A sulfur-fixing additive for high-sulfur coal and preparation method thereof

Abstract

The present invention provides a sulfur-fixing additive for high-sulfur coal and a preparation method thereof. The sulfur-fixing additive for high-sulfur coal provided by the present invention comprises the following components by weight: 6-7 parts of calcium oxide, 2-3 parts of zinc chloride and (3-4 parts of magnesium oxide). The sulfur-fixing additive is mixed with raw coal in a weight percentage of 90-94% of raw coal and 6-10% 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, to obtain direct combustion of semi-coke, and to achieve sulfur-fixing and emission reduction during combustion. The sulfur-fixing additive for high-sulfur coal 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 sulfur-fixing agents, and particularly relates to a sulfur-fixing additive for high-sulfur coal 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] Among coal sulfur fixers, calcium-based sulfur fixers are the most studied type of sulfur fixers because they are cheap and easy to obtain. However, single calcium-based sulfur fixers have problems such as low calcium utilization. Therefore, whether a calcium-based sulfur fixer with good sulfur fixation effect can be provided to reduce the release of sulfur oxides and significantly improve the high-temperature sulfur fixation effect of the sulfur fixer, especially for sulfur fixation of high-sulfur coal combustion, obviously improve its thermal efficiency of coal combustion, has become a technical problem to be solved in this field. Summary of the invention

[0008] The purpose of the present invention is to solve the above technical problems and provide a sulfur-fixing additive for high-sulfur coal and a preparation method thereof. The present invention provides a calcium-based sulfur-fixing agent for high-sulfur coal with good sulfur-fixing effect, which 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.

[0009] One of the purposes of the present invention is to provide a sulfur-fixing additive for high-sulfur coal, which comprises the following components by weight: 6-7 parts of calcium oxide, 2-3 parts of zinc chloride and 3-4 parts of magnesium oxide.

[0010] As a preferred solution, the desulfurization additive includes the following components by weight: 6.75 parts of calcium oxide, 2.25 parts of zinc chloride and 3.45 parts of magnesium oxide.

[0011] Furthermore, the amount of the desulfurization additive added to the raw coal is 6-10% by mass.

[0012] As a preferred solution, the amount of the desulfurization additive added to the raw coal is 8% by mass.

[0013] The second object of the present invention is to provide a clean coal containing the above-mentioned sulfur-fixing additive for high-sulfur coal. The clean coal comprises the following components by weight percentage: 90-94% of raw coal and 6-10% of the sulfur-fixing additive.

[0014] The third object of the present invention is to provide a method for preparing the above-mentioned sulfur-fixing additive for high-sulfur coal, which is prepared by grinding the components of calcium oxide, zinc chloride and magnesium oxide in the sulfur-fixing additive and mixing them.

[0015] The fourth object of the present invention is to provide an application of the above-mentioned sulfur-fixing additive for high-sulfur coal, which is to mix the sulfur-fixing additive with raw coal, place it in an inert atmosphere for heating and pyrolysis, with a heating rate of 10°C / min and an end temperature of 900°C to obtain semi-coke for direct combustion, thereby achieving sulfur-fixing emission reduction during the combustion process.

[0016] The beneficial effects of the present invention are as follows:

[0017] The preparation method of the sulfur-fixing additive of the present invention is simple and has low cost. During the pyrolysis process, the sulfur-containing gas is collected once and for all, and the addition of calcium oxide, zinc chloride and magnesium oxide in an optimal ratio range can play a synergistic role, thereby achieving sulfur fixation and emission reduction during the combustion process. Moreover, the sulfur-fixing additive of the present invention is not only anthracite with better coal quality, but also has a good sulfur-fixing effect on low-priced high-sulfur coal. DETAILED DESCRIPTION

[0018] 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.

[0019] Example 1

[0020] After grinding each component, fully mix them to form a sulfur-fixing additive, wherein the weight portion of calcium oxide in the sulfur-fixing additive is 6.75 parts, the weight portion of zinc chloride is 2.25 parts, and the weight portion of magnesium oxide is 3.45 parts. The sulfur-fixing additive and raw coal are combined into a combustion sample (the weight percentage is 8% additive and 92% raw coal). The obtained sample is placed in an inert atmosphere for pyrolysis at a heating rate of 10°C / min and a final temperature of 900°C, and the obtained semi-coke is directly burned.

[0021] Example 2

[0022] After grinding each component, fully mix them to form a sulfur-fixing additive, wherein the weight portion of calcium oxide in the sulfur-fixing additive is 6 parts, the weight portion of zinc chloride is 2 parts, and the weight portion of magnesium oxide is 3 parts. 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.

[0023] Example 3

[0024] After grinding each component, fully mix them to form a sulfur-fixing additive, wherein the weight portion of calcium oxide in the sulfur-fixing additive is 7 parts, the weight portion of zinc chloride is 3 parts, and the weight portion of magnesium oxide is 4 parts. The sulfur-fixing additive and raw coal are combined into a combustion sample (the weight percentage is 6% additive and 94% 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.

[0025] Application Example 1

[0026] The sulfur-fixing additive of Example 1 was mixed with Ordos high-sulfur coal (the total sulfur content of Ordos high-sulfur coal was 3.02%, the ash content was 31.85%, the volatile matter was 15.86%, and the calorific value was 20.26MJ / kg) by weight, and the sulfur-fixing additive and 92% of Ordos high-sulfur coal were mixed and placed on a shaking table, and the temperature was increased 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-fixing rate of the mixed coal sample was measured to be 97.42%, and the combustion sulfur-fixing rate was 85.9% (the determination method of the sulfur-fixing rate refers to the determination method of the sulfur-fixing rate of modified clean coal in DB37 / T4021-2020, the same below).

[0027] Application Example 2

[0028] 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 25.54 MJ / kg) in a weight percentage of 10% sulfur-fixing additive and 90% Yangquan 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, and the obtained semi-coke was directly burned. The pyrolysis sulfur-fixing rate of the mixed coal sample was measured to be 82.92%, and the combustion sulfur-fixing rate was 74.59%.

[0029] Application Example 3

[0030] 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 6% sulfur-fixing additive and 94% 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, and the obtained semi-coke was directly burned. The pyrolysis sulfur-fixing rate of the mixed coal sample was measured to be 88.87%, and the combustion sulfur-fixing rate was 79.94%.

[0031] Comparative Example 1

[0032] 6.75 parts by weight of calcium oxide and 2.25 parts by weight of zinc chloride as a sulfur fixation additive were mixed with the above-mentioned Ordos high-sulfur coal (12% of the sulfur fixation additive and 82% 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. The obtained semi-coke was directly burned. The pyrolysis sulfur fixation rate of the mixed coal sample was measured to be 69.89%, and the combustion sulfur fixation rate was 66.75%.

[0033] Comparative Example 2

[0034] 8.2 parts by weight of calcium oxide and 4.5 parts by weight of magnesium oxide were mixed with the above Yangquan coal (16% of the sulfur-fixing additive and 84% of the Yangquan coal by weight), and then placed on a shaker, heated and pyrolyzed under an inert atmosphere at 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 70.16%, and the combustion sulfur fixation rate was 68.81%.

[0035] Comparative Example 3

[0036] 7.4 parts by weight of calcium oxide, 1.6 parts of zinc chloride and 2.8 parts of magnesium oxide were mixed with the above-mentioned ordinary coal (8% of the sulfur-fixing additive and 92% of the 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 75.58%, and the combustion sulfur fixation rate was 70.79%.

Claims

1. An application of clean coal containing high-sulfur raw coal, characterized in that: The clean coal is composed of the following components by weight percentage: 92% high-sulfur raw coal and 8% fixed sulfur additive; wherein the fixed sulfur additive is composed of the following components by weight: 6.75 parts of calcium oxide, 2.25 parts of zinc chloride and 3.45 parts of magnesium oxide; wherein the total sulfur content of the high-sulfur raw coal is 3.02%, the ash content is 31.85%, the volatile content is 15.86%, and the calorific value is 20.26 MJ / kg; the application is to mix the fixed sulfur additive with the high-sulfur raw coal, place it in an inert atmosphere for heating and pyrolysis, the heating rate is 10°C / min, the end temperature is 900°C, and the semi-coke is obtained and then directly burned.

2. The use of clean coal containing high-sulfur raw coal according to claim 1, characterized in that: The sulfur-fixing additive is prepared by grinding components of calcium oxide, zinc chloride and magnesium oxide and mixing them.