Heat Treat Temperature (HTT)

Dear friends: terra preta is fascinating in part because it involves so many disciplines. My viewpoint is that of a fuel scientist/chemical engineer.

My laboratory produces well-characterized charcoals for a wide variety of research endeavors, including carbon fuel cell studies, metallurgical charcoal applications, activated carbon production, and terra preta research (with my colleagues Dr. Goro Uehara, Dr. Jonathan Deenik, and Tai McClellan in the University of Hawaii’s College of Tropical Agriculture and Human Resources). With this message I wish to call your attention to the elementary properties of charcoal that I think about when I am producing a charcoal for one of our research endeavors.

Both the feedstock and the process (i.e. pyrolysis) conditions influence the properties of the charcoal product. For example, oak wood has little ash; consequently its charcoal also has little ash. On the other hand, rice hulls have much ash (nearly pure silica), and so does its charcoal.