636
Znd. Eng. Chem. Res. 1991,30,636-639
Humic Fertilizers by Oxidative Ammoniation of Hydrolyzed Corncob Residues Francisco A. Riera, Ricardo Alvarez, and Jose Coca* Department of Chemical Engineering, University of Ouiedo, 33071 Oviedo, Spain
Hydrolyzed corncob residues were oxiammoniated to obtain humic fertilizers. Samples were oxidized with nitric acid at the optimum conditions: T = 353 K,nitric acid concentration = 15 wt %, and reaction time = 30 min. The oxidized product was further ammoniated in liquid phase for a range of operating variables. The final product is a water-soluble fraction that contains most of the nitrogen (10-14 w t %) while the solid fraction has a very low nitrogen content (
