Humanitarian Engineering for Development Workers ERE 496 student Cambria Ziemer discusses solutions to help reach Millennium Development Goals 4, 6, and 7.
The news article “An analysis of combustion from a top-lit up-draft (TLUD) cookstove” reported in the second volume of the Journal of Humanitarian Engineering, which was published in 2013, discusses the design of a new type of stove and compares this stove to a traditional three stone fire. This stove reduces both fuel consumption and harmful emissions. An additional benefit of this stove is that remaining biomass after burning (biochar) can be added to soil as a carbon additive (Birzer et al., 2013). The stove works by filling the fuel chamber with biomass and lighting it from the top, which can be seen in Figure 1. As the biomass is heated, it is separated into charcoal and volatiles. This stove works as a gasifier, where the volatile gases produced through biomass decomposition combust with inflowing air to form the flame. Pots are placed on top of the chimney for cooking, as seen in Figure 2. This stove burns fuel more efficiently than a three stone fire and reduces the amount of particulate matter and carbon monoxide in the surrounding air. However, researchers found that proper fuel preparation is necessary for efficient burning and that this stove can increase carbon dioxide and nitrogen oxide emissions due to such efficient burning (Birzer et al., 2013). This article addresses the specific issue of the poor quality of indoor air caused by excessive smoke and incomplete burning from traditional cooking methods. Indoor air pollution causes 3.8 million premature deaths per year and is the leading cause of death in children under 5 (WHO, 2014). In addition, inefficient use of fuel increases the amount of biomass being collected, which in turn contributes to deforestation and ecosystem degradation. Thus, there is a need for more efficient and safe stoves in areas where traditional three stone fires are still being used. The technology discussed in this article improves both problems by using a method of cooking that reduces particulate matter in the air around the stove, which can improve human health, and also requires less fuel than a traditional fire, lessening the toll of biomass collection on the environment. This technology is appropriate in terms of cost because it can be constructed from recycled materials, such as paint or bean cans (Birzer et al., 2013). The labor required to construct this stove is also appropriate because it requires simple tools and no specialized skills or equipment, so any family that collects the materials can also build the stove. The labor involves puncturing the cans so they contain air vents as well as attaching the chimney, lid, and fuel chamber together in a secure fashion. This stove requires very little maintenance. The fuel chamber will need to be emptied on a regular basis since charcoal builds up inside. If any piece of the stove breaks, it can be replaced using similar recycled materials that were used to construct the original stove, which should be available locally on short notice. The design of this stove can be altered based on culture, to accommodate for the usual cooking pot size and cooking height (chimney height can be increased). If a culture requires multiple pots cooking simultaneously, this stove is not appropriate unless a family constructs several to use. Acceptance of this stove has been slow, even in areas where the need is high, due to hesitation from local users. Since the flame is not visible or as large as a traditional cooking fire, some users are not convinced it will work as well and are reluctant to use it. In addition, this stove may reduce the time spent collecting biomass fuel, but the fuel needs to be properly bundled or condensed to small, round pellets for proper air movement in the fuel chamber. This extra step prior to use discourages users who do not prepare fuel prior to use in their culture (Harper, 2013). The design of the stove is fairly appropriate, as it is small and can be adjusted based on the availability of local materials.
The combustion process of a top lit updraft stove (Higgins et al., 2013).
Assembled top lit updraft stove (Birzer et al., 2013).
This article addresses broader context areas described by several Millennium Development Goals including reducing child mortality, combating diseases, and ensuring environmental sustainability. Improving indoor air quality will improve the health of children by reducing particulate matter in the air which can cause pneumonia. This will reduce child mortality as children spent much of their early childhood with their mothers near the kitchen preparing food. Adult health will also be improved and reduce the number of preventable diseases caused by indoor air pollution, such as lung cancer. In addition, reducing harmful emissions and the amount of biomass collected from an ecosystem promotes environmental sustainability. The new stove in this article impacts the context area of human health by immediately eliminating negative effects of open fires while still allowing families to cook meals as necessary. Families will be able to enjoy cooking and not worry about their health if they were to construct a stove using this model. Martin et al. (2013) also found a correlation between the use of the top lit updraft stove and improved health, especially for children in Uganda. However these researchers found that this stove was mostly accepted for its fuel efficiency and economic benefits, rather than health benefits.
Another technology that has been used to improve indoor air quality is the rocket stove. This stove is also appropriate in terms of cost and labor, but generally materials are not recycled for this stove, but can still be acquired locally. The rocket stove can be made of brick or ceramics combined with sheet metal to form the combustion chamber (Mihelcic et al., 2009). There is very little maintenance involved for the rocket stove, a similar time commitment to the top lit updraft stove. However, the rocket stove has higher emissions than the top lit updraft stove and the remaining biomass after burning cannot be added to soil. This stove may be more culturally appropriate in areas where sticks are primarily used for fuel, since the top lit updraft stove requires fuel preparation into pellets (Anderson, 2011). The design of the rocket stove allows for increased heat to be directed at the pot and may be more appealing to users since there is a large flame visible to show the stove is working properly (Mihelcic et al., 2009).
Anderson, Paul (2011). TLUD in 2011. Biomass Energy Foundation, Presentation at 2011 ETHOS Conference.
Birzer, C., Medwell, P., Wilkey, J., West, T., Higgins, M., Macfarlene, G., et al. (2013). An analysis of combustion from a top-lit up-draft (TLUD) cookstove. Journal of Humanitarian Engineering, 2, 1-8.
Harper, Logan (2013). Cooking in Kampala. George Washington University, School of Public Health.
Higgins, M., MacFarlane, G., Read, M., West, T., Wilkey, J., et al. (2013). Cooking stoves for the developing world. The University of Adelaide.
Martin, S. L., Arney, J. K., Mueller, L. M., Kumakech, E., Walugembe, F., & Mugisha, E. (2013). Using formative research to design a behavior change strategy to increase the use of improved cookstoves in peri-urban kampala, uganda. International Journal of Environmental Research and Public Health, 10(12), 6920-6938.
Mihelcic, J., Fry, L., Myre, E., Phillips, L., Barkdoll, B, et al., (2009). Field Guide to Environmental Engineering for Development Workers. ASCE Press.
World Health Organization (2014). Household Air Pollution and Health. World Health Organization Fact Sheet N°292.