 1.4-2.6MPa, and the liquid space velocity is 0.6-10.0h -1 , the molar ratio of hydrogen to isooctyl aldehyde is 2-4:1.

[0014] Preferably, the specific operation of step 2) is: using isooctyl aldehyde and hydrogen as raw materials, under the catalysis of the second catalyst, undergoing liquid phase hydrogenation reaction and gas-liquid separation to obtain isooctyl alcohol, wherein the reaction temperature of the liquid phase hydrogenation reaction is 120-165°C, the reaction pressure is 1.45-1.8MPa, and the liquid space velocity is 0.6-8.0h -1 , the molar ratio of hydrogen to isooctylaldehyde is 2-4:1.

[0015] The specific operation of the preheating in step 1) is: using the isooctylaldehyde in step 1) as a cold medium and the isooctylaldehyde in step 1) as a hot medium, heat exchange is performed through a heat exchanger.

[0016] In step 2), the temperature of the isooctylaldehyde is 70-160° C. Preferably, in step 2), the temperature of the isooctylaldehyde is 100-125° C.

[0017] Step 1) the first catalyst is a palladium-based catalyst, and step 2) the second catalyst is a nickel-based catalyst.

[0018] Step 1) The active component content of the first catalyst is 0.22-0.30% by weight (abbreviated as wt%) of palladium oxide; the carrier phase of the first catalyst is γ-Al2O3 phase and SiO2 phase, and the bulk density of the catalyst is 0.68-0.70 kg / L.

[0019] Step 2) The active component content of the second catalyst is 23-26% by mass of nickel oxide; the carrier phase of the second catalyst is γ-Al2O3 phase and SiO2 phase, and cerium oxide is used as an active auxiliary agent, the cerium oxide content in the carrier is 1%-3% by mass, and the catalyst bulk density is 0.55-0.58kg / L.

[0020] The application of the process for producing isooctyl alcohol is specifically used for producing aldehydes and alcohols by liquid phase hydrogenation reaction using unsaturated olefinic aldehydes containing C=C bonds as raw materials.

[0021] The liquid space velocity in step 1) is the liquid space velocity of isooctylaldehyde; the liquid space velocity in step 2) is the liquid space velocity of isooctylaldehyde. In step 1) and step 2), the reaction temperature is the reaction hot spot temperature.

[0022] The hydrogen in step 2) comes from: the remaining hydrogen after the reaction in step 1) and the newly added hydrogen in step 2). The specific operation of adding hydrogen in step 2) is: adding hydrogen through online detection until the molar ratio of hydrogen to isooctylaldehyde in step 2) is reached.

[0023] In the process flow of the present invention, a hydrogen circulation machine or hydrogen purification equipment can be provided as required, and the purified hydrogen is returned to the reactor inlet.

[0024] Preferably, after the liquid phase hydrogenation reaction in step 1), the remaining hydrogen in the reaction is subjected to gas-liquid separation, a hydrogen circulation machine and / or a hydrogen purification device, and then used as a raw material again to participate in the liquid phase hydrogenation reaction in step 1).

[0025] Preferably, after the liquid phase hydrogenation reaction in step 2), the remaining hydrogen in the reaction is separated by gas and liquid, passed through a hydrogen circulation machine and / or a hydrogen purification device, and then used as a raw material again to participate in the liquid phase hydrogenation reaction in step 1).

[0026] Preferably, the liquid phase hydrogenation reaction in step 1) is carried out in a first stage reactor. Preferably, the first stage reactor is a shell-and-tube reactor. Preferably, the inner diameter of a single reaction tube of the first stage reactor is Φ32-50 mm, and the height of the catalyst bed is 3-12 m; preferably, the height of the catalyst bed is 6-8 m.

[0027] Preferably, the liquid phase hydrogenation reaction in step 2) is carried out in a second-stage reactor. Preferably, the second-stage reactor is a shell-and-tube reactor. Preferably, the inner diameter of a single reaction tube of the second-stage reactor is Φ32-50 mm, and the height of the catalyst bed is 3-12 m; preferably, the height of the catalyst bed is 6-8 m.

[0028] The outer walls of the first stage reactor and the second stage reactor are surrounded by a heat exchange medium layer or a heating layer, and the temperature of the liquid phase hydrogenation reaction is adjusted and controlled by heat exchange or heating. Preferably, the heat exchange medium layer is an oil bath.

[0029] Preferably, the method further comprises step 3) fractionation: the isooctyl alcohol obtained in step 2) is separated by a fractionation tower to obtain high-purity isooctyl alcohol.

[0030] Step 1) A method for preparing the first catalyst comprises the following steps: 1) 45-55 parts by weight of kaolin and 45-55 parts by weight of pseudo-boehmite are mixed, an auxiliary agent and water are added, the mixture is kneaded, extruded into strips, and calcined at 680-700° C. for 2-3 hours to obtain carrier a; 2) Weigh palladium chloride, add water to dissolve it, and adjust the pH value with hydrochloric acid to obtain a palladium salt palladium chloride solution with a concentration of 8.0-9.0 g / L and a pH value of 2.7-2.9; 3) Weigh carrier a and immerse it in a palladium chloride solution for 30-45 minutes, dry it at 110-125°C for 2-3 hours, and then calcine it at 420-470°C for 1.5-2 hours to obtain the first catalyst.

[0031] Preferably, the auxiliary agent in step 1) is at least one of sesbania powder, citric acid, nitric acid and cellulose. Preferably, the ingredients and amounts of the auxiliary agent and water in step 1) are: 2-4 parts by weight of sesbania powder, 2-4 parts by weight of citric acid, 2-4 parts by weight of nitric acid and 25-30 parts by weight of water.

[0032] The first catalyst is in the shape of a sphere with a diameter of 0.8-1.7 mm, or in the shape of a column with a diameter of 1.0-1.5 mm and a length of 0.5-1.0 cm; the column catalyst is in the shape of a cylindrical bar, a three-leaf clover bar or a four-leaf clover bar.

[0033] The pore volume of the first catalyst is 0.48-0.50cm 3 / g, specific surface area 108-122m 2 / g, average pore radius 8.79-9.0nm, bulk density 0.68-0.70kg / L, and average side pressure crushing strength greater than 170N / cm.

[0034] Step 2) A method for preparing the second catalyst comprises the following steps: 1) 35-60 parts by weight of kaolin and 40-60 parts by weight of carbonized aluminum hydroxide are mixed, 8-10 parts by weight of cerium nitrate hexahydrate, an auxiliary agent and water are added, kneaded, extruded into strips, and calcined at 680-700° C. for 2-3 hours to obtain carrier b; 2) Weigh nickel nitrate, add water to dissolve it, and prepare nickel nitrate solution; 3) Weigh carrier b and immerse it in nickel nitrate solution for 30-45 minutes, dry it at 110-125°C for 2-3 hours, and then calcine it at 450-470°C for 1.5-2 hours to obtain the second catalyst.

[0035] Preferably, the auxiliary agent in step 1) is at least one of sesbania powder, citric acid, nitric acid, and cellulose. Preferably, the ingredients and amounts of the auxiliary agent and water in step 1) are: 2-4 parts by weight of sesbania powder, 2-4 parts by weight of citric acid, 2-4 parts by weight of nitric acid, and 40-45 parts by weight of water. Preferably, the cerium nitrate hexahydrate in step 1) is dissolved in the water in step 1).

[0036] Preferably, the nickel nitrate solution in step 2) is a saturated nickel nitrate solution at room temperature, and the room temperature is 18-25°C.

[0037] The second catalyst is in the shape of a sphere with a diameter of 0.8-1.7 mm, or in the shape of a column with a diameter of 1.0-1.5 mm and a length of 0.5-1.0 cm; the column catalyst is in the shape of a cylindrical bar, a three-leaf clover column or a four-leaf clover column.

[0038] The second catalyst pore volume 0.0.37-39cm 3 / g, specific surface area 158-160m 2 / g, average pore radius 6.8-6.9nm, bulk density 0.52-0.57kg / L, and average side pressure crushing strength greater than 120N / cm.

[0039] The present invention is described as follows: 1. In the existing Davy gas phase hydrogenation process, the conversion rate of isooctyl aldehyde and the selectivity of isooctyl alcohol are quite high in the early and middle stages of the life cycle of the gas phase catalyst, and most of the time they are above 98%. The applicant found in the study that there are certain challenges in the reaction of using palladium or nickel-based catalysts to complete the liquid phase hydrogenation of isooctyl aldehyde to produce isooctyl alcohol in one reactor. In the reaction process, there are multiple reactions and side reactions. With the existing catalysts, the conversion rate of isooctyl aldehyde and the selectivity of isooctyl alcohol often have one value exceeding 98% and the other less than 98%, thereby reducing the economic efficiency.

[0040] The applicant has found through research that for the reaction of isooctylaldehyde hydrogenation to produce isooctylaldehyde, firstly, the reaction is a strong exothermic reaction, secondly, the impurity content generated by the side reaction will increase with the increase of the catalyst bed temperature, and again, hydrogen is a "double-edged sword" for the reaction. Excessive hydrogen will cause excessive hydrogenation to generate isooctyl alcohol, and insufficient hydrogen will cause low isooctylaldehyde hydrogenation rate, affecting reaction efficiency and economy. Therefore, with the help of a tubular reactor, the heat generated by the reaction is removed by using a heat exchange medium to prevent the catalyst bed temperature from "running out of control". The "running out of control" here does not mean that the main reaction is uncontrollable, but refers to the uncontrollable total amount of the side reaction, so as to control the reaction to a suitable degree and obtain the target product mainly based on isooctylaldehyde. In addition, when the temperature of the isooctylaldehyde raw material is greater than 138°C, the side reaction is more active, and the selectivity of isooctylaldehyde shows a downward trend.

[0041] 2. The first stage reactor of the present invention adopts a newly developed palladium catalyst, which uses aluminum oxide as the main carrier component. Through a series of experiments, it is believed that "high activity" should not be pursued in this reaction, and the catalyst can achieve the purpose with suitable activity. For example, US5756856 adopts a catalyst with a palladium content of 0.5%. The activity of the catalyst is high, which will increase the reaction amount of hydrogenation to generate isooctyl alcohol, so it is necessary to adopt a circulating method to reduce the isooctyl aldehyde content in the material, thereby reducing excessive hydrogenation. The nickel-based catalyst described in US4018831 is not active enough, so it is necessary to increase the isooctyl aldehyde hydrogenation rate in a circulating manner. Therefore, through research, the newly developed palladium catalyst, under suitable process conditions, preferentially completes the hydrogenation of C=C bonds, and minimizes the hydrogenation of C=O bonds, i.e., selective hydrogenation.

[0042] 3. The second-stage reactor of the present invention adopts a newly developed nickel-based catalyst, which also uses alumina as the main carrier component. The applicant has found through research that the hydrogenation activity of the nickel-based catalyst is lower than that of the palladium-based catalyst. It is difficult to use it to simultaneously complete the hydrogenation of C=O and C=C bonds, and to make the product of step 1) isooctanal and the product of step 2) isooctanol reach "double 98%". However, the applicant has found through research that when the first-stage reaction of step 1) has selectively hydrogenated isooctenal and enters the second-stage reaction of step 2), the raw materials of the nickel-based catalyst are mostly isooctanal. At this time, the disadvantage of the low hydrogenation activity of the nickel-based catalyst has become an advantage; it is only necessary to adjust the catalyst performance to make it better for the hydrogenation of C=O bonds, and effectively reduce the reaction of condensation to generate high-carbon by-products, thereby achieving the conversion rate and selectivity of the product of step 1) and the product of step 2) to reach "double 98%".

[0043] The invention uses liquid isooctyl aldehyde and gaseous hydrogen as raw materials, adopts a shell-and-tube reactor to carry out a gas-liquid-solid three-phase reaction to obtain a product mainly containing isooctyl aldehyde, then uses liquid isooctyl aldehyde and gaseous hydrogen as raw materials, adopts a shell-and-tube reactor to carry out a gas-liquid-solid three-phase reaction to obtain a product mainly containing isooctyl alcohol, and finally separates the products to obtain a high-purity product isooctyl alcohol.

[0044] In the process flow of the present invention, it is not necessary to set a circulating pump for liquid materials. The prior art is provided with a circulating pump, which is to enter isooctylaldehyde into step 1), hydrogenate the liquid phase, and then separate the gas and liquid, return a part of the liquid product and mix it with fresh isooctylaldehyde raw material, fresh hydrogen or circulating hydrogen, and enter step 1 again, and other liquid products enter the subsequent section. According to the existing patents or documents, the circulation ratio is also set very large, such as 1:8, that is, 9 parts enter the reactor, 8 parts return, and 1 part output, which leads to a very low production capacity of the device, increasing equipment investment and operating costs. The applicant's research found that it is related to the catalyst and reactor structure. In the prior art, the reactor structure is a conventional tubular reactor, which may cause problems. The catalyst activity is high, and the reaction is an exothermic reaction. The catalyst bed temperature quickly reaches a high temperature. The reaction emphasizes selectivity. At high temperature, the selectivity will deteriorate, and the economic efficiency of the product will decrease. The US patent does not conduct improved research on the catalyst, but only adopts a method of diluting the raw material. When the recycled material passes through the reactor again, it has the effect of taking away heat and reducing side reactions. In the process of the present invention, the first catalyst and the second catalyst used have high conversion rates and selectivities, so there is no need to set up a circulation pump for liquid materials in the process, which simplifies the process and improves the productivity of the process.

[0045] The isooctyl aldehyde product of step 1) and the isooctyl alcohol product of step 2) of the present invention can both be sold as products, and one process can be used to obtain two products, isooctyl aldehyde and isooctyl alcohol, or only isooctyl alcohol can be produced. The process of the present invention is convenient for flexible optimization of production according to market conditions; when the profit margin of isooctyl aldehyde is better than that of isooctyl alcohol, after the reaction of step 1), a part of the isooctyl aldehyde product of step 1) enters the fractionation tower for separation to improve the purity, and obtains refined isooctyl aldehyde, which can be sold as a commodity, and at the same time, another part of the isooctyl aldehyde product of step 1) continues to be operated in step 2) to obtain the isooctyl alcohol product of step 2), and after separation in the fractionation tower to improve the high purity, refined isooctyl alcohol is obtained, and refined isooctyl alcohol can be sold as a product, thereby achieving one process to obtain two products. When the profit margin of isooctyl alcohol is better, all the isooctyl aldehyde product of step 1) is used as the raw material of step 2), and only the isooctyl alcohol product of step 2) is produced.

[0046] Compared with the prior art, the present invention has the following beneficial effects: 1. The process for producing isooctyl alcohol of the present invention adopts liquid phase hydrogenation of isooctyl aldehyde to prepare isooctyl aldehyde, and then adopts liquid phase hydrogenation of isooctyl aldehyde to prepare isooctyl alcohol, the conversion rate and selectivity of isooctyl aldehyde both reach above 98%, and the conversion rate and selectivity of isooctyl alcohol both reach above 98%.

[0047] First, the process cost of producing isooctyl alcohol of the present invention is low and the energy consumption is small. The present invention provides a method for producing aldehydes and alcohols by hydrogenation and its application, and uses relatively mature reactor technology to achieve the purpose of the present invention. For the existing isooctyl alcohol device, especially the device using the Davy process, the existing gas phase hydrogenation reactor can be replaced by liquid phase hydrogenation through low-cost technical transformation. The energy consumption of the liquid phase hydrogenation process is lower than that of the gas phase hydrogenation. The process flow is reasonably designed and the process operation is simple, which can effectively reduce the energy consumption of the reaction process. By adjusting the process flow, isooctyl aldehyde products or isooctyl alcohol products can be flexibly produced.

[0048] Secondly, the isooctyl aldehyde conversion rate and selectivity obtained by the process for producing isooctyl alcohol of the present invention are high, and the isooctyl alcohol conversion rate and selectivity are high. In the process for producing isooctyl alcohol of the present invention, when the first stage is used for preparing isooctyl aldehyde by liquid phase hydrogenation of isooctyl aldehyde, the isooctyl aldehyde hydrogenation conversion rate is ≥99.5%, and the isooctyl aldehyde selectivity is ≥98%; when the second stage is used for preparing isooctyl alcohol by liquid phase hydrogenation of isooctyl aldehyde, the isooctyl aldehyde hydrogenation conversion rate is ≥99.5%, and the isooctyl alcohol selectivity is ≥98%.

[0049] 2. The application of the process for producing isooctyl alcohol of the present invention can be used to produce aldehydes and alcohols by liquid phase hydrogenation of unsaturated olefinic aldehydes containing C=C bonds, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a process flow chart for producing isooctyl alcohol according to Example 1-2 of the present invention.

[0051] Among them: 1. First-stage reactor; 2. Heat exchanger; 3. Second-stage reactor; 4. Distillation tower. DETAILED DESCRIPTION

[0052] Reference Figure 1 The process flow chart for producing isooctyl alcohol, the process system for producing isooctyl alcohol, comprises a first stage reactor 1, a second stage reactor 3 and a fractionation tower 4 connected in sequence, a first feed port of the first stage reactor 1 is connected to an isooctyl aldehyde input pipe, isooctyl aldehyde is preheated by a heat exchanger 2 and then introduced into the first stage reactor 1 through the isooctyl aldehyde input pipe; a first feed port of the first stage reactor 1 is connected to a hydrogen input pipe; a first discharge port of the first stage reactor 1 is connected to an isooctyl aldehyde output pipe. After heat exchange in the heat exchanger 2, the isooctyl aldehyde output pipe is connected to the second feed port of the second stage reactor 3, so that isooctyl aldehyde is introduced into the second stage reactor 3.

[0053] In heat exchanger 2, the preheating method of isooctylaldehyde is specifically as follows: using the raw material isooctylaldehyde of step 1) as the cold medium and the product isooctylaldehyde of step 1) as the hot medium, heat exchange is performed through heat exchanger 2, thereby fully utilizing the heat of the product isooctylaldehyde of step 1) and reducing energy consumption.

[0054] The second stage feed port of the second stage reactor 3 is connected with a hydrogen inlet pipe for replenishing hydrogen to achieve the molar ratio of hydrogen to isooctene aldehyde in step 2). Both the first stage reactor 1 and the second stage reactor 3 are shell-and-tube reactors.

[0055] The first stage reactor 1 is filled with a first catalyst, and the first catalyst is used in step 1) to catalyze the liquid phase hydrogenation of isooctyl aldehyde to produce isooctyl aldehyde.

[0056] The second stage reactor 3 is filled with a second catalyst. The first catalyst is used in step 2) to catalyze the liquid phase hydrogenation of isooctyl aldehyde to produce isooctyl alcohol.

[0057] Examples and Comparative Examples The present invention is further described below in conjunction with specific examples, wherein Example 1 is the best example. The comparative examples are designed to compare the technical effects of the examples. Sources of raw materials in the examples and comparative examples: The kaolin used in the first catalyst is produced in Zhungeer Banner, Inner Mongolia. The main substances are: SiO2 content 69.23%, Al2O3 content 17.51%; pseudo-boehmite is produced by Shandong Hengyi Chemical; The kaolin used in the second catalyst is from China Kaolin Co., Ltd., produced in Suzhou. The main substances are: Al2O3 content 43.36%, SiO2 content 52.81%; carbonized aluminum hydroxide is produced by Shandong Hengyi Chemical.

[0058] Example 1 The preparation method of the first catalyst used in step 1) comprises the following steps: 1) 55 parts by weight of kaolin and 45 parts by weight of pseudo-boehmite were mixed, 3 parts by weight of sesbania powder, 3 parts by weight of citric acid, 3 parts by weight of nitric acid, and 29 parts by weight of water were added, and the mixture was kneaded and extruded to obtain cylindrical bars with a diameter of 1.5 mm and a length of 0.5 cm. The cylindrical bars were dried at 125°C for 3 hours and calcined at 700°C for 2 hours to obtain carrier a. The quality inspection results of carrier a showed that the water absorption rate was 49% and the specific surface area was 119 m 2 / g, average pore size 8.61nm; 2) Weigh palladium chloride, add water to dissolve it, and adjust the pH value with hydrochloric acid to obtain a palladium chloride solution with a concentration of 8.2 g / L and a pH value of 2.8; 3) Weigh carrier a and immerse it in palladium chloride solution for 45 minutes, dry it at 125℃ for 2 hours, and then calcine it at 420℃ for 2 hours to obtain the first catalyst. Quality inspection results of the first catalyst: active component content (calculated as palladium oxide) is 0.24 wt%, the phases are γ-Al2O3 phase and SiO2 phase, and the pore volume is 0.48cm 3 / g, specific surface area 108m 2 / g, the average pore radius is 8.97nm, the bulk density is 0.68kg / L, and the average side pressure crushing strength is greater than 170N / cm.

[0059] The preparation method of the second catalyst used in step 2) comprises the following steps: 1) 60 parts by weight of kaolin and 40 parts by weight of carbonized aluminum hydroxide were mixed, 3 parts by weight of sesbania powder, 3 parts by weight of citric acid, 3 parts by weight of nitric acid, and 45 parts by weight of water (8.5 parts by weight of cerium nitrate hexahydrate was dissolved in water), kneaded, extruded into strips, and cylindrical strips with a diameter of 1 mm and a length of 1 cm were obtained. The strips were dried at 125°C for 3 hours and calcined at 700°C for 3 hours to obtain carrier b. Carrier b quality inspection results: water absorption rate 58%, specific surface area 307m 2 / g, average pore size 4.81nm.

[0060] 2) Weigh nickel nitrate, add water to dissolve it, and prepare a saturated nickel nitrate solution at room temperature; 3) Weigh carrier b and immerse it in nickel nitrate solution for 45 minutes, dry it at 110°C for 3 hours, and then calcine it at 450°C for 2 hours to obtain the second catalyst; the quality inspection results of the second catalyst are as follows: the nickel content of the active component (calculated as nickel oxide) is 23 wt%, the phases are γ-Al2O3 phase and SiO2 phase, and the pore volume is 0.39 cm 3 / g, with a specific surface area of ​​158m 2 / g, the average pore radius is 6.9nm, the bulk density is 0.56kg / L, and the average side pressure crushing strength is greater than 120N / cm.

[0061] The first stage reactor 1 and the second stage reactor 3 of this embodiment: The first stage reactor 1 is a tubular reactor, and the first stage reactor 1 has 4 parallel reaction tubes. The inner diameter of a single reaction tube of the first stage reactor 1 is Φ32 mm, the catalyst bed height is 6 m, and the first catalyst sample is loaded, and each tube is loaded with 3.28 kg; The second stage reactor 3 is a shell-and-tube reactor. The first stage reactor 1 has 4 parallel reaction tubes. The inner diameter of a single reaction tube of the first stage reactor 1 is Φ40 mm. The catalyst bed height is 6 m. The second catalyst sample is loaded, and each tube is loaded with 4.22 kg.

[0062] The process for producing isooctyl alcohol of the present embodiment comprises the following steps: 1) First stage reaction: preheat isooctyl aldehyde to 80°C; then, isooctyl aldehyde and hydrogen are used as raw materials, and are subjected to liquid phase hydrogenation reaction and gas-liquid separation under the catalysis of the first catalyst to obtain isooctyl aldehyde. The reaction temperature of the liquid phase hydrogenation reaction is 95°C, the reaction pressure is 1.75MPa, and the liquid space velocity is 5.0h -1 , the molar ratio of hydrogen to isooctene aldehyde is 4:1; 2) Second stage reaction: 90℃ isooctyl aldehyde and hydrogen are used as raw materials, and isooctanol is obtained by liquid phase hydrogenation reaction and gas-liquid separation under the catalysis of the second catalyst. The reaction temperature of the liquid phase hydrogenation reaction is 121℃, the reaction pressure is 1.5MPa, and the liquid space velocity is 3.2h -1 , the molar ratio of hydrogen to isooctylaldehyde is 3:1; Test results: step 1) product and step 1) product sampling analysis; Step 1) The product has an isooctyl aldehyde content of 97.31 wt%, an octanol content of 0.96 wt%, an isooctyl aldehyde hydrogenation rate of 99.68%, and an isooctyl aldehyde selectivity of 98.70%; Step 2) The isooctyl alcohol content in the product is 97.67 wt%, the isooctyl aldehyde hydrogenation rate is 99.25%, and the isooctyl alcohol selectivity is 98.81%.

[0063] Example 2 The preparation method of the first catalyst used in step 1) comprises the following steps: 1) 45 parts by weight of kaolin and 55 parts by weight of pseudo-boehmite were mixed, 3 parts by weight of sesbania powder, 3 parts by weight of citric acid, 3 parts by weight of nitric acid, and 29 parts by weight of water were added, and the mixture was kneaded and extruded to obtain cylindrical bars with a diameter of 1.5 mm and a length of 0.5 cm. The cylindrical bars were dried at 125°C for 3 hours and calcined at 700°C for 2 hours to obtain carrier a. The quality inspection results of carrier a showed that the water absorption rate was 49% and the specific surface area was 124 m 2 / g, average pore size 8.52nm; 2) Weigh palladium chloride, add water to dissolve it, and adjust the pH value with hydrochloric acid to obtain a palladium chloride solution with a concentration of 8.2 g / L and a pH value of 2.8; 3) Weigh carrier a and immerse it in palladium chloride solution for 45 minutes, dry it at 125℃ for 2 hours, and then calcine it at 420℃ for 2 hours to obtain the first catalyst. Quality inspection results of the first catalyst: active component content (calculated as palladium oxide) is 0.30 wt%, the phases are γ-Al2O3 phase and SiO2 phase, and the pore volume is 0.50cm 3 / g, specific surface area 122m 2 / g, average pore radius 8.79nm, bulk density 0.70kg / L, and average side pressure crushing strength greater than 175N / cm.

[0064] The preparation method of the second catalyst used in step 2) comprises the following steps: 1) 35 parts by weight of kaolin and 60 parts by weight of carbonized aluminum hydroxide were mixed, 3 parts by weight of sesbania powder, 3 parts by weight of citric acid, 3 parts by weight of nitric acid, and 45 parts by weight of water (8.5 parts by weight of cerium nitrate hexahydrate was dissolved in water) were added, kneaded, extruded to obtain cylindrical bars with a diameter of 1 mm and a length of 1 cm, dried at 125° C. for 3 hours, and calcined at 700° C. for 3 hours to obtain carrier b; 2) Weigh nickel nitrate, add water to dissolve it, and prepare a saturated nickel nitrate solution at room temperature; 3) Weigh carrier b and immerse it in nickel nitrate solution for 45 minutes, dry it at 110°C for 3 hours, and then calcine it at 450°C for 2 hours to obtain the second catalyst; the quality inspection results of the second catalyst are as follows: the nickel content of the active component (calculated as nickel oxide) is 25 wt%, the phases are γ-Al2O3 phase and SiO2 phase, and the pore volume is 0.37cm 3 / g, with a specific surface area of ​​160m 2 / g, the average hole radius is 6.83m, the bulk density is 0.55kg / L, and the average side pressure crushing strength is greater than 125N / cm.

[0065] The first stage reactor 1 and the second stage reactor 3 of this embodiment: The first stage reactor 1 is a tubular reactor, which has 4 parallel reaction tubes. The inner diameter of a single reaction tube of the first stage reactor 1 is Φ50mm, the catalyst bed height is 3m, and the 3A sample is loaded, and each tube is loaded with 4.12kg; The second stage reactor 3 is a shell-and-tube reactor. The first stage reactor 1 has 4 parallel reaction tubes. The inner diameter of a single reaction tube of the first stage reactor 1 is Φ50 mm. The catalyst bed height is 3 m. It is loaded with 4A samples, and each tube is loaded with 3.24 kg.

[0066] The process for producing isooctyl alcohol of the present embodiment comprises the following steps: 1) First stage reaction: preheat isooctyl aldehyde to 75°C; then, isooctyl aldehyde and hydrogen are used as raw materials, and are subjected to liquid phase hydrogenation reaction and gas-liquid separation under the catalysis of the first catalyst to obtain isooctyl aldehyde. The reaction temperature of the liquid phase hydrogenation reaction is 93°C, the reaction pressure is 1.75MPa, and the liquid space velocity is 6.0h -1 , the molar ratio of hydrogen to isooctene aldehyde is 3:1; 2) Second stage reaction: 90℃ isooctyl aldehyde and hydrogen are used as raw materials, and isooctanol is obtained by liquid phase hydrogenation reaction and gas-liquid separation under the catalysis of the second catalyst. The reaction temperature of the liquid phase hydrogenation reaction is 113℃, the reaction pressure is 1.5MPa, and the liquid space velocity is 3.2h -1 , the molar ratio of hydrogen to isooctylaldehyde is 4:1; Test results: step 1) product and step 1) product sampling analysis; Step 1) The product has an isooctyl aldehyde content of 97.45 wt%, an octanol content of 1.01 wt%, an isooctyl aldehyde hydrogenation rate of 99.99%, and an isooctyl aldehyde selectivity of 98.96%; Step 2) The isooctyl alcohol content in the product is 98.28 wt%, the isooctyl aldehyde hydrogenation rate is 99.93%, and the isooctyl alcohol selectivity is 99.42%.

[0067] Example 3 The preparation method of the first catalyst used in step 1) comprises the following steps: 1) 50 parts by weight of kaolin and 50 parts by weight of pseudo-boehmite were mixed, 3 parts by weight of sesbania powder, 3 parts by weight of citric acid, 3 parts by weight of nitric acid, and 29 parts by weight of water were added, and the mixture was kneaded and extruded to obtain cylindrical bars with a diameter of 1.5 mm and a length of 0.5 cm. The cylindrical bars were dried at 125°C for 3 hours and calcined at 700°C for 2 hours to obtain carrier a. The quality inspection results of carrier a showed that the water absorption rate was 50% and the specific surface area was 126 m 2 / g, average pore size 8.49nm; 2) Weigh palladium chloride, add water to dissolve it, and adjust the pH value with hydrochloric acid to obtain a palladium chloride solution with a concentration of 8.5 g / L and a pH value of 2.7; 3) Weigh carrier a and immerse it in palladium chloride solution for 30 minutes, dry it at 110℃ for 2 hours, and then calcine it at 450℃ for 2 hours to obtain the first catalyst. Quality inspection results of the first catalyst: active component content (calculated as palladium oxide) is 0.23 wt%, the phases are γ-Al2O3 phase and SiO2 phase, and the pore volume is 0.49cm 3 / g, specific surface area 120m 2 / g, the average pore radius is 8.89nm, the bulk density is 0.68kg / L, and the average side pressure crushing strength is greater than 170N / cm.

[0068] The preparation method of the second catalyst used in step 2) comprises the following steps: 1) 40 parts by weight of kaolin and 60 parts by weight of carbonized aluminum hydroxide were mixed, 3 parts by weight of sesbania powder, 3 parts by weight of citric acid, 3 parts by weight of nitric acid, and 45 parts by weight of water (8.5 parts by weight of cerium nitrate hexahydrate was dissolved in water), kneaded, extruded into strips, and cylindrical strips with a diameter of 1 mm and a length of 1 cm were obtained. The strips were dried at 125°C for 3 hours and calcined at 700°C for 3 hours to obtain carrier b. Carrier b quality inspection results: water absorption rate 57%, specific surface area 304m 2 / g, average pore size 4.76nm.

[0069] 2) Weigh nickel nitrate, add water to dissolve it, and prepare a saturated nickel nitrate solution at room temperature; 3) Weigh carrier b and immerse it in nickel nitrate solution for 30 minutes, dry it at 125°C for 2 hours, and then calcine it at 450°C for 2 hours to obtain the second catalyst; the quality inspection results of the second catalyst are as follows: the nickel content of the active component (calculated as nickel oxide) is 23 wt%, the phases are γ-Al2O3 phase and SiO2 phase, and the pore volume is 0.38 cm 3 / g, with a specific surface area of ​​159m 2 / g, the average pore radius is 6.9nm, the bulk density is 0.54kg / L, and the average side pressure crushing strength is greater than 120N / cm.

[0070] The first stage reactor 1 and the second stage reactor 3 of this embodiment: The first stage reactor 1 is a tubular reactor, wherein the first stage reactor 1 has 4 parallel reaction tubes, the inner diameter of a single reaction tube of the first stage reactor 1 is Φ32 mm, the catalyst bed height is 6 m, and the first catalyst sample is loaded, and each tube is loaded with 3.28 kg; The second stage reactor 3 is a shell-and-tube reactor. The first stage reactor 1 has 4 parallel reaction tubes. The inner diameter of a single reaction tube of the first stage reactor 1 is Φ40 mm. The catalyst bed height is 6 m. The second catalyst sample is loaded, and each tube is loaded with 4.22 kg.

[0071] The process for producing isooctyl alcohol of the present embodiment comprises the following steps: 1) First stage reaction: preheat isooctyl aldehyde to 100°C; then, isooctyl aldehyde and hydrogen are used as raw materials, and are subjected to liquid phase hydrogenation reaction and gas-liquid separation under the catalysis of the first catalyst to obtain isooctyl aldehyde. The reaction temperature of the liquid phase hydrogenation reaction is 125°C, the reaction pressure is 1.75MPa, and the liquid space velocity is 5.0h -1 , the molar ratio of hydrogen to isooctene aldehyde is 5:1; 2) Second stage reaction: 100℃ isooctyl aldehyde and hydrogen are used as raw materials, and isooctanol is obtained by liquid phase hydrogenation reaction and gas-liquid separation under the catalysis of the second catalyst. The reaction temperature of the liquid phase hydrogenation reaction is 130℃, the reaction pressure is 1.5MPa, and the liquid space velocity is 3.2h -1 , the molar ratio of hydrogen to isooctylaldehyde is 4:1; Test results: step 1) product and step 1) product sampling analysis; Step 1) The product has an isooctyl aldehyde content of 97.28 wt%, an octanol content of 1.03 wt%, an isooctyl aldehyde hydrogenation rate of 99.86%, and an isooctyl aldehyde selectivity of 98.45%; Step 2) The isooctyl alcohol content in the product is 97.18 wt%, the isooctyl aldehyde hydrogenation rate is 98.83%, and the isooctyl alcohol selectivity is 98.31%.

[0072] Comparative Example 1 In this comparative example, the first catalyst used in step 1) is the same as that in Example 1, and the active component impregnated and loaded on the carrier a is the same as that in Example 1 of patent US5756856 (0.5% Pd / Al2O3, Engelhard); In this comparative example, the second catalyst used in step 2) is the same as that in Example 1; The first stage reactor 1 and the second stage reactor 3 of this comparative example are the same as those of Example 1; The process for producing isooctyl alcohol in this comparative example is the same as that in Example 1.

[0073] Test results: in step 1), the isooctyl aldehyde content in the product is 93.31 wt%, the octanol content is 3.49 wt%, the isooctyl aldehyde hydrogenation rate is 99.87%, and the isooctyl aldehyde selectivity is 96.27%.

[0074] Comparative Example 2 In this comparative example, the first catalyst used in step 1) is the same as that in Example 1; In this comparative example, the second catalyst used in step 2) was prepared according to Example 1 of patent CN1268595C.

[0075] The first stage reactor 1 and the second stage reactor 3 of this comparative example are the same as those of Example 1; The process for producing isooctyl alcohol in this comparative example is the same as that in Example 1.

[0076] Test results: In step 2), the hydrogenation rate of isooctyl aldehyde in the product is 70.59%, and the selectivity of isooctyl alcohol is 92.23%.

[0077] Comparative Example 3 In this comparative example, the first catalyst used in step 1) is the same as that in Example 1; In this comparative example, the second catalyst used in step 2) was prepared according to Example 1 of patent CN1217899C.

[0078] The first stage reactor 1 and the second stage reactor 3 of this comparative example are the same as those of Example 1; The process for producing isooctyl alcohol in this comparative example is the same as that in Example 1.

[0079] Test results: In step 2), the hydrogenation rate of isooctyl aldehyde in the product is 71.44%, and the selectivity of isooctyl alcohol is 94.00%.

[0080] Comparative Example 4 The gas phase hydrogenation process of DAVY Company in China usually sets up a hydrofining reactor after gas phase hydrogenation. The reactor currently has three or four catalyst beds, such as the reactor of the Second Fertilizer Plant of Sinopec Qilu Branch, which has four layers. Therefore, it is conceivable whether the current hydrofining reactor can be adopted or utilized for the second stage reactor of the present invention. The working conditions of the reactor can be seen in the technical status of this material.

[0081] The product of step 1) of Example 1 was collected and used as the test raw material. The test was conducted using a laboratory 100mL-level hydrogenation evaluation device. The test was conducted using the second catalyst of Example 1 and the QAH-01 octanol liquid phase hydrogenation refining catalyst developed by Qilu Research Institute.

[0082] Conditions: Catalyst loading: 100 mL; preheat the material to 80°C in the mixer before entering the catalyst bed, and use a back pressure valve to control the outlet pressure to 1.5 MPa. The feed liquid space velocity and hydrogen ratio are the same as in Example 2.

[0083] result: 2A catalyst, hot spot temperature 166℃, product isooctyl aldehyde hydrogenation rate 99.98%, isooctyl alcohol selectivity 97.75%.

[0084] QAH-01 catalyst, hot spot temperature 168 ℃, product isooctyl aldehyde hydrogenation rate 99.98%, isooctyl alcohol selectivity 96.05%.

[0085] Comparative Example 5 The kaolin used in the first catalyst is from China Kaolin Co., Ltd., produced in Suzhou. The main substances are: Al2O3 content 43.36%, SiO2 content 52.81%; carbonized aluminum hydroxide is produced by Shandong Hengyi Chemical; The kaolin used in the second catalyst is produced in Zhungeer Banner, Inner Mongolia. The main substances are: SiO2 content 69.23%, Al2O3 content 17.51%; pseudo-boehmite is produced by Shandong Hengyi Chemical; In this comparative example, the first catalyst used in step 1) is the same as that in Example 1, except that the weight parts of kaolin and pseudo-boehmite are different, but the ratio of Al2O3 to SiO2 in the finished catalyst is maintained; in the preparation method of the first catalyst in this comparative example: 72.1 weight parts of kaolin and 9.1 weight parts of pseudo-boehmite are mixed; the first catalyst obtained has an active component of 0.24 wt% in terms of palladium oxide, a phase of γ-Al2O3 phase and SiO2 phase, and a pore volume of 0.47 cm 3 / g, specific surface area 110m 2 / g, average pore radius 8.89nm, bulk density 0.69kg / L, average side crushing strength greater than 170N / cm; In this comparative example, the second catalyst used in step 2) is the same as that in Example 1, except that: the weight parts of kaolin and carbonized aluminum hydroxide are different, but the ratio of Al2O3 and SiO2 in the finished catalyst is maintained; in the preparation method of the second catalyst in this comparative example: 45.8 weight parts of kaolin and 69.9 weight parts of carbonized aluminum hydroxide are mixed; the obtained second catalyst: the active component is 23 wt% of nickel oxide, the phases are γ-Al2O3 phase and SiO2 phase, and the pore volume is 0.40 cm3 / g, with a specific surface area of ​​161m 2 / g, average pore radius 6.79nm, bulk density 0.55kg / L, average side crushing strength greater than 120N / cm; The first stage reactor 1 and the second stage reactor 3 of this comparative example are the same as those of Example 1; The process for producing isooctyl alcohol in this comparative example is the same as that in Example 1; Test results: In step 1), the isooctyl aldehyde content in the product is 93.27 wt%, the octanol content is 3.48 wt%, the isooctyl aldehyde hydrogenation rate is 99.79%, and the isooctyl aldehyde selectivity is 96.19%; Step 2) The isooctyl alcohol content in the product is 94.98 wt%, the isooctyl aldehyde hydrogenation rate is 96.40%, and the isooctyl alcohol selectivity is 96.08%.

[0086] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A process for producing isooctyl alcohol, characterized in that: The steps include: 1) One-stage reaction: first preheat isooctenal; then, isooctenal and hydrogen are used as raw materials, and the isooctenal is subjected to liquid phase hydrogenation reaction and gas-liquid separation under the catalysis of the first catalyst to obtain isooctenal; 2) Second stage reaction: using isooctyl aldehyde and hydrogen as raw materials, under the catalysis of the second catalyst, undergoing liquid phase hydrogenation reaction and gas-liquid separation, isooctyl alcohol is obtained.

2. A process for producing isooctyl alcohol according to claim 1, characterized in that: The specific operation of step 1) is as follows: first preheating isooctyl aldehyde to 70-150°C; then using isooctyl aldehyde and hydrogen as raw materials, under the catalysis of the first catalyst, undergoing liquid phase hydrogenation reaction and gas-liquid separation to obtain isooctyl aldehyde, wherein the reaction temperature of the liquid phase hydrogenation reaction is 70-160°C, the reaction pressure is 1.6-2.7MPa, and the liquid space velocity is 0.3-6.0h -1 , the molar ratio of hydrogen to isooctene aldehyde is 1.8-5.0:

1.

3. A process for producing isooctyl alcohol according to claim 1, characterized in that: The specific operation of step 2) is as follows: using isooctyl aldehyde and hydrogen as raw materials, under the catalysis of the second catalyst, undergoing liquid phase hydrogenation reaction and gas-liquid separation to obtain isooctyl alcohol, wherein the reaction temperature of the liquid phase hydrogenation reaction is 90-180°C, the reaction pressure is 1.4-2.6MPa, and the liquid space velocity is 0.6-10.0h -1 , the molar ratio of hydrogen to isooctyl aldehyde is 2-4:

1.

4. A process for producing isooctyl alcohol according to claim 1 or 2, characterized in that: The specific operation of the preheating in step 1) is: using the isooctylaldehyde in step 1) as a cold medium and the isooctylaldehyde in step 1) as a hot medium, heat exchange is performed through a heat exchanger.

5. A process for producing isooctyl alcohol according to claim 1 or 3, characterized in that: Step 2) The temperature of the isooctylaldehyde is 70-160°C.

6. A process for producing isooctyl alcohol according to claim 1, characterized in that: Step 1) the first catalyst is a palladium-based catalyst, and step 2) the second catalyst is a nickel-based catalyst.

7. A process for producing isooctyl alcohol according to claim 1, 2 or 6, characterized in that: Step 1) The active component content of the first catalyst is 0.22-0.30% by mass of palladium oxide; the carrier phase of the first catalyst is γ-Al2O3 phase and SiO2 phase, and the bulk density of the catalyst is 0.68-0.70 kg / L.

8. A process for producing isooctyl alcohol according to claim 1, 3 or 6, characterized in that: Step 2) The active component content of the second catalyst is 23-26% by mass of nickel oxide; the carrier phase of the second catalyst is γ-Al2O3 phase and SiO2 phase, and cerium oxide is used as an active auxiliary agent, the cerium oxide content in the carrier is 1%-3% by mass, and the catalyst bulk density is 0.55-0.58kg / L.

9. The application of a process for producing isooctyl alcohol according to any one of claims 1 to 8, characterized in that: It is used to produce aldehydes and alcohols by liquid phase hydrogenation reaction using unsaturated olefinic aldehydes containing C=C bonds as raw materials.

Images