Relationship between High and Low Power Carbon Monoxide and Particulate Matter Emissions in Rocket Stoves (pdf)
Dean Still and Nordica MacCarty, Aprovechoi Research Center, July 13th, 2006

The following graphs show preliminary results from seven single tests of various Rocket stoves. The stoves were tested using the 2003 revised UCB water boiling test under the Aprovechoi laboratory emissions hood. During the WBT, the stove emissions are recorded at both high and low power when bringing the water to boil and when simmering. The study was funded by the USEPA/Partnership for Clean Indoor Air and the Shell Foundation.

The question has been raised whether measured COi emissions can predict levels of PMi. In Rocket stoves during combustion, the levels of COi and PMi are often inversely related. It may be that cleaner burning stoves end up producing less COi and PMi and that dirtier stoves create more of both types of pollution. However, in a Rocket type stove while the fire is burning:

• COi Emissions are usually lower during boiling but higher during simmering when there is less flame.

• PMi Emissions are higher during boiling when there is more flame but lower during simmering.

COi emissions are reduced when the gas is exposed to flame which burns it and converts the COi to CO2. However, PMi is often produced in the flames. For example, in the Rocket side-feed stove with secondary air, COi levels increased from 8.3 g/kg at high power to 22 g/kg when the stove was at low power making smaller flames. PMi was reduced from 1.6 to 0.4 mg/kg when the stove was turned down for simmering.