Deep Underground Science and Engineering

A novel technological conception of integrated large-scale CO2 storage, water recovery, geothermal extraction, hydrogen production, and energy storage

Huiling Ci, Bing Bai, Tiancheng Zhang, Hongwu Lei

Abstract

Carbon capture, utilization, and storage (CCUS) is widely recognized as a technological system capable of achieving large-scale carbon dioxide emission reductions. However, its high costs and potential risks have limited its large-scale implementation. This study focuses on enhancing the economic viability of traditional CCUS by proposing a novel technological concept and system that integrates CCUS with water extraction, geothermal energy harvesting, hydrogen production, and energy storage. The system comprises three interconnected modules: (1) upstream CO2-enhanced water recovery (CO2-EWR), (2) midstream green hydrogen synthesis, and (3) downstream energy utilization. Through detailed explanations of the fundamental concept and related technological systems, its feasibility is demonstrated. Preliminary estimates indicate that under current conditions, the system lacks economic advantages. However, significant reductions in hydrogen production costs could enable the system to yield a profit of nearly 1000 Chinese Yuan (approximately 145 US dollars) per ton of CO2 in the future. Following an in-depth investigation, priority implementation in China's Tarim Basin and Ordos Basin is recommended. This technological system could significantly extend the industrial chain of traditional CCUS projects, promising additional social and ecnomic benefits. Furthermore, the involved gas–water displacement technology can help manage formation pressure and reduce leakage risks in large-scale carbon storage projects.