A catalyst for improving the calorific value of coal, and a preparation method and application thereof

Abstract

The application discloses a catalyst for improving the calorific value of coal and a preparation method and application thereof, and comprises an A agent and a B agent, the A agent comprises titanium oxide, cerium oxide and hydrogen peroxide aqueous solution, and the B agent comprises a biological enzyme aqueous solution which comprises oxidase, cellulase and water. The catalyst, the preparation method and the application thereof are used, after the A agent and the B agent are sprayed on the coal, the nano cerium oxide and the titanium oxide in the A agent can reduce the combustion activation energy in the combustion of the coal by 20-30%, the biological enzyme of the B agent can decompose hydrogen peroxide into water and oxygen, a certain oxygen environment is generated in the internal stack of the coal storage, sterilization and bacteriostasis effects on anaerobic bacteria, methane bacteria and sulfate bacteria existing in the coal are simultaneously generated, the methane bacteria and the sulfate bacteria cannot decompose carbon molecules in the coal, and the overall calorific value of the coal can be increased by about 250-450 kcal under the comprehensive effect of the catalyst materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal-burning catalysts, and in particular relates to a catalyst for improving the calorific value of coal, a preparation method thereof and an application thereof. Background Art

[0002] Although coal's share of total energy consumption is declining, it remains a vital industrial energy source in my country, with total demand showing a growing trend. my country not only produces enough coal to meet its needs, but also imports significant quantities. With increasing coal mining, the storage of coal is susceptible to the presence of naturally occurring anaerobic bacteria, such as methanogens and sulfate bacteria. These bacteria, without the need for oxygen, can break down carbon molecules in the coal to form methane gas, which in turn triggers the production of large quantities of combustible gases, leading to spontaneous combustion in some coal mining areas. Furthermore, post-mining coal also suffers from a continuous loss of calorific value during storage and transportation. This loss is primarily due to the presence of methanogens and sulfate bacteria in the coal. These bacteria break down carbon molecules in an oxygen-free environment, resulting in the formation of methane gas, which evaporates in large quantities upon exposure to air. This not only wastes resources, but also the carbon dioxide and methane emissions from spontaneous combustion have become a major source of greenhouse gas emissions, following industrial emissions. Therefore, the present invention proposes an application of a catalyst and a method for preparing the catalyst that can inhibit the loss of coal calorific value during coal storage and transportation and increase the calorific value of coal. Summary of the Invention

[0003] The purpose of the present invention is to provide a catalyst for increasing the calorific value of coal, and its preparation method and application, so as to solve the problem of calorific value loss caused by the storage and transportation of coal.

[0004] To achieve the above-mentioned object, the present invention provides a catalyst for improving the calorific value of coal, comprising agent A and agent B, wherein agent A comprises titanium oxide, cerium oxide and a hydrogen peroxide aqueous solution, and agent B comprises a biological enzyme aqueous solution, wherein the biological enzyme aqueous solution comprises oxidase, cellulase and water.

[0005] Preferably, the mass ratio of titanium oxide to cerium oxide in agent A is 1:1, the concentration of the hydrogen peroxide aqueous solution is 10-30%, and the content of titanium oxide and cerium oxide added to the hydrogen peroxide aqueous solution is 5-10%.

[0006] Preferably, the titanium oxide is anatase type with a purity of 95% or more.

[0007] Preferably, the purity of cerium oxide is above 95%.

[0008] Preferably, the mass ratio of oxidase to cellulase is 2:1, and the concentration of the biological enzyme aqueous solution is 1-10%.

[0009] Preferably, the oxidase is amino acid oxidase, and the cellulase is endo-β-glucanase.

[0010] A second aspect of the present invention provides a method for preparing a catalyst for increasing the calorific value of coal, comprising the following steps:

[0011] (1) Preparation method of agent A

[0012] The ground titanium oxide and cerium oxide are mixed and added into a furnace for calcination, and then ground again after calcination to obtain a nanoscale main body material, and the formed nanoscale main body material is added into a hydrogen peroxide aqueous solution, mixed and stirred to form agent A;

[0013] (2) Preparation method of agent B

[0014] Add oxidase and cellulase into water to form a biological enzyme aqueous solution, namely agent B.

[0015] Preferably, titanium oxide is first prepared into a particle size of 2500 mesh using a grinder, and then the ground titanium oxide and cerium oxide of 1500 mesh are added to an electric arc furnace and calcined at a high temperature of 1500°C. After calcination, the material is ground again to form a nanoscale main material with a particle size of less than 100 nm.

[0016] A third aspect of the present invention provides an application of a catalyst for increasing the calorific value of coal. The catalyst can be applied in a coal mining process.

[0017] Preferably, the specific application process is: after coal mining, when coal washing and crushing is carried out, when the coal has not yet formed into powder or small and medium-sized particles of coal or coal powder, ash and sulfur are washed in the coal washing plant, and before the conveyor belt enters the crusher and before the coal falls, the catalyst is atomized and sprayed, so that the catalyst and coal are in contact over a large area.

[0018] Preferably, the prepared agent A is diluted 8-10 times with water at a ratio of 2.5-1 / 1000 of the weight of the coal powder, and is sprayed evenly on the coal by pressurized atomization; the prepared agent B is diluted 8-10 times with water at a ratio of 1-2 / 1000 of the weight of the coal powder, and is sprayed evenly on the coal by pressurized atomization. Finally, the coal powder sprayed with agents A and B is left for 15-30 days.

[0019] Therefore, the present invention adopts a catalyst for improving the calorific value of coal using the above structure, and its preparation method and application, which have the following beneficial effects:

[0020] (1) After the agent A and the agent B are sprayed on the coal, the biological enzyme in the agent B can decompose the hydrogen peroxide in the coal into water and oxygen, thereby generating a certain oxygen environment in the coal storage pile, and can simultaneously produce a bactericidal and antibacterial effect on the anaerobic bacteria methane bacteria and sulfate bacteria present in the coal, thereby preventing the methane bacteria and sulfate bacteria from decomposing the carbon molecules of the coal, thereby reducing and inhibiting the calorific value. The oxidase and hydrogen peroxide in the enzyme can simultaneously form an oxygen-rich film on the surface of the coal.

[0021] (2) After the agent A and the agent B are sprayed on the coal, the nano-cerium oxide and titanium oxide in the agent A can reduce the combustion activation energy during the combustion of the coal, reducing the combustion activation energy by 20% to 30%, and the oxygen-rich film formed on the surface of the coal by the biological enzyme has an oxygen-enhancing effect, which can increase and supplement oxygen during combustion, thereby increasing the calorific value of the coal during combustion. Under the combined effect of the above-mentioned catalyst materials, the overall calorific value of the coal can be increased by about 250 to 450 kcal.

[0022] The technical solution of the present invention is further described in detail below through examples. DETAILED DESCRIPTION

[0023] The present invention will be further described below. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and specific operation process, but the present invention is not limited to this embodiment.

[0024] Example 1

[0025] The preparation process of Agent A is as follows: first, titanium oxide is prepared into a particle size of 2500 mesh using a grinder, and then the 2500 mesh titanium oxide and 1500 mesh cerium oxide are added in a ratio of 1:1 into an electric arc furnace, and calcined at a high temperature of 1500 degrees Celsius in the electric furnace. Under the high-temperature calcination condition, a second grinding is performed to form a nano-scale main material with a particle size of less than 100 nanometers. The titanium oxide is preferably anatase type with a purity of more than 95%, and the cerium oxide is preferably with a purity of more than 95%. The formed nano-scale main material is added to a 20% hydrogen peroxide aqueous solution at a ratio of 5% to 10%, and the mixture is mixed and stirred to form Agent A.

[0026] The preparation process of agent B is as follows: amino acid oxidase and cellulase are added to clean water at a ratio of 2:1 to form a 5% biological enzyme aqueous solution, wherein the oxidase is preferably amino acid oxidase and the cellulase is preferably endo-β-glucanase.

[0027] Industrial application methods of catalysts:

[0028] The catalyst is mainly used during coal washing and crushing after coal mining. The specific application method is to spray the catalyst at the coal falling point before the conveyor belt enters the crusher, when the coal has not yet formed into powder or small and medium-sized coal blocks or coal powder, and after washing the ash and sulfur in the coal washing plant. This can effectively bring the catalyst into even contact with the coal over a large area, prompting the catalyst to carry out catalytic and antibacterial reactions on the coal surface.

[0029] The specific spraying process is to dilute the prepared agent A with water at a ratio of 2.5 parts per thousand by 8 times, and spray it evenly on the coal by pressure atomization. Dilute the prepared agent B with water at a ratio of 1 part per thousand by 8 times, and spray it evenly on the coal by pressure atomization.

[0030] Example 2

[0031] The difference from Example 1 is that the specific spraying process is to dilute the prepared agent A by 1 / 1000 with water 10 times, and spray it evenly on the coal by pressure atomization. The prepared agent B is diluted by 10 times with water at a ratio of 2 / 10000, and spray it evenly on the coal by pressure atomization.

[0032] The coal sprayed with Agent A and Agent B (coal with additives) and the coal not sprayed with Agent A and Agent B (coal without additives) in Examples 1 and 2 were allowed to stand for 21 days. The calorific value of the coal sprayed with catalyst and the coal without additives in Examples 1 and 2 was measured in accordance with the national standard GB / T213-2008. The results are shown in Table 1.

[0033] Table 1 Calorific value measurement data of coal with additives and coal without additives

[0034]

[0035] As can be seen from Table 1, compared with the coal without additives after spraying with the agent A and agent B in the present invention, the low calorific value of Example 1 and Example 2 after catalyst spraying is higher, indicating that the catalyst in the present invention can increase the calorific value of coal.

[0036] Example 3

[0037] (1) Coal laboratory test evaluation and analysis:

[0038] Catalysts A and B were added to Shaanxi coal, Neigu coal, and Indonesian coal, respectively. The experimental group, consisting of 20 kg of raw coal, was treated with 2.5 parts per million of Catalyst A and 1 part per million of Catalyst B. The Indonesian coal was sprayed with Catalysts A and B and then left for 15 days, the Neigu coal was sprayed with Catalysts A and B and then left for 30 days, and the Shaanxi coal was sprayed with Catalysts A and B and then left for 20 days. A control group, consisting of 20 kg of raw coal, was not treated with Catalysts A and B and left for 20 days.

[0039] The coal after adding catalyst was sent for testing and measured using oxygen bomb calorimeter according to the international standard (GB / T213-2008). The test results are as follows:

[0040] The calorific value of raw Neigu coal increased from 5529 kcal to 5670 kcal, an increase of 141 kcal;

[0041] The calorific value of Indonesian coal increased from 5486 kcal to 5701 kcal, an increase of 215 kcal;

[0042] The calorific value of raw Shaanxi coal has increased from 4779 kcal to 5210~5342 kcal, an increase of 431~563 kcal.

[0043] From the above results, it can be seen that the catalyst of the present invention has the effect of increasing the calorific value of coal from multiple production areas.

[0044] (2) Evaluation and analysis of actual burning of industrial power plants

[0045] A 220-ton fluidized bed furnace was used to compare the effects of boilers 1 and 2 before and after 5 days of use. The power plant used a mixture of Indonesian coal and domestic coal in a ratio of 7:3. Agent A was added at a ratio of 2.5 parts per million and Agent B at a ratio of 1 part per million, respectively. The mixture was diluted 10 times with water and added to the coal conveyor belt. The test coal was stored for 15 days after adding the catalyst before use. The data before and after use are as follows:

[0046] Use-by date: May 1st to May 8th;

[0047] Use date: May 12 to May 19;

[0048] May 9th to May 11th are not included in the calculation because new and old coal are mixed.

[0049] The test results are shown in Table 2-3 below.

[0050] Table 2 Coal combustion data before adding catalyst

[0051]

[0052]

[0053] Table 3 Coal combustion data after adding catalyst

[0054]

[0055] From Table 3 and Table 4, it can be seen that for No. 1-8, the average coal consumption per ton of steam was 133.6 kg without using the catalyst, while for No. 12-18, the average coal consumption per ton of steam was 128.49 kg after using the catalyst. Compared with before and after using the catalyst, the coal saving was 3.82%.

[0056] Comparative Example 1

[0057] The difference from Example 1 is that the titanium oxide in Catalyst A is removed and replaced with the same amount of cerium oxide.

[0058] Comparative Example 2

[0059] The difference from Example 1 is that the cerium oxide in Catalyst A is removed and replaced with the same amount of titanium oxide.

[0060] Comparative Example 3

[0061] The difference from Example 1 is that the amino acid oxidase in catalyst B is replaced by glucose oxidase.

[0062] Comparative Example 4

[0063] The difference from Example 1 is that the endo-β-glucanase in the catalyst B is replaced by the C1 enzyme.

[0064] Comparative Example 5

[0065] The difference from Example 1 is that only Agent A is sprayed on the coal.

[0066] Comparative Example 6

[0067] The difference from Example 1 is that only agent B is sprayed on the coal.

[0068] The calorific value of the additive coal in Comparative Examples 1-6 was measured using the same method as in Example 1. The measurement results are shown in Table 4.

[0069] Table 4 Calorific value determination results of comparative examples 1-6

[0070] Lower calorific value (cal / g) No additive coal 4779 Example 1 5210 Comparative Example 1 5000 Comparative Example 2 4996 Comparative Example 3 5007 Comparative Example 4 4979 Comparative Example 5 4930 Comparative Example 6 4904

[0071] It can be seen from Table 4 that the agent A and the agent B in the present invention have a synergistic effect, which jointly increases the calorific value of the unadulterated coal and solves the problem of calorific value loss during coal transportation and storage.

[0072] Therefore, the present invention adopts a catalyst having the above structure for increasing the calorific value of coal, as well as its preparation method and application. After agent A and agent B are sprayed on the coal, the nano-cerium oxide and titanium oxide in agent A can reduce the combustion activation energy during coal combustion by 20% to 30%. The biological enzyme in agent B can decompose hydrogen peroxide in the coal into water and oxygen, creating a certain oxygen environment in the coal storage pile. It can simultaneously produce a bactericidal and antibacterial effect on the anaerobic methane bacteria and sulfate bacteria present in the coal, thereby preventing the methane bacteria and sulfate bacteria from decomposing the carbon molecules of the coal. Under the combined action of the above catalyst materials, the overall calorific value of the coal can be increased by about 250 to 450 kcal.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A catalyst for increasing the calorific value of coal, characterized in that The method comprises an agent A and an agent B, wherein the agent A comprises titanium oxide, cerium oxide and a hydrogen peroxide aqueous solution, and the agent B comprises a biological enzyme aqueous solution, wherein the biological enzyme aqueous solution comprises oxidase, cellulase and water; The mass ratio of titanium oxide to cerium oxide in agent A is 1:1, the concentration of the hydrogen peroxide aqueous solution is 10-30%, and the content of titanium oxide and cerium oxide added to the hydrogen peroxide aqueous solution is 5-10%; The mass ratio of oxidase to cellulase is 2:1, and the concentration of the biological enzyme aqueous solution is 1-10%; The oxidase is amino acid oxidase, and the cellulase is endo-β-glucanase; The preparation method of Agent A comprises grinding titanium oxide into a particle size of 2500 mesh, adding cerium oxide of 1500 mesh, adding the mixture into an electric arc furnace, calcining the mixture at a high temperature of 1500° C., and then grinding the mixture again under the high temperature calcination condition to form a nanoscale main material with a particle size of less than 100 nanometers. The nanoscale main material is added into a hydrogen peroxide aqueous solution, and the mixture is mixed and stirred to form Agent A. The preparation method of Agent B comprises the following steps: adding amino acid oxidase and cellulase into clean water to form a biological enzyme aqueous solution, namely Agent B.

2. The use of a catalyst for increasing the calorific value of coal according to claim 1, characterized in that: Catalysts can be used in coal mining processes.

3. The use of a catalyst for increasing the calorific value of coal according to claim 2, characterized in that: The specific application process is: after coal mining, when coal washing and crushing is carried out, when the coal has not yet formed into powder or small and medium-sized particles of coal or coal powder, ash and sulfur are washed in the coal washing plant, and before the conveyor belt enters the crusher and before the coal falls, the catalyst is atomized and sprayed, so that the catalyst and coal are in contact over a large area.

4. The use of a catalyst for increasing the calorific value of coal according to claim 3, characterized in that: The prepared agent A is diluted 8-10 times with water at a ratio of 2.5-1 / 1000 of the weight of the coal powder, and is sprayed evenly on the coal by pressurized atomization; the prepared agent B is diluted 8-10 times with water at a ratio of 1-2 / 1000 of the weight of the coal powder, and is sprayed evenly on the coal by pressurized atomization. Finally, the coal powder sprayed with agents A and B is left for 15-30 days.

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