Abstract:
Objective This study aims to address the intermittency and high energy consumption challenges of direct air capture (DAC) of CO2 for low-concentration sources.
Method Four continuous DAC systems with different photovoltaic (PV)-coupled power supply configurations were developed for distributed carbon capture in the oil and gas industry, taking a PV project in the Qaidam Basin as a case study. Economic indicators, including levelized cost of electricity (LCOE) and levelized cost of DAC (LCOD), were calculated. An in-depth sensitivity analysis was then conducted to assess the impact of key factors, such as annual solar irradiance, PV capacity, sorbent cost, and capture energy intensity, on system performance.
Result First, compared to PV-battery, PV-thermal, and PV-grid systems, the PV system coupled with both thermal and battery energy storage (PV-TES-BESS) achieves an LCOD of 265 USD/t. Although slightly higher than that of the PV-grid system, it provides 100% renewable power supply and lifecycle carbon negativity, representing a more competitive solution. Second, assuming an annual 5% improvement in PV technology over the next decade, the LCOD is expected to decrease by approximately half, and system scale-up will significantly reduce unit costs. Third, the LCOD exhibits linear sensitivity to capture energy intensity, ranging from 265 to 946 USD/t, as the energy intensity increases from 1400 to 5000 kW·h/t.
Conclusion These findings demonstrate the significant economic potential of off-grid PV-coupled driven continuous DAC systems through reductions in energy intensity and technological advancements, providing a distributed green-power-based carbon capture solution for the low-carbon transition of oil and gas fields.