Plant oil-fueled cookstove

A potential solution to problems brought about by the use of traditional cooking device is a functional and efficient plant oil-fueled cookstove developed, optimized, and evaluated at the Leyte State University (LSU). The stove is advantageous because of its CO2 neutral emission; it is clean and safe; and it uses plant oil - a high powered and renewable source of fuel. Among the different types of plant oils, coconut oil is the most widely available in the Philippines. Guarte et al. (LSU) developed this stove called 'protos'. It consisted of a tank, pump, frame, valve, fuel line, and a vaporizer originally made from the University of Hohenheim and acquired by the BSH Bosch and Siemens Home Appliances Group in Germany. Its performance was evaluated using two different fuel types. Type 1 fuel included refined and crude coconut oil, used vegetable oil from fast foods and restaurants, kerosene, diesel, biodiesel, and used mechanical oil. Type 2 fuel included plant oils that are not common in the Philippines such as canola, corn, sunflower, and soya oils. Also, the stove was tested and compared with the different stoves commonly used in the Philippines and further field-tested to 100 households in Leyte. Its economic viability for commercial production was likewise determined. In operating the plant oil cook stove, the tank was filled with plant oil to a deserved level of about three-fourths of the tank capacity. The tank was then closed and filled with air using a foot pump to a desired pressure of about 3 bars. The stove was then pre-heated using 40 mL of denatured alcohol. After preheating for 6 minutes, the value was slowly opened allowing oil to pass through the heated vaporizer. In the process, the oil evaporated and was emitted through a nozzle in a combustion area. Here the jet rebounded at a rebounding plate, mixed with the surroundings air, and then burned into a blue flame, ready for boiling water or for cooking food. Findings of the study revealed the following: For preheating the stove, plant oil in combination with cotton, tissue paper, coconut husk, and newspaper can be used as alternative to using expensive denatured alcohol under Philippine conditions, combinations of plant oil with tissue paper or plant oil with coconut husk are recommended. Using different fuel types, biodiesel gave the highest power output of 4.37 kW and lowest CO2 emission of 18 ppm compared to refined coconut oil power output of 3.58 kW and 20 ppm CO2 emission. Crude coconut oil and used cooking oil from restaurant were very good substitutes for refined coconut oil. Fossil-based fuel showed potential for the stove but produced high emission of CO2. The stove was competitive with existing stoves fuelled by LPG, kerosene, and charcoal in terms of daily usage. The cooking cost per day using fuel wood was still the lowest. When other factors were considered like emission, safety, life span, CO2 emission and other factors, the plant oil stove gave the highest performance. Field-testing of 100 units of the stoves to 100 selected household cooperators in selected areas in Leyte showed that the average preheating time of the stove users was 7.86 minutes. Their average monthly oil consumption was 11.64 L at a daily cooking time of 1.53 hours. Based on the results of six small restaurants at the LSU market, which served as project cooperators, the average monthly consumption was 28 L at an average daily cooking time of 5.24 hours. Commercial production of the stove 'Protos' was economically viable with net present value (NPV) of PhP 666,017, internal rate of return (IRR) fo 25%, and benefit cost ratio (BCR) of 1.02. Promotion and marketing of the stove started in Leyte in November 2006 as well as in countries such as Tanzania, India, and Sri Lanka through the support of BSH Bosch and Siemens Home Appliances Group. Researches recommended commercialization of the stove by virtue of its technical performance, its sustainable and environment-friendly source of fuel, and its very low CO2 emission.