JP2000093800A - Method for regenerating hydrogenation catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for regenerating a hydrogenation catalyst by which the activity of the catalyst can be recovered beyond the level of the activity of the conventional catalyst. SOLUTION: The regeneration of a hydrogenation catalyst containing copper which is deactivated is achieved by cleaning the oil content of the deactivated catalyst with a solvent, then removing the residual solvent in the catalyst, oxidizing the catalyst with an oxygen-containing gas at 150-400 deg.C temperature and reduction-activating the catalyst. Further, carboxylic acid or the ester thereof is catalytically reduced with hydrogen by a fixed bed continuous reaction process using the regenerated catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for regenerating a deactivated hydrogenation catalyst containing copper and a method for producing an alcohol using the same.

[0002]

2. Description of the Related Art As a method for regenerating a hydrogenation catalyst, there is a method disclosed in JP-A-6-63406. In this method, a degraded catalyst is pre-treated in a stream of hydrogen or an inert gas or a mixed gas thereof at a temperature of 20 to 300 ° C., then oxidized, and then reduced and activated. However, in this regenerating method, the removal of oil during the pretreatment is not sufficient, and the catalyst is affected by the heat of combustion in the oxidation step, and furthermore, there is a concern that the oil itself may be oxidized, and the catalyst may be degraded such as elution of copper by fatty acids generated. You.

Accordingly, an object of the present invention is to provide a method for regenerating a hydrogenation catalyst in which the activity of the catalyst is recovered more than before.

[0004]

The present invention comprises the following step (a):
, (B), the regeneration method of the deactivated hydrogenation catalyst containing copper having (c), and using the catalyst regenerated by this regeneration method, the carboxylic acid or its ester hydrogen by a fixed bed continuous reaction system Is a method for producing an alcohol which is catalytically reduced by (a) washing the deactivated catalyst oil with a solvent, and then removing the solvent remaining on the catalyst; (b) oxidizing the catalyst obtained in the step (a) with an oxygen-containing gas within a temperature range of 150 to 400 ° C. (c) a step of reducing and activating the catalyst obtained in the step (b).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The deactivated hydrogenation catalyst containing copper in the present invention is, for example, a product obtained by reducing and activating a copper-containing hydrogenation catalyst precursor with hydrogen in an inert solvent to produce alcohol. Deactivated catalyst. Here, the term "deactivation" refers to a state in which the activity is lower than that of a new catalyst, and it is desirable to perform a regeneration treatment for the target reaction from the viewpoint of productivity, cost, and the like.

[0006] Copper-containing hydrogenation catalyst precursors include copper-chromium oxide catalysts, copper-zinc oxide catalysts, copper-iron oxide catalysts, copper-aluminum oxide catalysts, and copper-silica oxidation catalysts. The catalyst content is preferably 5 to 98% by weight, preferably 20 to 98% by weight, based on the total weight of the catalyst precursor.
80% by weight is more preferred. These catalyst precursors may be those supported on a carrier such as silica, alumina, zirconia oxide, titanium oxide, and silica-alumina, and the total catalyst precursor weight referred to here means the weight including these carriers. To tell.

[0007] The shape of the catalyst precursor to be molded is preferably such that it does not hinder the operation of the fixed bed reactor. The catalyst precursor is formed into a columnar tablet-formed or extruded catalyst precursor or spherical particles of 1 to 20 mm. The molded catalyst precursor is preferred in that it can be easily and inexpensively manufactured.

In the present invention, the steps (a) to (c) are carried out in a fixed bed reactor, so that the operation of extracting and refilling the catalyst from the reactor can be omitted, and the cost and efficiency of the regeneration can be reduced. It is preferable. Further, by reusing the regenerated catalyst, the cost of the catalyst in the product can be significantly reduced.
Hereinafter, each step will be described.

[Step (a)] This step not only suppresses the heat generation due to the burning of oil during the oxidation in step (b), and particularly reduces the sintering of copper or its oxide as an active site. This is an important step from the viewpoint of suppressing deterioration of the catalyst, such as elution of copper by fatty acids generated by oxidizing the oil itself remaining in the catalyst.

The solvent used in this step may be any solvent as long as it can dissolve oil (reaction raw materials, products, etc.), but a relatively inexpensive solvent which is easily dried and removed is preferred. For example, methanol, ethanol, acetone and the like are preferable. When a fixed-bed reactor is used, the liquid supply of the solvent is 0.5 to 5.0 times the volume of the catalyst layer per hour, that is, the liquid hourly space velocity is 0.5 to 5.
0 h ^-1 is preferred. The supply time of the solvent is preferably 3 to 48 hours, more preferably 5 to 36 hours. The temperature of the catalyst layer at the time of solvent washing is preferably 40 to 80 ° C, and the solvent washing is desirably performed in a state where the solvent is liquefied.

Further, before or simultaneously with the solvent washing, hydrogen, an inert gas, or a mixed gas thereof used in producing alcohol or the like is supplied to remove a certain amount of oil in the catalyst. This is preferable because the amount of solvent used during solvent washing can be reduced. The catalyst layer temperature at this time is 60 to 250
° C is preferable, and gas supply is oil removal efficiency, equipment,
From the viewpoint of cost, 100 to 100
It is preferably 16000 times, that is, the gas hourly space velocity is 100 to 16000 h ^-1 , more preferably 1000 to 8000 h ^-1 . The supply time is 3 to 24 hours, more preferably 5 to 12 hours.
The pressure is desirably at a pressure during the reaction to 0 MPaG (gauge pressure).

Subsequently, the solvent remaining on the catalyst after the solvent washing is removed. Insufficient removal of the solvent remaining in the catalyst may cause deterioration of the catalyst in the next step (b), and since oxygen is supplied at a high temperature, it is necessary to sufficiently remove the solvent from the viewpoint of safety .

The removal of the solvent may be performed at a pressure under which the solvent is gasified, but normal pressure is preferable from the viewpoint of equipment load, and an inert gas such as nitrogen, helium, or argon is supplied from the viewpoint of removal efficiency. It is preferable to perform while doing. The temperature of the catalyst layer at this time is preferably 60 to 120 ° C, and 70 to 110 ° C.
Is more preferred. The gas supply from the removal efficiency and cost of the solvent, preferably from 10 to 10000 h ^-1 at a gas hourly space velocity, and more preferably 100 to 5000 h ^-1. By sufficiently removing the oil content of the catalyst in this step, the control of the temperature of the catalyst layer during the oxidation in the step (b) becomes easy, and the heat load on the catalyst and the deterioration of the catalyst can be suppressed.

[Step (b)] In this step, the catalyst is mixed with 150 to 40
The temperature is raised to 0 ° C., and oxidation treatment is performed with an oxygen-containing gas. The heating rate is preferably 0.5 to 40 ° C./h from the viewpoints of shortening the time, suppressing a rapid increase in the oxidation temperature, and controlling the oxidation temperature.
30 ° C./h is more preferred, and 5-20 ° C./h is even more preferred. The oxidation may be performed during the heating or after the heating.

The oxygen concentration of the oxygen-containing gas (or air) at the inlet of the catalyst layer is preferably adjusted to 0.3 to 10 vol% by diluting with an inert gas. The bed temperature is 150-400 ° C, preferably
Adjust to 200-350 ° C. If the temperature is lower than 150 ° C,
Oxidation becomes insufficient. If the temperature exceeds 400 ° C., the effect of heat causes the activity after reduction activation to decrease. Examples of the inert gas used here include nitrogen, helium, argon, and the like. As the oxygen-containing gas, air diluted with nitrogen is desirable from the viewpoint of cost. The pressure at the time of oxidation is preferably 0 to 1.0 MPaG. The oxidation time is preferably 2 hours or more for performing sufficient oxidation, and more preferably 5 to 200 hours.

The supply and heat removal effect of the oxidation heat of the oxygen-containing gas, controlling the oxidation temperature, the facility of view, 50-16000 h ^-1 is preferred as the gas space velocity, and more preferably ranging from 100 to 10000 h ^-1 . The end of the oxidation is determined by confirming the end of heat generation from the temperature in the catalyst layer and / or by measuring the oxygen concentration at the inlet and the outlet of the catalyst layer and confirming that the oxygen concentrations at the inlet and the outlet are equal. It is not necessary to completely convert copper to copper oxide (CuO 2), and copper oxide (Cu ₂ O) may partially remain, and heat generation due to oxidation can be reduced, which is preferable. According to this regeneration method, from the viewpoint of activity improvement, copper oxide / cuprous oxide = 100
It is preferable to oxidize in the range of / 0 to 60/40 (X-ray diffraction intensity ratio).

[Step (c)] This step is a step in which the copper-containing hydrogenation catalyst precursor oxidized in step (b) is reduced and activated with hydrogen, and particularly in the temperature range of 20 to 250 ° C. Liquid phase reduction with hydrogen in an active solvent is preferred.

The inert solvent does not cause elution of copper oxide or metallic copper, irreversible adsorption, and formation of a compound with copper, and is in a liquid state under the conditions for the activation and reduction of the catalyst precursor. Oils, esters, alcohols, hydrocarbons and the like are preferred. Most preferred are glyceride oils, fatty acid esters, aliphatic alcohols, hydrocarbons and the like which do not adversely affect the quality of the produced alcohol in alcohol production, and these may be used alone or in combination of two or more. Specifically, glyceride oil is monoglyceride composed of fatty acids having 6 to 22 carbon atoms, diglyceride and triglyceride, for example, coconut oil, palm kernel oil, palm oil, tallow, tallow, etc., derived from plants or It is a glyceride of natural fatty acids of animal origin. The fatty acid esters are a fatty acid having at least one carboxyl group having 2 to 22 carbon atoms and a fatty acid having 1 carbon atom.
~ 22 aliphatic esters. As the aliphatic alcohol, at least one of C2 to C22 is used.
It is an alcohol having individual hydroxyl groups and presenting a liquid under the conditions for activating the catalytic reduction. Examples of the hydrocarbons include liquid paraffin and cyclic hydrocarbons such as cyclohexane, cyclooctane, decalin, benzene, toluene, xylene, and naphthalene. Also, ether,
Other inert solvents, such as aldehydes, ketones, can also be used. The passage of the inert solvent is performed at a liquid hourly space velocity of 0.1 to 5.0 from the viewpoint of making the catalyst precursor wet by the solvent uniform and economical.
h ^-1 is preferred, and 0.1 to 3.0 h ^-1 is more preferred.

The reduction in this step is performed while contacting and supplying hydrogen gas or a mixed gas of hydrogen and an inert gas to the catalyst precursor. As the inert gas, nitrogen, helium, argon, methane or the like is used. The hydrogen concentration in the mixed gas is preferably 0.1 vol% or more and less than 100 vol%, but considering the time required for activation, it is desirable to set the hydrogen concentration so that the hydrogen partial pressure becomes 1 atm or more. The gas is preferably supplied under a pressure of normal pressure to 30 MPaG under a solvent flow from an economical viewpoint. The supply of gas is efficient removal of heat removal effect and reduced product water from the facility of view, is preferably carried out at a gas hourly space velocity 50~10000 h ^-1, 100~5000h ^-1 it is more preferred.

[0020] The temperature in the liquid phase reduction is preferably from 20 to 250 ° C, more preferably from 40 to 200 ° C, particularly preferably from 50 to 140 ° C. Further, the reduction time is preferably 1.5 hours or more, more preferably 6 to 100 hours, from the viewpoint of progress of activation and economical aspects. The heating rate is preferably from 0.5 to 40 ° C / h, more preferably from 1 to 30 ° C / h, most preferably from 5 to 20 ° C / h from the viewpoint of shortening the time and controlling the reduction reaction.

The copper-containing hydrogenation catalyst regenerated by the method of the present invention is used mainly for the production of alcohol by a fixed bed continuous reaction system, hydrogenation of aldehyde group or ketone group, hydrogenation of olefins, It can be used for various hydrogenation reactions such as hydrogenation of a group. Therefore, if the regeneration method of the present invention is carried out in a reactor for continuous fixed-bed reaction, the obtained activated catalyst can be used as it is for production of alcohol and the like.

In the process for producing an alcohol of the present invention, when a carboxylic acid or its ester is catalytically reduced with hydrogen in a fixed bed continuous reaction system, a copper-containing hydrogenation catalyst regenerated by the above-mentioned method is used.

The carboxylic acids used as raw materials include coconut oil,
Palm kernel oil, palm oil, tallow, synthetic fatty acids and the like in addition to animal and plant natural fatty acids obtained from lard,
As the ester, a fat or oil or a fatty acid ester is desirable. As fats and oils, monoglycerides, diglycerides and triglycerides composed of saturated or unsaturated fatty acids having 6 to 22 carbon atoms, and as fatty acid esters, linear or branched chains having 1 or more carbon atoms and containing at least one ester group Alternatively, unsaturated fatty acid esters may be used. Such fatty acid esters include, for example, formate, acetate, caproate, caprylate, caprate, undecenoate,
Lauric esters, myristic esters, palmitic esters, stearic esters, isostearic esters, oleic esters, arachiic esters, behenic esters, oxalic esters, maleic esters, adipic esters, sebacic esters, etc. Can be The alcohol constituting the fatty acid ester is preferably an aliphatic alcohol having 1 to 22 carbon atoms. Esters subjected to hydrogenation in the present invention are not limited to fatty acid esters, but alicyclic carboxylic esters such as cyclohexane carboxylic esters, benzoic esters, and aromatic carboxylic esters such as phthalic esters. And its derivatives.

In the present invention, when hydrogenating a carboxylic acid or an ester thereof, a fixed bed continuous reaction system is employed. Here, after regenerating the catalyst in the fixed-bed continuous reactor by the regeneration method of the present invention, it is preferable to hydrogenate the carboxylic acid or its ester to produce an alcohol in the same reactor, which is industrially advantageous. is there. Although a solvent can be used for the hydrogenation reaction, it is preferable to perform the reaction without a solvent in consideration of productivity. When a solvent is used, an alcohol, dioxane, paraffin or the like that does not adversely affect the reaction is selected. The reaction temperature is 130
To 300 ° C is preferred, and 160 to 250 ° C is more preferred. The reaction pressure is preferably from 0.0098 to 30 MPaG. Further, the liquid hourly space velocity of the raw material supply is arbitrarily determined according to the reaction conditions, but is preferably 0.2 to 5.0 h ^{-1 in} consideration of productivity or reactivity.

[0025]

Reference Example 1 According to the method described in Example 5 of JP-A-5-177140, a catalyst precursor having CuO, ZnO and BaO supported on TiO ₂ was obtained. The obtained precursor powder was formed into a columnar tablet and then calcined at 450 ° C. for 2 hours to obtain a molded catalyst precursor having the following weight composition and a diameter of 3 mm and a height of 3 mm.

CuO: ZnO: BaO: TiO ₂ = 43.5%: 2.4%: 4.1%: 50.0% 500 mL of the obtained shaped catalyst precursor was placed in a fixed bed flow reactor (3
5.5 mmID x 800 mmH), and then laminating lauryl alcohol (purity = 4.0 NL / h (gas space velocity 8.0 h ^-1 ) while flowing nitrogen at 4.0 NL / h (gas space velocity 8.0 h ^-1 ) to sufficiently wet the catalyst with the solvent at a temperature of 60 ° C. 99.8%) at a flow rate of 600 mL / h (liquid hourly space velocity 1.2 h
^-1 ) for 6 hours (normal pressure (0 MPaG)). Then, the pressure was increased to 1.96 MPaG, and hydrogen gas (50 vol% of hydrogen and 50 vol% of nitrogen) diluted to 50 vol% was supplied at a flow rate of 78.6 NL / h (gas space velocity: 157.2 h ^-1 ), and lauryl alcohol (purity = 99.8 %) At a flow rate of 250 mL / h (liquid hourly space velocity 0.5 h
^-1 ). After the liquid and gas flow rates have stabilized,
The temperature of the catalyst layer was increased to 130 ° C at a rate of 0 ° C / h, and
Hold at 0 ° C. for 23 hours. The reduction time was a total of 30 hours from the temperature increase.

After the reduction activation of the catalyst precursor was completed, lauryl alcohol was switched to a fatty acid methyl ester having a chain length distribution of 8 to 18 carbon atoms (saponification value = 243), and 220
The hydrogenation reaction was carried out at 4.9 MPaG, 500 mL / h (liquid hourly space velocity: 1.0 h ^-1 ), and 100 times the hydrogen flow rate of the fatty acid methyl ester. Here, the saponification value (SV)
(JIS K0070 reference) was determined, and the activity kv of the catalyst was determined by the following formula.

Kv = ln ((243−SVe) / (SV−SVe)) (SVe is an equilibrium value, ln is a natural logarithm) The selectivity of the reaction is determined by gas chromatographs such as hydrocarbons and ether compounds. Evaluation was based on the amount of the product. Based on the activity and selectivity of this new catalyst, it is relatively evaluated with the following Examples and Comparative Examples. Table 1 shows the results.

Example 1 First, in order to confirm the activity before regeneration of the deactivated catalyst after passing the flow rate [kg-raw material / kg-catalyst] 1420 times with the same catalyst as in Reference Example 1, reference Example 1 was used. Same reactor (catalyst charge 500mL)
The hydrogenation reaction was carried out under the above conditions, and the activity kv was calculated from the saponification value.

Next, in order to regenerate the deactivated catalyst, after evaluating the activity before regeneration, the catalyst layer was first cooled to 60 ° C. while maintaining the supply of hydrogen and the pressure. The oil was removed for a total of 6 hours, including the cooling time. Subsequently, in this state, methanol was supplied at 250 mL / h (liquid hourly space velocity: 0.5 h ^-1 ) for 24 hours, and the catalyst was washed with a solvent (the reactant at the outlet of the reactor was taken out, and the oil was sufficiently removed by gas chromatography. And finished.) Then return to normal pressure,
After purging the system with nitrogen, the temperature of the catalyst layer is set to 80 ° C, and the nitrogen is
/ h (gas hourly space velocity of 160 h ^-1 ) was supplied for 24 hours to remove the residual solvent of the catalyst. In addition, NL shows a gas volume in a standard state.

Next, after confirming that the oxygen concentration in the system is 0%, nitrogen is added.
The catalyst layer was heated to 200 ° C. at a rate of 20 ° C./h while being supplied from the upper part of the reactor at a flow rate of 300 NL / h (gas hourly space velocity 600 h ⁻¹ ). Subsequently, the flow rate from air was adjusted so that the oxygen concentration of the supply gas became 1 vol%, and oxidation was started. Oxidation is performed using a thermometer provided in the direction of the center axis of the catalyst layer.The gas supply rate to the reactor is checked at 300NL / h (gas space velocity 600h
^-1 ), at a pressure of 0.29 MPaG and in a circulating condition. After the thermometer reading at the bottom of the catalyst layer had settled at 200 ° C., the oxygen concentrations at the inlet and outlet of the reactor were measured, and it was confirmed that the concentrations were equal, and the process was terminated (oxygen concentration 1.2 vol%). After completion of the oxidation, the reactor was cooled to room temperature, a few grams of the catalyst were sampled, and analyzed by X-ray diffraction (XRD). As a result, all the copper was oxidized, and the strength ratio of copper oxide / cuprous oxide was 73/27.

The catalyst precursor obtained by the above oxidation was activated by liquid phase reduction under the same conditions as in Reference Example 1. A hydrogenation reaction was performed under the same conditions as in Reference Example 1 to evaluate the activity. The selectivity of the reaction was evaluated based on the amounts of by-products such as hydrocarbons and ether compounds determined by gas chromatography.

Here, the activity and selectivity after regeneration were compared with each other on the basis of the new catalyst. In the relative comparison, the larger the activity, the better the activity, and the smaller the selectivity, the better the selectivity. Table 1 shows the results.

Example 2 First, the activity of the deactivated catalyst before regeneration was confirmed after passing the flow rate [kg-raw material / kg-catalyst] 5590 times with the same catalyst as in Reference Example 1. The same reactor as in Example 1 (catalyst charge 500m
Hydrogenation reaction was performed under L) and conditions. After the reaction, the saponification value was determined from the analysis, and the activity kv was calculated.

Subsequently, the oil content of the catalyst and the solvent were removed under the same conditions as in Example 1. Next, in the oxidation step,
The conditions up to 200 ° C were the same as in Example 1. After the thermometer reading at the bottom of the catalyst layer settled at 200 ° C, the oxygen concentrations at the inlet and outlet of the reactor were measured, and the concentrations were equal (oxygen concentration 1.
0 vol%). Subsequently, the temperature of the catalyst layer was raised to 250 ° C. while checking the temperature inside the catalyst layer at a rate of 20 ° C./h in a state where oxygen was supplied as it was, and further raised to 300 ° C. at the same rate. The oxygen concentration at the entrance and exit of the reactor was measured, and it was confirmed that the concentrations were equal.
%). As a result of the analysis by the X-ray diffraction method, all the copper was oxidized, and the intensity ratio of copper oxide / cuprous oxide was 79/21.

Hereinafter, the conditions for the reduction activation and hydrogenation reaction were the same as in Reference Example 1, and the activity and selectivity after regeneration were evaluated. As in Example 1, the activity and selectivity after regeneration were compared relative to the new catalyst. Table 1 shows the results
Shown in

Comparative Example 1 Using the same reactor as in Reference Example 1, the flow rate was [kg-raw material / kg-
[Catalyst] was passed 1420 times, and the same deactivation catalyst regeneration treatment as in Example 1 was performed. In this regeneration treatment, washing of the catalyst oil and removal of the solvent were not performed, and the other conditions were the same as in Example 1, and the activity and selectivity after regeneration were evaluated. As in Example 1, the activity and selectivity after regeneration were compared relative to the new catalyst. Table 1 shows the results.

Comparative Example 2 Using the same reactor as in Reference Example 1, the flow rate was [kg-raw material / kg-
[Catalyst] was passed 5590 times, and the same deactivation catalyst regeneration treatment as in Example 2 was performed. In this regeneration process, the oxidation temperature was set at 100
The activity and selectivity after regeneration were evaluated under the same conditions as in Example 2 except that the temperature was changed to ° C. As in Example 1, the activity and selectivity after regeneration were compared relative to the new catalyst. Table 1 shows the results.

[0039]

[Table 1]

[0040]

The catalyst obtained by the regeneration method of the present invention comprises:
By regenerating the deactivated catalyst in a fixed-bed reactor, the operation of extracting and refilling the reactor can be reduced, and the regeneration can be performed at low cost and efficiently. Further, by reusing the regenerated catalyst, the cost of the catalyst in the product can be significantly reduced.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 29/149 C07C 29/149 31/02 31/02 // C07B 61/00 300 C07B 61/00 300 ( 72) Inventor Osamu Tabata 1334 Minato, Wakayama, Wakayama Pref.

Claims (4)

[Claims] 1. A method for regenerating a deactivated hydrogenation catalyst containing copper, comprising the following steps (a), (b) and (c). (a) washing the deactivated catalyst oil with a solvent, and then removing the solvent remaining on the catalyst; (b) oxidizing the catalyst obtained in the step (a) with an oxygen-containing gas within a temperature range of 150 to 400 ° C. (c) a step of reducing and activating the catalyst obtained in the step (b). 2. The regeneration method according to claim 1, wherein step (c) is a step of performing liquid phase reduction with hydrogen in an inert solvent within a temperature range of 20 to 250 ° C. 3. The regeneration method according to claim 1, wherein steps (a) to (c) are carried out in a fixed-bed reactor. 4. A method for producing an alcohol, wherein a carboxylic acid or an ester thereof is catalytically reduced with hydrogen by a fixed bed continuous reaction system using the catalyst regenerated by the regeneration method according to claim 1. Description: .