01 September 2023

CO2-free Calcium Carbide Manufacturing

Calcium carbide is considered a possible key component in the sustainable carbon cycle, including convenient recycling of carbon wastes to industrial uptake. However, currently employed CaC2 manufacturing process produces significant amounts of CO2. One of the main factors of its appearance is the formation of carbon oxide during the reaction. The reaction of lime ore with coal inevitably results in the formation of CO and the loss of one carbon atom. CO is usually burnt, forming CO2 to maintain the required high temperature during synthesis – 2200 °C. In the present study, we discuss that the use of calcium metal instead of lime represents a good opportunity to prevent CO2 emission since the reaction of Ca with carbon occurs in an atom-efficient manner and results in only CaC2 at a much lower temperature of 1100 °C. Here, the reaction of Ca with carbon was successfully tested to synthesize CaC2. The desired product was isolated in gram-scale amounts in 97.2% yield and 99% purity. The environmental friendliness of the proposed method originates from the calculations of the E-factor and much lower reaction temperature. Rationalization is provided concerning the cost factor of Ca within the considered process.

Reference: Chin. J. Chem., 2023, ASAP.

DOI: 10.1002/cjoc.202300358