Odor and FT-IR Analysis of Chemical Species from Wood Materials in Pre-combustion Condition

Abstract

Not only are signals about smoke and temperature rise, given by fire, but there is also a burnt smell characteristic of fire. Focusing on the odor quality changing, it was applied to fire detection in the early stages. In order to clarify the relationship between changes in odor quality and temperature during oxidation pyrolysis and pyrolysis, the generated odor gas is collected in a sampling bag attached to the exhaust port of the TG-DTA/FT-IR system. FT-IR was used to measure pyrolysis and combustion gases to determine chemical species based on temperature rise rate. The overall odor of the molecules generated by pyrolysis and oxidative pyrolysis in the collected gas every 300 s was then measured using electronic noses. The representation test sample was Japanese cedar. For TG-DTA, the oxygen concentration was set to 0–20% and the temperature rise rate was set to 2–20 K/min. The FT-IR results for the aldehyde group showed a lower temperature at which the absorption peaked than that by the CO. As a result of comparison between odor changes and chemical species during fire combustion, the similarity index of aldehyde groups to the odor at the time of initial fire increased by oxidative pyrolysis. From these facts, in wood and related material it was found that detection of substances based on aldehyde groups among odors generated during pyrolysis and/or combustion can be used as a possibility of fire detection for wooden materials.