In Benin, a new stove turns rice waste into clean fuel

FAO

COTONOU, Benin (Thomson Reuters Foundation) – Naman Abibate’s business is hard to miss. A towering pile of neatly arranged logs, collected by her husband from a forest near their village home, sits at the side of the busy Cotonou-to-Niger highway, north of Benin.


Abibate makes 10,000 CFA ($16) a month selling wood, much of it to women who use it for parboiling rice, a process of partially cooking rice in the husk before it is milled.

Rice is a staple food in Benin, and parboiling the grain requires a lot of heat, which means a lot of wood. The process is a major culprit behind Benin’s worrisome deforestation rate and a big contributor to health problems due to the inhalation of wood smoke.

But researchers at the Africa Rice Center (AfricaRice), a pan-African rice research group, aim to tackle those problems with a stove that runs on a free, sustainable and abundant fuel: rice husks.

AfricaRice’s stove is fed by a solar-powered fan and is designed to burn off most of the gas released by the burning husks. Compared with a wood-burning stove, the clean stove produces fewer emissions and heats water faster.

“The stove … burns husks directly to produce thermal energy for cooking and heating water and the solar panel provides light while firing the blower,” said Sali Atanga Ndindeng, a technology expert at AfricaRice’s Cotonou station who worked with women and engineers 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,” he said.

FIRE AND RICE
The search for alternatives to wood fuel is crucial to Benin, which has an annual deforestation rate of 2.5 percent – one of the highest in the world – according to figures from the U.N. Food and Agriculture Organisation (FAO).

Using rice husks to run a stove not only takes advantage of a readily available fuel source, but also helps rice farmers deal with the waste and pollution that comes with disposing of the husks.

Every harvest season, Benin’s rice farmers struggle to get rid of the mountains of husks that accumulate after they have threshed their crops. The husks are no good as animal feed and take a long time to rot, so can’t be used as compost. With no other option, millers often just set the husks on fire, spewing smoke into the air.

And it’s a lot of smoke. One hectare of irrigated land yields about five tonnes of rice and a tonne of husks. On average, farmers in Benin produce over 40,000 tonnes of husks per season.

After three years of designing and testing, AfricaRice figured out how to turn the mountains of rice waste into fuel. The husk-burning stove was recently approved for commercial production, and the organisation 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 35,000 CFA ($50).

AfricaRice has also made the fuel for their stove more efficient by developing a hydraulic press to squeeze rice husks into briquettes and pellets. These are easier to handle than loose husks and burn longer.

LESS WOOD, LESS SMOKE
According to AfricaRice’s Ndindeng, many of the women who tested the prototype of the stove were most excited by the prospect of cooking without filling their homes and lungs with smoke. The soot produced by open-fire and indoor cooking using wood and crop residue kills more than 4 million people annually, according to the World Health Organization.

Salabanya Tabaitou, a rice farmer from Malanville District, 750 kilometres north of Cotonou, does a lot of rice parboiling using wood fuel, a process she says is cumbersome and unhealthy.

“A stove that does not use wood, produces no smoke, will make cooking better and cleaner,” said Tabaitou, who has tried out the clean stove. “Especially that the stove would use husks, which we have tonnes of in our fields.”

Ndindeng told Thomson Reuters Foundation that researchers are now looking at adapting AfricaRice’s stove for large-scale parboiling, rice drying and water heating, which require a stove that can hold over double the capacity and handle much more heat than the current models.

The hope, Ndindeng added, is to make the process of preparing Benin’s staple food safer, cleaner and more efficient for everyone.

“Husks are a proven energy source that can save our trees and reduce reliance on wood fuel in Benin,” he said.

(Reporting by Busani Bafana; editing by Jumana Farouky and Laurie Goering :; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, climate change, women’s rights, trafficking and property rights.