MMIJ 2020,Sendai
Sep 8 - Sep 10, 2020Online
MMIJ 2020,Sendai
Sep 8 - Sep 10, 2020Online
[1K0101-10-10]Hydrogen production with CO2 utilization and storage through hydrothermal alteration of peridotite
○Jiajie Wang1, Noriaki Watanabe1, Atsushi Okamoto1, Kengo Nakamura1, Komai Takeshi1(1. Tohoku University)
The chairman: Takashi FUJII (National Institute of Advanced Industrial Science and Technology)
Keywords:
Carbon storage,Hydrogen production,Peridotite,CCUS,Hydrothermal
Carbon dioxide (CO2) storage and hydrogen (H2) energy replacement of fossil fuel have been regarded as promising ways to develop a sustainable low-carbon society. However, the existing CO2 storage technologies are unprofitable and H2 production processes usually emit CO2. Thus, our research group tried to develop a new system to combine CO2 storage with H2 production by using Fe(II)-bearing ultramafic rocks.
Peridotite was selected for experiments in this study, it is the dominant rock of mantle and abundant on the Earth’s surface, which consists mainly of olivine [(Mg,Fe)2SiO4]. In our study, the hydrothermal alteration of peridotite under CO2-rich conditions was found not only to produce H2 by the oxidation of Fe(II) in it but also to simultaneously store CO2 by cations carbonation. With the use of a CO2-rich solution (e.g., 0.5 mol/L HCO3-) at a moderate temperature (250-300 °C), the rate of H2 production during peridotite hydration can be drastically enhanced. The CO2 after being utilized to promote H2 production was stored in magnesite [(Mg,Fe)CO3] or reduced to formic acid (HCOOH).
Our research group has successfully controlled the behaviors of Fe(II) and Mg during H2O-peridotite-CO2 reactions by varying reaction conditions for H2 production and CO2 storage, respectively, on lab-scale. The mechanisms and thermodynamics of H2O-peridotite-CO2 reactions in different environments were also revealed. Based on experimental results, possible large-scale systems were proposed with the efficient utilization of geothermal or industrial wasted heat.
This study proposed a new H2 production with CO2 storage system based on natural phenomena. It has a potential contribution to sustainable low-carbon society development by providing an environmentally friendly avenue for large scale H2 production with considerable CO2 utilization and storage.
Peridotite was selected for experiments in this study, it is the dominant rock of mantle and abundant on the Earth’s surface, which consists mainly of olivine [(Mg,Fe)2SiO4]. In our study, the hydrothermal alteration of peridotite under CO2-rich conditions was found not only to produce H2 by the oxidation of Fe(II) in it but also to simultaneously store CO2 by cations carbonation. With the use of a CO2-rich solution (e.g., 0.5 mol/L HCO3-) at a moderate temperature (250-300 °C), the rate of H2 production during peridotite hydration can be drastically enhanced. The CO2 after being utilized to promote H2 production was stored in magnesite [(Mg,Fe)CO3] or reduced to formic acid (HCOOH).
Our research group has successfully controlled the behaviors of Fe(II) and Mg during H2O-peridotite-CO2 reactions by varying reaction conditions for H2 production and CO2 storage, respectively, on lab-scale. The mechanisms and thermodynamics of H2O-peridotite-CO2 reactions in different environments were also revealed. Based on experimental results, possible large-scale systems were proposed with the efficient utilization of geothermal or industrial wasted heat.
This study proposed a new H2 production with CO2 storage system based on natural phenomena. It has a potential contribution to sustainable low-carbon society development by providing an environmentally friendly avenue for large scale H2 production with considerable CO2 utilization and storage.