Study on the Adsorptive Removal of CO2 in Indoor Spaces

초록

Carbon dioxide (CO2) concentration in indoor spaces is strongly dependent on the number of residents because CO2 is exhaled from the breathing of residents. CO2 concentration in a 5 m3 of tight space without any ventilation can increase upto 5,000 ppm within in 40 mins when two residents are breathing inside. Though CO2 itself is known to be nontoxic to human, CO2 is still not healthful because it may cause many adverse effects like headache and drowsiness leading to the discomfort. Ventilation is commonly used to lower CO2 concentration, but there many cases it is not available, for example, the indoor space is the subway car running through tunnels. Usually, tunnels are polluted by various kinds of particulate matters or heavy metals, and ventilation may cause the intake of these hazardous pollutants. In this paper, study on the adsorptive removal of CO2 for indoor space, like subway cabin, was carried out. CO2 adsorption characteristics of zeolite modified with metal hydroxide was tested. It was observed that CO2 concentration of indoor space could be kept lower than 1,000 ppm. The regeneration system for reuse of these adsorbents is under study.