What to do when out goes forest and in comes garbage

Born in Nairobi in 1937, Oxford-trained architect James Archer’s name is synonymous with many of the most iconic buildings in Kenya.

To his credit are the tall and elegant I&M and Lonrho towers, as well as the Nation Centre.

His firm, Planning Systems Services Ltd, has also designed the planned Nairobi light-rail system, which will bring commuter trains into the city in the coming years.

The decidedly more humble Community Cooker project began taking shape in Mr Archer’s mind in the mid-1990s, when the unspoiled Kenyan nature of his childhood was little more than a memory.

“I began to get really concerned about the amount of rubbish in Kenya,” he said. “When I was small, this was a very, very clean country; pristine, really”.

He was deeply dismayed that once-proud forests had been razed to produce charcoal, and that all manner of trash was spoiling Kenya’s spectacular natural scenes. He imagined a day in the future when the supply of charcoal would simply run out completely.

“Then it suddenly hit me,” he says. “If we were really clever, we’d find a way of converting the rubbish to heat for cooking.”

Archer and his staff at Planning Systems spent the next 10 years scheming and tinkering, investing some $200,000 (Sh16 million) and countless hours of professional time into the corporate social responsibility project.

By the time the Community Cooker began operating in 2008, word was beginning to spread that someone had figured out how to turn waste into useable power.

At the 2008 World Architectural Festival in Barcelona, the Community Cooker was placed second in the world in the waste and recycling category, beating some other 700 entries.

Since then, the Jiko ya Jamii has attracted the interest of United Nations Environmental Programme (Unep) and the United Nations Development Programme (UNDP), who are looking at ways to build cookers in slums around the world.

The project has also received corporate sponsorship from Basco Paints and engineering firm Arup.

Burning plastic is tricky because of all the dangerous, noxious gases that are released when the material goes up in smoke.

That’s why finding a way to do it safely remained a riddle to Jim Archer for years before he realised he was unable to solve it alone.

The key to burning plastic safely is very high temperatures. According to the World Health Organisation, plastic must be burned at over 800 degrees centigrade to eliminate poisonous gas by-products.

But as it turned out, getting the community cooker to this high temperature — which is hot enough to melt aluminium or brass — was easier said than done.

“Originally, we could only get the temperatures to 250 degrees centigrade,” says Archer. “I was beginning to get depressed.”

He was experimenting with a stationary bicycle, rigged to a fan to blow air into the cooker and boost temperatures, one day when a slum dweller approached with a better idea.

“Mzee, we can make this work,” he said, his eyes flashing with intelligence and ingenuity.

The young man then demonstrated that used engine oil, or sump oil — when combined with water and dripped onto a hot surface — can produce fire of remarkable heat and intensity.

Archer and his new friend then installed two buckets to the incinerator, one for water and one for old oil.

By adding just a single droplet of each into the firebox every few seconds, the burning temperature rose from 250 degrees to 850 degrees.

The young man had saved the Community Cooker project. “It was as simple as that,” Archer recalls, almost sheepishly.

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