Tour of Stove Workshop and Pellet Factory

Our visit with Partners for Development and Kiwia & Laustsen Limited continued on Wednesday, May 9th. First, Mr. Pommerville and Mr. Laustsen gave us a tour of the PFD stove factory in Arusha. Four to five laborers produce approximately 150 stoves per week. The factory contains several large pieces of equipment including a shear for cutting the inner and outer sheet metal cylinders, rollers, a circle cutter and drill press for making the bottom grate, and a universal nibbling machine for cutting the mixing tab plate. The workshop has been open for one year, but already PFD is looking into expanding to a larger workshop and mechanizing some of the processes. Although DHE will never produce stoves at PFD's large scale, we found it very informative to visit the workshop and consider ways we could streamline our stove design to make it easier to manufacture.  

Our next stop was Diligent Tanzania Limited, a factory for producing biomass pellets and briquettes.The "moto bomba" pellets which fuel  the "jiko bomba" are made of rice husk, sawdust, and jatropha press cake. Large shipments of these raw materials are delivered to Diligent, and once processed the pellets are distributed and sold throughout northern Tanzania. 

Jatropha is a poisonous, tropical shrub. It is often planted in hedges at the edge of farms to serve as a live fence for animals. As part of its Jatropha Agriculture & Nutrition Initiative, PFD buys Jatropha from a collective of 42,000 farmers spread across eight regions of Tanzania.

Jatropha seeds are crushed to extract jatropha oil, which can be processed to form a biodiesel fuel. The jatropha press cake residue can be used as a fertilizer, or in this case, mixed with other biomass to form pellets or briquettes. 

The first step in producing the "moto bomba" pellets is mixing the jatropha press cake, sawdust, and rice husks. 

Next, the mixture is run through a pelleting machine five times. Each time the mixture passes through, the pellets are heated and become harder, developing an oily patina on the outside. 

Lastly, the pellets are dried in the sun. Production is slowest during the rainy season of March through May. 

The pellets are distributed to "jiko bomba" users throughout northern Tanzania at a price of 350 shillings per kilogram. A household of five which uses PFD's stove will save about $17-25 per month on fuel.

Diligent also produces briquettes from jatropha press cake for industrial-scale applications.The briquettes are sold to local restaurants, schools, and hospitals to fuel stoves and hot water heaters.  Each briquette is a cylinder with a diameter of eight centimeters and length of one meter. The jatropha press cake is poured into the machine below, and the briquette is slowly extruded from the chamber with a high temperature and pressure.