X-ray translucent reaction cell for simulation of carbon mineral storage reservoir environments

Abstract

Understanding how in-situ mineralization of CO₂ affects the porosity, permeability, and pore network of the host rock is critical to assessing the viability of basalt reservoirs as carbon dioxide repositories. Here, we present an x-ray translucent environmental cell which allows carbon mineralization, and other fluid–rock reactions to be studied in real time and on the grain scale under simulated geological reservoir conditions using microtomographic imaging. The cell operates autonomously from a CT instrument and is periodically quenched and relocated for scanning, enabling long duration operando experiments. Samples are reacted under controlled conditions of chemistry, temperature, and fluid pressure. Porosity and permeability changes are tracked through digital image analysis of successive CT scans. Samples are fully recoverable, allowing for a suite of post-mortem analyses. The cell design uses readily available materials, can sustain long-term operating temperatures of up to 200 °C, and is reproducible at low cost with a centre lathe and a mill using a conveniently equipped mechanical workshop.