摘要
固体废物资源化利用具有重要意义。以废粘土砖为原料,采用水热法合成了高CO_(2)吸附性能的A型分子筛和A/X共晶分子筛。研究了碱灰比(质量比)、煅烧温度、晶化温度和晶化时间对废粘土砖基分子筛合成的影响,采用XRD、XRF、SEM、N_(2)吸/脱附和FTIR等手段对分子筛进行了表征。结果表明,硅铝比(物质的量之比)固定为1,在碱灰比分别为0.6和1.6、煅烧温度为750℃、晶化温度为90℃和晶化时间为24 h的条件下,合成了最佳形貌的A型分子筛和A/X共晶分子筛。测试发现,二者比表面积分别为61.3 m^(2)/g和326.7 m^(2)/g,30℃、CO_(2)气氛(CO_(2)体积分数为10%)下CO_(2)的吸附量分别为2.96 mmol/g和3.22 mmol/g,再生5次后的吸附量均能维持在初始吸附量的88%以上。通过吸附动力学模型和限速扩散模型,对两种分子筛的CO_(2)吸附机理进行了研究,发现CO_(2)分子由于内/外孔扩散以及分子间库仑引力而吸附在分子筛上,主要为物理吸附。本研究可为废粘土砖基分子筛的合成及其应用提供参考。
The utilization of solid waste resources is of important significance.Waste clay brick was used as the raw material to synthesize high CO_(2) adsorption performance type A zeolite and A/X eutectic zeolite through the hydrothermal method.The effects of alkali to ash ratio(mass ratio),calcination temperature,crystallization temperature and crystallization time on the synthesis of zeolite from waste clay brick were investigated.The synthesized zeolites were characterized using XRD,XRF,SEM,N_(2) adsorption/desorption and FTIR.The results show that,with a fixed Si to Al ratio(mole ratio)of 1,the optimal morphology of type A zeolite and A/X eutectic zeolite is obtained under the conditions of an alkali to ash ratio of 0.6 and 1.6,respectively,calcination temperature of 750℃,crystallization temperature of 90℃ and crystallization time of 24 h.Testing reveals that their specific surface areas are 61.3 m^(2)/g and 326.7 m^(2)/g,and their CO_(2) adsorption capacities are 2.96 mmol/g and 3.22 mmol/g at 30℃ under a CO_(2) atmosphere(CO_(2) volume fraction of 10%),respectively.After five regeneration cycles,their adsorption capacities remain above 88% of the initial adsorption capacity.The CO_(2) adsorption mechanism of the two zeolites was studied through adsorption kinetics and rate-limiting diffusion models.It is found that CO_(2) molecules are adsorbed on the zeolites due to internal/external pore diffusion and intermolecular Coulomb forces,mainly through physical adsorption.This study can provide a reference for the synthesis and application of zeolites from waste clay brick.
作者
陈云
龚海淳
许培峰
马永清
王君雅
张玉
CHEN Yun;GONG Haichun;XU Peifeng;MA Yongqing;WANG Junya;ZHANG Yu(College of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming 650031,Yunnan,China;National and Local Joint Engineering Research Center for Waste Gas Recycling in Metallurgical and Chemical Industry,Kunming 650031,Yunnan,China)
出处
《低碳化学与化工》
北大核心
2025年第1期101-110,共10页
Low-Carbon Chemistry and Chemical Engineering
基金
云南省重点研发计划(202303AC100008)
云南省应用基础研究计划(202101AT070107)。
