"It is a matter of shame that even 61 years after independence about 60% of our rural population has no electricity and they use ancient kerosene lantern for lighting. Besides in quite a large number of rural households the only light is from the cook stove (chulha). Lighting which is the basic necessity and a fundamental need of humans is missing in the life of majority of rural population. Without adequate lighting the lives of these people cannot be improved and India cannot join the developed nation’s league."

"Besides the poor light output kerosene lanterns also produce soot and other pollutants in the confined space of rural households leading to serious lung ailments. Thus there is a need to develop a light source which runs on locally produced fuel, is environmentally friendly and produces bright light equivalent to that from a 100 W electric bulb. This paper presents one such lantern running on low grade ethanol fuel which also doubles up as a cooking stove thereby solving the twin problem of cooking and lighting for rural households. Nimbkar Agricultural Research Institute (NARI) is the first to propose and develop a dual purpose lantern running on 55-60% ethanol-water mixture."

"Almost all the liquid fuel lighting in rural areas is kerosene based. The quality of light obtained from flame type devices (hurricane lanterns, candles, etc.) is very poor (< 100 lumens). It is based upon incomplete combustion principle. Hence the yellow flame produces soot, CO and CO2. In the confined space of rural households, use of such lanterns can be injurious to health. However, light from pressurized mantle lamps (Petromax type) is comparable to that from light bulbs or fluorescent lamps and hence may offer the best option for rural lighting. The good lanterns in this genre have efficient and complete combustion of fuel. Presently available ‘Petromax’ lamps in India were developed in Europe in early 1920s and have been copied all over the world. In India they are available in hundreds of ‘avatars’ with varying quality. Their manufacturing is in the unorganized sector and hence the quality of majority of them is quite poor. Recently, there has been an upsurge of liquid petroleum gas (LPG)-powered mantle lamps. However, small gas cylinders are not readily available in rural areas besides being costly."

"Also kerosene is a non-renewable fuel, is costly and environmentally unfriendly. Biodiesel which is renewable is not suitable for lighting in the existing lanterns because of high viscosity, tendency of gumming and soot formation. Low grade ethanol is one such fuel which can be locally produced, is environmentally friendly and safe for household purposes."

"Ethanol has roughly similar limits of inflammability (limits of fuel-to-air ratio in which combustion will proceed) to those of the component gases of LPG. Due to the extremely low value (4.3%) of the lower limit of inflammability, the use of pure ethanol for household purposes is dangerous. This problem can be overcome by the use of dilute ethanol mixtures in a suitably designed lantern."

"Consequently an efficient cooking device was developed based on heat pipe principle so as to use the heat of flue gases for cooking a meal for a family of four. This is a slow cooker where the food is brought to boil via steam cooking and thereafter it cooks in its own heat. These type of cookers called “Janata Cookers” were in vogue in India in early 1950s and 60s and used charcoal as fuel. These cookers were made of mild steel and had brass utensils which made them quite heavy. The present stove was modified to make it lighter by the use of lightweight stainless steel for utensils and jacket. It also had an insulated outer jacket to reduce the heat losses. This cooker was mounted on top of the lantern."

"Field testing of this lantern revealed that users had to pump the lantern frequently and this was cumbersome and inconvenient especially when food was being cooked. Also filling the lantern every day with 55-60% low grade ethanol mixture could lend itself to the possibility of misuse and diversion of the alcohol for drinking purposes."

"Thus a new strategy was employed where the low grade ethanol was filled in a cylinder, pressurized to 5-6 kg/cm2 and delivered to the user who could attach it to the lantern and use it just like the existing LPG cooking systems. Besides the convenience of lighting, this strategy also ensures that alcohol cannot be used for drinking since the user cannot access it from the system without damaging the cylinder."

"Field testing of the dual fuel lantern is underway and the initial results are very favorable."

Contact details

Anil K. Rajvanshi
Director, Nimbkar Agricultural Research Institute,
PHALTAN-415523,
Maharashtra,
India
E-mail: nariphaltan at gmail.com

Further information

Read the article in full here

For more on NARI's household energy work click here