1, 4-butynediol reactor and preparation method

Abstract

The invention belongs to the technical field of reaction engineering and separation, and particularly relates to a 1, 4-butynediol reactor and a preparation method. The 1, 4-butynediol reactor comprises a shell, a catalyst feeding port and a gas outlet are formed in the top of the shell, a membrane separation assembly outlet and a catalyst discharging port are formed in the side portion of the shell, an acetylene port and a formaldehyde port are formed in the bottom of the shell, and a membrane separation assembly and an acetylene distribution assembly are arranged in the shell. The invention also provides a preparation method of 1, 4-butynediol, which comprises the following steps: (A) activating a catalyst; (B) continuous reaction; (C) continuously filtering; (D) catalyst interception; (E) backwashing flux recovery; (F) supplement of an activation catalyst; and (G) pulverization and quitting of the deactivated catalyst.

Description

Technical Field

[0001] The present invention belongs to the technical fields of reaction engineering and separation technology, and particularly relates to a 1,4-butyne diol reactor and a preparation method thereof. Technical Background

[0002] The INVISTA suspension bed process in the United States is the most important process for preparing 1,4-butyne diol in China. It belongs to the improved Reppe method. Multiple candle filters are arranged in the suspension bed reactor, and a stirrer is provided at the bottom of the equipment. Acetylene and formaldehyde enter the reactor from the lower part. Through the upward movement of the gas, formaldehyde forms a slurry liquid with the catalyst and is evenly distributed. The 1,4-butyne diol reaction liquid flows out of the reactor through the candle filter. A gas pipeline is arranged in each group of filters to export the gas entering the filter. The candle filter uses a filter cloth to separate the product from the catalyst. The filter cloth has poor anti-pollution ability, and generally the bag needs to be replaced after running for 2 - 4 months. In addition, the catalyst life is about 3 months, so generally the bag and the catalyst need to be replaced after 3 months.

[0003] The INVISTA suspension bed 1,4-butyne diol technology has the following disadvantages:

[0004] Batch operation, with a low production load;

[0005] The filter cloth of the candle filter has poor anti-pollution ability and needs to be replaced regularly, making continuous operation impossible;

[0006] The number of acetylene gas distribution pipes is small, the reaction flow field is blocked and damaged by the candle filter, the material contact is insufficient, and the reaction efficiency is low;

[0007] The catalyst is deposited at the bottom of the reactor, resulting in serious waste of the catalyst. The one-time loading amount is much larger than the demand;

[0008] The mass transfer of gas-liquid-solid three phases is poor, and there are many by-products such as acetylene polymers, which affect the filtration and reaction;

[0009] Batch operation has a high labor intensity for workers, and the production wastewater is relatively large, bringing pressure to environmental protection;

[0010] Pan Junguang, Discussion and Analysis of the Extraction of Butyne Diol, Sichuan Chemical Industry, Issue 2, 2021, pointed out that: The extraction of butyne diol is related to the service life of the synthesis catalyst. The extraction of butyne diol was discussed by combining aspects such as the installation of the candle filter, the adjustment of backwashing, the catalyst matrix, and operation and maintenance. However, it failed to effectively improve the catalyst service cycle and the extraction cycle and capacity of the candle filter.

[0011] Chinese Utility Model Patent Application Publication No. CN208542037U, a BYD reactor filtration device, provides a new type of filter form, using a metal membrane tube filter instead of a bag filter. The quality of the clarified liquid of 1,4-butynediol drawn out by this device is high, but the selected metal membrane is easily blocked and has poor backwashing effect, which is not suitable for filtering the 1,4-butynediol reaction liquid.

[0012] Chinese Invention Patent Publication No. CN 105622336 A, a method for preparing 1,4-butynediol, uses a 1μm metal membrane to replace the bag filter for extraction, and the backwashing cycle is increased to 80S. This method improves the interception accuracy of the filter element and the backwashing intensity in order to obtain better flux recovery and improve the extraction capacity of the filter. However, due to the structural limitation of the filter, although the backwashing intensity increases, the extraction capacity of the filter has not been improved.

[0013] Chinese Invention Patent Application Publication No. CN 115212821 A, a new type of 1,4-butynediol reactor and preparation method, combines a reactor with an external filter. The gas-liquid distributor distributes acetylene gas into bubbles of different sizes to strengthen mass transfer. The catalyst is extracted and added in the filtrate pipe to achieve continuous reaction and separation of 1,4-butynediol. However, the implementation method and equipment of the gas-liquid distributor are vague, and the catalyst is prone to pulverization and deactivation in the case of acetylene gas cut-off. The combination method of the reactor and the external filter cannot guarantee the catalytic activity of the catalyst.

[0014] Therefore, in view of the above problems existing in the prior art, there is an urgent need in the art to develop a simple and effective 1,4-butynediol reactor and preparation method that can solve the short service life of the existing candle bag filter, achieve long-term extraction; realize continuous addition of the catalyst and withdrawal of the deactivated and pulverized catalyst; reduce the catalyst addition amount, reduce side reactions, and improve the catalyst use efficiency. Summary of the Invention

[0015] The purpose of the present invention is to provide a 1,4-butynediol reactor, which can realize continuous reaction in the modified Reppe method for preparing 1,4-butynediol from alkynal, improve the catalytic efficiency of the catalyst, and improve the reaction efficiency; the present invention also provides a method for preparing 1,4-butynediol, which is scientific, reasonable, simple and feasible.

[0016] The 1,4-butynediol reactor described in the present invention includes 1) - a shell, (1) - a catalyst inlet and (5) - a gas outlet are provided at the top of the shell, (7) - a membrane separation module outlet and (6) - a catalyst outlet are provided at the side of the shell, (4) - an acetylene inlet, (3) - a formaldehyde inlet are provided at the bottom of the shell, and (8) - a membrane separation module and (9) - an acetylene distribution module are provided inside the shell.

[0017] (2) - Catalyst inlet: For the first addition of catalyst and the addition of activated catalyst during the reaction process;

[0018] Preferably, the (2) - catalyst inlet extends vertically to the bottom of the reactor;

[0019] (5) - Gas outlet: Located at the top of the reactor, used to discharge unreacted acetylene gas from the reactor and re - enter the reactor through the (9) - acetylene distribution component after re - configuration;

[0020] (6) - Catalyst withdrawal outlet: During the reaction process, the pulverized and deactivated catalyst is withdrawn from the reactor together with the reaction liquid;

[0021] Preferably, the (6) - catalyst withdrawal outlet is located below the liquid level of the reaction liquid in the upper part of the membrane separation component;

[0022] (7) - Membrane separation component outlet: The outlet for the 1,4 - butynediol reaction liquid, located on the side wall of the reactor;

[0023] Preferably, through a loop pipe collection, a backwashing port is provided at each branch outlet for the restoration and regeneration of the membrane separation component group;

[0024] (8) - Membrane separation component: The number of groups of the membrane separation component is 8 - 100 groups; The combination mode of the membrane separation component is row - tube type, loop - tube type or membrane stack type; The filter element is a metal filter element, including sintered metal filter element, sintered wire mesh filter element, and wedge - wire filter element; The filter element form is internal deep conduit without residual liquid type or ordinary type, and the installation method is inverted hanging type or upright type; The precision of the filter element is 0.5 - 50μm, the diameter is 20 - 400mm, and the length is 100 - 5000mm;

[0025] Preferably, the number of groups of the membrane separation component is 12 - 24 groups; The combination mode of the membrane separation component is row - tube type; The filter elements are sintered metal filter element and wedge - wire filter element; The installation method of the filter element is inverted hanging type, and the filter element adopts the internal deep conduit without residual liquid type; The precision of the filter element is 0.5 - 20μm, the diameter is 40 - 80mm, and the length is 1200 - 2400mm;

[0026] (9)-The acetylene distribution component is arranged at the bottom of the reactor, and the catalyst is located in the reactor on the acetylene distribution component; the acetylene distribution component is composed of a dense structural member and a distribution element. The distribution element is in the shape of a disc, a ring or other shapes and is embedded on the dense structural member. The connection mode between the distribution element and the dense structural member is installation union type, crimping type or welding form; the diameter of the distribution element is φ10-φ500mm, and the number is 1-1000; the gas supply mode of the distribution element is centralized gas supply, grouped gas supply or individual gas supply; the distribution element is a metal filter plate, which can be one or a combination of sintered powder metal filter plates, sintered wire mesh filter plates and wedge wire filter plates; the precision of the distribution element is 0.5-50μm, and the catalyst particles cannot penetrate the distribution element or enter the interior of the distribution element; the absolute gas velocity of the gas passing through the distribution element is 1-70m / s to ensure the boiling state of the catalyst in the reaction system;

[0027] Preferably, the acetylene distribution element is in the shape of a disc, and the distribution element and the dense structural member are connected by installation union type for easy disassembly and assembly; the distribution element is φ50-φ30mm, and the number is 100-300; the distribution element adopts the individual gas supply mode; the distribution element is a sintered powder metal filter plate or a wedge wire filter plate; the precision of the distribution element is 0.5-10μm;

[0028] Preferably, in the gas flow rising area of the acetylene distribution component, the acetylene gas flow drives the reaction liquid and the catalyst to move upward to form a boiling area; at the edge of the gas flow rising area, the gas flow driving force decreases, and the catalyst particles settle downward and are re-introduced into the boiling area after contacting the rising gas flow; the catalyst is suspended in the reactor, and the gas-liquid-solid mass transfer efficiency is high, improving the catalytic effect and reducing the catalyst dosage.

[0029] A preparation method of a 1,4-butyne diol reactor comprises the following steps:

[0030] (A) Catalyst activation: The mass ratio of the copper-bismuth catalyst to the 35-55wt% formaldehyde solution is 1:(10-30). First, add the formaldehyde solution into the reactor, introduce acetylene into the reactor through the (9)-acetylene distribution component, and add the purified water slurry of the copper-bismuth catalyst into the reactor. In the reactor, the copper-bismuth catalyst is converted into the acetylene copper / bismuth active catalyst;

[0031] (B) Acetylene forms a boiling state with the catalyst in the reactor through the (9)-acetylene distributor: Control the pressure in the reaction kettle to be 15-50kpa and the temperature to be 70-100°C. Continuously introduce acetylene gas into the reactor through the (9)-acetylene distribution component. The acetylene superficial gas velocity is 0.02-0.06m / s, and the gas velocity of acetylene entering the reactor is 1-70m / s, and the direction is upward to drive the formaldehyde solution and the catalyst to move upward. The catalyst is in a boiling state in the reactor; continuously add the formaldehyde solution into the reactor through the (3) formaldehyde port to make the reaction proceed;

[0032] (C) Continuous filtration: In the reactor, the 1,4-butynediol mixture obtained in step (B) is filtered through the (7)-membrane separation module, and the filtrate enters the next process;

[0033] (D) Catalyst interception: The catalyst is intercepted in the reactor by the (7)-membrane separation module and continues to participate in the reaction;

[0034] (E) Supplementary addition of activated catalyst: During the preparation of 1,4-butynediol, as the catalyst is continuously broken, pulverized and deactivated, the formaldehyde conversion rate will continuously decrease. When the formaldehyde content in the filtrate is detected to be ≥10% or the catalyst content in the reactor is lower than the process requirements, fresh activated catalyst is supplemented through the (2)-catalyst inlet at the bottom of the reactor;

[0035] (F) Withdrawal of pulverized and deactivated catalyst: Driven by the gas, the reaction liquid and the catalyst move upward, and under the action of gravity of the catalyst particles, most of the pulverized and deactivated small particle catalysts are located above the reaction liquid. The pulverized and deactivated catalyst exits the reactor together with the reaction liquid through the (6)-catalyst outlet;

[0036] Beneficial effects:

[0037] Compared with the prior art, the advantages of the present invention are as follows:

[0038] The continuous supplementation of the catalyst and the regular withdrawal of the pulverized and deactivated catalyst ensure the catalytic activity of the catalyst and realize the continuity of the reaction;

[0039] Reduce the bottom deposition of the catalyst, improve the mixing effect of the gas-liquid-solid three-phase, improve the catalyst conversion efficiency, different particle size catalysts are distributed in different spaces of the reaction liquid, and the deactivated catalyst can be selectively withdrawn;

[0040] The lateral extraction of the 1,4-butynediol reaction liquid, through the grouping method, improves the ratio of the backwashing amount to the separation element accommodation capacity. Each membrane separation module branch is provided with a separate backwashing device, which strengthens the backwashing effect, improves the extraction capacity, and prolongs the extraction cycle;

[0041] Using a metal filter element as the filtering element reduces the use of filter cloth consumables;

[0042] The metal filter element with no residual liquid in the inner deep conduit realizes gas-liquid separation in the reactor, and the extraction of the 1,4-butynediol reaction liquid is more effective. Specific embodiments

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0044] Example 1:

[0045] As Figure 1As shown in the figure, a 1,4 - butynediol reactor of this embodiment includes (1) - a shell. There are (2) - a catalyst inlet and (5) - a gas outlet at the top of the shell. There are (7) - a membrane separation module outlet and (6) - a catalyst withdrawal outlet on the side of the shell. There are (4) - an acetylene inlet and (3) - a formaldehyde inlet at the bottom of the shell. There are (8) - a membrane separation module and (9) - an acetylene distribution module inside the shell.

[0046] (2) - The catalyst inlet is connected to a conduit that extends vertically to the bottom of the reactor, used for supplementing the catalyst for startup and activating the catalyst. The catalyst is transported to the upper part of the acetylene distribution module. Driven by the upward gas flow of acetylene gas, the catalyst is distributed in a boiling state in the reactor.

[0047] (6) - The relationship among the catalyst withdrawal outlet, (7) - the membrane separation module outlet, and (8) - the membrane separation module is as Figure 2 shown. The filter element is connected to the (7) - membrane separation module outlet through combination. Under the action of the pressure in the reactor, the clear liquid of the 1,4 - butynediol reaction solution leaves the reactor, and the catalyst is intercepted by the (8) - membrane separation module and remains in the reactor for continuous reaction. The (6) - catalyst withdrawal outlet is located below the reaction liquid level above the (8) - membrane separation module. Most of the pulverized and deactivated catalysts are concentrated above the reaction liquid, and the pulverized and deactivated catalysts are withdrawn from the reactor by withdrawing the reaction liquid.

[0048] (8) - The installation method of the membrane separation module is as Figure 3 shown, realizing the arrangement of the membrane separation module in the reactor. 8 - 1 - 1 is the distribution loop pipe, and 8 - 1 - 2 is the (7) - membrane separation module outlet; 8 - 2 - 1 is the distribution row pipe, and 8 - 2 - 2 is the (7) - membrane separation module outlet; 8 - 3 - 1 is the distribution membrane stack, and 8 - 3 - 2 is the (7) - membrane separation module outlet.

[0049] (9) - The acetylene distribution module distributes acetylene gas and intercepts catalyst particles in the reactor. Driven by the upward gas flow of acetylene gas, it drives the 1,4 - butynediol reaction solution and the catalyst to move upward, forming a boiling state. The (9) - acetylene distribution module is composed of a distribution element and a dense structural member, forming an upward gas flow area and a particle sedimentation area. The arrangement method of the distribution element is dense in the middle and sparse around, strengthening the swirl. As Figure 4 shown in the acetylene distribution module, 9 - 1 is the middle distribution element, and 9 - 2 is the edge distribution element; as Figure 5 shown is a structural form of a distribution module, which is in the form of a wedge - wire filter plate;

[0050] As Figure 6 , 7The figure shows the morphology of the catalyst and the reaction solution of 1,4-butynediol in the reactor. The catalyst is driven by the upward gas flow, and the catalyst is evenly distributed in the reactor without catalyst deposition at the bottom of the reactor, which improves the utilization rate of the catalyst and reduces the catalyst dosage; it strengthens the gas-liquid-solid three-phase mixing and reduces the deactivation of the catalyst due to the inability to contact acetylene gas;

[0051] A method for preparing 1,4-butynediol in this embodiment includes the following steps:

[0052] (A) Catalyst activation: The copper-bismuth catalyst and the formaldehyde solution with a mass percentage of 35-55wt% are added in a ratio of 1:(10-30); first, the formaldehyde solution is added to the reactor, acetylene is introduced into the reactor through the acetylene distribution component, and the purified water slurry of the copper-bismuth catalyst is added to the reactor, and the copper-bismuth catalyst in the reactor is converted into the acetylene copper / bismuth active catalyst;

[0053] (B) Acetylene forms a boiling state with the catalyst in the reactor through the acetylene distributor: Control the pressure in the reaction kettle at 15-50 kPa and the temperature at 70-100 °C. Continuously introduce acetylene gas into the reactor through the acetylene distribution component. The superficial gas velocity of acetylene is 0.02-0.06 m / s, and the gas velocity of acetylene entering the reactor is 1-70 m / s, and the direction is upward to drive the formaldehyde solution and the catalyst to move upward. The catalyst is in a boiling state in the reactor; continuously add the formaldehyde solution to the reactor through the formaldehyde feeding port to make the reaction proceed;

[0054] (C) Continuous filtration: In the reactor, the 1,4-butynediol mixed solution obtained in step (B) is filtered through the membrane separation component, and the filtered liquid enters the next process;

[0055] (D) Catalyst interception: The catalyst is intercepted in the reactor by the membrane separation component and continues to participate in the reaction;

[0056] (E) Supplementary addition of activated catalyst: During the preparation of 1,4-butynediol, as the catalyst is continuously broken, pulverized and deactivated, the formaldehyde conversion rate will continuously decrease. When the formaldehyde content in the filtered liquid is ≥10% or the catalyst content in the reactor is lower than the process requirements, fresh activated catalyst is supplemented through the activated catalyst port deep into the bottom of the reactor;

[0057] (F) Withdrawal of pulverized and deactivated catalyst: Driven by the gas, the reaction solution and the catalyst move upward, and under the action of gravity of the catalyst particles, most of the pulverized and deactivated small particle catalysts are located above the reaction solution. The pulverized and deactivated catalyst exits the reactor together with the reaction solution through the catalyst withdrawal port;

[0058] Example 2:

[0059] The difference between this example and Example 1 is only that as Figure 8As shown, a draft tube (10) is added inside the reactor - draft tube. The reaction liquid of 1,4 - butynediol is forced to flow upward through the draft tube and flow counter - currently outside the draft tube to form a reaction cycle. Description of the Drawings

[0060] The drawings are used to provide a further understanding of the present invention. They only form a part of this specification to further explain the present invention and do not constitute a limitation to the present invention.

[0061] Figure 1 is the structural form of the 1,4 - butynediol reactor;

[0062] Figure 2 is the installation form of the filter element of the 1,4 - butynediol reactor;

[0063] Figure 3 is the combination form of the membrane separation module of the 1,4 - butynediol reactor;

[0064] Figure 4 is the combination form of the acetylene distribution module of the 1,4 - butynediol reactor;

[0065] Figure 5 is the internal structure of the acetylene distribution element of the 1,4 - butynediol reactor;

[0066] Figure 6 is the state of the catalyst suspended in the reaction liquid according to an embodiment of the present invention;

[0067] Figure 7 is the state of the catalyst suspended in the reaction liquid according to another embodiment of the present invention;

[0068] Figure 8 is the structural form of a 1,4 - butynediol reactor (with an internal draft tube);

[0069] (1) - Shell; (2) - Activated catalyst inlet; (3) - Formaldehyde inlet; (4) - Acetylene inlet; (5) - Gas phase outlet; (6) - Catalyst withdrawal outlet; (7) - Membrane separation module branch outlet; (8) - Membrane separation module; (9) - Acetylene distribution module; (10) - Draft tube;

[0070] 8 - 1 - 1 Ring - shaped arrangement filter element installation method; 8 - 1 - 2 Ring - shaped arrangement membrane separation module branch outlet

[0071] 8 - 2 - 1 Tube - row arrangement filter element installation method; 8 - 2 - 2 Tube - row arrangement membrane separation module branch outlet

[0072] 8 - 3 - 1 Membrane stack arrangement filter element installation method; 8 - 3 - 2 Membrane stack arrangement membrane separation module branch outlet

[0073] 9-1 Acetylene distribution module, larger area distribution element; 9-2 Acetylene distribution module, smaller area distribution element;

[0074] 9-1-1 Composition structure of acetylene distribution element; 9-1-2 Gas gap of acetylene distribution element;

[0075] 10-1 Catalyst particle size distribution state of reaction liquid swirling flow distribution;

[0076] 10-2 Catalyst particle size distribution state of reaction liquid distribution.

Claims

1. A 1,4-butyne diol reactor, characterized in that, It includes: (1) - a shell, with a (2) - catalyst inlet and a (5) - gas outlet at the top of the shell, a (7) - membrane separation module outlet and a (6) - catalyst outlet at the side of the shell, a (4) - acetylene inlet and a (3) - formaldehyde inlet at the bottom of the shell, and a (8) - membrane separation module and a (9) - acetylene distribution module inside the shell.

2. (2) - Catalyst inlet: For the first catalyst addition and the addition of activated catalyst during the reaction process; (6) - Catalyst outlet: During the reaction process, the pulverized and deactivated catalyst is withdrawn from the reactor together with the reaction solution; (8) - Membrane separation module: The filter element is a metal filter element, arranged in a grouped, tube - arranged or loop - tube form. The clear liquid of the 1,4 - butynediol reaction solution leaves the reactor from the side wall of the reactor, and the catalyst is intercepted in the reactor for continuous reaction; (9) - Acetylene distribution module: The distribution element is a metal membrane plate, which drives the reaction solution and the catalyst to move upward through the gas to form a boiling state; 3. A 1,4 - butynediol reactor according to claim 1, wherein, The (2) - catalyst inlet extends deep into the bottom of the reactor through a vertical conduit; The (6) - catalyst outlet is located below the liquid level of the reaction solution above the membrane separation module; The branches of the (7) - membrane separation module outlet are collected through a loop tube; The combination mode of the (8) - membrane separation module is tube - arranged, loop - tube - arranged or membrane stack - arranged; the membrane separation modules are collected through a loop tube, and each membrane separation module is provided with a backwashing port separately. The number of groups of the membrane separation modules is 8 - 100 groups; the filter element is a metal filter element, including sintered metal filter element, sintered wire mesh filter element, and wedge wire filter element; the filter element form is an inner deep conduit without residual liquid type or ordinary type, and the installation method is inverted or upright; the precision of the filter element is 0.5 - 50μm, the diameter is 20 - 400mm, and the length is 100 - 5000mm; The (9) - acetylene distribution module is arranged at the bottom of the reactor, and the catalyst is located in the reactor on the acetylene distribution module; the acetylene distribution module is composed of a dense structural member and a distribution element. The distribution element is in the form of a disc, a ring or other shapes embedded on the dense structural member. The connection mode between the distribution element and the dense structural member is installation - type union, crimping or welding; the number of distribution elements is 1 - 1000; the gas supply mode of the distribution element is centralized gas supply, grouped gas supply, or individual gas supply; the distribution element is a metal filter plate, which can be a combination of one or more of sintered powder metal filter plate, sintered wire mesh filter plate, and wedge wire filter plate; the precision of the distribution element is 0.5 - 50μm, and the catalyst particles cannot penetrate the distribution element or enter the interior of the distribution element; the absolute gas velocity of the gas passing through the distribution element is 1 - 70m / s to ensure the boiling state of the catalyst in the reaction system; 4. A preparation method of a 1,4 - butynediol reactor according to any one of claims 1 - 2, characterized in that It includes the following steps: (A) Catalyst activation: The mass ratio of copper - bismuth catalyst to 35 - 55wt% formaldehyde solution is 1:(10 - 30). First, add the formaldehyde solution to the reactor, introduce acetylene into the reactor through the (9) - acetylene distribution module, and add the purified water slurry of the copper - bismuth catalyst to the reactor. In the reactor, the copper - bismuth catalyst is converted into copper / bismuth acetylide active catalyst; (B) Acetylene forms a boiling state with the catalyst in the reactor through the (9)-acetylene distributor: control the pressure in the reaction kettle at 15 - 50 kPa and the temperature at 70 - 100 °C, continuously introduce acetylene gas into the reactor through the (9)-acetylene distribution component, the acetylene superficial velocity in the empty tower is 0.02 - 0.06 m / s, and the velocity of acetylene entering the reactor is 1 - 70 m / s, with the direction upward to drive the formaldehyde solution and the catalyst to move upward, and the catalyst is in a boiling state in the reactor; continuously add formaldehyde solution to the reactor through the (3)-formaldehyde inlet to carry out the reaction; (C) Continuous filtration: In the reactor, the 1,4-butyne diol mixture obtained in step (B) is filtered through the (7)-membrane separation component, and the filtrate enters the next process; (D) Catalyst interception: The catalyst is intercepted by the (7)-membrane separation component in the reactor and continues to participate in the reaction; (E) Make-up of activated catalyst: During the preparation of 1,4-butyne diol, as the catalyst is continuously broken, pulverized and deactivated, the formaldehyde conversion rate will continuously decrease. When the formaldehyde content in the filtrate is detected to be ≥ 10% or the catalyst content in the reactor is lower than the process requirements, fresh activated catalyst is added through the (2)-catalyst inlet that reaches the bottom of the reactor; (F) Withdrawal of pulverized and deactivated catalyst: Under the drive of gas, the reaction liquid and the catalyst move upward, and under the action of gravity of the catalyst particles, most of the pulverized and deactivated small particle catalysts are located above the reaction liquid, and the pulverized and deactivated catalyst exits the reactor together with the reaction liquid through the (6)-catalyst outlet.

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