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做了基础研究。以工业废渣粉煤灰为原料，采用碱处理法制备沸石.将空气-二氧化碳混合气作为烟气，用沸石（我们称之为沸石粉煤灰）吸收其中的二氧化碳。以天然沸石和销售的人造沸石为吸附剂，在90℃左右加热16 h，使粉煤灰与1 N NaOH水溶液反应，生成钙十字沸石。采用X射线粉末衍射分析和阳离子交换容量测定等方法对粉煤灰的沸石化进行了研究。以粉煤灰为原料，以“kibushi”粘土为粘结剂，采用低温加热法将粉煤灰固化成直径为7 mm、高为6 mm的球团。这是因为粉煤灰经过沸石化处理后，在高温下钙钛矿型沸石被熄灭，沸石的性质消失，天然沸石的气体吸收速率比粉煤灰沸石化处理快4倍以上。由于天然沸石是由丝光沸石组成，其大孔半径大于钙十字沸石，实验表明粉煤灰可以有效地用作CO2的吸收剂，提出了一种新的CO2吸收方法，作为工业废弃物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.