煤气化细渣水热合成多孔材料及对氨氮的吸附性能研究

Hydrothermal synthesis of porous materials from coal gasification fine slag and its adsorption properties of ammonia nitrogen

为了拓展煤气化细渣高值化利用途径,采用碱溶水热法制备多孔复合吸附材料。通过调控碱浓度、水热时间、温度、搅拌时间等因素探究其对复合材料结构性能的影响规律,并通过分析不同制备条件下复合吸附材料的物相组成、表观形貌、孔隙结构,明晰复合材料与其对氨氮吸附能力的构效关系。结果表明:复合材料生成了以P型沸石为主要晶相的沸石结构。当碱浓度为2 mol/L、水热时间为30 h,水热温度为100℃,搅拌时间为10 min制备的复合材料的氨氮吸附量最高,当氨氮初始浓度为100 mg/L、吸附时间为5 h时,复合材料对氨氮的平衡吸附量达到15.65 mg/g。吸附材料对氨氮的等温吸附特性符合Langmuir方程,且反应过程符合准二级动力学方程。热力学分析表明煤气化细渣对氨氮的吸附为自发、吸热及熵增反应。

In order to expand the utilization path of coal gasification fine slag(CGFS),CGFS was used as raw material to prepare composite adsorption materials by hydrothermal alkali solution.The effects of hydrothermal time,alkali concentration,hydrothermal temperature,and stirring time on the ammonia nitrogen adsorption characteristics of composite materials were explored by designing orthogonal experiments.The structure-activity relationship between composite materials and adsorption capacity was determined by analyzing the composition,apparent morphology,and pore structure of composite adsorption materials under different preparation conditions.The results showed that the composites generated a zeolite structure with Ptype zeolite as the main crystalline phase.The maximum adsorption capacity of the composite adsorption material was obtained,when the hydrothermal time is 30 hours,the hydrothermal temperature is 100℃,the stirring time is 10 minutes,and the alkali concentration is 2 mol/L.When the initial ammonia nitrogen concentration is 100 mg/L and the adsorption time is 5 hours,the equilibrium adsorption capacity of the adsorption material for ammonia nitrogen reaches 15.65 mg/g.The isothermal adsorption characteristics of the adsorption material for ammonia nitrogen followed the Langmuir equation,and the reaction process followed the quasi-second-order kinetic equation.According to the thermodynamic analysis,the adsorption reaction of CGFS on ammonia nitrogen is spontaneous,endothermic,and entropy-increasing.