One-pot preparation of H-mixed CH fuel and CaO-based CO sorbent by the hydrogenation of waste clamshell/eggshell at room temperature.

The preparation of clean fuel or CO adsorbents using industrial and domestic garbage is an alternative way of meeting global energy needs and alleviating environmental problems. Herein, H-mixed CH fuel and CaO-based CO sorbent were first prepared in one pot by the mechanochemical reaction of pretreated clamshell or eggshell wastes (carbon and calcium source) with calcium hydride (hydrogen source) at room temperature. In the above reactions, CH was the sole hydrocarbon product, and its yield reached 78.23%. The H/CH ratio of the produced H-mixed CH fuel was tunable according to the need by changing the reaction conditions. It is inspiring that the simultaneously formed solid CaO/carbon products were efficient CaO-based sorbents, which possessed a higher CO adsorption capacity (49.81-58.74 wt.%) at 650 °C and could maintain good adsorption stability in 30 carbonation/calcination cycles (average activity loss per cycle of only 1.6%). The three achievements of the idea are that it can simultaneously eliminate clamshell or eggshell wastes, obtain valuable clean fuel, and acquire efficient CaO-based sorbents.