The Effects of Air Flow Rates, Secondary Air Inlet Geometry, Fuel Type, and Operating Mode on the Performance of Gasifier Cookstoves

Abstract

Development of biomass cookstoves that reduce emissions of CO and PM2.5 by more than 50% and 95%, respectively, compared to a three-stone fire has been promoted as part of efforts to reduce exposure to household air pollution (HAP) among people that cook with solid fuels. Gasifier cookstoves have attracted interest because some have been shown to emit less CO and PM2.5 than other designs. A laboratory test bed and new test procedure were used to investigate the influence of air flow rates, stove geometry, fuel type, and operating mode on gasifier cookstove performance. Power output, CO emissions, PM2.5 emissions, fuel consumption rates, producer gas composition, and fuel bed temperatures were measured. The test bed emitted <41 mg·MJd–1 PM2.5 and <8 g·MJd–1 CO when operating normally with certain prepared fuels, but order of magnitude increases in emission factors were observed for other fuels and during refueling. Changes in operating mode and fuel type also affected the composition of the producer gas entering the secondary combustion zone. Overall, the results suggest that the effects of fuel type and operator behavior on emissions need to be considered, in addition to cookstove design, as part of efforts to reduce exposure to HAP.

Energy and Exergy Analysis of an Advanced Cookstove-Based Annular Thermoelectric Cogeneration System

“…The secondary air (combustion air) injection of the proposed cookstove is skewed to an angle of 45°towards bottom grate [11,12,16]. This is to confirm the better turbulence in the course of volatile combustion and for the period of char combustion.…”

The Firepower Sweep Test: A novel approach to cookstove laboratory testing

“…As with other stove types, the WBT procedure for batch‐fed wood stoves missed several important operating regimes, including refueling and shut‐down. During refueling, room‐temperature fuel was added on top of the hot fuel bed, resulting in disruption of the secondary flame and a rapid release of unburned combustible gases . During shut‐down, firepowers and MCEs were lower than during the WBT because the secondary flame was extinguished.…”

“…Descriptions of the emissions sampling methodologies can be found in the literature . Briefly, emissions were captured and diluted in a total‐capture hood using a constant‐volume displacement pump.…”

“…Descriptions of the emissions sampling methodologies can be found in the literature. 24,35,36,42,43 Briefly, emissions were captured and diluted in a total-capture hood using a constant-volume displacement pump. Integrated particle emissions were sampled isokinetically from the main exhaust stream, drawn through a cyclone (URG, 16.7…”

“…During refueling, room-temperature fuel was added on top of the hot fuel bed, resulting in disruption of the secondary flame and a rapid release of unburned combustible gases. 42,43 During shut-down, firepowers and MCEs were lower than during the WBT because the secondary flame was extinguished.…”