Wednesday, November 15, 2006

Characterization of Pyrolysis Char for Use as an Agricultural Soil Amendment.

Keith Harris1, Julia Gaskin1, Leticia Sonon2, and K.C. Das1. (1) Dept. of Biol. & Ag. Eng., Univeristy of Georgia, Athens, GA 30602, (2) 2400 College Station Road, University of Georgia, University of Georgia, Ag & Environmental Services Laboratories, Athens, GA 30602

Abstract: Sandy soils in the coastal plain of the southeastern United States typically have very low nutrient content and cation exchange capacity (CEC). Char produced from peanut hull (PN), pine chip (PC), pine bark (PB), sawdust (SD), and hardwood chips (HW) pyrolyzed at approximately 380, 400, and 420° C were analyzed for properties that could increase the agricultural productivity of these soils. The available nutrient content of char varied with feedstock and pyrolyzing temperature. PN char pyrolyzed at 426° C (PN 426) contained the highest amounts of Mehlich I P, K, and Ca (769, 8,142, and 1,562 mg kg-1 respectively). PN pyrolyzed at 371° C (PN 371) contained the highest total N (2.03 %), but only a very small fraction was plant available based on a 24-day N mineralization study. Cation exchange capacity (CEC) of the char varied with feedstock and pyrolysis temperature. CEC ranged from 44.0 cmol kg -1 char for PN 402 to 14.1 cmol kg -1 char for the HW pyrolyzed at 426° C. CEC was significantly lower for feedstocks pyrolyzed at 420° C. Peanut hull char had a significantly higher CEC than the other feedstocks.

Handout (.pdf format, 138.0 kb)