CN114272748A

CN114272748A - Ammonia purification equipment and method

Info

Publication number: CN114272748A
Application number: CN202111578596.XA
Authority: CN
Inventors: 侯鹏; 钱吉; 李文强; 韩江江; 杨瑞云
Original assignee: Dalian Huabang Chemical Co ltd
Current assignee: Dalian Huabang Chemical Co ltd
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-04-05
Anticipated expiration: 2041-12-22
Also published as: CN114272748B

Abstract

The invention discloses ammonia purification equipment and a method, wherein the equipment is provided with an adsorption purification tank and a plasma excitation device which are connected in series, an adsorption layer and a catalyst layer are sequentially arranged in the adsorption purification tank from bottom to top, both ends of the adsorption purification tank and the plasma excitation device are connected with a filter, an ammonia purification catalyst is filled in the catalyst layer, and the ammonia purification catalyst consists of active components, an auxiliary agent, a carrier and a binder; mixing the mixed solution with a molecular sieve, adding ammonia water or sodium carbonate, filtering after complete precipitation, and drying to obtain a solid mixture; crushing the solid mixture, adding an adhesive for forming treatment to obtain a blank; drying and roasting the blank to obtain the ammonia gas purification adsorbent.

Description

Ammonia purification equipment and method

Technical Field

The invention relates to the field of gas purification, in particular to ammonia purification equipment and method.

Background

With the rapid development of the semiconductor industry, ammonia is not only used as an etching gas, but also used for preparing nitrides such as aluminum, gallium, indium and the like, so that the requirement on the purity of ammonia is higher and higher. The impurities in ammonia are mainly oil, metal ions, water, hydrogen, oxygen, carbon monoxide, carbon dioxide, methane, sulfides, particulate matter and the like, and the purity of ammonia gas is required to be further purified besides the improvement of the purity of synthesis gas (nitrogen and hydrogen).

The traditional purification treatment mainly adopts a rectification mode, and oil, a large amount of hydrogen, oxygen, carbon monoxide, carbon dioxide, methane and the like in ammonia are removed by rectification to obtain 5N-6N electronic grade ammonia. However, the distillation energy consumption is high, the operation and maintenance requirements are strict, and the purity of the obtained ammonia gas is not ideal. In order to further improve the purity of ammonia, a purification method combining adsorption and rectification, a catalyst adsorption purification method and the like are adopted at present, so that the impurities of ammonia gas can be removed to a 7N level (the analysis and detection limit of ammonia can only reach 7N levels at present).

A purification method combining adsorption and rectification, as in US7297181, is to remove hydrocarbons and water by adsorption with granulated activated carbon and calcium (VI) sulfate before distillation of liquid ammonia, and finally obtain ammonia gas with a purity of 99.9995%; the invention patent with Chinese patent publication No. CN 106495183B discloses a method for purifying ammonia, which comprises the following steps of firstly adopting a molecular sieve to adsorb and remove impurities from the ammonia, and then rectifying the ammonia:

step A: introducing high-temperature nitrogen into an adsorber to release impurities in the molecular sieve in the adsorber;

and B: a cooling device in the adsorber carries out cooling treatment on the adsorber;

and C: intermittently introducing high-purity ammonia gas into the adsorber, maintaining the temperature of the adsorber not to exceed 150 ℃ in the process of introducing the high-purity ammonia gas, and stopping introducing the high-purity ammonia gas until the working temperature in the adsorber is maintained at 20-40 ℃ and does not fluctuate any more;

step D: heating liquid ammonia in a raw material tank into ammonia gas, introducing the ammonia gas into the adsorber, and adsorbing and removing impurities from the ammonia gas by the molecular sieve;

step E: introducing the ammonia gas subjected to adsorption and impurity removal by the adsorber into a rectifying tower for rectifying treatment;

step F: introducing the ammonia gas subjected to rectification treatment in the rectification tower into a condenser to change the ammonia gas into liquid ammonia;

step G: transferring the liquid ammonia to a finished product tank;

after said step G, a step G1 is added: heating liquid ammonia to 20-30 ℃ by a heating device in the finished product tank, and releasing impurities in the liquid ammonia;

after the step G1, a step G2 is added: removing impurities precipitated at the bottom of the finished product tank;

before step a, add step a 0: compressing the gas in the raw material tank into a liquid ammonia tank of the raw material tank car, and increasing the pressure in the liquid ammonia tank; and liquid ammonia is filtered by the first filter and then is conveyed into the raw material tank.

The purification method combining adsorption and rectification can improve the purification precision of ammonia gas, but does not change the problems of higher energy consumption, strict operation and maintenance requirements and the like of rectification.

The method for adsorbing and purifying the catalyst does not need rectification, overcomes the problems existing in rectification, but can be realized only by combining a plurality of catalytic adsorption methods for different impurities due to different and mutually restricted performances of different impurities in the ammonia gas. Among the various methods, there are a method of removing water by bringing ammonia into contact with barium oxide, molecular sieves, copper sulfate, and the like; a method of removing carbon monoxide by contacting ammonia with a nickel catalyst; a process for deoxidizing the deoxidant containing Mn, Cu and Ti features that ammonia is contacted with the deoxidant containing Mn, Cu and Ti as its main active components, such as the "deoxidant drying tower for purifying ammonia" in Chinese patent No. 201920620070.5 and the "multi-component deoxidant with high activity" in the patent application No. 201610008772.9, and its preparing process and application. The used devices are basically allThe system is composed of a filter, an adsorber, a catalytic purifier, a water scrubber, a dryer, and the like, and different catalysts are provided in the catalytic purifier according to the type of impurities to be purified. The prior multiple methods combine purification to cause long whole purification flow, low purification efficiency, large occupied space of equipment, energy consumption of washing and drying, increased purification cost of ammonia, short service life of partial catalyst and the like. For example, the Chinese patent application with patent application number 201610008772.9 discloses a multi-element high-activity component deoxidizer which mainly comprises active components and a supporting carrier, wherein the active components are lower oxides of Mn, Ti and Cu: MnO, TiO and Cu₂O; the support carrier is high-alumina cement or gamma-Al₂O3, kaolin and diatomite. The specification (0028) is as follows: the deoxidizer of the invention has better effect than single component or double component deoxidizer, has the advantages of no loss of effective component of raw material gas, high deoxidation depth, large deoxidation capacity, strong fluctuation capability of impurity oxygen content of antigen material gas, low activation temperature, strong sintering resistance, long service life, high mechanical strength, difficult pulverization and the like, namely, the copper element in the reaction system is indispensable. However, when the deoxidizer is applied to ammonia gas, the existing copper element can be complexed with ammonia, so that the pulverization of the catalyst is accelerated, copper ions in the ammonia gas are increased, the subsequent use of the ammonia gas is influenced, and the deoxidizer is particularly difficult to be applied to electronic special gas with high requirements on the copper ions.

Disclosure of Invention

The invention aims to solve the technical problems in the prior art and provides ammonia purification equipment and method.

The technical solution of the invention is as follows: the utility model provides an ammonia purification equipment, is equipped with and adsorbs the purifying tank, and there is first import, the top of adsorbing the purifying tank has first export, adsorption layer, catalyst layer have by lower supreme in proper order in the adsorption purifying tank, the first export that adsorbs the purifying tank meets with the second import that is located plasma excitation device lower extreme, there is the second export upper end of plasma excitation device, first import, first export and second exit correspond respectively and set up first filter, second filter and third filter, the catalyst layer is filled with ammonia purification catalyst, ammonia purification catalyst comprises active ingredient, auxiliary agent, carrier and binder, and the mass ratio of active ingredient, auxiliary agent, carrier and binder is 5 ~ 75: 5-10: 10-55: 5-10, wherein the active components are Ni oxide, Fe oxide and Mn oxide, and the mass ratio is 5-10: 10-40: 5-30; the auxiliary agent is an oxide of Mg and an oxide of La, and the mass ratio of the Mg to the La is 1-8: 1-5, wherein the carrier is a molecular sieve; the ammonia purification catalyst is prepared by the following steps in sequence:

a. dissolving nickel salt and magnesium salt in a solvent, treating for at least 2 hours in ultrasonic waves, adding a surfactant, stirring for at least 1 hour, adding manganese salt, iron salt and lanthanum salt, and stirring for at least 1 hour to obtain a mixed solution, wherein the nickel salt, the magnesium salt, the manganese salt, the iron salt and the lanthanum salt are all nitrate or carbonate, and the surfactant is tween or hexadecyl trimethyl ammonium bromide;

b. mixing the mixed solution with a molecular sieve, stirring for at least 1 hour, adding ammonia water or sodium carbonate, filtering after complete precipitation, and drying to obtain a solid mixture;

c. crushing the solid mixture, adding an adhesive for forming treatment to obtain a blank;

d. drying and roasting the blank to obtain the ammonia gas purification adsorbent.

A method for purifying ammonia by using the ammonia purification equipment sequentially comprises the following steps:

step 1: high-temperature nitrogen at 380-420 ℃ enters an adsorption purification tank through a first filter and a first inlet, and is pretreated for 6-12 hours;

step 2: introducing low-concentration hydrogen to carry out reduction treatment on the ammonia purification catalyst under the condition that the temperature in the adsorption purification tank is 150-400 ℃;

and step 3: intermittently introducing high-purity ammonia gas into the adsorption purification tank under the condition that the temperature in the adsorption purification tank is lower than 150 ℃ until the temperature in the adsorption purification tank is constant at 10-50 ℃, and stopping introducing the high-purity ammonia gas;

and 4, step 4: and (3) enabling ammonia gas to be purified to enter the adsorption purification tank through the first filter and the first inlet, and collecting the purified ammonia gas at the outlet of the third filter.

The catalyst arranged in the equipment does not contain copper element which can be complexed with ammonia gas, and the nickel source as the main active component and the magnesium source as the auxiliary agent are fully mixed and treated in ultrasonic for at least 2 hours, so that a strong metal bond (Ni-Mg) is formed between the nickel as the main active component and the magnesium as the auxiliary agent, and then Tween or hexadecyl trimethyl ammonium bromide is added to wrap the Ni-Mg substance, thereby playing a role of space confinement, and simultaneously playing a role of coaction with the manganese source, the iron source, the lanthanum source, the molecular sieve and the like, so that the impurities such as sulfide, hydrogen, carbon monoxide, carbon dioxide, oxygen, a small amount of water and the like in the ammonia gas can be removed simultaneously, the oil, particles and the like in the ammonia gas can be removed by the filter and the adsorption layer, the plasma excitation device can provide ionization energy for the metal ions in the ammonia gas, so that the metal ions are enriched on the enrichment rod in the plasma excitation device to be removed, no water washing and drying unit is needed. The method can obtain the ammonia gas with impurities at least removed to 7N, overcomes the problems of long purification flow, low purification efficiency, large occupied space of equipment, energy waste, high cost and the like in the prior art, reduces the probability of forming a complex compound by active components and the ammonia gas, and prolongs the service life of the catalyst.

Drawings

Fig. 1 is a schematic structural diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a process flow diagram of an embodiment of the invention.

Detailed Description

Example 1:

an ammonia purification device of the invention is shown in fig. 1, and is provided with an adsorption purification tank 1, a first inlet 2 is arranged at the bottom end of the adsorption purification tank 1, a first outlet 3 is arranged at the top end of the adsorption purification tank 1, an adsorption layer 4 and a catalyst layer 5 are sequentially arranged in the adsorption purification tank 1 from bottom to top, the first outlet 3 of the adsorption purification tank 1 is connected with a second inlet 7 positioned at the lower end of a plasma excitation device 6, a second outlet 8 is arranged at the upper end of the plasma excitation device 6, a first filter 9, a second filter 10 and a third filter 11 are respectively and correspondingly arranged at the first inlet 2, the first outlet 3 and the second outlet 8, the adsorption layer 4 can be divided into fillers such as an activated carbon layer and a molecular sieve layer, and the specific type and the amount can be determined according to the condition of a feed gas; the plasma excitation device 6 is commercially available, such as an argon ion laser manufactured by Modu laser of America, and an atmospheric pressure plasma generator manufactured by Ruilong of Germany; the catalyst layer 5 is filled with an ammonia purification catalyst, the ammonia purification catalyst is composed of active components, auxiliaries, a carrier and a binder, and the mass ratio of the active components to the auxiliaries to the carrier to the binder is 5-75: 5-10: 10-55: 5-10, wherein the active components are Ni oxide, Fe oxide and Mn oxide, and the mass ratio is 5-10: 10-40: 5-30; the auxiliary agent is an oxide of Mg and an oxide of La, and the mass ratio of the Mg to the La is 1-8: 1-5, wherein the carrier is a molecular sieve; the ammonia purification catalyst is prepared by the following steps in sequence:

a. weighing 40g of nickel nitrate and 12g of magnesium nitrate, dissolving in 250g of deionized water, and treating for 2 hours by adopting ultrasonic waves; adding 0.5g of tween, stirring for 1 hour, adding 195g of manganese nitrate solution with the mass concentration of 50%, 160g of ferric nitrate and 9.5g of lanthanum nitrate, and stirring for 1 hour to obtain a mixed solution;

b. adding 12g of MCM-22 molecular sieve, continuously stirring for more than 1 hour, adding ammonia gas as a precipitator for precipitation, filtering after complete precipitation, and drying to obtain a solid mixture;

d. drying and roasting the blank to obtain the ammonia gas purification catalyst.

Example 2:

the ammonia purification equipment has the same structure as that of the embodiment 1, and is different from the embodiment 1 in that the ammonia purification catalyst is prepared by the following method in sequence:

a. weighing 18g of basic nickel carbonate and 8g of basic magnesium carbonate, dissolving in 100g of dilute nitric acid, and treating for 2 hours by adopting ultrasonic waves; adding 0.5g of Tween, stirring for 1 hour, and adding 64g of manganese carbonate to obtain a mixed solution A; weighing 160g of ferric nitrate and 9.5g of lanthanum nitrate, dissolving in 200g of deionized water to obtain a mixed solution B, and mixing the mixed solution A and the mixed solution B to obtain a mixed solution;

b. adding 12g of MCM-22 molecular sieve into the mixed solution, stirring for more than 1 hour, adding sodium carbonate as a precipitator for precipitation, filtering after complete precipitation, and drying to obtain a solid mixture;

Example 3:

a. weighing 40g of nickel nitrate and 12g of magnesium nitrate, dissolving in 250g of deionized water, and treating for 2 hours by adopting ultrasonic waves; adding 0.5g of hexadecyl trimethyl ammonium bromide and stirring for 1 hour; adding 195g of manganese nitrate solution with the mass concentration of 50%, 160g of ferric nitrate and 9.5g of lanthanum nitrate, and stirring for more than 1 hour to obtain a mixed solution;

b. adding 12g of MCM-41 molecular sieve into the mixed solution, stirring for more than 1 hour, adding ammonia gas as a precipitator for precipitation, filtering after complete precipitation, and drying to obtain a solid mixture;

Example 4:

b. adding 12g of SBA-15 molecular sieve into the mixed solution, stirring for more than 1 hour, adding ammonia gas as a precipitator for precipitation, filtering after complete precipitation, and drying to obtain a solid mixture;

Example 5:

a. weighing 25g of nickel nitrate and 42g of magnesium nitrate, dissolving in 250g of deionized water, and treating for 2 hours by adopting ultrasonic waves; adding 0.5g of Tween and stirring for 1 hour; adding 65g of a manganese nitrate solution with the mass concentration of 50%, 43g of ferric nitrate and 16g of lanthanum nitrate, and stirring for more than 1 hour to obtain a mixed solution;

b. adding 55g of SBA-15 molecular sieve into the mixed solution, stirring for more than 1 hour, adding ammonia gas as a precipitator for precipitation, filtering after complete precipitation, and drying to obtain a solid mixture;

Example 6:

a. weighing 35g of nickel nitrate and 30g of magnesium nitrate, dissolving in 250g of deionized water, and treating for 2 hours by adopting ultrasonic waves; adding 0.5g of hexadecyl trimethyl ammonium bromide and stirring for 1 hour; adding 115g of a manganese nitrate solution with the mass concentration of 50%, 107g of ferric nitrate and 9.5g of lanthanum nitrate, and stirring for more than 1 hour to obtain a mixed solution;

b. adding 32g of SBA-15 molecular sieve into the mixed solution, stirring for more than 1 hour, adding ammonia gas as a precipitator for precipitation, filtering after complete precipitation, and drying to obtain a solid mixture;

Example 7:

a. weighing 25g of nickel nitrate and 18g of magnesium nitrate, dissolving in 250g of deionized water, and treating for 2 hours by adopting ultrasonic waves; adding 0.5g of Tween and stirring for 1 hour; adding 38g of a manganese nitrate solution with the mass concentration of 50%, 86g of ferric nitrate and 6g of lanthanum nitrate, and stirring for more than 1 hour to obtain a mixed solution;

b. adding 40g of SBA-15 molecular sieve into the mixed solution, stirring for more than 1 hour, adding ammonia gas as a precipitator for precipitation, filtering after complete precipitation, and drying to obtain a solid mixture;

Comparative example:

the structure is the same as example 1, and the difference with example 1 is that the ammonia purification catalyst is prepared according to the following method in sequence:

a. weighing 40g of nickel nitrate, 12g of magnesium nitrate, 195g of manganese nitrate solution with the mass concentration of 50%, 160g of ferric nitrate and 9.5g of lanthanum nitrate, dissolving in 250g of deionized water once, and stirring for more than 1 hour to obtain a mixed solution;

b. adding 12g of MCM-22 molecular sieve into the mixed solution, stirring for more than 1 hour, adding ammonia gas as a precipitator for precipitation, filtering after complete precipitation, and drying to obtain a solid mixture;

The purification method of the comparative example and the examples 1 to 7 of the present invention specifically comprises the following steps:

step 1: high-temperature nitrogen at 380 ℃ enters the adsorption purification tank 1 through the first filter 9 and the first inlet 2, and is pretreated for 10 hours;

step 2: introducing low-concentration hydrogen (2-10%) into the adsorption purification tank 1 at the temperature of 300 ℃ to reduce the ammonia purification catalyst;

and step 3: intermittently introducing high-purity ammonia gas into the adsorption purification tank 1 under the condition that the temperature in the adsorption purification tank 1 is less than 150 ℃ until the temperature in the adsorption purification tank 1 is constant at 30 ℃, and stopping introducing the high-purity ammonia gas;

and 4, step 4: a gas source (ammonia gas to be purified) enters the adsorption tank 1 through the first filter 9 and the first inlet 2,

purified ammonia gas is collected at the outlet of the third filter 11. The purification process is as shown in fig. 2, and the gas source sequentially passes through a first filter, an adsorbent, an ammonia purification catalyst, a second filter, a plasma excitation device and a third filter to obtain a product gas (purified ammonia gas).

The purity of the outlet ammonia gas was analyzed and the results are shown in the following table:

the results show that the ammonia impurities treated by the catalyst of the embodiment of the invention are at least removed to be more than 7N (99.99999%), and the purity and the service life of the ammonia are higher than those of the comparative example.

Claims

1. An ammonia purification apparatus, characterized in that: is provided with an adsorption purification tank (1), the bottom end of the adsorption purification tank (1) is provided with a first inlet (2), the top end is provided with a first outlet (3), an adsorption layer (4) and a catalyst layer (5) are sequentially arranged in the adsorption purification tank (1) from bottom to top, a first outlet (3) of the adsorption purification tank (1) is connected with a second inlet (7) positioned at the lower end of the plasma excitation device (6), a second outlet (8) is arranged at the upper end of the plasma excitation device (6), a first filter (9), a second filter (10) and a third filter (11) are respectively and correspondingly arranged at the first inlet (2), the first outlet (3) and the second outlet (8), the catalyst layer (5) is filled with an ammonia purification catalyst, the ammonia purification catalyst is composed of active components, auxiliaries, a carrier and a binder, and the mass ratio of the active components to the auxiliaries to the carrier to the binder is 5-75: 5-10: 10-55: 5-10, wherein the active components are Ni oxide, Fe oxide and Mn oxide, and the mass ratio is 5-10: 10-40: 5-30; the auxiliary agent is an oxide of Mg and an oxide of La, and the mass ratio of the Mg to the La is 1-8: 1-5, wherein the carrier is a molecular sieve; the catalyst is prepared by the following steps in sequence according to purification:

2. A method for purifying ammonia by using the ammonia purification apparatus of claim 1, characterized by sequentially performing the following steps:

step 1: high-temperature nitrogen at 380-420 ℃ enters the adsorption purification tank (1) through the first filter (9) and the first inlet (2) and is pretreated for 6-12 hours;

step 2: introducing low-concentration hydrogen into the adsorption purification tank (1) at the temperature of 150-400 ℃ to reduce the ammonia purification catalyst;

and step 3: intermittently introducing high-purity ammonia gas into the adsorption purification tank (1) under the condition that the temperature in the adsorption purification tank (1) is less than 150 ℃ until the temperature in the adsorption purification tank (1) is constant at 10-50 ℃, and stopping introducing the high-purity ammonia gas;

and 4, step 4: the ammonia gas to be purified enters the adsorption tank (1) through the first filter (9) and the first inlet (2), and the purified ammonia gas is collected at the outlet of the third filter (11).