CN104910366B - Organic quicklime composite desiccant and preparation method therefor - Google Patents

Abstract

The present invention relates to the field of desiccant preparation, and discloses an organic quicklime composite desiccant, which is in the form of granules and is formed by agglomerating particles with a core-shell structure. The core material of the particles is quicklime, and the outer shell material of the particles is polymerized Polyethylene oxide on the surface of quicklime particles; the particle size of the desiccant is between 2-5mm. The preparation method of the organic quicklime composite desiccant is as follows: A), purging the high-temperature and high-pressure reactor with nitrogen, adding quicklime and potassium hydroxide and stirring; B), adding ethylene oxide, and heating and stirring the reactor with nitrogen , circulating cold water in the reactor to dissipate heat; C), after the reaction is completed, the product obtained is taken out and cooled to obtain the organic quicklime composite desiccant. The organic quicklime composite desiccant of the invention has good hygroscopic effect, moderate reaction after absorbing water, and good safety. The desiccant prepared by the method of the invention has good parameter uniformity, simple process, low cost and is suitable for large-scale production.

Description

Organic quicklime composite desiccant and preparation method thereof

technical field

The invention relates to the field of desiccant preparation, in particular to an organic quicklime composite desiccant and a preparation method thereof.

Background technique

Quicklime, mainly composed of calcium oxide, chemical formula CaO, is a common inorganic compound; it is usually heated to 500–600°C by a substance containing calcium carbonate to decompose it into calcium oxide and carbon dioxide. The shape is white and amorphous. Widely used in desiccants. Used in iron and steel, pesticides, medicines, desiccants, tanning and alcohol dehydration, etc. Quicklime generally contains burnt lime, burnt lime is slow to slaking, if slaking occurs after the lime slurry is hardened, it will be swollen due to the expansion of slaking Cause swelling and cracking. Quicklime reacts chemically with water, and it is immediately heated to a high temperature exceeding 300°C.

Since calcium oxide has a very high reactivity with water (hydration reaction), calcium hydroxide is formed, which has an excellent water absorption effect, so it is an excellent desiccant raw material. However, the hydration reaction of calcium oxide will exotherm rapidly, and the high reactivity and uncontrollable heat generation of the hydration reaction often cause explosions and fires during storage.

Ultra-high molecular weight polyethylene oxide, also known as polyoxyethylene, has more hydroxyl groups, good water solubility, good hygroscopicity, can undergo esterification reaction, and is easy to associate with electron acceptor groups or autoxidation. Polyethylene oxide can be polymerized by heterogeneous catalysis, and the catalysts are carbonates, alkaline earth metal oxides, alkyl zinc, hydrates of iron halides, etc.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides an organic quicklime composite desiccant and its preparation method. The desiccant prepared by the present invention overcomes the shortcoming that quicklime reacts more violently when it absorbs water and dries without affecting the hygroscopic performance of quicklime. . In the preparation of the desiccant, quicklime is used as a catalyst to polymerize hydrophilic ultra-high molecular weight polyethylene oxide molecules on the surface of quicklime. The invention adopts quicklime as the main component, has low cost, simple preparation method and is suitable for large-scale production.

The specific technical scheme of the present invention is: an organic quicklime composite desiccant, which is in the form of granules. The desiccant is formed by agglomerating particles with a core-shell structure. It is polyethylene oxide polymerized on the surface of the quicklime particle; the particle size of the desiccant is between 2-5mm.

In the organic quicklime composite desiccant of the present invention, the surface of the quicklime powder is polymerized with a layer of polyethylene oxide shell to form a particle with a core-shell structure. Due to the viscosity of polyethylene oxide, a large number of particles are agglomerated into granules Particles with a diameter of 2-5mm.

The advantage of this structure is that polyethylene oxide itself has good water absorption. When polyethylene oxide is coated on the surface of quicklime, the moisture in the air cannot be directly absorbed by quicklime, and it needs to be absorbed by the polyethylene ring first. Oxyethane is absorbed and then transferred to the quicklime inside. Since the water is slowly transferred to the quicklime, the reaction speed between the quicklime and water is slowed down, and a large amount of heat is avoided due to the rapid reaction between the quicklime and a large amount of water. The influence of the outside world is small and the security is good.

At the same time, due to the regular structure and high crystallinity of ultra-high molecular weight polyethylene oxide, the tensile strength of polyethylene oxide is close to that of medium-density polyethylene. When coated on the surface of quicklime, it can prevent the violent reaction of quicklime It also has better protection against explosion, which further improves safety.

In addition, compared with the single quicklime water-absorbing material, since the desiccant of the present invention is composed of quicklime and polyethylene oxide, the water-absorbing performance is also improved to a certain extent.

Preferably, the relative molecular weight of the polyethylene oxide is between 500,000-2,000,000.

A preparation method of an organic quicklime composite desiccant, comprising the steps of:

A), purging the high temperature and high pressure reactor with nitrogen, after the air in the high temperature and high pressure reactor is removed, adding quicklime powder and potassium hydroxide powder into the high temperature and high pressure reactor and stirring.

B), pressurized ethylene oxide is liquefied with a pressurized storage tank, nitrogen is passed into the pressurized storage tank so that the ethylene oxide is extruded and charged into a high-temperature and high-pressure reaction kettle, under a nitrogen atmosphere Heat and stir the material in the high-temperature and high-pressure reactor, and circulate cold water in the high-temperature and high-pressure reactor to dissipate heat; the mass ratio of the quicklime powder to ethylene oxide is 100: (3-10), and the ethylene oxide The mass ratio of potassium hydroxide to potassium hydroxide is 100:(3-7); the air pressure in the high-temperature and high-pressure reactor is 0.2-0.6MPa, the temperature is 120-210°C, and the reaction time is 2-5h, wherein the reaction process is divided into There are three stages, the first stage is the reaction between 0-0.5h, the stirring rate is 500-750r/min, the second stage is 0.5-1.5 hours, the stirring rate is 300-500r/min, the third stage is the remaining reaction time, the stirring rate is 150-300r/min.

Ethylene oxide is easy to react violently with air, and the safety can be ensured by removing the air in the high-temperature and high-pressure reactor and polymerizing under nitrogen atmosphere.

C), after the reaction is completed, the obtained product is taken out and cooled to obtain the organic quicklime composite desiccant.

In the method of the present invention, quicklime is used as a catalyst, and at the same time it is the carrier of the reaction. Under the catalysis of quicklime and potassium hydroxide, ethylene oxide is adsorbed on the surface of quicklime particles and polymerized to generate polyethylene oxide. , The polyethylene oxide combined on different quicklime particles agglomerates with each other, so that a large number of quicklime particles also agglomerate to form granules. Strictly controlling the reaction conditions during the reaction, especially controlling the stirring rate in stages, is beneficial to the uniformity of the molecular weight of the generated polyethylene oxide and the uniformity of the particle size of the final product. The polyethylene oxide prepared by the method of the invention has regular structure, high crystallinity, high tensile strength, good water absorption and good binding force with quicklime.

The present invention selects quicklime from a wide range of sources as the main component, and has low cost; the process of the present invention is simple and suitable for large-scale production.

As preferably, the quicklime powder is passed through a 80-200 mesh sieve

Preferably, the air pressure in the high-temperature and high-pressure reactor is 0.3 MPa, the temperature is 130° C., and the reaction time is 3 hours.

Preferably, the mass usage ratio of the quicklime powder to ethylene oxide is 100:5, and the mass usage ratio of ethylene oxide to potassium hydroxide is 100:5.

As a preference, in the three reaction stages of the step (B), the stirring rate of each reaction stage is gradually reduced at a uniform speed.

Compared with the prior art, the beneficial effect of the present invention is that the organic quicklime composite desiccant of the present invention has good hygroscopic effect, moderate reaction after absorbing water, and good safety. The desiccant prepared by the method of the invention has good parameter uniformity, simple process, low cost and is suitable for large-scale production.

detailed description

The present invention will be further described below in conjunction with embodiment.

Example 1

A preparation method of an organic quicklime composite desiccant, comprising the steps of:

A), purging the high-temperature and high-pressure reactor with nitrogen, after the air in the high-temperature and high-pressure reactor is removed, get 100 parts of quicklime powder and 0.25 part of potassium hydroxide powder to be added to the high-temperature and high-pressure reactor Stir in;

B), ethylene oxide is pressurized and liquefied with a pressurized storage tank, nitrogen is passed into the pressurized storage tank so that 5 parts of ethylene oxide are extruded and charged into a high-temperature and high-pressure reactor, and nitrogen is passed The material in the high-temperature and high-pressure reactor is heated and stirred under the atmosphere, and the cold water is circulated in the high-temperature and high-pressure reactor to dissipate heat. The air pressure in the high-temperature and high-pressure reactor is 0.3MPa, the temperature is 130°C, and the reaction time is 3h, wherein the reaction process is divided into three stages, the first stage is between 0-0.5h of reaction, and the stirring rate is 500-750r /min, the second stage is 0.5-1.5 hours, the stirring rate is 300-500r/min, the third stage is 1.5-3h, the stirring rate is 150-300r/min.

C), after the reaction is completed, the obtained product is taken out and cooled to obtain the organic quicklime composite desiccant.

The organic quicklime composite desiccant prepared above is in the form of granules, and the desiccant is formed by agglomerating particles with a core-shell structure, the core material of the particles is quicklime, and the shell material of the particles is aggregated on the surface of the quicklime particles of polyethylene oxide. The particle diameter of the desiccant is about 3 mm, and the relative molecular weight of the polyethylene oxide is about 800,000-1,300,000.

The organic quicklime composite desiccant prepared in this example has a moisture absorption of about 33%, which is slightly higher than that of quicklime with a moisture absorption of about 30%, and the alkalinity is 27% lower than that of quicklime. About 28% lower than quicklime.

Example 2

A preparation method of an organic quicklime composite desiccant, comprising the steps of:

A), purging the high-temperature and high-pressure reactor with nitrogen, after the air in the high-temperature and high-pressure reactor is excluded, get 100 parts of quicklime powder and 0.7 part of potassium hydroxide powder to be added to the high-temperature and high-pressure reactor Stir in.

B), ethylene oxide is pressurized and liquefied with a pressurized storage tank, nitrogen is passed into the pressurized storage tank so that 10 parts of ethylene oxide are extruded and charged into a high-temperature and high-pressure reactor, and nitrogen is passed The material in the high-temperature and high-pressure reactor is heated and stirred under the atmosphere, and the cold water is circulated in the high-temperature and high-pressure reactor to dissipate heat. The air pressure in the high temperature and high pressure reactor is 0.6MPa, the temperature is 120°C, and the reaction time is 5h. The reaction process is divided into three stages, the first stage is between 0-0.5h, the stirring rate is 500-750r/min, the second stage is 0.5-1.5 hours, the stirring rate is 300-500r/min, the third The stage is 1.5-5h, and the stirring rate is 150-300r/min; and the stirring rate of each reaction stage gradually decreases at a uniform speed.

C), after the reaction is completed, the obtained product is taken out and cooled to obtain the organic quicklime composite desiccant.

The organic quicklime composite desiccant prepared above is in the form of granules, and the desiccant is formed by agglomerating particles with a core-shell structure, the core material of the particles is quicklime, and the shell material of the particles is aggregated on the surface of the quicklime particles of polyethylene oxide. The particle diameter of the desiccant is about 5 mm, and the relative molecular weight of the polyethylene oxide is about 500,000-1,000,000.

The moisture absorption of the organic quicklime composite desiccant prepared in this example is about 31%, which is slightly higher than that of quicklime with a moisture absorption of about 30%, and the alkalinity is 23% lower than that of quicklime. About 24% lower than quicklime.

Example 3

A preparation method of an organic quicklime composite desiccant, comprising the steps of:

A), purging the high-temperature and high-pressure reactor with nitrogen, after the air in the high-temperature and high-pressure reactor is excluded, get 100 parts of quicklime powder and 0.21 part of potassium hydroxide powder to be added to the high-temperature and high-pressure reactor Stir in.

B), ethylene oxide is liquefied under pressure with a pressurized storage tank, and nitrogen is passed into the pressurized storage tank so that 3 parts of ethylene oxide are extruded and charged into a high-temperature and high-pressure reactor, and nitrogen is passed The materials in the high-temperature and high-pressure reactor are heated and stirred under the atmosphere, and the circulating cold water is passed through the high-temperature and high-pressure reactor to dissipate heat. The air pressure in the high temperature and high pressure reactor is 0.2MPa, the temperature is 210°C, and the reaction time is 2h. The reaction process is divided into three stages, the first stage is between 0-0.5h, the stirring rate is 500-750r/min, the second stage is 0.5-1.5 hours, the stirring rate is 300-500r/min, the third The stage is 1.5-2h, and the stirring rate is 150-300r/min; and the stirring rate of each reaction stage gradually decreases at a uniform speed.

C), after the reaction is completed, the obtained product is taken out and cooled to obtain the organic quicklime composite desiccant.

The organic quicklime composite desiccant prepared above is in the form of granules, and the desiccant is formed by agglomerating particles with a core-shell structure, the core material of the particles is quicklime, and the shell material of the particles is aggregated on the surface of the quicklime particles of polyethylene oxide. The particle diameter of the desiccant is about 2 mm, and the relative molecular weight of the polyethylene oxide is about 1,000,000-1,500,000.

The moisture absorption of the organic quicklime composite desiccant prepared in this example is about 34%, which is slightly higher than that of quicklime with a moisture absorption of about 30%, and the alkalinity is 30% lower than that of quicklime. About 29% lower than quicklime.

Example 4

A preparation method of an organic quicklime composite desiccant, comprising the steps of:

A), purging the high-temperature and high-pressure reactor with nitrogen, after the air in the high-temperature and high-pressure reactor is excluded, get 100 parts of quicklime powder and 0.15 part of potassium hydroxide powder to be added to the high-temperature and high-pressure reactor Stir in.

B), ethylene oxide is liquefied under pressure with a pressurized storage tank, nitrogen is passed into the pressurized storage tank so that 5 parts of ethylene oxide are extruded and charged into a high-temperature and high-pressure reactor, and nitrogen is passed The materials in the high-temperature and high-pressure reactor are heated and stirred under the atmosphere, and the circulating cold water is passed through the high-temperature and high-pressure reactor to dissipate heat. The air pressure in the high-temperature and high-pressure reactor is 0.4 MPa, the temperature is 150° C., and the reaction time is 4 hours. The reaction process is divided into three stages, the first stage is between 0-0.5h, the stirring rate is 500-750r/min, the second stage is 0.5-1.5 hours, the stirring rate is 300-500r/min, the third The stage is 1.5-4h, and the stirring rate is 150-300r/min; and the stirring rate of each reaction stage gradually decreases at a uniform speed.

C), after the reaction is completed, the obtained product is taken out and cooled to obtain the organic quicklime composite desiccant.

The organic quicklime composite desiccant prepared above is in the form of granules, and the desiccant is formed by agglomerating particles with a core-shell structure, the core material of the particles is quicklime, and the shell material of the particles is aggregated on the surface of the quicklime particles of polyethylene oxide. The particle diameter of the desiccant is about 3 mm, and the relative molecular weight of the polyethylene oxide is about 800,000-1,200,000.

The moisture absorption of the organic quicklime composite desiccant prepared in this example is about 32%, which is slightly higher than that of quicklime with a moisture absorption of about 30%, and the alkalinity is 28% lower than that of quicklime. About 28% lower than quicklime.

Example 5

A preparation method of an organic quicklime composite desiccant, comprising the steps of:

A), purging the high-temperature and high-pressure reactor with nitrogen, after the air in the high-temperature and high-pressure reactor is removed, get 100 parts of quicklime powder and 0.4 part of potassium hydroxide powder to be added to the high-temperature and high-pressure reactor Stir in.

B), ethylene oxide is pressurized and liquefied with a pressurized storage tank, and nitrogen gas is passed into the pressurized storage tank so that 8 parts of ethylene oxide are extruded and charged into a high-temperature and high-pressure reactor, and nitrogen gas is passed The materials in the high-temperature and high-pressure reactor are heated and stirred under the atmosphere, and the circulating cold water is passed through the high-temperature and high-pressure reactor to dissipate heat. The air pressure in the high temperature and high pressure reactor is 0.3MPa, the temperature is 180°C, and the reaction time is 3h. The reaction process is divided into three stages, the first stage is between 0-0.5h, the stirring rate is 500-750r/min, the second stage is 0.5-1.5 hours, the stirring rate is 300-500r/min, the third The stage is 1.5-3h, and the stirring rate is 150-300r/min; and the stirring rate of each reaction stage gradually decreases at a uniform speed.

C), after the reaction is completed, the obtained product is taken out and cooled to obtain the organic quicklime composite desiccant.

The organic quicklime composite desiccant prepared above is in the form of granules, and the desiccant is formed by agglomerating particles with a core-shell structure, the core material of the particles is quicklime, and the shell material of the particles is aggregated on the surface of the quicklime particles of polyethylene oxide. The particle diameter of the desiccant is about 2 mm, and the relative molecular weight of the polyethylene oxide is about 1,300,000-2,000,000.

The organic quicklime composite desiccant prepared in this example has a moisture absorption of about 34%, which is slightly higher than that of quicklime with a moisture absorption of about 30%, and the alkalinity is 28% lower than that of quicklime. About 25% lower than quicklime.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any way. All simple modifications, changes and equivalent transformations made to the above embodiments according to the technical essence of the present invention still belong to the technical solution of the present invention. scope of protection.

Claims (7)

1. a kind of organic quick lime composite drying agent, is in granular form, it is characterised in that the desiccant is by with nucleocapsid structure Particle agglomeration form, the core material of the microgranule is quick lime, and the sheathing material of microgranule is micro- to be aggregated in the quick lime The poly(ethylene oxide) on grain surface；The particle diameter of the desiccant is between 2-5mm.

2. organic quick lime composite drying agent as claimed in claim 1, it is characterised in that relative point of the poly(ethylene oxide) Son amount is between 500000-2000000.

3. a kind of preparation method of organic quick lime composite drying agent, it is characterised in that comprise the steps：

A), with nitrogen to purging in high-temperature high-pressure reaction kettle, after in the high-temperature high-pressure reaction kettle, air is excluded, will be raw Lime powder and potassium hydroxide powder are stirred in being added to high-temperature high-pressure reaction kettle；

B it is), oxirane is pressurized liquefied with pressurized storage tank, lead to nitrogen into the pressurized storage tank so as to by oxirane Extrude and fill and be added in high-temperature high-pressure reaction kettle, under logical nitrogen atmosphere to high-temperature high-pressure reaction kettle in material carry out heating and stir Mix, and lead to circulating water in high-temperature high-pressure reaction kettle and radiated；The quality of the quick lime powder and oxirane is used Amount is than being 100:（3-10）, oxirane is 100 with the quality amount ratio of potassium hydroxide:（3-7）；The high-temperature high-pressure reaction kettle Interior air pressure is 0.2-0.6MPa, and temperature is 120-210 DEG C, and the response time is 2-5h, and wherein course of reaction is divided into three phases, First stage is for, between reaction 0-0.5h, stir speed (S.S.) is 500-750r/min, and second stage is 0.5-1.5 hours, stirs speed Rate is 300-500r/min, and the phase III is the remaining response time, and stir speed (S.S.) is 150-300r/min；

C), after completion of the reaction, the product of gained is taken out and is cooled down, that is, organic quick lime composite drying agent is obtained.

4. the preparation method of organic quick lime composite drying agent as claimed in claim 3, it is characterised in that the calcium lime powder 80-200 mesh sieves are crossed at end.

5. the preparation method of organic quick lime composite drying agent as claimed in claim 3, it is characterised in that the High Temperature High Pressure Air pressure in reactor is 0.3MPa, and temperature is 130 DEG C, and the response time is 3h.

6. the preparation method of organic quick lime composite drying agent as claimed in claim 3, it is characterised in that the calcium lime powder End is 100 with the quality amount ratio of oxirane:5, oxirane is 100 with the quality amount ratio of potassium hydroxide:5.

7. the preparation method of organic quick lime composite drying agent as claimed in claim 3, it is characterised in that in the step (B), in three stages of reaction, the stir speed (S.S.) of the respective stage of reaction is progressively at the uniform velocity reduced.