The Environmental Journal of Southern Appalachia
Friday, 29 September 2023 11:53

Appalachian State Energy Center is crushing it with biochar

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community_biochar-reduced.pngCommunity biochar production in Boone.  Appalachian State Energy Center

Appalachian State University research helps farmers and crop yield

This article was provided by Appalachian State University. Hei-Young Kim is laboratory manager and research assistant with the Appalachian Energy Center.

BOONE The Appalachian State Nexus Project experiments continue to advance agricultural innovations with biochar to help local farmers. Biochar is a charcoal-like material produced from plant material such as grass, agricultural and forest residues that  produce carbon-rich material used for agriculture and horticulture purposes. 

Adding biochar to soil increases surface area, pH, plant nutrient availability, and enhances water-holding capacity, according to Appalachian State researchers. It also can sequester carbon in the ground for extended periods of time, which may otherwise find its way into the atmosphere as CO2 or methane.

The qualities of biochar vary depending upon the material it comes from — timber slash, corn stalks or manure. 

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-reduced.jpgHammer mill project at Appalachian State University.  Appalachian State Energy Center

 sink_disposal-reduced.pngSink disposal crusher at Appalachian State University.Appalachian State Energy Center

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Last modified on Tuesday, 03 October 2023 01:13