UC Berkeley

Absent unvented combustion, in occupied indoor spaces, CO2 concentrations depend primarily on three factors: Outdoor CO2 concentrations, CO2 emission rates from human metabolism, and the outdoor-air ventilation rate. Indoor CO2 levels are generally managed by means of dilution with outdoor air. In this work, we investigate an alternative approach to controlling indoor CO2: Active removal using a solid sorbent. We report parameterizations of chemical kinetics and uptake capacity to soda-lime sorbent across a range of conditions relevant to indoor environments. Reaction rate constants for the interaction of Ca(OH) 2 present in soda-lime and CO2 range from 1.8×10-2 to 1.5×10-1 m2 mol-1 s-1, increasing with higher relative humidity (RH). Uptake capacities range from 0.04 to 0.36 g CO2/g sorbent, also increasing with higher RH. These data facilitate assessment of the technical feasibility of soda-lime scrubbers in buildings as an option for controlling indoor CO2.