Experimental study on a smoke airflow CO filtration and elimination device based on particulate Co3O4 catalyst

The large amounts of CO gas produced during tunnel blasting operations pose a serious threat to safe production, and finding an effective method to eliminate CO from smoke and airflow remains a significant challenge. Based on the characteristics of thermal regeneration and the principle of catalytic oxidation, we designed a CO filtration and elimination device for smoke and airflow that can perform in-situ thermal regeneration. The device eliminates CO by drawing it from the smoke and airflow and bringing it into contact with catalytic particles. The Co3O4 catalyst, synthesized through particle forming processes, exhibits good strength and catalytic activity, meeting the application requirements of the device. Catalyst regeneration is accomplished through in-situ heating and hot air purging. Multiple modular testing experiments validated the feasibility of the particle-based catalyst device. Subsequently, a full set of small-scale prototypes was developed, and CO concentration surge experiments demonstrated that under ambient humidity conditions of 61.2 %-68.5 %, the prototype achieved a CO elimination rate of 72.59 % after 500 seconds. Finally, full-scale tests in the Dalian Bay subsea tunnel further verified its practical performance, with CO elimination rates exceeding 71.4 % in two elimination cycles and a regeneration rate of over 98 %. The test results indicate that the smoke and airflow CO filtration and elimination device can effectively remove CO from smoke and airflow, and holds great potential for widespread application in tunnel blasting operations.