Preparation method of sulfurizing porous nanometer material for high-efficiency hydrargyrum removal

Abstract

The invention relates to high-efficiency sulfurizing hydrargyrum-removing porous nanometer carbon and a preparation method thereof, belonging to the field of chemistry. The preparation method comprises the following steps of: mixing porous nanometer carbon and sulfur, and then placing into a closed pressure vessel with dry ice or liquid carbon dioxide together; heating the closed pressure vessel to 31-200 DEG C to make the carbon dioxide reach a supercritical state, keeping for 1-48 hours, or heating the carbon dioxide to the supercritical state, then injecting into the closed pressure vesselcontaining a mixture of the porous nanometer carbon and the sulfur, and keeping for 1-48 hours; and then cooling to room temperature, and evacuating the carbon dioxide so as to prepare the sulfurizing porous nanometer carbon, wherein the mass percent of the sulfur contained in the sulfurizing porous nanometer carbon is 2-50 percent. According to the invention, high sulfurizing quantity and the quantity as well as the specific surface area of the sulfur available during hydrargyrum removal are furthest ensured by tactfully adopting the gas-liquid dual property of the supercritical carbon dioxide, and therefore an optimal hydrargyrum removing effect is achieved; in addition, the advantages of simple process, high efficiency, environment friendliness and low cost are achieved.

Description

technical field [0001] The invention belongs to the field of chemistry, and in particular relates to a method for preparing a sulfur-loaded porous nanometer material for efficient mercury removal. Background technique [0002] Mercury and mercury-containing raw materials are used in numerous industrial processes and fields. Mercury has a relatively high vapor pressure (15mg / m 3 , 20°C), so it is very easy to enter or exist in various gases in various ways, such as air, hydrogen, chlorine, carbon dioxide, natural gas, petroleum gas, artificial synthesis gas, fuel waste gas and industrial exhaust gas, etc. Mercury is not only highly biotoxic and environmentally hazardous, but can poison many industrial catalytic processes. In order to remove mercury from various gases, traditional wet and dry technologies and corresponding mercury removal agents mainly include the following: [0003] 1. Let the mercury-containing gas pass through the potassium sulfate solution, and the merc...

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Problems solved by technology

[0004] 2. Let mercury-containing gas pass through an adsorbent such as activated carbon to absorb mercury. This method has low mercury removal activity and mercury removal capacity.

[0005] 3. Using sulfuric acid, nitric acid or persulfate oxidation method, NH 2 NH 2 2 HCl solution impregnation method or high-temperature gas phase reaction, etc., to modify the surface of activated carbon, that is, to infiltrate elements such as sulfur, iodine, chlorine on the surface or regulate surface functional groups to improve the adsorption specificity and adsorption capacity of activated carbon to mercury, but the process of this method Complex, costly, and inefficient

The biggest disadvantage of the above method is that the reaction time is too long, the specific surface area of ​​the sulfur-loaded activated carbon produced is very small, and its mercury removal capacity and mercury removal reactivity are limited.

The concentration of sulfur vapor in the gas phase of the above method is low, the mass of sulfur atom clusters is large, the diffusion into the complex pores of activated carbon is slow, and the pores are easily blocked, so it is still unable to make full use of the high specific surface area and porosity of activated carbon to achieve the ideal load. Sulfur amount and utilization rate, mercury removal capacity and mercury removal reaction rate are still limited