CN-121988291-A - Method for preparing efficient flue gas desulfurization and denitrification adsorbent by modifying carbon material

CN121988291ACN 121988291 ACN121988291 ACN 121988291ACN-121988291-A

Abstract

The invention provides a method for preparing a high-efficiency flue gas desulfurization and denitrification adsorbent by modifying a carbon material, which comprises the steps of selecting the carbon material raw material, crushing the crushed carbon material raw material, screening the screened carbon material raw material, drying the screened carbon material raw material, preparing a composite modifier solution by adopting a nitric acid solution and a ferrous sulfate solution, uniformly stirring the composite modifier solution and the carbon material raw material, mixing the composite modifier solution with the carbon material raw material, simultaneously adding titanium dioxide to obtain a mixed material, uniformly stirring the mixed material, carrying out a modification reaction under a preset modification reaction condition, separating a reaction mixture after the modification reaction is finished, separating a solid product and a waste liquid, recycling the modifier for the solid product, and drying and roasting the solid product at a low temperature to obtain the dry flue gas desulfurization and denitrification adsorbent. The method has the advantages of convenient operation, high modification efficiency, low cost and good environmental protection, and the prepared flue gas desulfurization and denitrification adsorbent has excellent performance and important industrialized application value and environmental benefit.

Inventors

ZENG DUO
LI QIUNAN
LONG HAIBO
YANG YUHANG
ZHOU GANG
WANG LELE
YU CHANGKAI
HE CHUAN
WU XUN
CHENG FENG
FENG JIANGUANG

Assignees

华能重庆珞璜发电有限责任公司
西安热工研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20260403

Claims (10)

1. The method for preparing the efficient flue gas desulfurization and denitrification adsorbent by modifying the carbon material is characterized by comprising the following steps of: Selecting a carbon material raw material, crushing, screening the crushed carbon material raw material, and drying the screened carbon material raw material; Preparing a composite modifier solution by adopting a nitric acid solution and a ferrous sulfate solution, and uniformly stirring; Mixing the composite modifier solution with the carbon material raw material, and simultaneously adding titanium dioxide to obtain a mixed material; Uniformly stirring the mixed materials, and carrying out modification reaction under preset modification reaction conditions; after the modification reaction is finished, separating a reaction mixture to obtain a solid product and a waste liquid; recovering the modifier from the solid product; and drying and roasting the solid product at a low temperature to obtain the dry flue gas desulfurization and denitrification adsorbent.
2. The method of claim 1, wherein preparing the composite modifier solution from the nitric acid solution and the ferrous sulfate solution comprises: Mixing 0.6 mol/L-1.2 mol/L nitric acid solution and 0.3 mol/L-0.5 mol/L ferrous sulfate solution according to a volume ratio of 2:1 to prepare the composite modifier solution.
3. The method of claim 1, wherein mixing the composite modifier solution with the carbon material feedstock while adding titanium dioxide to obtain the mixed material comprises: mixing the composite modifier solution with the carbon material raw material according to the mass ratio of (4-6): 1, and simultaneously adding titanium dioxide, wherein the mass of the titanium dioxide is 5% -8% of that of the carbon material raw material.
4. The method of claim 1, wherein uniformly stirring the mixed material comprises: and uniformly stirring the mixed material in a mode of combining ultrasonic vibration and mechanical stirring, wherein the ultrasonic power is controlled to be 300-350W, and the stirring rotating speed is controlled to be 70-80 r/min.
5. The method according to claim 1, wherein the modification reaction occurs under preset modification reaction conditions, comprising: And (3) controlling the reaction temperature to be 55-65 ℃ by adopting a water bath temperature control mode, monitoring the pH value and the temperature of a reaction system in real time with the temperature control precision +/-2 ℃, and controlling the reaction time to be 40 min-70 min to finish the modification reaction.
6. The method of claim 1, wherein the recovery of the modifier from the solid product comprises: and performing filter pressing dehydration treatment on the separated solid product to reduce the water content of the solid product, and extruding the residual modifier in the solid product to recycle.
7. The method of claim 6, wherein the recovery of the modifier from the solid product further comprises: Washing the solid product subjected to filter pressing and dehydration by deionized water until the pH value of the washing liquid reaches 6.5-7.5; and collecting the washing wastewater, carrying out regeneration treatment on the washing wastewater, and recovering the modifier in the washing wastewater.
8. The method of claim 1, wherein drying and low temperature calcination of the solid product comprises: drying the solid product by adopting a hot air circulation drying mode, wherein the drying temperature is controlled to be 115-120 ℃ and the drying time is controlled to be 40-50 min; And (3) carrying out low-temperature roasting activation treatment on the dried solid product, wherein the roasting temperature is controlled to be 250-280 ℃ and the roasting time is controlled to be 1.5-2 h.
9. The method of claim 1, wherein after saturation of the adsorbent adsorption, the method further comprises: And (3) adopting a hot air blowing regeneration mode, controlling the blowing temperature to be 180-200 ℃ and the blowing time to be 30-40 min, and blowing the dried flue gas desulfurization and denitrification adsorbent to realize the regeneration of the adsorbent.
10. The method according to claim 9, wherein the method further comprises: The quality detection is carried out on the flue gas desulfurization and denitrification adsorbent after drying and the regenerated adsorbent, SO that the adsorption capacity of the flue gas desulfurization and denitrification adsorbent to SO 2 is more than or equal to 200mg/g, the adsorption capacity to NO x is more than or equal to 150mg/g, the SO 2 removal rate is more than or equal to 98%, and the NO x removal rate is more than or equal to 95%.

Description

Method for preparing efficient flue gas desulfurization and denitrification adsorbent by modifying carbon material Technical Field The invention belongs to the technical field of adsorbent preparation, and particularly relates to a method for preparing an efficient flue gas desulfurization and denitrification adsorbent by modifying a carbon material. Background The pollutants such as SO 2、NOx contained in the industrial flue gas are one of main causes of environmental problems such as acid rain, haze and the like, and seriously harm the ecological environment and human health. With the increasing strictness of environmental protection standards, flue gas desulfurization and denitrification treatment becomes a necessary link for industrial enterprises to reach the standard for emission. The carbon material has the characteristics of large specific surface area, developed pore structure, excellent adsorption performance, strong chemical stability and the like, is an ideal raw material for preparing the flue gas desulfurization and denitrification adsorbent, can realize high-efficiency adsorption and conversion of SO 2、NOx, and promotes the carbon material to be upgraded from basic application to high-valued application. At present, the carbon material-based desulfurization and denitrification adsorbent is prepared by adopting a single modification mode, so that the problems of low adsorption capacity, poor desulfurization and denitrification synchronous efficiency, poor adsorbent regeneration performance, short service life and the like exist, the modifier is low in utilization rate, high in energy consumption and easy to cause secondary pollution in waste liquid and waste gas in the modification process, and the industrialized large-scale application of the carbon material-based desulfurization and denitrification adsorbent is limited. In addition, the existing adsorbent is difficult to adapt to complex smoke components (such as dust-containing smoke and wet smoke), the problems of high adsorption saturation, high performance attenuation and the like are easy to occur, and the requirements of deep desulfurization and denitrification (the SO 2 removal rate is more than or equal to 98% and the NO x removal rate is more than or equal to 95%) of industrial smoke cannot be met. Chinese patent document CN 103232036A discloses a method for preparing desulfurization and denitrification active carbon. Comprises a) dipping active carbon in alkali liquor at constant temperature, b) oxidizing and drying the dipped active carbon, and spraying to obtain the desulfurization and denitrification active carbon. The main defects of the technology related to the CN 103232036A in the Chinese patent document are that ① is modified by only a single alkali liquor and no catalytic component is introduced, the pore structure and active site of the carbon material are limited to promote, the desulfurization and denitrification performance is difficult to meet the requirements of industrial advanced treatment, ② alkali liquor is not recovered, a non-targeted washing process is not needed, secondary pollution is easy to cause, the stability of a product is easily influenced, ③ is not provided with accurate parameter regulation and regeneration processes, the quality of the product is uneven, and the use cost is high. In view of the above problems, it is necessary to provide a method for preparing an efficient flue gas desulfurization and denitrification adsorbent by modifying a carbon material, which is reasonable in design and effectively solves the above problems. Disclosure of Invention The invention aims at solving at least one of the technical problems in the prior art and provides a method for preparing an efficient flue gas desulfurization and denitrification adsorbent by modifying a carbon material. The invention provides a method for preparing an efficient flue gas desulfurization and denitrification adsorbent by modifying a carbon material, which comprises the following steps: Selecting a carbon material raw material, crushing, screening the crushed carbon material raw material, and drying the screened carbon material raw material; Preparing a composite modifier solution by adopting a nitric acid solution and a ferrous sulfate solution, and uniformly stirring; Mixing the composite modifier solution with the carbon material raw material, and simultaneously adding titanium dioxide to obtain a mixed material; Uniformly stirring the mixed materials, and carrying out modification reaction under preset modification reaction conditions; after the modification reaction is finished, separating a reaction mixture to obtain a solid product and a waste liquid; recovering the modifier from the solid product; and drying and roasting the solid product at a low temperature to obtain the dry flue gas desulfurization and denitrification adsorbent. Optionally, preparing a composite modifier solution from a nitric acid solution and a ferrous sulf