Emissions reduction in a household biomass cook stove with a simple modification

Air pollution is the world’s largest single environmental health risk. Globally, 3.8 million deaths were attributable to household air pollution in 2016, almost all in low-and middle-income countries. This is mainly due to cooking with solid biomass in substandard traditional stoves, as 2,700 million people (38 % of world population) rely on this method. These traditional processes produce very high emissions of unburnt products as CO, volatile organic compounds (VOC), polycyclic aromatic hydrocarbons (PAH), and soot, which lead to several health problems. One possible solution to address this situation is to re-engineer the employed devices and methods, with concepts such as the top-lit updraft gasifier (TLUD). In this work, a TLUD-based cook stove employed in Uganda is further optimized in order to reduce its emissions. The conducted simple modification increases the residence time of the flue gas in sufficiently high temperatures for combustion (> 700-750 °C). In this way, the CO emissions are reduced from 8.5 to 2.2 gCO/MJdel. The obtained 75 % reduction in CO emissions can be therefore achieved with simple measures. These concepts can then lead to significant health improvements for biomass cook stove users.