Low-Cost Catalytic Biomass Cookstove for Improved Indoor Air Quality

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DESCRIPTION: An estimated 2.5 billion people, or about one-third of the world's population, rely on biomass fuel for cooking. Emissions from biomass cook stoves contribute to global climate change, indoor/local air quality issues, and related health effects. In particular, indoor ir quality issues related to biomass cook stoves contribute significantly to rates of acute respiratory infection. Recently developed forced air and "rocket" stoves offer improvements but are unlikely to consistently meet WHO guidelines for indoor air quality. Emissions of CO, unburned hydrocarbons (including air toxics like formaldehyde) and particulate matter (PM) are particularly problematic. Similar to the evolution of emissions controls for automobiles, advanced biomass cook stoves have progressed to the point where inclusion of an oxidation catalyst is the logical next step. However, the widely used noble-metal oxidation catalysts are prohibitively expensive. Instead, we propose the inclusion of a low-cost alternative oxidation catalyst that is integrated into the stove. The proposed catalyst, originally developed as a diesel soot oxidation catalyst, has previously been synthesized and tested in our laboratory, and its activity for oxidation of black carbon particles has been confirmed. Further catalyst development activities that will be addressed in this program include optimization of the constituent ratios, determining the activity for oxidation of CO and unburned hydrocarbons, and testing in a real-world combustion application. To maximize heat transfer to the contents of the pot, the proposed stove design also includes design features that allow fine tuning of the air flow, fuel/ai mixing, and heat release. The proposed Phase I approach will rely heavily on computational fluid dynamics (CFD), rapid prototyping, and laboratory testing. Laboratory measurements of PM, CO, and hydrocarbon emissions will be performed for both baseline stoves and the prototype low-cost, catalytic stove. The commercialization strategy for the advanced cook stove seeks to manufacture the stoves in developing countries like Kenya, where the stoves would be sold. This approach will lower manufacturing costs and provide local jobs. Unlike other catalysts, the proposed catalyst requires no specialized wet chemistry methods for its synthesis. In contrast, the catalyst synthesis is essentially the same as traditional glass making and requires only a furnace and commodity chemicals. All stages of the development will consider local manufacturability, maintenance, and user acceptance. User acceptance will depend on local cooking traditions and variability of local biomass fuels. We plan to work closely with the CDC and the Global Alliance for Clean Cook stoves to understand user needs and to arrange field trials in Phase II.