A novel approach for active and synchronous removal of fire-generated CO based on Co-La0.1 catalyst: From lab-scale to full-scale tests

CO is an invisible killer that severely threatens the safety of trapped personnel in fire disasters. The existing CO removal approaches are passive and ineffective, which could not satisfy the emergency rescue needs. An active and synchronous CO removal approach (ASCR) based on catalytic oxidation is proposed. By spraying dry powder extinguishant and catalyst powder, the isolation layer and oxidation layer are formed on the fuel surface. CO removal is achieved by both combustion suppression and CO oxidation methods. The synthesized Co-La0.1 catalyst exhibited superior catalytic activity, thermal stability, and selectivity, which met the application requirements of the ASCR approach. The results of lab-scall tests demonstrated that the CO concentration in the smoke flow decreased from 135 ppm to 0 ppm immediately once employing the ASCR approach. Full-scale tests in the confined tunnel further verified the practical application performance. With spraying 2 kg extinguishant and 0.9 kg catalyst powder, CO concentration increased merely by ∼ 20 ppm within 50 min, which was far lower than that without taking any disposal measures (∼800 ppm). This approach can effectively control the CO concentration below the safety threshold in fire disasters and is significant for emergency rescue.