CN116606678A - Method of Deashing Raw Coal Using Deep Eutectic Solvent - Google Patents

Abstract

The invention relates to a method for deashing raw coal with a deep eutectic solvent. In the technical scheme, firstly, the hydrogen bond acceptor and the hydrogen bond donor are heated and mixed according to a certain molar ratio to prepare a deep eutectic solvent, and then the raw coal is It is mixed with the prepared deep eutectic solvent according to a certain mass ratio, and the deashing process is carried out. Finally, the treated coal is washed with deionized water by utilizing the property of the deep eutectic solvent that it is easily soluble in water. According to the invention, the ash content of raw coal can be reduced by 9-18%, and the technical scheme is simple to operate, low in cost, and harmless to human body and environment.

Description

Method of Deashing Raw Coal Using Deep Eutectic Solvent

technical field

The invention relates to the technical field of coal chemical industry, in particular to a method for treating raw coal with a deep eutectic solvent, which can reduce the ash content in the raw coal for preparing low-ash coal and clean coal.

Background technique

At present, coal is one of the main energy sources in the world. In the face of increasingly poor oil resources, how to efficiently utilize coal resources has become a hot issue. In my country, particulate pollutants have gradually become the primary pollutant of urban air pollution, and coal combustion in power plants is one of the main sources of pollution. During the combustion of coal, the ash content of coal will turn into fine particles. The surface of these particles is enriched with heavy metal elements, which will cause great harm to the human body and the environment after being discharged into the air, and the ash content of coal will inhibit the transfer of combustion heat. Thereby reducing thermal efficiency, resulting in greatly reduced utilization of coal. Therefore, it is particularly important to carry out the deashing process of coal before utilization.

Currently, some deashing methods being studied are mainly physical and chemical. The physical deashing methods of coal mainly include magnetic separation method, electrostatic separation method and flotation method, etc., which are determined based on the properties of minerals in coal and the physical properties of some coal. The chemical deashing methods of coal mainly include acid method and alkali method, which react the organic components in coal with chemical substances to effectively remove minerals, and then achieve the purpose of reducing ash content. However, the existing technology requires high cost and complicated operation, and most of the chemical reagents used are harmful to the human body and the environment, and are corrosive to instruments and equipment.

Therefore, providing a low-cost, green and environment-friendly raw coal deashing method is of great significance for improving the utilization rate of coal resources.

Contents of the invention

In view of this, the present invention provides a method for deashing raw coal using a deep eutectic solvent, which effectively removes ash in raw coal, reduces production costs, reduces environmental hazards, improves coal quality, and has good economic benefits.

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

The method for deashing raw coal by using a deep eutectic solvent comprises the following steps:

(1) After the raw coal is naturally air-dried for 12-24 hours, the raw coal is crushed to obtain coal powder;

(2) Mix hydrogen bond acceptor and hydrogen bond donor reagents in a certain molar ratio, heat up, and continue stirring to prepare a deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2) in proportion, heat up and keep stirring, then suction filter while it is hot, and wash with deionized water , drying the obtained coal powder.

Preferably, the pulverized raw coal in the step (1) has a particle size of 100-300 μm, and a small particle size increases the contact area between the raw coal and the reagent, improving the processing efficiency and effect.

Preferably, the heating temperature in the step (2) is 70-90° C. until all the solids are melted and the solvent is transparent.

Preferably, the mass ratio of coal powder to deep eutectic solvent in the step (3) is 1:2.

Preferably, in the step (3), the heating temperature is 50-180° C., and the reaction is stirred for 3-5 hours.

Preferably, the step (3) is washed with deionized water until the filtrate is neutral, so as to ensure that the deep eutectic solvent is completely removed.

Preferably, the drying temperature in the step (3) is 50-90° C., and the drying time is 20-24 hours.

Through the above technical solution, compared with the existing technology, the technical solution of the present invention uses the hydrogen bond acceptor and the hydrogen bond donor to prepare the deep eutectic solvent and then deashes the raw coal, and utilizes the affinity of the deep eutectic solvent to The water-based method separates the treated coal from the solvent, so as to achieve the purpose of reducing ash and improving the quality of coal. The method has the advantages of low cost, environmental protection, simple method and process, and realizes good economic and practical benefits.

specific implementation plan

The technical solutions in the embodiments of the present invention are clearly and completely described below. The described embodiments are only some, not all, embodiments of the present invention. Based on the examples in the present invention. All other embodiments made by other people on the premise of no creative development fall within the protection scope of the present invention.

Example 1

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix proline and p-toluenesulfonic acid at a molar ratio of 1:2, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 50°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 9.39%.

Example 2

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix acetamide and p-toluenesulfonic acid at a molar ratio of 1:3, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 50°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 9.92%.

Example 3

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix acetamide and glutaric acid at a molar ratio of 1:2, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 50°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 9.00%.

Example 4

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix choline chloride and p-toluenesulfonic acid at a molar ratio of 1:2, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 50°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 11.65%.

Example 5

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix choline chloride and urea at a molar ratio of 1:2, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 150°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 11.09%.

Example 6

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix choline chloride and ethylene glycol at a molar ratio of 1:2, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 150°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 18.12%.

Example 7

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix choline chloride and p-toluenesulfonic acid at a molar ratio of 1:2, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 150°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 15.97%.

Example 8

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix tetrabutylammonium chloride and p-toluenesulfonic acid at a molar ratio of 1:2, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 150°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 16.26%.

Example 9

The invention provides a method for deashing raw coal using a deep eutectic solvent, comprising the following steps:

(1) After natural air-drying the raw coal for 18 hours, crush the raw coal to a particle size of 200 μm to obtain coal powder;

(2) Mix choline chloride and glycerol at a molar ratio of 1:2, heat up to 80°C after mixing, and continue stirring until no solid remains, and complete the preparation of the deep eutectic solvent;

(3) Add the coal powder obtained in the step (1) into the deep eutectic solvent obtained in the step (2), the mass ratio of the two is 1:2, heat up to 150°C, and continue stirring for 3 hours , suction filtered while it was hot, and washed with deionized water, and the obtained coal powder was dried in a drying oven at 70° C. for 12 hours.

After testing the ash before and after treatment, the ash removal rate reached 17.15%.

The different conditions of embodiment 1-11 and relevant data refer to table 1

Table 1 Relevant conditions and data of Examples 1-11

Example Hydrogen bond acceptor (HBA) Hydrogen Bond Donor (HBD) Mass ratio of HBA to HBD Mass ratio of deep eutectic solvent to coal temperature reflex Deashing rate Example 1 proline p-Toluenesulfonic acid 1:2 1:2 50℃ 9.39% Example 2 Acetamide p-Toluenesulfonic acid 1:3 1:2 50℃ 9.92% Example 3 Acetamide glutaric acid 1:2 1:2 50℃ 9.00% Example 4 Choline chloride p-Toluenesulfonic acid 1:2 1:2 50℃ 11.65% Example 5 Choline chloride urea 1:2 1:2 150°C 11.09% Example 6 Choline chloride ethylene glycol 1:2 1:2 150°C 18.12% Example 7 Choline chloride p-Toluenesulfonic acid 1:2 1:2 150°C 15.97% Example 8 Tetrabutylammonium chloride p-Toluenesulfonic acid 1:2 1:2 150°C 16.26% Example 9 Choline chloride Glycerol 1:2 1:2 150°C 17.15%

According to the data in Table 1, it can be known that the deashing treatment of raw coal according to the treatment method provided by the present invention can remove 9.00%-18.12% of ash in the coal.

According to the data comparison of Examples 1-4 and Examples 5-9, it can be seen that under high temperature conditions, the deep eutectic solvent has a better desulfurization effect on coal.

Through the tests of the above specific embodiments, the hydrogen bond acceptor and hydrogen bond donor reagents used in the technical solution of the present invention are relatively common, low in cost, non-toxic and pollution-free, and have a good deashing effect.

The focus of each embodiment in this specification is mainly on the selection and mixing ratio of hydrogen bond acceptors and hydrogen bond donors in the deep eutectic solvent, and the different mixing temperatures of the deep eutectic solvent and raw coal. Due to the structure and composition of different coal samples Different, the deashing effect of deep eutectic solvents on different coals is quite different, so the same and similar parts in each embodiment can be referred to each other.

It should be understood that the descriptions of the above disclosed embodiments are only for exemplary description. For those skilled in the art, various modifications, equivalent replacements, improvements, etc. can be made to the above-mentioned embodiments, and the general principles defined herein can appear in other embodiments without departing from the spirit and scope of the technical solution. Among the examples. Therefore, the above-mentioned embodiments will not constitute a limitation to the present invention, and the scope of limitation should be the widest range consistent with the principles and innovations disclosed in the technical solution.

Claims (7)

1. The method for deashing raw coal by adopting the eutectic solvent is characterized by comprising the following steps of:

(1) Natural air-drying raw coal for 12-24h, and crushing the raw coal to obtain coal dust;

(2) Mixing a hydrogen bond acceptor and a hydrogen bond donor reagent according to a certain molar ratio, heating to raise the temperature, and continuously stirring to prepare a eutectic solvent;

(3) And (3) adding the pulverized coal obtained in the step (1) into the eutectic solvent obtained in the step (2) in proportion, heating, continuously stirring, filtering while the pulverized coal is hot, washing the pulverized coal with deionized water, and drying the obtained pulverized coal.

2. The method for deashing raw coal using a eutectic solvent according to claim 1, wherein the crushed raw coal in the step (1) has a particle size of 100-300 μm.

3. The method for deashing raw coal using a eutectic solvent according to claim 1, wherein the heating temperature in the step (2) is 70-90 ℃ until the solid is completely melted, and the solvent is transparent.

4. The method for deashing raw coal using a eutectic solvent according to claim 1, wherein the mass ratio of pulverized coal to the eutectic solvent in the step (3) is 1:2.

5. The method for deashing raw coal using a eutectic solvent according to claim 1, wherein the heating temperature in the step (3) is 50-180 ℃, and the reaction is stirred for 3-5 hours.

6. The method for deashing raw coal using eutectic solvents according to claim 1, wherein the step (3) is performed with deionized water until the filtrate is neutral.

7. The method for deashing raw coal using a eutectic solvent according to claim 1, wherein the drying temperature in the step (3) is 50-90 ℃ and the drying time is 20-24 hours.