American Association for Aerosol Research - Abstract Submission

AAAR 38th Annual Conference
October 5 - October 9, 2020

Virtual Conference

Abstract View


The Effects on Emissions of Modified Operation of Pellet-Fed Gasifier Stoves

STEPHANIE PARSONS, Ky Tanner, Andrew Grieshop, North Carolina State University

     Abstract Number: 399
     Working Group: Combustion

Abstract
Field tests of biomass pellet-fed stoves in Rwanda found lower emissions compared to other biomass stoves, in many cases approaching that of current “gold standard” technologies such as liquefied petroleum gas. However, emission factors (EFs) of particulate matter (PM2.5) and carbon monoxide (CO) during high emitting pellet tests were as high as those during low emitting wood and charcoal tests, emitting the most PM2.5 and black carbon (BC) at the startup and the end of cooking (i.e. the burnout phase). We conducted two sets of laboratory tests, based on the Water Boiling Test and the International Organization for Standardization Laboratory Sequence, to observe how varying stove operation affects emissions of PM2.5, CO, organic and elemental carbon (OC, EC), BC, and particle number. Three different variations were examined: startup operation, shut down operation, and refueling. Using kindling to ignite the stove produced almost three times higher CO and PM2.5 emissions compared to using kerosene. Low, medium, and high fan speeds during the burnout phase resulted in CO EFs 71%, 92%, and 118% higher than with the fan off, respectively. Likewise, a slight increasing trend in PM2.5 EFs was observed between the fan off and low speed compared to the medium and high speeds. Refueling with hot pellet embers blocking the gasifier holes (highest refuel height) resulted in 300% (50%) higher CO (PM2.5) EFs than the lowest refuel height. Particle number emissions increased with increasing fan speed during burnout, with the high speed emitting five times more particles than the fan off, and with increasing height of hot embers used for refueling, with the highest refuel height emitting 50% more particles than the lowest. We will communicate results to the stove manufacturer to possibly influence the stove design and operation specifications to decrease improper use.