Biochar kiln loaner program

Biochar kilns are generally the most expensive equipment required to make biochar at a farm scale. The university program built a series of five “flame-cap” kilns (USDA Oregon Kiln design) and initiated a kiln loaner program to equip farmers with the means to produce their own biochar safely and effectively. These kilns are simple and easy to use, but are capable of transforming large volumes of wood waste into biochar. The kilns have a volume of approximately 260 gallons and can produce about 100 gallons of biochar per batch. The process takes between 3-4 hours. The kilns have been loaned for use by local farms and community members.

Biochar has many factors

The particle size of the material used has a great impact on physical properties, which enhances water-holding capacity and growth of soil. The post-processing treatments of biochar, crushing/grinding is a key factor in improving it’s properties. Many low-tech methods are accompanied by a water quenching process to terminate combustion and cool down. The biochar produced in this way is wet. During experimentation, crushing it with a hammer mill caused clogging so as a cost-effective solution, Appalachian State built a wet biochar crusher using a sink disposal. This effectively crushes biochar without clogging.

Another project in the works — a wet biochar crusher using a sewage pump — might prove to be quicker and more robust than the sink disposal and require less water to operate.

Further study will continue in an effort to make these systems more energy efficient.

Hammer mill project at Appalachian State University.  Appalachian State Energy Center

 Sink disposal crusher at Appalachian State University.Appalachian State Energy Center