Highly Acidic, γ-Al2O3 Nanorods and SiO2 Nanoparticles Recovered from Solid Wastes as Promising Catalysts for Production of Ethylene and Diethyl Ether Biofuels

Abstract

Herein, low-cost effective, highly acidic γ-Al 2 O 3 and silica were recovered from alumina can and silica bead wastes respectively, using simple precipitation method, the prepared catalysts were characterized using different characterization techniques such as TGA, DSC, XRD, FT-IR, SEM, TEM and BET surface area measurements. Quantitative and qualitative measurements of total surface acidity and their types (Brönsted and Lewis) were measured using temperature programmed desorption of pyridine (PY-TPD) and dimethyl pyridine (DMPY-TPD) as probe molecules. Then prepared catalysts were tested in the dehydration of bioethanol to bioethylene and diethyl ether at temperature range of 300-400°C. The results indicated the superiority of γ-Al 2 O 3 catalyst than silica at all reaction temperatures. Different kinetic parameters, such as the effect of weight hourly space velocity and the effect of stability and durability for four successive catalytic cycles were studied for γ-Al 2 O 3 catalyst at a temperature range of 200-400°C, where catalyst shown remarkable stability for all catalytic cycles.