Characterization of biochar produced from Al Ghaf Tree for CO₂ Capture

Climate change, global warming, and rise in water levels are environmental problems caused by the high emissions of greenhouse gases, and the most harmed one is carbon dioxide. Biochar is a material produced by thermochemical conversions with oxygen-depleted conditions of organic materials, and this process calls pyrolysis. Recently, it has been evaluated as a carbon dioxide capture, and its porous structure, structural properties, and production methods are easy. Al Ghaf (Prosopis cineraria) tree is one of the United Arab Emirates’ national trees with a wide range of intriguing properties, including high nutritional value, medicinal/pharmaceutical potential, and biosorption. This paper focuses on the biochar synthesized from three parts of the Al Ghaf tree: leaves, roots, and branches, to determine which part can achieve the maximum carbon dioxide capture. The ability of the produced biochar to capture carbon dioxide was tested through direct gas–solid​ interaction inside an integrated fluidized bed reactor. The carbon dioxide adsorption capacity was expressed by two methods related to (a) the loaded biochar mass and (b) the total amount of carbon dioxide fed to the reactor. The carbon dioxide adsorption capacity results concerning the loaded mass were 6.88%, 5.50%, and 3.63% for leaves, roots, and branches, respectively. At the same time, the results based on the total amount of carbon dioxide fed were 65.5%, 58.7%, and 37.7% for leaves, roots, and branches, respectively. Such results were confirmed by the physicochemical characteristics of the synthesized biochar using Scanning Electron Microscopy with Energy Dispersive X-ray Analysis, Thermogravimetric analysis (TGA), and X-ray diffraction analysis. Al Ghaf tree requires further study and inquiry to identify the most appropriate applications.