碳罐用活性炭的制备及应用进展

 随着汽车排放标准的日益严格和汽车尾气净化技术的成熟应用,燃油蒸发在整车排放中的比例逐渐提高。碳罐是汽油车燃油蒸发控制的关键部件,其核心材料是汽油吸附用成型活性炭。碳罐技术要求成型活性炭具有高的比表面积、大的有效孔容(2~5 nm孔的孔容)和高强度,具有快速吸附和脱附汽油的性能。化学法和化学物理耦合的办法是制备高比表面和大孔容活性炭的有效途径,成型活化一体化是成型活性炭制备的发展趋势。本文综述碳罐用成型活性炭的性能要求、表征方法、制备技术及原理和在未来VOCs净化中的应用。

Preparation and progress of active carbon for canister

With the increasingly stringent exhaust emission standard and the mature application of exhaust treatment technics, fuel evaporation has become the main source of vehicle emission. Canister containing formed active carbon is the key part of automotive fuel evaporator to reduce emission and reuse fuel vapor significantly. Formed active carbon needs to have a large surface area and large effective pore volume (pore size of 2~5 nm) for high working capacity, high structural strength, fast adsorption and desorption of fuel, which are typically obtained by chemical and physical-chemical activation methods. Chemical and physical methods are common in preparation of activate carbon, chemical activation may produce pollution, which leads to environment problems, although to develop a preferable structure of pore, the physical activation costs a large amount of energy and investment, and the pore structure by this method is relatively poor. Chemi-physical methods can combine the benefits of both physical and chemical activations to decrease the pollution and produce high quality activate carbon. Activation and formation are the main processes for preparation of formed activate carbon; the precursor can change into activate carbon through the activation, and then have the solid shape and structural strength after formation. The integration of formation and activation is the development trend of preparation of formed activated carbon. The performance, characterization, preparation and related mechanisms, and the application in VOCs removal of formed active carbon are reviewed.