Converting CO2 from a Harmful Gas to a Renewable Source of Matter and Energy: A Review

Abstract

The emission of greenhouse gases, specifically CO2, has reached non-acceptable levels causing global warming with adverse effects. Owing to rigorous ongoing research, these harmful substances might be converted to beneficial sources. The main objective of this study was to review the most effective processes that might utilize carbon dioxide to produce various substances, chemicals, and energy. For this, different existing and projected short-term and long-term strategies have been presented and discussed. Specifically, processes like the artificial tree of Lackner to capture CO2, chemical looping combustion (CLC), the application of CO2 in the food and processing industry, wastewater treatment, supercritical and refrigerant CO2, hydrogenation of CO2, the cultivation of microalgae, thermolysis, electrolysis, and photoelectrocatalysis techniques for producing hydrogen and biofuels, based on thermochemical processes, are the most promising ways to reduce and reuse CO2. Such behavioral changes can lead to the exchange of CO2 between natural reservoirs and help to maintain CO2 equilibrium among the atmosphere, the upper mixed layer of the sea, and the deep sea. Consequently, the mean global temperature and the climate are directly affected.