The beneficial use of ultrasound in free template synthesis of nanostructured ZSM-5 zeolite from rice husk ash used in catalytic cracking of light naphtha: Effect of irradiation power

A series of ZSM-5 zeolite has been synthesized with ultrasonic energy and their catalytic activity has been investigated in catalytic cracking of light naphtha. ZSM-5 zeolites have been synthesized from rice husk ash without using the organic template. Effect of ultrasound power (100, 200 and 300 W) on physicho-chemical properties of synthesized zeolite was investigated. It was found that with varying of the ultrasound irradiation power, the physico-chemical properties of prepared ZSM-5 changed significantly. The XRD analysis showed that the applying ultrasound energy led to decrease the crystal size and crystalinity of ZSM-5. The FESEM analysis showed that the morphology of synthesized ZSM-5 changed from microscale hexagonal-shaped to much smaller rough spheres. Furthermore, the external surface area and meso pore volume of ZSM-5 depend on the ultrasound power. Results of catalytic activity test showed that the ultrasound power has great influence on the activity of ZSM-5 and the sample which synthesized with ultrasound power of 200 W showed the highest catalytic activity. TGA-DTG analysis of spent catalyst showed that the amount of coke deposited on the samples is depended on the acidity of catalysts. Furthermore, synthesized catalyst with ultrasound power of 200 W showed the highest structure stability after 12hr catalytic test. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V.