Absorption Capability of CO2 Scrubbers Under Variable Metabolic Loadings.

Abstract

The objective of this project was to demonstrate the effects of varying metabolic loadings on the absorption capability of carbon dioxide scrubbers. The study's main purpose was to determine whether prebreathing a canister, that is, subjecting it to a low initial CO2 loading, would result in a longer lifetime for the canister. At present there exists no means for predicting the performance of a canister which sees non-cyclic metabolic profiles. The experimental study was conducted in the Coastal engineering Laboratory at the United States Naval academy. Carbon dioxide was injected into a closed circuit system simulating the human breathing cycle. The carbon dioxide effluent level was measured with an infrared analyzer and recorded on a strip-chart recorder. Each test was continued until effluent C02 levels reached 1.0%. - Four C02 injection profiles were chosen for this experiment. Each profile was run twice, for a total of eight tests. Canister efficiency for each test was approximately 20 to 30%. For this experiment, prebreathing the canisters did not result in a longer CO2 scrubber lifetime. The results were contrary to what was expected: the canisters which were subjected initially to low C02 loadings reached breakthrough time much sooner than canisters which were subjected initially to high loadings.