Insights into the hydrogen generation from water-iron rock reactions at low temperature and the key limiting factors in the process

摘要

Hydrogen generation from water-rock reactions is mostly studied at high temperature. This study investigated the process at low temperature (5-20 degrees C) using both synthetic and natural iron minerals (magnetite, goethite and hematite) for a better understanding about the reaction pathway and the key factors involved. Maximum hydrogen generation detected was 6.8 mu mol/g with natural goethite. Characterization of the minerals by X-ray diffraction (XRD), X-ray fluorescence (XRF), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS) and aqueous phase by Inductively coupled plasma atomic emission spectrometer (ICP-AES) and ferrozine spectrophotometry revealed hydrogen generation to be related to the composition and specific surface area of the minerals. Low concentration of methane (200 nmol/g from natural magnetite) was also detected from natural minerals, which indicated catalytic effects. The study is significant for hydrogen generation at low temperature and yield insights on fate of carbon dioxide in the underground reservoirs and a sustainable environment. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.