Carl Charcoal technology seems very much the wrong way to go about "helping" Africa. One of their problems is deforestation caused by heavy reliance on wood for cooking now. Updating the small scale coal mining technologies from the early 20th century would probably help more.

Also the big problem is democracy, which in practice amounts to keeping the cities quiet. I remember reading about a decade ago that most African countries controlled the prices of food so much to keep the city people on their side, that it was uneconomical (ie, a dead loss) for farmers to sell to the market, so they only grew enough for themselves. I don't know how much this may have changed recently in some countries, but given what's going on in Zimbabwe, probably not much.