Activation method and application of nickel-aluminum alloy catalyst

Abstract

The invention provides an activation method and application of a nickel-aluminum alloy catalyst. The method comprises the following steps: activating the nickel-aluminum alloy catalyst filled in a fixed bed reactor by using alkali liquor; a temperature induction meter and a flow meter are arranged at an alkali liquor inlet of the fixed bed reactor; a plurality of temperature induction meters are arranged on a catalyst bed layer in the fixed bed reactor; in the activation process, the total amount M of dissolved aluminum of the nickel-aluminum alloy catalyst, the activation time t, the temperature rise T in the fixed bed reactor meet the condition that # imgabs0 # temperature rise T and the alkali liquor flow F1 at an alkali liquor inlet meet the condition that when the total amount M of dissolved aluminum is more than 0 wt% and less than or equal to 12 wt%, if T is more than or equal to 8 DEG C and less than or equal to 10 DEG C, the flow F1 is 2-4 t / h; if T < 8 DEG C or T > 10 DEG C, the alkali liquor flow is increased / decreased at the rate of v1, and T is larger than or equal to 8 DEG C and smaller than or equal to 10 DEG C. The invention also provides application of the method in preparation of 1, 4-butanediol through catalytic hydrogenation of 1, 4-butynediol, and the method provided by the invention realizes automatic activation in the activation process and accurately controls the activation endpoint.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst activation, and specifically to an activation method for a nickel-aluminum alloy catalyst for accurately controlling the rate and total amount of dissolved aluminum during the activation process. Background Art

[0002] Since nickel is wrapped in aluminum, nickel-aluminum alloy catalysts do not show activity before activation. The activation process of nickel-aluminum alloy catalysts refers to the use of alkali solution and aluminum to react to remove surface aluminum to form a skeleton, while exposing nickel to show activity. In order to meet the activity requirements, different nickel-aluminum alloy catalysts have clear indicators for the rate of aluminum dissolution and the total amount of aluminum dissolution. Taking the hydrogenation of 1,4-butynediol to 1,4-butanediol as an example, the rate of aluminum dissolution is required to be controlled at 3-3.5wt% / h. When the aluminum dissolution rate is lower than 3wt% / h, the amount of alkali solution is manually increased; when the rate is higher than 3.5wt% / h, the amount of alkali solution is manually reduced. There are many operations and there is hysteresis. The target endpoint cannot be accurately controlled, which has a certain impact on the activity of the catalyst.

[0003] In order to achieve the catalyst activation index, personnel are required to continuously take samples and analyze the changes in the inlet and outlet NaOH concentrations to calculate the dissolution rate and total amount of aluminum dissolved. Since aluminum and alkali solution produce hydrogen, this operation has certain operational risks. Summary of the invention

[0004] In view of the above-mentioned problems in the prior art, the present invention provides a method for activating a nickel-aluminum alloy catalyst. The temperature rise ΔT of the activation process is calculated by the reactor temperature and the release amount of the activated tail gas. The aluminum dissolution rate at this time is calculated based on ΔT, and the dissolved aluminum rate and total amount are monitored in real time to ensure accurate control of the activation target. No sampling and analysis by personnel is required, thereby essentially reducing operational risks.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for activating a nickel-aluminum alloy catalyst, wherein an alkali solution is used to activate the nickel-aluminum alloy catalyst loaded in a fixed bed reactor; a temperature sensor and a flow meter are arranged at the alkali solution inlet of the fixed bed reactor to measure the inlet temperature T7 of the alkali solution, and the alkali solution is controlled to enter the fixed bed reactor at a flow rate F1; a plurality of temperature sensors are arranged on the catalyst bed in the fixed bed reactor to measure the temperature T of each point;

[0007] During the activation process, the total amount of dissolved aluminum M in the nickel-aluminum alloy catalyst, the activation time t, and the temperature rise △T in the fixed bed reactor satisfy the following relationship:

[0008]

[0009] Wherein, the temperature rise in the fixed bed reactor ΔT = T max -T7, T max is the highest temperature in each catalyst bed in the fixed bed reactor;

[0010] The temperature rise ΔT in the fixed bed reactor and the alkali solution flow rate F1 at the alkali solution inlet satisfy the following relationship:

[0011] When the total amount of dissolved aluminum M is 0wt%<M≤12wt%, then

[0012] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 2~4t / h;

[0013] If △T<8℃, increase the alkali solution flow rate at the rate of v1 so that 8℃≤△T≤10℃;

[0014] If △T>10℃, reduce the alkali solution flow rate at the rate of v1 so that 8℃≤△T≤10℃;

[0015] When the total amount of dissolved aluminum M is 12wt%<M≤21wt%, then

[0016] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 4~8t / h;

[0017] If △T<8℃, increase the alkali solution flow rate at the rate of v2 so that 8℃≤△T≤10℃;

[0018] If △T>10℃, reduce the alkali solution flow rate at the rate of v2 so that 8℃≤△T≤10℃;

[0019] When the total amount of dissolved aluminum M is 21wt%<M≤26wt%, then

[0020] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 8~12t / h;

[0021] If △T<8℃, increase the alkali solution flow rate at the rate of v3 to make 8℃≤△T≤10℃;

[0022] If △T>10℃, reduce the alkali solution flow rate at the rate of v3 so that 8℃≤△T≤10℃;

[0023] When the total amount of dissolved aluminum M>26wt%, the alkali solution is stopped from entering the fixed bed reactor; wherein, v1<v2<v3.

[0024] In some specific embodiments, an activation tail gas flow meter is provided in the fixed bed reactor to measure the activation tail gas flow F2 of the nickel-aluminum alloy catalyst during the activation process; according to the activation tail gas flow F2, the temperature rise ΔT in the fixed bed reactor is corrected to [0.05×F2 / (T max-T7)]+(T max -T7).

[0025] In some specific embodiments, the nickel content in the nickel-aluminum alloy catalyst of the present invention is 40-70 wt %; for example, the nickel-aluminum ratio in the nickel-aluminum alloy catalyst is 58:42.

[0026] In some specific embodiments, the alkali solution is selected from lithium hydroxide aqueous solution, sodium hydroxide aqueous solution or potassium hydroxide aqueous solution; specifically, the concentration of the alkali solution is 5-50wt%, for example, 10wt%, 15wt%, 40wt%, 45wt%, preferably 20-35wt%, for example, 25wt%, 30wt%.

[0027] In some specific embodiments, v1 is 0.2-0.5 t / h, v2 is 0.5-1 t / h, and v3 is 1-4 t / h.

[0028] In some specific embodiments, before activating the catalyst, the nickel-aluminum alloy catalyst in the fixed bed reactor is washed with water for 2 to 4 hours to remove impurities on the surface of the nickel-aluminum alloy catalyst.

[0029] In some specific embodiments, when the total amount of dissolved aluminum reaches the required amount, the introduction of the alkali solution is stopped and the catalyst is washed with desalted water for 4 to 8 hours.

[0030] In a second aspect, the present invention further provides a method for preparing 1,4-butanediol by catalytic hydrogenation of 1,4-butynediol. Before the hydrogenation reaction, the hydrogenation catalyst is activated by the above activation method.

[0031] In some specific embodiments, the conversion of 1,4-butynediol is greater than 99.8%, and the selectivity of 1,4-butanediol is greater than 99.2%.

[0032] The above technical solution has the following technical effects:

[0033] The activation method provided by the present invention calculates the temperature rise ΔT during the activation process through a temperature rise module, and then establishes a series control relationship between ΔT and the alkali solution flow rate F1, thereby achieving accurate control of the aluminum dissolution rate and the activation end point during the activation process. DETAILED DESCRIPTION

[0034] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0035] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0036] The invention provides a method for activating a nickel-aluminum alloy catalyst, which uses an alkali solution to activate the nickel-aluminum alloy catalyst loaded in a fixed bed reactor; a temperature sensor and a flow meter are arranged at the alkali solution inlet of the fixed bed reactor to measure the inlet temperature T7 of the alkali solution, and the alkali solution is controlled to enter the fixed bed reactor at a flow rate F1; a plurality of temperature sensors are arranged on the catalyst bed layer in the fixed bed reactor to measure the temperature T of each point;

[0037] During the activation process, the total amount of dissolved aluminum M in the nickel-aluminum alloy catalyst, the activation time t, and the temperature rise △T in the fixed bed reactor satisfy the following relationship:

[0038]

[0039] Wherein, the temperature rise in the fixed bed reactor ΔT = T max -T7, T max is the highest temperature in each catalyst bed in the fixed bed reactor;

[0040] The aluminum dissolution rate v and the temperature rise ΔT in the reactor satisfy the following relationship: v=0.25×ΔT+1; the activation rate v is controlled by the temperature rise ΔT in the reactor, so as to meet the activation aluminum dissolution rate requirement before the catalyst is used; for example, when the catalyst is activated, it is required to control the activation rate at 3-3.5wt% / h, which can be achieved by controlling the temperature rise ΔT in the reactor at 8-10°C.

[0041] Taking 1,4-butynediol hydrogenation catalyst as an example, the aluminum dissolution rate during activation is controlled to be 3-3.5wt% / h, and the temperature rise ΔT in the fixed bed reactor and the alkali solution flow rate F1 at the alkali solution inlet satisfy the following relationship:

[0042] When the total amount of dissolved aluminum M is 0wt%<M≤12wt% (i.e., the initial stage of catalyst activation),

[0043] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 2~4t / h, for example, 2.5t / h, 3t / h;

[0044] If △T<8℃, increase the alkali solution flow rate at the rate of v1 so that 8℃≤△T≤10℃;

[0045] If △T>10℃, reduce the alkali solution flow rate at the rate of v1 so that 8℃≤△T≤10℃;

[0046] When the total amount of dissolved aluminum M is 12wt%<M≤21wt% (i.e., the middle stage of catalyst activation),

[0047] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 4~8t / h, for example, 5t / h, 6t / h, 7t / h;

[0048] If △T<8℃, increase the alkali solution flow rate at the rate of v2 so that 8℃≤△T≤10℃;

[0049] If △T>10℃, reduce the alkali solution flow rate at the rate of v2 so that 8℃≤△T≤10℃;

[0050] When the total amount of dissolved aluminum M is 21wt%<M≤26wt% (i.e., the late stage of catalyst activation),

[0051] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 8~12t / h;

[0052] If △T<8℃, increase the alkali solution flow rate at the rate of v3 so that 8℃≤△T≤10℃; if △T>10℃, reduce the alkali solution flow rate at the rate of v3 so that 8℃≤△T≤10℃;

[0053] When the total amount of dissolved aluminum M>26wt%, the alkali solution is stopped from entering the fixed bed reactor; wherein, v1<v2<v3.

[0054] In some specific embodiments, v1 is taken from 0.2 to 0.5 t / h (including 0.5 t / h), v2 is taken from 0.5 to 1 t / h (excluding 0.5 t / h and including 1 t / h), and v3 is taken from 1 to 4 t / h (excluding 1 t / h and including 4 t / h).

[0055] In some embodiments, during the activation process, the aluminum reacts with the alkali solution to release heat, causing the reactor bed to heat up. The activation method of the present invention establishes a series control relationship between the maximum temperature rise ΔT between the beds and the alkali solution flow rate F1, controls the activation temperature rise by the alkali solution flow rate, and thus accurately controls the aluminum dissolution rate. In some specific embodiments, T max The temperature of each bed point in the reactor can be compared and screened. For example, an online temperature rise module can be added for comparison to obtain the highest temperature in each catalyst bed in the reactor.

[0056] In order to reduce the influence of the ambient temperature on the temperature rise ΔT in the reactor, the activation method of the present invention further comprises calibrating ΔT using the activated exhaust gas in the fixed bed reactor; in some specific embodiments, an activated tail gas flowmeter is arranged in the fixed bed reactor to measure the activated tail gas flow rate F2 of the nickel-aluminum alloy catalyst during the activation process; according to the activated tail gas flow rate F2, the temperature rise ΔT in the fixed bed reactor is corrected to [0.05×F2 / (T max -T7)]+(T max -T7).

[0057] In some specific embodiments, the nickel content in the nickel-aluminum alloy catalyst of the present invention is 40-70 wt %; for example, the nickel-aluminum ratio in the nickel-aluminum alloy catalyst is 58:42.

[0058] In some specific embodiments, the alkali solution is selected from lithium hydroxide aqueous solution, sodium hydroxide aqueous solution or potassium hydroxide aqueous solution; specifically, the concentration of the alkali solution is 5-50wt%, for example, 10wt%, 15wt%, 40wt%, 45wt%, preferably 20-35wt%, for example, 25wt%, 30wt%.

[0059] In some specific embodiments, before activating the catalyst, the nickel-aluminum alloy catalyst in the fixed bed reactor is washed with water for 2 to 4 hours to remove impurities on the surface of the nickel-aluminum alloy catalyst.

[0060] In some specific embodiments, when the total amount of dissolved aluminum reaches the required amount, the introduction of the alkali solution is stopped and the catalyst is washed with desalted water for 4 to 8 hours to clean the alkali solution and residues on the catalyst surface, and the catalyst activation process is completed.

[0061] The present invention also provides a method for preparing 1,4-butanediol by catalytic hydrogenation of 1,4-butynediol. Before the hydrogenation reaction, the hydrogenation catalyst is activated by the above activation method.

[0062] In some specific embodiments, the conversion of 1,4-butynediol is greater than 99.8%, and the selectivity of 1,4-butanediol is greater than 99.2%.

[0063] The following embodiments take the fixed bed reactor for preparing 1,4-butanediol by hydrogenation of 1,4-butynediol as an example to specifically illustrate the activation method of the present invention.

[0064] A certain amount (generally 18t~20t) of nickel-aluminum alloy catalyst (nickel: aluminum mass ratio of 58:42) is loaded into the fixed bed reactor, and then nitrogen is introduced into the reactor for purging. After the air tightness is tested, it is washed with water for 2~4h. A temperature sensor and a flow meter are set at the inlet of the alkali solution in the fixed bed reactor to measure the inlet temperature T7 and the flow rate F1 of the alkali solution. At the same time, several temperature sensors are set on the catalyst bed of the fixed bed reactor to measure the temperature T of different locations in the reactor, and the maximum value in each catalyst bed is screened and compared through the online temperature rise module and recorded as T max .

[0065] Example 1

[0066] 18616 kg of nickel-aluminum alloy catalyst (nickel-aluminum ratio of 58:42) was loaded into the fixed bed reactor. Before the catalytic hydrogenation reaction, the nickel-aluminum alloy catalyst was activated using a 28 wt % sodium hydroxide aqueous solution.

[0067] Add an online temperature rise module in the fixed bed reactor to screen out T max , and calculate △T (△T=T max -T7, T7 is the inlet temperature of the alkali solution), the total amount of dissolved aluminum M of the nickel-aluminum alloy catalyst has the following relationship with the activation time t and the temperature rise △T in the fixed bed reactor:

[0068]

[0069] During the activation process, the △T calculated by the temperature rise module is used to control the alkali solution flow rate F1 in series (the alkali solution initially enters the fixed bed reactor from the alkali solution inlet at a flow rate F1 of 2t / h); specifically, the following logical relationship is satisfied:

[0070] When the activation process just begins and the total amount of aluminum dissolved in the catalyst M is 0wt%<M≤12wt%, then

[0071] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 2~4t / h;

[0072] If △T<8℃, increase the alkali solution flow rate at a rate of (0.5t / h) to make 8℃≤△T≤10℃;

[0073] If △T>10℃, reduce the alkali solution flow rate at a rate of (0.5t / h) so that 8℃≤△T≤10℃;

[0074] When the total amount of dissolved aluminum M is 12wt%<M≤21wt%, then

[0075] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 4~8t / h;

[0076] If △T<8℃, increase the alkali solution flow rate at a rate of (0.8t / h) to make 8℃≤△T≤10℃;

[0077] If △T>10℃, reduce the alkali solution flow rate at a rate of (0.8t / h) so that 8℃≤△T≤10℃;

[0078] When the total amount of dissolved aluminum M is 21wt%<M≤26wt%, then

[0079] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 8~12t / h;

[0080] If △T<8℃, increase the alkali solution flow rate at a rate of (1.2t / h) to make 8℃≤△T≤10℃;

[0081] If △T>10℃, reduce the alkali solution flow rate at a rate of (1.2t / h) to make 8℃≤△T≤10℃;

[0082] When the total amount of dissolved aluminum M>26wt%, the activation endpoint has been reached, and the alkali solution is stopped from entering the fixed bed reactor, followed by washing with desalted water for 4h.

[0083] Example 2

[0084] 18616 kg of nickel-aluminum alloy catalyst (nickel-aluminum ratio of 58:42) was loaded into the above-mentioned fixed-bed reactor. Before carrying out the catalytic hydrogenation reaction, the nickel-aluminum alloy catalyst was activated using 28 wt% alkali solution (sodium hydroxide aqueous solution), and an activated tail gas flowmeter was set in the fixed-bed reactor to measure the activated tail gas flow F2 of the nickel-aluminum alloy catalyst during the activation process.

[0085] Add an online temperature rise module in the fixed bed reactor to screen out T max , the temperature rise module △T is further calibrated using the activated exhaust gas flow F2, △T=[0.05×F2 / (T max -T7)]+(T max -T7), the total amount of dissolved aluminum M of the nickel-aluminum alloy catalyst has the following relationship with the activation time t and the temperature rise ΔT in the fixed bed reactor:

[0086]

[0087] During the activation process, the △T calculated by the temperature rise module is used to control the alkali solution flow rate F1 in series (the alkali solution initially enters the reactor from the alkali solution inlet at a flow rate F1 of 2t / h); specifically, the following logical relationship is satisfied:

[0088] When the activation process just begins and the total amount of aluminum dissolved in the catalyst M is 0wt%<M≤12wt%, then

[0089] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 2~4t / h;

[0090] If △T<8℃, increase the alkali solution flow rate at a rate of (0.5t / h) to make 8℃≤△T≤10℃;

[0091] If △T>10℃, reduce the alkali solution flow rate at a rate of (0.5t / h)) so that 8℃≤△T≤10℃;

[0092] When the total amount of dissolved aluminum M is 12wt%<M≤21wt%, then

[0093] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 4~8t / h;

[0094] If △T<8℃, increase the alkali solution flow rate at a rate of (0.8t / h) to make 8℃≤△T≤10℃;

[0095] If △T>10℃, reduce the alkali solution flow rate at a rate of (0.8t / h) so that 8℃≤△T≤10℃;

[0096] When the total amount of dissolved aluminum M is 21wt%<M≤26wt%, then

[0097] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 8~12t / h;

[0098] If △T<8℃, increase the alkali solution flow rate at a rate of (1.2t / h) to make 8℃≤△T≤10℃;

[0099] If △T>10℃, reduce the alkali solution flow rate at a rate of (1.2t / h) so that 8℃≤△T≤10℃;

[0100] When the total amount of dissolved aluminum M>26wt%, the activation endpoint has been reached, and the alkali solution is stopped from entering the fixed bed reactor, followed by washing with desalted water for 4h.

[0101] Example 3

[0102] 18616 kg of nickel-aluminum alloy catalyst (nickel-aluminum ratio of 50:50) was loaded into the fixed bed reactor. Before the catalytic hydrogenation reaction, the nickel-aluminum alloy catalyst was activated using a 28 wt % sodium hydroxide aqueous solution.

[0103] Add an online temperature rise module in the fixed bed reactor to screen out T max , and calculate △T (△T=T max -T7, T7 is the inlet temperature of the alkali solution), the total amount of dissolved aluminum M of the nickel-aluminum alloy catalyst has the following relationship with the activation time t and the temperature rise △T in the fixed bed reactor:

[0104]

[0105] During the activation process, the △T calculated by the temperature rise module is used to control the alkali solution flow rate F1 in series (the alkali solution initially enters the reactor from the alkali solution inlet at a flow rate F1 of 2t / h); specifically, the following logical relationship is satisfied:

[0106] When the activation process just begins and the total amount of aluminum dissolved in the catalyst M is 0wt%<M≤12wt%, then

[0107] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 2~4t / h;

[0108] If △T<8℃, increase the alkali solution flow rate at a rate of (0.4t / h) to make 8℃≤△T≤10℃;

[0109] If △T>10℃, reduce the alkali solution flow rate at a rate of (0.4t / h) so that 8℃≤△T≤10℃;

[0110] When the total amount of dissolved aluminum M is 12wt%<M≤21wt%, then

[0111] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 4~8t / h;

[0112] If △T<8℃, increase the alkali solution flow rate at a rate of (0.7t / h) to make 8℃≤△T≤10℃;

[0113] If △T>10℃, reduce the alkali solution flow rate at a rate of (0.7t / h) so that 8℃≤△T≤10℃;

[0114] When the total amount of dissolved aluminum M is 21wt%<M≤26wt%, then

[0115] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 8~12t / h;

[0116] If △T<8℃, increase the alkali solution flow rate at a rate of (1.3t / h) to make 8℃≤△T≤10℃;

[0117] If △T>10℃, reduce the alkali solution flow rate at a rate of (1.3t / h) so that 8℃≤△T≤10℃;

[0118] When the total amount of dissolved aluminum M>26wt%, the activation endpoint has been reached, and the alkali solution is stopped from entering the fixed bed reactor, followed by washing with desalted water for 4h.

[0119] Example 4

[0120] 18616 kg of nickel-aluminum alloy catalyst (nickel-aluminum ratio of 50:50) was loaded into the above-mentioned fixed-bed reactor. Before carrying out the catalytic hydrogenation reaction, the nickel-aluminum alloy catalyst was activated using a 28 wt % sodium hydroxide aqueous solution, and an activated tail gas flowmeter was set in the fixed-bed reactor to measure the activated tail gas flow F2 of the nickel-aluminum alloy catalyst during the activation process.

[0121] Add an online temperature rise module in the fixed bed reactor to calculate and screen out T max , the temperature rise module △T is further calibrated using the activated exhaust gas flow F2, △T=[0.05×F2 / (T max -T7)]+(T max-T7), the total amount of dissolved aluminum M of the nickel-aluminum alloy catalyst has the following relationship with the activation time t and the temperature rise ΔT in the fixed bed reactor:

[0122]

[0123] During the activation process, the △T calculated by the temperature rise module is used to control the alkali solution flow rate F1 in series (the alkali solution initially enters the reactor from the alkali solution inlet at a flow rate F1 of 2t / h); specifically, the following logical relationship is satisfied:

[0124] When the activation process just begins and the total amount of aluminum dissolved in the catalyst M is 0wt%<M≤12wt%, then

[0125] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 2~4t / h;

[0126] If △T<8℃, increase the alkali solution flow rate at a rate of (0.4t / h) to make 8℃≤△T≤10℃;

[0127] If △T>10℃, reduce the alkali solution flow rate at a rate of (0.4t / h) so that 8℃≤△T≤10℃;

[0128] When the total amount of dissolved aluminum M is 12wt%<M≤21wt%, then

[0129] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 4~8t / h;

[0130] If △T<8℃, increase the alkali solution flow rate at a rate of (0.7t / h) to make 8℃≤△T≤10℃;

[0131] If △T>10℃, reduce the alkali solution flow rate at a rate of (0.7t / h) so that 8℃≤△T≤10℃;

[0132] When the total amount of dissolved aluminum M is 21wt%<M≤26wt%, then

[0133] If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 8~12t / h;

[0134] If △T<8℃, increase the alkali solution flow rate at a rate of (1.3t / h) to make 8℃≤△T≤10℃;

[0135] If △T>10℃, reduce the alkali solution flow rate at a rate of (1.3t / h) so that 8℃≤△T≤10℃;

[0136] When the total amount of dissolved aluminum M>26wt%, the activation endpoint has been reached, and the alkali solution is stopped from entering the fixed bed reactor, followed by washing with desalted water for 4h.

[0137] In the above implementation mode, the activation process does not require sampling and analysis by the operator. The activated catalyst is used for hydrogenation of 1,4-butynediol to prepare 1,4-butanediol. The reaction temperature is 130° C. and the pressure is 30 MPaG. The evaluation results of the catalytic hydrogenation reaction are shown in Table 1 below:

[0138] Table 1

[0139]

[0140]

[0141] Key impurity TBA * : The impurity 2-(4-hydroxybutoxy)-tetrahydrofuran in the product after the reaction.

[0142] Comparative Example 1

[0143] A certain amount (generally 18t~20t) of nickel-aluminum alloy catalyst (nickel:aluminum mass ratio is 58:42) is loaded into the fixed bed reactor, and then nitrogen is introduced into the reactor for purging. After the air tightness is tested and qualified, it is washed with water for 2~4h.

[0144] A 28wt% sodium hydroxide aqueous solution is introduced into the fixed bed reactor to react with the aluminum in the nickel-aluminum alloy catalyst for activation. The operator manually adjusts the flow rate F1 of the alkali solution, and samples and analyzes at the outlet of the fixed bed reactor every 15 minutes. The rate and total amount of dissolved aluminum are calculated by analyzing the concentration and flow at the alkali solution inlet and the fixed bed reactor outlet. The rate of dissolved aluminum during the activation process is controlled to be 3wt% / h to 3.5wt% / h. When the total amount of dissolved aluminum reaches 25wt%, the alkali solution is stopped from being introduced into the reactor, and then desalted water is used for washing for more than 4 hours, and the activation is completed.

[0145] Comparative Example 2

[0146] A certain amount (generally 18t~20t) of nickel-aluminum alloy catalyst (nickel:aluminum mass ratio is 50:50) is loaded into the fixed bed reactor, and then nitrogen is introduced into the reactor for purging. After the airtightness is tested and qualified, it is washed with water for 2~4h.

[0147] A 28wt% sodium hydroxide aqueous solution is introduced into the fixed bed reactor to react with the aluminum in the nickel-aluminum alloy catalyst for activation. The operator manually adjusts the flow rate F1 of the alkali solution, and samples and analyzes at the reactor inlet and outlet every 15 minutes. The rate and total amount of dissolved aluminum are calculated by analyzing the concentration and flow rate of the alkali solution inlet and reactor outlet, and the rate of dissolved aluminum during the activation process is controlled to be 3wt% / h to 3.5wt% / h. When the total amount of dissolved aluminum reaches 25wt%, the alkali solution is stopped from being introduced into the reactor, and then desalted water is used for washing for more than 4 hours, and the activation is completed.

[0148] The activated catalyst was used for hydrogenation of 1,4-butynediol to prepare 1,4-butanediol. The reaction temperature was 130°C and the pressure was 30 MPaG. The evaluation results of the catalytic hydrogenation reaction are shown in Table 2 below:

[0149] Table 2

[0150]

[0151] Key impurity TBA * : The impurity 2-(4-hydroxybutoxy)-tetrahydrofuran in the product after the reaction.

[0152] It can be seen from the data in Tables 1 and 2 that the activation method provided by the present invention controls the flow rate of the alkali solution entering the reactor in series through the temperature rise in the reactor, so that the activation rate is maintained at 3-3.5wt% / h, the automation of the activation process is realized, and the activation end point is accurately controlled; at the same time, the low activation efficiency caused by the lag in personnel operation and the high risk of the sampling process due to the presence of the dangerous medium hydrogen are avoided.

Claims

1. A method for activating a nickel-aluminum alloy catalyst, characterized in that: The nickel-aluminum alloy catalyst loaded in the fixed bed reactor is activated by using alkali solution; a temperature sensor and a flow meter are arranged at the alkali solution inlet of the fixed bed reactor to measure the inlet temperature T7 of the alkali solution and control the alkali solution to enter the fixed bed reactor at a flow rate F1; A plurality of temperature sensors are arranged on the catalyst bed in the fixed bed reactor to measure the temperature T at each point; During the activation process, the total amount of dissolved aluminum M in the nickel-aluminum alloy catalyst, the activation time t, and the temperature rise △T in the fixed bed reactor satisfy the following relationship: Wherein, the temperature rise in the fixed bed reactor ΔT = T max -T7, T max is the highest temperature in each catalyst bed in the fixed bed reactor; The temperature rise ΔT in the fixed bed reactor and the alkali solution flow rate F1 at the alkali solution inlet satisfy the following relationship: When the total amount of dissolved aluminum M is 0wt%<M≤12wt%, then If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 2~4t / h; If △T<8℃, increase the alkali solution flow rate at the rate of v1 so that 8℃≤△T≤10℃; If △T>10℃, reduce the alkali solution flow rate at the rate of v1 so that 8℃≤△T≤10℃; When the total amount of dissolved aluminum M is 12wt%<M≤21wt%, then If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 4~8t / h; If △T<8℃, increase the alkali solution flow rate at the rate of v2 so that 8℃≤△T≤10℃; If △T>10℃, reduce the alkali solution flow rate at the rate of v2 so that 8℃≤△T≤10℃; When the total amount of dissolved aluminum M is 21wt%<M≤26wt%, then If 8℃≤△T≤10℃, control the flow rate F1 of alkali solution to 8~12t / h; If △T<8℃, increase the alkali solution flow rate at the rate of v3 to make 8℃≤△T≤10℃; If △T>10℃, reduce the alkali solution flow rate at the rate of v3 so that 8℃≤△T≤10℃; When the total amount of dissolved aluminum M>26wt%, the alkali solution is stopped from entering the fixed bed reactor; Among them, v1<v2<v3.

2. The activation method according to claim 1, characterized in that An activated tail gas flow meter is arranged in the fixed bed reactor to measure the activated tail gas flow F2 of the nickel-aluminum alloy catalyst during the activation process; According to the activated tail gas flow rate F2, the temperature rise ΔT in the fixed bed reactor is corrected to [0.05×F2 / (T max -T7)]+(T max -T7).

3. The activation method according to claim 1 or 2, characterized in that The nickel content in the nickel-aluminum alloy catalyst is 40-70 wt%.

4. The activation method according to claim 3, characterized in that v1 is taken from 0.2~0.5t / h, v2 is taken from 0.5~1t / h, and v3 is taken from 1~4t / h.

5. The activation method according to claim 4, characterized in that The alkali solution is selected from lithium hydroxide aqueous solution, sodium hydroxide aqueous solution or potassium hydroxide aqueous solution.

6. The activation method according to claim 5, characterized in that The concentration of the alkali solution is 5-50wt%, preferably 20-35wt%.

7. The activation method according to any one of claims 1 to 6, characterized in that Prior to activation, the nickel-aluminum alloy catalyst in the fixed bed reactor was washed with water; Preferably, the nickel-aluminum alloy catalyst is washed with water for 2 to 4 hours.

8. The activation method according to claim 7, characterized in that After stopping the introduction of alkali solution into the fixed bed reactor, the catalyst bed is washed with desalted water; Preferably, the desalted water is used for washing for 4 to 8 hours.

9. A method for preparing 1,4-butanediol by catalytic hydrogenation of 1,4-butynediol, characterized in that: Before the hydrogenation reaction, the hydrogenation catalyst is activated by the activation method according to any one of claims 1 to 8.

10. The method according to claim 9, characterized in that The conversion rate of 1,4-butynediol is greater than 99.2%, and the selectivity of 1,4-butanediol is greater than 98.5%.

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