African researchers have developed a stove that burns rice husks while emitting much less pollution than conventional wood-burning stoves.
The stove, developed for women in Benin by researchers from the Africa Rice Centre, is not only more environmentally friendly, but could also help reduce the demand for wood in areas suffering from excessive deforestation.
The researchers chose to use rice husks, which are ubiquitous and cheap in places like Benin, where rice is a staple food. The stove is fitted with a solar panel that powers a fan and a source of light.
"The stove burns husks directly to produce thermal energy for cooking and heating water,” explained Sali Atanga Ndindeng, a technology expert at AfricaRice's Cotonou station who worked with engineers and potential users to develop the stove.
"We have tested the stove for emissions and have seen that it has very low emissions, making it ideal to use in the home."
According to the engineers, the stove burns off most of the gas released by the burning husk, thus generating only very little in the way of harmful fumes. The researchers also claim the stove heats water faster than conventional wood-burning devices.
For Benin, which at 2.5 per cent has one of the highest deforestation rates in the world, a rice-waste burning stove could make quite a difference. Moreover, wider adoption of the technology would also help local rice-growers, who produce large amounts of rice husks that are difficult to dispose of. The husks can’t be fed to animals and as they take too long to rot, they can’t even be used in compost. The only way to deal with them is to burn them but that is extremely polluting.
The husk-burning stove was recently approved for commercial production, and the Africa Rice Centre is now teaching metal smiths in Benin and Nigeria how to make it.
It comes in various sizes - the smallest, for household and restaurant cooking, is fed with 900 grams of husks and the largest, designed for industrial use, can take over 5 kilograms of husks. The small unit went on the market in April for $50.
The stove burns the husks pressed into tight briquettes and pellets, which are easier to handle and burn longer.
The researchers said that women involved in a pilot scheme hailed the device for not filling their homes with smoke. People in rural African communities frequently cook indoors on open fire. It is believed that the soot that pollutes the indoor environment contributes to some four million deaths every year.