Establishing a Market for Carbon-Neutral Technology in Concrete Waste Recycling by Sequestering Flue CO2: An Evolutionary Game Theory–Based Case Study in Hong Kong

The construction sector significantly impacts the environment through concrete waste and CO2 emissions. Carbonation technology not only enhances the strength properties of recycled materials such as recycled concrete aggregate (RCA) and waste concrete powder (WCP) but also sequesters CO2, thereby potentially increasing the value of RCA and WCP for concrete production. Large-scale adoption of this technology can reduce CO2 emissions, improve air quality, and enhance recycling by utilizing flue CO2 from cement plants, creating efficient practices and new business opportunities. However, the financial feasibility of scaling up carbonation technology in concrete recycling remains underexplored, particularly in relation to market incentives and stakeholder behavior. This study addresses this gap by developing an integrated decision-making framework that combines evolutionary game theory, cost–benefit analysis, and rationality constraints to guide the formation of carbon-neutral construction markets. This paper assesses the financial motivations of key stakeholders—governments, recycling facilities, and cement manufacturers—to establish a concrete recycling market, focusing on integrating flue CO2 and underutilized WCP. Based on evolutionary game theory, this study establishes a robust framework that integrates benefit–cost analysis and the individual rationality condition to comprehensively address technical, environmental, and financial factors while analyzing strategic decisions and optimizing stakeholder interactions. This study highlights the importance of balanced CO2 pricing in the initial market development stage to minimize subsidies and ensure financial sustainability. With a subsidy, CO2 is priced at 1,456 HKD/t; without it, the price rises to 1,525 HKD/t, requiring adjustments to RCA and WCP prices or additional subsidies to maintain stability. In a stable market without subsidies, the recycling facility can achieve financial independence by procuring CO2 at 1,456 HKD/t, with minimum product prices of 156 HKD/t for RCA and 159 HKD/t for WCP to cover costs and remain competitive. This study offers key insights to kickstart the market for carbon-neutral waste-based concrete production, advancing the sustainability of the construction and demolition recycling industry. Additionally, it supports the development of carbon markets, enabling organizations that capture and sequester CO2 to earn carbon credits, further promoting sustainable practices.