Assessment of the Climate Benefits and Economic Feasibility of Carbon Dioxide Utilization Pathways

[Introduction] Carbon utilization technologies, which convert CO2 into valuable products such as fuels, chemicals, and building materials, represent an innovative approach to mitigating climate change and promoting resource recycling. The analysis of climate benefits and economic viability is a significant challenge in current research on carbon utilization technologies and is key to their development and implementation. [Method] This study developed a methodology for quantifying the emission abatement benefits and economic viability of carbon utilization technologies, based on background analysis, baseline selection, boundary definition, and indicator calculation. Using this methodology, key indicators such as emission abatement per unit, levelized cost of emission abatement, and abatement benefit per unit for four typical CO2 utilization technologies were analyzed. [Result] The study shows that CO2 enhanced oil recovery (CO2-EOR) achieves a unit emission abatement of 1.62～5.85 t CO2/t oil. When the price per barrel of oil is around 390 yuan, the abatement benefit for CO2-EOR varies from 2 to 1152 yuan/t CO2 under different injection-production ratios. The CO2 and green hydrogen-based methanol production achieves a unit emission abatement of 4.89 t CO2/t methanol, with a negative abatement benefit, requiring subsidies or equivalent carbon pricing support of 18 to 833 yuan/t CO2 to break even on abatement. The carbon capture and utilization of steel slag for building material production yields a unit emission abatement of 0.94 t CO2/t steel slag powder, with an abatement benefit of 36 to 164 yuan/t CO2. The microalgae cultivation for biodiesel production achieves a unit emission abatement of 0.36 t CO2/t algae powder, and the abatement benefit can reach 30,000 to 90,000 yuan/t CO2. Beyond the key indicators emphasized in this paper, actual project decisions must also consider the impact of technological stability, market environment, and resource conditions on economic feasibility. [Conclusion] The carbon abatement effectiveness and applicability of different carbon utilization technologies vary across different scenarios. To ensure their positive contribution to emission abatement, it is necessary to improve institutional frameworks, facilitate the integration of these technologies into carbon markets, and assess their actual climate impact, thereby supporting technologies that provide genuine climate benefits.