Measurement and Modeling of Carbon Monoxide Emission Rates from Multiple Wood Pellet Types

Abstract

There is a potential hazard associated with bulk storage of wood pellets because they have been shown to off-gas carbon monoxide (CO). The risk to building occupants from the emission of and exposure to CO from stored pellets has not yet been fully studied. The present study was designed to measure the emission rates from wood pellets and develop a model to predict the CO emission rate. The 20 gallon steel drums were filled to approximately 50% of their volume with wood pellets and CO, and oxygen (O2), carbon dioxide (CO2), temperature (T), and relative humidity (RH) were measured as a function of time. A variety of conditions were tested including the type of wood, age of the pellets, volume of the headspace, humidity, surface/volume ratio, and temperature. An improved kinetic model was developed to predict the CO emission rate. The model assumes that the reaction generating CO is surface-area-limited. The measurements were well-fit by the mathematical model (R2 in the range of 0.93–0.99), suggesting tha...