First injera baking biomass gasifier stove to reduce indoor air pollution, and fuel use

Nearly 40% of the world population use biomass as their primary energy source, especially for cooking; but traditional and inefficient three-stone fires cause serious health issues and
their high fuel consumption leads to deforestation problems. Ethiopian cuisine is mainly based on vegetable and meat dishes in the form of a thick stew, served on top of injera, a large sourdough flatbread made out of fermented teff flour. Injera is known for its energy intensive and time consuming baking. It has remained rarely researched for alternative energy sources, although some improved biomass firing stoves have been introduced in the Ethiopian market. Thus, there is a need for a new efficient and clean stove that can drastically reduce the fuel consumption, emissions and indoor air pollution. In the present manuscript, the first injera biomass gasification baking stove is presented and its performance reported. A thermal efficiency of 16% is achieved, the specific fuel consumption is reduced by 12.8% , and baking time reduced by 19% compared with the three-stone fire. CO (Carbon Monoxide) and PM (Particulate matter) emissions are reduced, compared to the three-stone fire, by 99% and 87%, respectively. Heat losses and stored heat in the system are also calculated. Results show that it is possible to increase the efficiency and reduce the fuel consumption if the insulation is improved, the heating up time between consecutive baked injeras reduced and longer injera baking sessions, like in community kitchens, promoted. This first successful attempt to bake injera using a biomass gasifier stove in the eastern part of Africa shows promising result and can lead to an efficient and clean biomass gasifier stove that could be widely disseminated for injera baking.