Change Mechanism Of Physical Structure And Surface Functional Groups Of Activated Semi-Cokes Used In SO₂ Removal From Flue Gas

China is one of the largest country in the primary energy production and consumption in the world, and in primary energy production and consumption structure China regards coal as principle. The combustion of coal in massive amounts has produced a great quantity of air pollutants such as SO₂. The damage and lose from the acid rain caused by the release of sulfur dioxide have severely baffled sustainable economic development of our country. On the other hand, China is the largest agriculture country in the world, a great deal of sulfuric acid has been produced to meet the needs of fertilizer industry production. However, the sulfur resources to meet the needs of domestic sulfuric acid production is relatively insufficient in our country and the sulfur has been imported in great quantities annually, which costs a huge sum of foreign exchange. Therefore, the investigation on SO₂ removal from flue gas with sulfur recycling has great significance. SO₂ removal from flue gas using activated carbonaceous material has been taken into account for removing SO₂ and NO_x simultaneously and recycling sulfur, but its industrial application was influenced by its precursor and modification process. To study the precursor, modification mechanism, physical texture, surface chemical functional groups, the relationship between texture and SO₂ removal efficiency, and SO₂ removal mechanism of surface chemical functional groups of activated carbonaceous material will contribute to industrial application of SO₂ removal technology using activated carbonaceous material.In this paper, a series of activated semi-cokes were prepared from raw semi-coke from lignite in Inner Mongolia by means of hydrothermal treatment, HNO₃ oxidation and heat treatment at high temperature as well as their combined modification. The proximate analysis, ultimate analysis, inorganic oxide content and surface acidic or basic groups content were carried on for raw semi-coke and the activated semi-coke samples. The analysis results show that, raw semi-coke is higher in oxygen-containing functional groups content and lower in fixed carbon content than traditional active carbon, including ash...