Exhaust gas purification process using fly ash-based sorbents

A fly ash-based sorbents has been designed for NO2 capture and separation from exhaust gases at room temperature. NO2 adsorbents-Na-X, SBA-15, MCM-41 were prepared by synthesizing from fly ash and modifying with polyethylene glycol (PEG). The sorption capacity of sorbents have been evaluated for NO2 removal from the simulated gas streams in a thermogravimetric analyzer TGA/DSC1at 25 degrees C under atmospheric pressure. The results show that the highest sorption capacity characterized zeolite Na-X-(FA) 44.7 mg NO2 g(-1) sorbent. After impregnation with PEG, the sorption capacity of SBA-15(FA) increased from 1.6 mg NO(2)g(-1) to 3.2 mg NO(2)g(-1), while for Na-X(FA) and MCM-41(FA) dropped after impregnation with PEG. In addition, the spent sorbent can be regenerated easily and completely by heating to 100 degrees C. With this study the present study may open a new window for developing high-performance fly ash-based sorbents for NO2 removal from exhaust gases.