STUDY ON THE ADSORPTIVE REMOVAL OF INDOOR CARBON DIOXIDE IN SUBWAY

초록

High carbon dioxide (CO2) concentration of subway is one of the big environmental concerns in many countries. In Korea, new indoor air quality guideline for and subway was set to keep CO2 concentration lower than 3,500 ppm at rush hours. In this study, CO2 levels in Seoul metropolitan subway cars were monitored to check if CO2 concentration in subway is really serious. And, it was found that CO2 levels were often higher than 3,500 ppm during running. Usually, the ventilation is most widely used to control CO2 concentration for normal indoor space. However, as for subway, because the outdoor air is usually polluted with high concentration of particulate matters, the ventilation is not appropriate sometimes. In addition, the ventilation in summer or winter season requires large amount of additional cooling or heating energy. Therefore, the introduction of an alternative way to substitute ventilation is urgently needed. In this study, an adsorptive CO2 removal system was suggested. Zeolite was used as the adsorbent with our system. A prototype CO2 removal system was tested in a subway car in which CO2 is continually supplied artificially. The indoor CO2 concentration could be kept lower than 1,500 ppm when the initial CO2 was around 5,000 ppm. Further study on the regeneration method of used CO2 adsorbent is undergoing.