Building a better briquette: Conservation students improve charcoal production in Kenya

In Kenya, a country where one in four people lacks access to electricity, charcoal is a staple fuel source. It’s light, small, easy to store, burns longer and hotter than wood, and is nearly smokeless.

It’s also speeding up the country’s deforestation.

“So, (we wanted) to see if there was a difference in charcoal yield from different species of trees that they were growing in the area,” said Jacob Rankin. “We were trying to determine if there was a significant difference in yield – if Kenyans can make charcoal more efficiently with a particular tree versus another.”

Rankin and his research partner, Emily Ruder, graduated from UWM this spring with majors in conservation and environmental science. Last summer, though, the pair spent two months in Kenya experimenting with charcoal productions techniques at the Drylands Natural Resource Center, an NGO in Mbunbuni, Kenya that promotes sustainability practices in agriculture and land management.

“Hopefully our research provides them with some more knowledge of their local resources to improve the way they do things – more sustainably,” Rankin said.

(From left to right) UWM conservation and environmental science students Emily Ruder and Jacob Rankin smile with a student from Kenya. The three met while Ruder and Rankin were conducting research to improve charcoal efficiency at the Drylands Natural Resource Center in Kenya. Photo courtesy of Jacob Rankin.

Baking a briquette

Most Americans thinking about charcoal will envision a Kingsford bag next to a Weber grill.

“In Kenya, it’s a little bit more rugged,” Ruder said. “To make charcoal, you need an organic material, and you need to cut it off from any access to oxygen, and then put it under super-high heat. You can make charcoal out of any kind of organic material, as long as it’s thick enough.”

Traditionally, Kenyans and other cultures around the world have made charcoal using earth mounds – piles of dirt where they bury branches and logs to prevent exposure to oxygen. Then, they light a fire beneath the mound and wait for the high heat to carbonize the buried wood.

“The problem with that way of production is that it contributes to forest degradation. The forest resource is now of lower quality. It also has really low conversion rates of wood to charcoal,” Rankin said.

The Drylands Natural Resource Center improved the process by teaching farmers to create charcoal in steel drums, which are more air-tight than earth mounds. But Ruder and Rankin were more interested in the raw material. Do different types of wood make for better charcoal? Does it matter how dry the wood is beforehand?

Building a better briquette

Rankin and Ruder tested seven different types of wood and experimented with different lengths of drying time. Their results were encouraging: They found it’s not so much the type of wood that impacts charcoal efficiency, but the part of the tree.

“You have the bark that was around the wood and then the actual, good hardwood inside the bark. When you carbonize that, you can literally peel the bark off of the wood and then you’re left with two types (of charcoal): One is the briquette, or non-premium kind of charcoal, which is from that bark, and then the other piece you have left is the premium charcoal,” Ruder said.

Finished charcoal sits in a bag, ready for use. Photo by Jacob Rankin.

The charcoal made from bark is lower quality, burning for less time at lower temperatures and producing more smoke than charcoal from hardwood. With that in mind, Rankin and Ruder were able to make some recommendations.

“For example, Terminalia brownii is a very dense wood. The premium charcoal that is yielded from it is really high quality. But it also has a lot of bark surrounding it, so it also makes a lot of non-premium charcoal,” Rankin explained. “Whereas with a species such as Senna spectabilis, it yields a lot of premium charcoal, but the bark is minimal.”

“We also found that there was a significant difference between drying the wood for two months versus drying it for three months,” Ruder added. “If you’re drying the wood between one and two months, it’s not going to make a difference. But drying it for three months will make that extra difference, so that’s what we recommended. It dries it out more, and once it’s drier, it produces a better yield of charcoal.”

And, she noted, better yields of charcoal will lead to less deforestation.

UWM conservation and environmental science major Emily Ruder analyzes a piece of wood for her experiment. Ruder and her research partner, Jacob Rankin, were trying to improve charcoal production in Kenya. Photo by Jacob Rankin.

Next steps

Rankin and Ruder presented their research at the virtual UWM Undergraduate Research Symposium in April, where they were awarded an “Outstanding Presentation” ribbon for their work.

The pair are currently packaging their research into an official set of recommendations to present to the Drylands Natural Resource Center, and they’ve submitted draft of a scientific report on their work to the Proceedings of the National Conference of Undergraduate Research. It should be published sometime in the fall.

“We’re hoping that this research can help the DNRC in their charcoal production and create a model and an example for other small-scale production,” Rankin said. “This is knowledge that they can share in their workshops, not only within their village, but maybe around Kenya and the region in general.”

By Sarah Vickery, College of Letters & Science

The Drylands Natural Resource Center

The Drylands Natural Resource Center was founded in Mbunbuni, Kenya, in 2008 by Nicholas Syano. Syano is a UWM graduate who was mentored by Mai Phillips, the coordinator of UWM’s conservation and environmental science program. Phillips also mentored Rankin and Ruder.

The DNRC is devoted to helping subsistence farmers practice better resource and land management to address issues like deforestation, land degradation, and climate change. The center holds sustainability and permaculture classes, drawing audiences from across Africa to learn new techniques.

The DNRC has also established a program with local farmers to address the region’s fuel needs.

“They have a tree nursery,” Ruder explained. “They sell those trees to the local farmers; the local farmers grow the trees and then they prune from those trees and sell the wood back to the DNRC to turn into charcoal. It’s kind of like a closed-loop charcoal system.”

By experimenting to find the best practices for producing charcoal, Rankin and Ruder hope that farmers can provide better quality wood to the DNRC to produce higher charcoal yields and maximize profits for both parties.

Abroad in Africa

Performing research in Africa came with a bit of culture shock.

“This was both of our first time living completely off the grid. There was no electricity, no running water. We had to wash all of our clothes by hand,” Rankin said. “It was an impactful, eye-opening experience living in a different country in those conditions. We were in a mud hut. It was a really nice mud hut! It had curtains and nice beds and mosquito nets.”

Ruder recounts her experiences making friends with college students from the Democratic Republic of the Congo who were studying at the Drylands Natural Resource Center at the same time as she and Rankin.

“We took a trip to Denali Beach, so we did a little bit of a vacation because my birthday was that week. That was amazing. There were beautiful white sand beaches and monkeys everywhere,” she said.

Rankin and Ruder ended their abroad experience with a trip to Tanzania, where they climbed Mt. Kilimanjaro.