JPH0356141A - Reactivation of catalyst - Google Patents

Abstract

PURPOSE:To reactivate a catalyst and to extend the life thereof by adding a phosphorus-containing substance to a used catalyst and replenishing an eluted phosphoric acid component. CONSTITUTION:A phosphorus-containing substance such as phosphoric acid or phosphoric ester is dissolved or suspended in a solvent such as water, methyl alcohol or ethyl alcohol and a catalyst lowered in its function during use and containing phosphoric acid or a condensate thereof is immersed in the resulting solution or suspension and drained to be dried. This reactivation can be carried out without taking out the catalyst from a reactor in a case using a fixed bed system. In the case of a batchwise system, the phosphorus-containing substance is also added other than the catalyst in reacting ammonia or ethylenediamine with monoethanolamine to reactivate the catalyst.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to reacting ammonia or ethylene diamine with monoethanolamine to produce ethylene diamine,
This paper relates to a method for reactivating catalysts used in the production of acyclic ethyleneamines such as diethylenetriamine and triethylenetetramine. [Prior Art] As a method for producing ethyleneamines, a method is known in which ammonia or ethylenediamine is reacted with monoethanol in the presence of a phosphorus-containing substance (for example, JP-A-61-183249, JP-A-51- 147600
), [Problems to be Solved by the Invention] However, the above-mentioned catalyst (phosphorus-containing substance) had the disadvantage of a short lifespan. An object of the present invention is to provide a method for extending the life of the above-mentioned catalyst. (Means for solving the problem) In order to solve the above problems, the present inventors analyzed the used catalyst and found that the cause of the short life was the elution of phosphoric acid from the catalyst. investigated a method for reactivating a used catalyst and completed the present invention.That is, the present invention is based on the method of reactivating a spent catalyst by combining ammonia or ethylenediamine and monoethanolamine with phosphoric acid or a catalyst containing phosphoric acid or a condensation thereof. This is a catalyst reactivation method characterized by adding a phosphorus-containing substance to the catalyst to reactivate the catalyst when producing acyclic ethylene amines by reacting in the presence of the present invention.

Examples of the catalyst containing phosphoric acid or its condensate used in the present invention include phosphoric acid, pyrophosphoric acid, triphosphoric acid, polyphosphoric acid, ammonium phosphate, ammonium pyrophosphate,
There are ammonium triphosphate, etc. supported on a carrier such as silica, alumina, silica alumina, diatomaceous earth, and clay, as well as metal salts of phosphoric acid, birophosphoric acid, triphosphoric acid, and polyphosphoric acid. Specific examples of metal salts of phosphoric acid include beryllium trihydrogen phosphate, magnesium dihydrogen phosphate, calcium dihydrogen phosphate, strontium dihydrogen phosphate, barium dihydrogen phosphate, and beryllium monohydrogen phosphate. ,
Magnesium monohydrogen phosphate, calcium monohydrogen phosphate,
Strontium monohydrogen phosphate, barium monohydrogen phosphate,
and a reaction product of a group 3A metal compound of the periodic table and phosphoric acid, with a P/metal atomic ratio of 1 to 6, such as scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, Examples include reaction products of hydroxides or oxides of terbium, dysprosium, ξium, erbium, thulium, ytterbium, and lutetium and phosphoric acid. Also, reaction products of Group 4A metal compounds of the periodic table and phosphoric acid, such as compositions with a P/metal atomic ratio of 1 to 6, such as hydroxides or oxides of titanium, zirconium, and hafnium, and phosphoric acid. There are several reactions to this. Specific compound names that are known include titanium monohydrogen phosphate, zirconium monohydrogen phosphate, and hafnium monohydrogen phosphate. In addition, the reaction of a metal compound of group 5A of the periodic table with phosphoric acid is a raw material with a P/metal atomic ratio of 1 to 6, such as vanadium, niobium, tantalum hydroxide or oxide and phosphoric acid. There is a reaction to this.

Known specific compound names include vanadyl dihydrogen phosphate (P/V atomic ratio 2). In addition, metals similar to those exemplified in the section of metal phosphates and birophosphoric acid,
Salts with triphosphoric acid or polyphosphoric acid are also used. When ammonia and monoethanolamine are reacted in the method of the present invention, the reaction is usually carried out at an ammonia/monoethanolamine molar ratio of 1 or more. If the reaction is carried out while the ammonia/monoethanolamine molar ratio is less than 1, a large amount of cyclic substances such as piperazine and ξnoethylbiperazine will be produced. Preferably this molar ratio is 6
~50. As this molar ratio increases, the production of cyclic substances is suppressed, but the production efficiency becomes worse.

When ethylenediamine and monoethanolamine are reacted, the reaction is usually carried out at a molar ratio of ethylenediamine/monoethanolamine of 0.1 to 10. If the reaction is carried out while this molar ratio is less than 0.1, a large amount of cyclic substances such as viperazine and atomethylpiperazine will be produced. Preferably, this molar ratio is in the range of 1-5. As this molar ratio increases, the production of cyclic compounds can be suppressed, but the production efficiency deteriorates. The reaction temperature is 150-400°C. If the temperature is less than 150°C, the reaction rate will be slow, and if it exceeds 400°C, the thermal decomposition of viable polyamines will increase. Preferably 200~
350"C. The reaction pressure is usually 1 to 1000 kg/cd when ammonia and monoethanolamine are reacted. The higher the pressure, the higher the selectivity to acyclic ethylene amines. Ethylene diamine and mono When reacting with ethanolamine, it is usually 1 to 200 kg/cd. This reaction can be carried out in either a batch method or a continuous method. In the case of a batch method, the amount of catalyst is 1 mole of monoethanolamine. 0.01 to 1 in terms of phosphorus element
Use moles. If it is less than 0.01 mol, the reaction rate is slow.
One mole is sufficient for the reaction rate and usually no further addition is required. The reaction time is usually about 30 minutes to 10 hours. In the case of a continuous type, a moving bed can also be used, but a fixed bed type is more convenient. At that time, the feed rate of the reactant is 0
．． 05-30 preferably 0.2-10g total reactants/(g
Catalyst/hr) is adopted. At this time, the catalyst can also be supported on a material such as silica, alumina, silica-alumina, diatomaceous earth, clay, etc. Silica is preferred as the carrier. For example, when using a reaction product of phosphoric acid and a titanium compound or a zirconium compound as a catalyst, it is preferable to use silica as a carrier to increase the strength of the catalyst.

Separation of the product from the reaction solution can be easily carried out, for example, by distillation. The ammonia, ethylenediamine, and monoethanolamine separated at this time can be returned to the reactor and reused. Reactivation of the catalyst is carried out by adding a phosphorus-containing substance to the catalyst. This can be carried out, for example, by dissolving or suspending a phosphorus-containing substance in a solvent, immersing the catalyst therein, draining the liquid, and then drying the catalyst. As the solvent, water, methyl alcohol, ethyl alcohol, isopropyl alcohol, monoethanolamine, etc. can be used. There is no limit to the drying temperature of the catalyst, and it is usually 10 to 700°C, preferably 50 to 200°C. Following drying, the catalyst can be calcined, but this is not necessary. 10-40
When drying at 0°C, the drying atmosphere is usually nitrogen, argon, etc., and is carried out in the absence of oxygen gas. When drying at 400°C or higher, oxygen gas may be present since organic matter adhering to the catalyst can be burned off. The drying time is not particularly limited and is usually about 1 to 10 hours. This reactivation of the catalyst can also be carried out without removing the catalyst from the reactor when using a fixed bed system. In addition, in the case of a batch method, when reacting ammonia or ethylenediamine with monoechnolamine,
In addition to the catalyst, a phosphorus-containing substance can also be added to reactivate the catalyst and produce acyclic ethylene amines. The phosphorus-containing substances used in the method of the present invention include, in addition to substances containing phosphoric acid or its condensates, substances containing phosphoric acid or its condensates under the conditions of the reaction between ammonia or ethylenediamine and monoethanolamine. You can also use those that are converted to . Phosphorus-containing substances include phosphoric acid, birophosphoric acid, triphosphoric acid, polyphosphoric acid, phosphorous acid, ammonium phosphate, ammonium birophosphate, ammonium triphosphate, ammonium polyphosphate, ammonium phosphite, and each acid and Esters with alcohols having 1 to 4 carbon atoms are also used. For example, phosphoric acid esters include monomethyl phosphate,
Examples include dimethyl phosphate, trimethyl phosphate, monoethyl phosphate, diethyl phosphate, triethyl phosphate, monobrobyl phosphate, dipropyl phosphate, triprobyl phosphate, monobutyl phosphate, dibutyl phosphate, and tributyl phosphate. These phosphorus-containing substances can be used alone or as a mixture of two or more. The amount of these phosphorus-containing substances added is determined according to the target P/metal atomic ratio of the catalyst (Once the pore volume of the catalyst, P/metal ratio, etc. are determined, it is possible to calculate the amount of phosphorus-containing substances added. be.).

In addition, when reactivating the catalyst, it is also possible to heat-treat the catalyst with oxygen-containing gas to burn off organic matter adhering to the catalyst, and then add a phosphorus-containing substance to the catalyst (usually 400% Heat treatment is carried out at ~600°C.) However, this is not absolutely necessary. The method of the present invention makes it possible to produce acyclic amines such as ethylenediamine, diethylenetriamine, and triethylenetetramine in high yield from ammonia or ethylenediafruit and monoethanolamine, and its industrial value is extremely high. It's big. [Example] Example 1 39.95 g of catalytic titanium dioxide and 172.9 g of 85% phosphoric acid
4 g was added and kneaded. Next, fine silica gel 97
．． 61 g and 190 g of water were added, kneaded, and extruded (3 holes in diameter). Thereafter, it was dried at 150°C for 3 hours, and then burned at 500°C for 5 hours. The catalyst thus produced was cut into lengths of 3(1).

54.84 g of this catalyst was packed into a stainless steel reactor with an inner diameter of 25.8 mm, and 3.5 g of monoethanolamine was added.
The reaction was carried out for 4000 hours at a temperature of 280'C and a pressure of 400kg/cdG. Thereafter, the reaction was stopped by cooling, and the catalyst was extracted. The P/Ti atomic ratio of the extracted catalyst with decreased activity is l. 55 (P/Ti atomic ratio before the start of the reaction was 3.00). Reactivation of the Catalyst Add 10 g of the catalyst with reduced activity (12 g in advance) to a solution containing 11.0 g of phosphoric acid in 20 cc of phosphoric acid aqueous solution.
(dried in a nitrogen stream) at 0″C for 3 hours,
It was held for 3 hours. Next, the catalyst was taken out of the solution, drained, and dried in a nitrogen stream at 120°C for 3 hours to reactivate the catalyst (P/Ti atomic ratio 2.95), reaction inner diameter 10 mm, length 766 mn+. A reaction tube was filled with 10 g of the reactivated catalyst. Monoethanolamine2.
46 g/hr, ammonia was supplied to the reaction tube at a rate of 10.30 g/hr, and the temperature was 280'C and the pressure was 400 K.
The reaction was carried out under the conditions of g/c+aG. Results first
It is shown in the table. Comparative Example 1 Using 10g of a catalyst with reduced activity before reactivation,
The reaction was otherwise carried out under the same conditions as in Example 1. The results are shown in Table 1. Reference example 1 Using log of the new catalyst before conducting the reaction for 4000 hours,
The reaction was otherwise carried out under the same conditions as in Example 1. The results are shown in Table 1. Table 1 Number of moles of MEA consumed in the reaction [Effects of the invention] As described in Table 1, the catalyst (Comparative Example 1) with reduced activity used in the reaction between ammonia and monoethanolamine was phosphorused. The catalyst produced by adding acid (Example 1) was
It is clear from the conversion rate of monoethanol ξ and the selectivity to the three components that the catalyst was reactivated to almost the same extent as the new catalyst (Reference Example 1).

Claims (1)

[Claims] 1 When ammonia or ethylenediamine and monoethanolamine are reacted in the presence of a catalyst containing phosphoric acid or its condensate to produce acyclic ethyleneamines, a phosphorus-containing substance is added to the catalyst to regenerate the catalyst. A method for reactivating a catalyst characterized by activation.