Untreated rice husk showed a lower activation energy followed by lower initial lower thermal degradation (T2) than those
from treated rice husk (Tables 3–5). Cateto rice husk treated with water increased both activation energy and T2, from 120.4 kJ mol−1 to 136.7 kJ mol−1, and from 263 ◦C to 268 ◦C. Cateto rice husk treated with acid solutions present higher activation energy and T2 than those submitted under water treatment. Agulhinha rice