Materials for a low-cost, clean cookstove

Award Year 

According to the World Health Organization, toxic fumes from traditional cookstoves and open fi res cause the premature deaths of nearly 2 million people worldwide every year. Further, these emissions are estimated to account for discharge of up to one-third of the world’s black carbon, which has been implicated as a significant contributor to global warming.Envirofit International is a U.S. tax-exempt, nonprofit corporation that manufactures low-cost, clean cookstoves for the developing world. (more) The company has developed and implemented new combustion chamber technology that significantly reduces emissions and improves effi ciency. Its initial cookstove product utilized a ceramic combustion chamber. Although successful, the ceramic material limited future design options for further reductions in emissions. The fragility of ceramics also led to a shorter product life, and complicated the transportation and delivery of cookstoves to remote areas in the developing world due to component breakage. Envirofi t contacted Oak Ridge National Laboratory (ORNL) in 2007 for assistance selecting low-cost metal alloys capable of surviving the harsh, high-temperature and highly corrosive conditions encountered in cookstove combustion chambers. Several technology transfer mechanisms were used by ORNL to assist Envirofi t. ORNL was able to quickly provide materials selection guidance by leveraging extensive past experience in hightemperature materials gained under Departmentof Energy programs. This effort resulted in a joint U.S. patent application among Envirofi t, Colorado State University (which provided research and development services to Envirofi t), and ORNL.Ongoing materials characterization studies by ORNL are being used to provide guidance for specifying and optimizing acceptable alloy composition ranges and impurity levels to achieve the lowest cost material that also meets durability requirements. Envirofi t’s G-3300 cookstove, utilizing the metal combustion chamber, was successfully launched in the summer of 2009. The G-3300 has been demonstrated to reduce smoke and harmful gases by up to 80%, reduce fuel use by up to 60%, and reduce cooking time by up to 50% compared with traditional cooking fi res and stoves. Th e core technology developed for the G-3300 has now been integrated across six models of wood and charcoal stoves. To date, more than 150,000 units have been sold in the developing world. (less)