Study Of The Synthesis Of High-performance Rock Asphalt-based Activated Carbon On Mercury Adsorption

China is rich in coal resources and coal-fired power plant is an important energy source to support China’s economic development. Mercury emission from coal-fired flue gas is the largest source of anthropogenic emissions, accounting for about 40% of China’s annual mercury emissions. Therefore, it is very urgent to carry out research on flue gas mercury emission control technology. Activated carbon injection is one of the most mature technologies for flue gas mercury removal. The high cost of activated carbon seriously restricts the universal application of the technology. Since the 1970s, many researchers have carried out extensive research on activated carbon materials. Rock asphalt is an excellent material for the preparation of activated carbon, due to its high carbon content. Currently, rock asphalt is oversupplying in China with few usages, so research on the preparation of rock asphalt-based activated carbon has broad prospects.In this study, rock asphalt is selected as raw material and the orthogonal design is adopted in the preparation of activated carbon under different activation methods and preparation conditions. Fixed-bed mercury adsorption experiment is integrated with thennogravimetry, infrared radiation, nitrogen isothermal adsorption, scanning electron microscopy and X-ray spectra to analyze the impacts of activation methods and preparation conditions on activated carbon.This study concludes that H2O steam can not be used alone in the rock asphalt-based activated carbon preparation and the carbon precipitation in the form of volatile can be suppressed by KOH in the rock asphaltene which leads to the yield increase of activated carbon. In single KOH activation process, BET of activated carbon should be closely related with its mercury adsorption capacity. Furthermore, KOH/C ratio is the most important factor to determine the surface area of activated carbon and mercury adsorption capacity. The second important factor is the time of carbonization. In the case of H2O-KOH combined activated carbon, KOH/C ratio is the most important factor to control the surface area of activated carbon. The activation temperature is the second most important factor. H2O steam amount is the most important factor to determine the mercury adsorption capacity and activation temperature is the second most important factor. There is no oxygen functional group on the surface of original rock asphalt-based activated carbon and its mercury adsorption performance mainly depends on the volμme and proportion of micro-pore and mesoporous. KOH activated carbon has higher mercury adsorption speed and larger mercury adsorption capacity than that of H2O-KOH activated carbon.