A kind of coal desulfurization additive and preparation method thereof

Abstract

The present invention provides a coal sulfur-fixing additive and a preparation method thereof. The coal sulfur-fixing additive provided by the present invention comprises the following components by weight: 5-6 parts of calcium oxide, 3-5 parts of sodium carbonate and 1-2 parts of manganese dioxide. The sulfur-fixing additive is mixed with raw coal in a weight percentage of 90-95% of raw coal and 5-10% of the sulfur-fixing additive, and then placed in an inert atmosphere for heating and pyrolysis, with a heating rate of 10°C / min and a termination temperature of 900°C, and then directly burned after obtaining semi-coke to achieve sulfur-fixing and emission reduction during combustion. The coal sulfur-fixing additive of the present invention can significantly reduce the release of sulfur oxides, and can significantly improve the high-temperature sulfur-fixing effect of the sulfur-fixing agent and the thermal efficiency of coal combustion, and has great prospects for promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of coal desulfurization agents, and in particular relates to a coal desulfurization additive and a preparation method thereof. Background Art

[0002] The continuous development of the world's industry has led to an increasing demand for energy. China has rich coal resources and a long history of coal development. However, the development and utilization of coal has brought about a series of environmental pollution problems, seriously damaging the environment on which human beings depend for survival. Among the environmental pollutants caused by the large-scale use of coal, SO2 and NO x The pollution is the most serious, which has toxic side effects on the environment and human body, and causes certain losses to my country's economy. In order to solve this problem, a variety of desulfurization technologies have emerged in the industry. In the new era of increasingly stringent environmental protection requirements and increasingly improved energy optimization, the standards for the treatment of coal-fired flue gas pollutants are more stringent. At present, industrial coal combustion has achieved "near zero emissions".

[0003] The energy structure of rich coal, poor oil and little gas means that my country will continue to use coal as the main energy source for a long time in the future. The direct combustion of coal is an important cause of environmental problems such as haze and acid rain. At present, my country's high-quality coal resources have been consumed in large quantities in the past few decades of mining, while high-sulfur coal with a low degree of coalification has abundant reserves. If the abundant low-grade high-sulfur coal can be used cleanly, the current environmental pollution and energy shortage problems can be effectively alleviated.

[0004] The desulfurization technologies used in industry mainly include pre-combustion desulfurization, in-furnace desulfurization and post-combustion flue gas desulfurization. In-furnace desulfurization technology is to add a sulfur-fixing agent in the furnace so that the sulfur dioxide produced during the combustion of coal directly reacts with the sulfur-fixing agent and is solidified, thereby achieving the effect of reducing the release of sulfur dioxide. However, for a long time, domestic coal-saving agents, sulfur-fixing agents, combustion-aiding agents and other products have been difficult to promote in large quantities due to their high prices and single product performance. Some products have a sulfur-fixing effect, but the increased cost is very high, which is difficult for enterprises to accept.

[0005] On the other hand, briquette technology is an important technology for clean and efficient utilization of coal. Encouraging the use of civilian clean fuels and briquette and reducing the scattered burning of civilian bituminous coal is an important measure to control air pollution. However, the desulfurization agents used in briquette products on the market generally have poor high-temperature desulfurization effects and reduce the combustion performance of briquette, which has caused a certain waste of resources.

[0006] There are two main ways to improve the desulfurization effect: one is to increase the utilization rate of the desulfurizer; the other is to improve the combustion technology. Therefore, under certain combustion conditions, enhancing the high-temperature desulfurization effect of the desulfurizer and improving the thermal efficiency of the briquette is an effective way.

[0007] In addition, the winter in northern my country is cold, and the vast rural areas are restricted by various economic, geographical and other conditions, making it difficult to achieve centralized heating. They mainly rely on individual households to burn scattered coal to survive the winter, which causes great environmental pollution. If high-sulfur coal and sulfur-fixing agent are first concentrated and co-pyrolyzed to obtain semi-coke with good combustion and sulfur-fixing performance, and then these semi-cokes are used for individual heating, it will be able to effectively deal with environmental pollution problems, and also realize the national energy strategy of using coal according to quality and distributing it according to demand. In addition, the small amount of sulfur-containing gas released during the pyrolysis process can be combined with flue gas sulfur fixation to further reduce sulfur-containing gas emissions.

[0008] Among coal desulfurizers, calcium-based desulfurizers are cheap and easy to obtain, and are currently the most studied type of desulfurizers. However, single calcium-based desulfurizers have problems such as low calcium utilization. Therefore, whether a calcium-based desulfurizer with good desulfurization effect can be provided to reduce the release of sulfur oxides, and can significantly improve the high-temperature desulfurization effect of the desulfurizer and improve the thermal efficiency of coal combustion has become a technical problem to be solved in this field. Summary of the invention

[0009] The purpose of the present invention is to solve the above technical problems, thereby providing a coal desulfurization additive and a preparation method thereof. The present invention provides a calcium-based desulfurization agent with good desulfurization effect, which can significantly reduce the release of sulfur oxides, and can significantly improve the high-temperature desulfurization effect of the desulfurization agent and improve the thermal efficiency of coal combustion, and has great prospects for promotion and application.

[0010] One of the purposes of the present invention is to provide a coal desulfurization additive, which comprises the following components by weight: 5-6 parts of calcium oxide, 3-5 parts of sodium carbonate and 1-2 parts of manganese dioxide.

[0011] As a preferred solution, the desulfurization additive includes the following components by weight: 5.4 parts of calcium oxide, 3.6 parts of sodium carbonate and 1.2 parts of manganese dioxide.

[0012] Furthermore, the amount of the desulfurization additive added to the raw coal is 5-10% by mass.

[0013] As a preferred solution, the amount of the desulfurization additive added to the raw coal is 9% by mass.

[0014] The second object of the present invention is to provide a clean coal containing the above-mentioned sulfur-fixing additive. The clean coal comprises the following components by weight percentage: 90-95% of raw coal and 5-10% of the sulfur-fixing additive.

[0015] The third object of the present invention is to provide a method for preparing the above-mentioned coal desulfurization additive, which is prepared by mixing the components of the desulfurization additive, namely, calcium oxide, sodium carbonate and manganese dioxide.

[0016] The fourth object of the present invention is to provide an application of the coal desulfurization additive as described above, which is to mix the desulfurization additive with raw coal, place it in an inert atmosphere for pyrolysis at a heating rate of 10°C / min and an end temperature of 900°C, obtain semi-coke and burn it directly to achieve desulfurization emission reduction during the combustion process.

[0017] The beneficial effects of the present invention are as follows:

[0018] The preparation method of the sulfur-fixing additive of the present invention is simple and the cost is low. The sulfur-containing gas can be collected once in a centralized manner during the pyrolysis process. The added calcium oxide, sodium carbonate and manganese dioxide can play a good synergistic role under the optimal ratio, thereby achieving sulfur fixation and emission reduction during the combustion process. The sulfur-fixing additive of the present invention has a good sulfur-fixing effect not only on anthracite with good coal quality, but also on low-priced high-sulfur coal. In addition, the added carbon sulfur-fixing additive can also promote the combustion of coal and improve its combustion efficiency. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described in detail below in conjunction with the embodiments. It is necessary to point out that the following embodiments are only used to explain and illustrate the present invention and are not used to limit the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content still belong to the protection scope of the present invention.

[0020] Example 1

[0021] The components are fully mixed to form a sulfur-fixing additive, wherein the weight portion of calcium oxide in the sulfur-fixing additive is 5.4 parts, the weight portion of sodium carbonate is 3.6 parts, and the weight portion of manganese dioxide is 1.2 parts. The sulfur-fixing additive and raw coal are combined into a combustion sample (9% additive and 91% raw coal by weight), and the obtained sample is placed in an inert atmosphere for heating and pyrolysis, with a heating rate of 10°C / min and a final temperature of 900°C, and the obtained semi-coke is directly burned.

[0022] Example 2

[0023] The components are fully mixed to form a sulfur-fixing additive, wherein the weight portion of calcium oxide in the sulfur-fixing additive is 5 parts, the weight portion of sodium carbonate is 3 parts, and the weight portion of manganese dioxide is 1 part. The sulfur-fixing additive and raw coal are combined into a combustion sample (the weight percentage is 10% additive and 90% raw coal), and the obtained sample is placed in an inert atmosphere for heating and pyrolysis, the heating rate is 10°C / min, the final temperature is 900°C, and the obtained semi-coke is directly burned.

[0024] Example 3

[0025] The components are fully mixed to form a sulfur-fixing additive, wherein the weight proportion of calcium oxide in the sulfur-fixing additive is 6 parts, the weight proportion of sodium carbonate is 5 parts, and the weight proportion of manganese dioxide is 2 parts. The sulfur-fixing additive and raw coal are combined into a combustion sample (the weight percentage is 5% additive and 95% raw coal), and the obtained sample is placed in an inert atmosphere for heating and pyrolysis, the heating rate is 10°C / min, the final temperature is 900°C, and the obtained semi-coke is directly burned.

[0026] Application Example 1

[0027] The sulfur-fixing additive in Example 1 and the Ordos high-sulfur coal (the total sulfur content of the Ordos high-sulfur coal is 3.02%, the ash content is 31.85%, the volatile matter is 15.86%, and the calorific value is 20.26MJ / kg) are mixed in a weight percentage of 9% sulfur-fixing additive and 91% Ordos high-sulfur coal, and then placed on a shaking table, heated and pyrolyzed under an inert atmosphere, with a heating rate of 10°C / min and a final temperature of 900°C, and the obtained semi-coke is directly burned. The pyrolysis sulfur-fixing rate of the mixed coal sample is measured to be 88.65%, and the combustion sulfur-fixing rate is 87.05% (the determination method of the sulfur-fixing rate refers to the determination method of the sulfur-fixing rate of modified clean coal in DB37 / T 4021-2020, the same below).

[0028] Application Example 2

[0029] The sulfur-fixing additive in Example 2 was mixed with Yangquan coal (the total sulfur content in Yangquan coal was 2.11%, the ash content was 18.96%, the volatile content was 5.87%, and the calorific value was 25.54MJ / kg) in a weight percentage of 10% sulfur-fixing additive and 90% Yangquan coal, and then placed on a shaker, heated and pyrolyzed under an inert atmosphere, with a heating rate of 10°C / min and a final temperature of 900°C. The obtained semi-coke was directly burned. The pyrolysis sulfur-fixing rate of the mixed coal sample was measured to be 85.22%, and the combustion sulfur-fixing rate was 77.01%.

[0030] Application Example 3

[0031] The sulfur-fixing additive in Example 3 was mixed with ordinary coal (the total sulfur content in ordinary coal was 1.41%, the ash content was 16.25%, the volatile matter was 34.42%, and the calorific value was 31.17 MJ / kg) in a weight percentage of 5% sulfur-fixing additive and 95% ordinary coal, and then placed on a shaking table, heated and pyrolyzed in an inert atmosphere, with a heating rate of 10°C / min and a final temperature of 900°C. The obtained semi-coke was directly burned. The pyrolysis sulfur-fixing rate of the mixed coal sample was measured to be 86.78%, and the combustion sulfur-fixing rate was 80.14%.

[0032] Comparative Example 1

[0033] 5.4 parts by weight of calcium oxide and 3.6 parts by weight of sodium carbonate as a sulfur fixation additive were mixed with the Ordos high-sulfur coal (15% of the sulfur fixation additive and 85% of the Ordos high-sulfur coal by weight), and then placed on a shaker, heated and pyrolyzed under an inert atmosphere, with a heating rate of 10°C / min and a final temperature of 900°C, and the resulting semi-coke was directly burned. The pyrolysis sulfur fixation rate of the mixed coal sample was measured to be 67.32%, and the combustion sulfur fixation rate was 65.21%.

[0034] Comparative Example 2

[0035] 6.8 parts by weight of calcium oxide and 2.1 parts by weight of sodium carbonate as a sulfur fixation additive were mixed with the above Yangquan coal (12% sulfur fixation additive and 92% Yangquan coal by weight), and then placed on a shaker, heated and pyrolyzed under an inert atmosphere, with a heating rate of 10°C / min and a final temperature of 900°C, and the obtained semi-coke was directly burned. The pyrolysis sulfur fixation rate of the mixed coal sample was measured to be 65.54%, and the combustion sulfur fixation rate was 63.38%.

[0036] Comparative Example 3

[0037] 6.5 parts by weight of calcium oxide, 2.5 parts by weight of sodium carbonate and 0.8 parts by weight of manganese dioxide as a sulfur fixation additive were mixed with the above-mentioned ordinary coal (10% of the sulfur fixation additive and 90% of the ordinary coal by weight), and then placed on a shaker, heated and pyrolyzed under an inert atmosphere, with a heating rate of 10°C / min and a final temperature of 900°C, and the obtained semi-coke was directly burned. The pyrolysis sulfur fixation rate of the mixed coal sample was measured to be 70.96%, and the combustion sulfur fixation rate was 67.83%.

Claims

1. A clean coal containing a sulfur-fixing additive, characterized in that: The desulfurization additive is composed of the following components by weight: 5.4 parts of calcium oxide, 3.6 parts of sodium carbonate and 1.2 parts of manganese dioxide; the clean coal includes the following components by weight percentage: 91% of raw coal and 9% of the desulfurization additive; the desulfurization additive is prepared by mixing the components of calcium oxide, sodium carbonate and manganese dioxide.

2. An application of a coal desulfurization additive, characterized in that: The method comprises mixing the sulfur-fixing additive as claimed in claim 1 with raw coal, placing the mixture in an inert atmosphere for pyrolysis at a heating rate of 10°C / min and a termination temperature of 900°C, and then directly burning the semi-coke obtained.