A kind of modified chitosan is used as raw material to prepare desulfurization and mercury removal agent and preparation method thereof

Abstract

The invention relates to the technical field of desulfuration and demercuration agents, in particular to a desulfuration and demercuration agent prepared by taking modified chitosan as a raw material and a preparation method of the desulfuration and demercuration agent. The desulfuration and demercuration agent is prepared by mixing modified chitosan and pyrolusite; the raw materials of the desulfuration and demercuration agent are easy to obtain; the cost is lower; the desulfuration and demercuration agent can oxidize sulfur dioxide in smoke into sulfuric acid and elemental mercury in the smoke into ion mercury that enters a solution and is subjected to complex precipitation by the added modified chitosan; a mercury ingredient is separated by a filter cup; a content of sulfur dioxide and the mercury ingredient in the exhausted smoke is close to zero; and a removal rate reaches above 98%.

Description

technical field [0001] The invention relates to the technical field of desulfurization and mercury removal agents, in particular to a desulfurization and mercury removal agent prepared from modified chitosan as a raw material and a preparation method thereof. Background technique [0002] Coal occupies a dominant position in my country's energy production and consumption structure, accounting for about 70% of the country's primary energy production. In an environment where coal energy is so abundant, the pattern of coal-based power generation energy will be maintained for a long time. Coal-fired thermal power generation units occupy a dominant position in my country's electric power industry. However, the burning of coal is accompanied by the serious deterioration of the ecological environment. In recent years, it is necessary to treat the coal before using it in thermal power plants. The reason for the treatment of coal-fired tail gas emissions from thermal power plants is ...

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Problems solved by technology

Coal-fired thermal power generation units occupy a dominant position in my country's electric power industry. However, the burning of coal is accompanied by the serious deterioration of the ecological environment. In recent years, it is necessary to treat the coal before using it in thermal power plants. The reason for the treatment of coal-fired tail gas emissions from thermal power plants is that my country's coal resources contain a large amount of sulfur and mercury components. After sulfur components enter the environment, it is easy to cause acid rain. Mercury in the environment, it enters organisms , will form methyl mercury with methyl, and methyl mercury is highly toxic and will seriously affect the metabolism of organisms

[0003] In the existing technology, there are many studies on the removal of sulfur components in the process of coal-fired emissions, such as installing a limestone-gypsum wet desulfurization device on the coal-fired exhaust pipe of a power plant, so that the sulfur components in the flue gas outlet can be discharged up to the standard; and For the above-mentioned devices, it is difficult to remove the mercury components in the flue gas, and using the above-mentioned devices for treatment will cause a large amount of gypsum to be produced, resulting in an increase in post-treatment burden, and the sulfur components in the flue gas cannot be rationally utilized.

[0004] For this reason, some researchers used pyrolusite and manganese carbonate to combine and prepare slurry treatment, so that the manganese dioxide in pyrolusite can catalyze the oxidation of sulfur dioxide and elemental mercury, so that the sulfur dioxide in the flue gas can be discharged up to the standard; at the same time, it can The elemental mercury in it is converted into ionized mercury and enters the pulp to achieve desulfurization and mercury removal; there is also a method of using pyrolusite dry method to remove sulfur and mercury in the flue gas, but no matter whether the pulp is used or the dry method is used to treat the flue gas The removal rate of sulfur and mercury is low, and the removal rate of sulfur can only reach about 70%, and the removal rate of mercury can reach about 64%, so that the flue gas still contains a large amount of sulfur and mercury components , is still likely to cause environmental pollution

[0005] Based on this, some researchers have studied the desulfurization and mercury removal agent, using manganese dioxide, magnetic iron oxide Fe 21.333 o 32 As the active ingredient, the active ingredient is combined with the carrier, so that the removal rate of sulfur and mercury reaches more than 99%. However, due to the high preparation cost of the magnetic iron oxide Fe21.333O32 component, it is difficult to obtain, making industrial application High cost, difficult to achieve industrial application

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