Attapulgite carrier catalyst for oxidation of elemental mercury in flue gas and preparation method thereof

Abstract

The invention relates to a modified attapulgite supported catalyst for oxidation of elemental mercury and a preparation method thereof, and belongs to the field of atmospheric pollution treatment technologies and environmental protection catalytic materials. The preparation method comprises the following steps of: preparing a modified attapulgite of a transition metal selected from Fe, Zn, Cu, Mn and Ce through an ion exchange method and using the attapulgite as a catalyst carrier; adding a certain amount of an active oxide component of one or more metal elements selected from Fe, Zn, Cu, Mn, Ce, W, Co, Ag, Au, Pd and V by the adoption of a sol-gel method; drying, calcining, and sieving to prepare the catalyst. Based on the total mass of the catalyst as the reference, the content of the loaded active metal oxide is 10-30 wt%. The catalyst has characteristics of high activity and low-temperature adaptability, and has a wide application prospect in the field of mercury cleaning in flue gas.

Description

technical field [0001] The invention relates to a catalyst for oxidation of elemental mercury (HgO) with modified attapulgite as a carrier and a preparation method thereof, belonging to the fields of air pollution control technology and environmental protection catalytic materials. Background technique [0002] Mercury is a toxic trace heavy metal element with strong cohesion and is stable in the air. After long-term accumulation, it will pollute the environment and have toxic effects on organisms and humans. Coal contains trace amounts of mercury. Due to the huge amount of coal burned in the world every year, mercury emissions during coal combustion have become the main source of mercury pollution. In coal-fired flue gas, mercury mainly exists in three forms: elemental mercury (Hg 0 ), oxidized mercury (Hg 2+ ), particulate mercury (Hg p ). Among them, Hg 2+ and Hg p The proportion is small, and it is easily absorbed by the desulfurization device and dust removal devi...

AI Technical Summary

Problems solved by technology

But TiO 2 The specific surface area is low, and activated carbon is expensive, so the selection of new and effective catalyst supports has become one of the research hotspots of SCR catalysts

The publication number is CN101528343, and the invention patent titled "Metallic Mercury Oxidation Catalyst" proposes molybdenum and vanadium composite oxidation catalyst (MoV 2 o 8 ), has excellent elemental mercury conversion efficiency without increasing catalyst consumption, yet molybdenum and vanadium oxides are heavy metal oxides with high toxicity and high pollution, so it is difficult to promote and practical application; the publication number is CN1698931 and the name is " Catalytic Oxidation Flue Gas Mercury Removal Method” patent proposes a method for catalytic oxidation of mercury in flue gas, using oxides of transition metals such as Fe, Co, Ni, Cu, Mn as active components to catalyze the oxidation of elemental mercury. However, this The operating temperature of the catalyst proposed in the patent is generally above 200°C to exert a good catalytic adsorption effect, while the temperature of the flue gas after conventional desulfurization and dust removal is generally lower than 160°C. If the catalytic oxidation performance of the catalyst for elemental mercury is to be exerted, Flue gas must be reheated, which will greatly increase system energy consumption and operating costs

In addition, US2003170159, WO2006009079 and other patents report on the mercury oxidation performance of some noble metal or transition metal oxide catalysts, but these patents pay little attention to the catalyst support and low-temperature catalytic performance

Images