Study on the Absorption of Carbon Dioxide by Zeolite transformed from Coal Fly Ash

本研究为开发一种新的二氧化碳物理吸收方法进行了基础研究。本研究采用碱法将工业废渣中的粉煤灰转化为沸石。沸石（我们称之为“沸石化煤粉煤灰”）被用来吸收空气中含有的二氧化碳——二氧化碳混合气体被认为是烟道气。用天然沸石和市面上出售的人造沸石作为吸附剂，在气体吸附实验中比较了吸附剂的吸收率。粉煤灰与氢氧化钠水溶液在90℃左右加热16 h，形成Phillipsite型沸石。采用x射线粉末衍射分析和阳离子交换容量测定对粉煤灰的沸石化进行了表征。将粉状沸石粉煤灰以“kibushi”粘土为粘结剂，低温加热固化成球团（高度为diameter×6mm 7mm）。由于沸石化后的粉煤灰经高温加热后，使philsite型沸石熄灭，沸石的性质消失。天然沸石对气体的吸收速度是沸石煤粉煤灰的4倍以上。因为天然沸石是由丝光沸石组成的，其大孔半径比红唇沸石大。实验表明，粉煤灰可以有效地作为二氧化碳吸附剂。提出了一种新的二氧化碳吸收方法，作为工业废渣粉煤灰的回收利用技术。

This study was conducted as a basic research for the development of a new physical absorption method of carbon dioxide. In this study, coal fly ash of industrial waste was transformed into zeolite by alkali treatment. And the zeolite (we call it "zeolitized coal fly ash") was used to absorb carbon dioxide contained in air-carbon dioxide mixing gas considered as flue gases. Natural zeolites and artificial zeolite being on sale were also used for absorbent to compare the absorptivity in the gas absorption experiments.Phillipsite type zeolites were formed through reaction of coal fly ash with IN NaOH aqueous solution by heating about 90℃ for 16 hours. The zeolitization of coal fly ash was checked by X-ray powder diffraction analysis and cation exchange capacity measurement. Powdery zeolitized coal fly ash was solidified to pellet(7mm in diameter×6mm in height) by heating at low temperature with 'kibushi'clay for binder. Because, upon being heated at high temperature, zeolitized coal fly ash was extinguished the phillipsite type zeolites and disappeared properties of zeolite.The rate of gas absorption by natural zeolite was four times faster or more than zeolitized coal fly ash. Because natural zeolite was composed of mordenite with larger macropore radius than phillipsite.It was clarified experimentally that coal fly ash could be applied to absorbent of carbon dioxide effectively.A new absorption method of carbon dioxide was proposed as a technology for recycling of coal fly ash of industrial waste.