半焦基多孔石墨化炭可控制备及其吸附性能研究

Controllable preparation and adsorption properties of semi-coke-based porous graphitized carbon

作为烟煤中低温干馏的产物,半焦具有含碳量高、化学活性及电阻率高等特点,开发利用半焦材料的应用新技术,对于低阶煤提质增效具有重要意义。本文以神府半焦为原料,通过催化活化技术实现半焦的初步扩孔,进而采用水热浸渍法将催化剂(硝酸铁)与炭基体充分接触融合,并通过石墨化技术实现多孔石墨化炭的制备。利用XRD、Raman、BET等手段分析多孔石墨化炭的晶体结构和孔隙结构,并以其作为吸附剂研究其碘吸附性能。结果表明:当混合催化剂中Fe∶Ca原子比为4∶1时,所得活化半焦比表面积最大,可达470.32 m^2·g^-1;通过进一步催化石墨化制得的多孔石墨化炭,其比表面积提高至795.41 m^2·g^-1,且以微孔为主,当以其为吸附剂时,碘吸附值可达650.66 mg·g^-1。半焦基石墨化炭优异的吸附性能为半焦的增值利用提供了新的方向。

Semi-coke,a product of the low temperature carbonization of bituminous coal,has the advantages of high carbon content,high chemical activity,and high specific resistance.The development of new technologies for the utilization of semi-coke material is of great significance for the improvement of low-rank coal.In this paper,semi-coke from Shenfu is used as raw material,and iron oxide and calcium oxide are used as catalysts.Activated semi-coke is first obtained via preliminary pore expansion achieved by catalytic activation.Then,the catalyst(iron nitrate)is fully contacted with the carbon matrix by a hydrothermal impregnation method,and the porous graphitized carbon is successfully prepared through low-temperature graphitization.XRD,Raman,low temperature nitrogen adsorption and other methods are used to analyze the crystal and pore structure of porous graphitized carbon.Additionally,the iodine adsorption ability of porous graphitized carbon is also analyzed.The results show that the largest specific surface area of the activated semi coke(up to 470.32 m^2·g^-1)is obtained when the mixed catalyst’s atomic ratio of Fe∶Ca is 4∶1.Furthermore,the specific surface area of porous graphitized carbon increases to 795.41 m^2·g^-1,likely due to micropore formation.When it is used as an adsorbent,its iodine adsorption value reaches 650.66 mg·g^-1.Its excellent adsorption performance provides a new way for the value-added use of semi-coke.