Effect of the Fluorine Resource Conversion Process of SF6 Gas for a Circular Economy

Currently, SF6 gas recovered from electrical equipment and deemed unnecessary is treated by wet combustion and then disposed of as sludge. In the future, if the need for SF6 gas decomposition treatment increases, the utilization of the products after SF6 gas decomposition treatment as fluorine resources again is desirable from the perspective of circular economy. We have developed an entirely new decomposition processing technology that reduces SF6 with hydrogen. This technology decomposes SF6 gas by hydrogen reduction at high temperatures, then utilizes gas-solid reactions with calcium carbonate to separate fluorine and sulfur components, thereby extracting them as high-purity fluorine resources. Based on fundamental reaction data, a demonstration facility with a processing capacity of 1 kg/h of SF6 gas was designed. Calculations of CO2 emissions from the developed process confirmed that emissions can be reduced to levels equivalent to or lower than those of conventional treatment methods.