Reengineering of the carbon-to-acetylene process featuring negative carbon emission

Various sources of carbon can be converted into acetylene (C2H2) by using the key intermediate calcium carbide (CaC2). However, the production of CaC2 is a typical energy-intensive process, accompanied by considerable carbon dioxide (CO2) emissions and a large amount of industrial solid waste. In this study, a sustainable methodology for carbon-to-acetylene and carbon monoxide (CO) co-production as well as CO2 capture based on BaCO3−BaC2−Ba(OH)2−BaCO3 looping was first established, in which BaC2 replaced CaC2 as the key intermediate of the carbon-to-acetylene process to generate C2H2. The kinetic behavior investigation of the BaC2 formation indicated that the solid-phase synthesized BaC2 is a promising intermediate for the carbon-to-acetylene conversion owing to its faster kinetics, lower formation temperature, and no carbon dioxide release compared with those observed for the CaC2 production. Moreover, the lab-scale recovery of barium to carbide formation was conducted as the proof-of-concept to validate the coupling process of carbon-to-acetylene with CO2 capture based on Ba looping, resulting in less carbide slag waste and negative carbon emission. The facile co-production of carbon monoxide, environmentally friendly process, and convenience of large-scale production, as well as possible independent manufacturing of fossil resources, make barium carbide-based carbon-to-C2H2 -CO a promising key chemical platform for sustainable development. The proposed technology would provide new insights into the reengineering process of carbon to chemicals.