Generation of hydrogen gas from polyethylene mechanically milled with Ni-doped layered double hydroxide

A process for generating hydrogen gas from polyethylene (PE) by milling and heating with Ni-doped layered double hydroxide (LDH), which was prepared also by a mechanochemical route of two-step milling operation, was reported in this work. A mixture of PE and the prepared Ni-doped LDH was first milled in a planetary ball mill for 1 h followed by heating the milled product to 700 °C under He/Ar gas environment for hydrogen emission. Characterizations by a set of analytical methods of X-ray diffraction (XRD), thermogravimetry-mass spectroscopy (TG-MS) and gas chromatography (GC) were performed on the milled and heated samples to monitor the process. Gaseous products obtained during heating mainly consisted of H2, CH4, CO, CO2 with H2 concentration over 80% between 450 and 550 °C. Such a process could be developed to treat hydrocarbon based solid wastes for hydrogen generation.