An estimated 2.5 billion people, or about one-third of the world's population, rely on biomass fuel for cooking. Emissions from biomass cookstoves contribute to global climate change, indoor/local air quality issues, and related health effects. I particular, indoor air quality issues related to biomass cookstoves 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 toxins like formaldehyde) and particulate matter (PM) are especially problematic. Similar to the evolution of emissions controls for automobiles, advanced biomass cookstoves 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 proposed the inclusion of a low-cost, alternative oxidation catalyst that is integrated into the stove. In Phase I, the catalyst, originaly developed as a diesel soot oxidation catalyst, was synthesized, characterized, and tested in a specialized prototype cookstove. Further catalyst development activities were undertaken to optimize the constituent ratios, determine catalyst lifetime, and develop simple methods for deposition on the support. The prototype stove designed and tested in Phase I improved heat transfer to the cooking vessel and included design features that allow fine tuning of the air flow, fuel/air mixing, and heat release. In addition, the prototype stove includes several design features to improve ease-of-use and safety. The Phase I technical approach relied heavily on computational fluid dynamics (CFD), rapid prototyping, and laboratory testing. Laboratory measurements of PM, CO, and hydrocarbon emissions have been performed for both baseline stoves and the prototype low-cost, catalytic stove. The Phase II technical approach includes refinement of the catalyst, improvements to the stove design to better accommodate the catalyst, field trials to gauge real-world performance and user acceptance, and design for manufacturing (DFM) analysis. The commercialization strategy for the advanced cookstove seeks to manufacture the stoves in developing countries like Kenya and Guatemala, 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. Stove customization options will be developed to accommodate local cooking traditions and variability of local biomass fuels.
of the Proposed Project to Public Health Exposure to high indoor air pollutant levels from cooking with biomass fuels is responsible for an estimated 1.6 million deaths annually and about 3% of the global burden of disease. The proposed effort seeks to develop a low-cost, catalytic biomass cookstove that will substantially reduce emissions, mitigate climate change, and save lives.
