Template free ZSM-5 from siliceous rice hull ash with varying C contents

Green technology or use of environmentally friendly chemical process is now gaining popularity because of the demand from the conscientious consumers and strict environmental regulations. For manufacturing ZSM-5, tetrapropylammonium cations are used as a template. The use of toxic tetrapropylammonium hydroxide for templating ZSM-5 is a common practice and it also adds to the production costs. In this paper, a template free synthesis of ZSM-5 with various C contents using siliceous rice hulls, a byproduct of rice milling industries, is discussed. These ZSM-5 zeolites composited with amorphous C could be commercially exploited for the removal of volatile organic compounds (VOCs) from either wastewater or air. Carbon free ZSM-5 was also produced by pyrolyzing the C-containing ZSM-5 at 773 K for 3 h.