A critical review on CO₂ sequestration using construction and demolition waste: Future scope and perspective

In recent years, the building industry has looked for technological ways to protect the environment and preserve natural resources. Since the COVID-19 epidemic, there has been a shortage of building materials, which has caused construction costs to go up. This has made it more important for sustainable development to be based on the principles of the circular economy. This gives an opportunity to utilise various reliable materials as substitutes, like construction and demolition (C&D) waste. (C&D) wastes are made up of a large chunk of all solid waste, which causes many environmental problems. The most important factor in the struggle against climate change is the reduction of CO₂ emissions from the construction sector. At the same time, globally, climate change caused in part by carbon dioxide (CO₂) emissions is an important problem that requires innovative carbon sequestration strategies. Because C&D waste is alkaline-rich (e.g., calcium hydroxide and calcium-silicate-hydrate (C-S-H)), it can be used to sequester CO₂ by converting it into thermodynamically stable carbonates. Temperature, partial pressure of CO₂, time, process route, humidity, and the water-to-solid ratio (w/s) can affect the CO₂ sequestration over the C&D wastes.