AbstractAgricultural residues, including sugar cane bagasse, maize stalks, rice straw and rice hulls, were ammoniated at high temperature and pressure. Products containing more than 2% fixed nitrogen were obtained. The highest level of nitrogen was found after ammoniation of sugar cane bagasse. Maize stalks, rice straw and rice hulls contained decreasing amounts. The level of ammoniation achieved was related to the pentosan content of the residue used.