Quantitative studies by differential scanning calorimetry of the reaction between hydrogen peroxide and lignocellulose

Abstract

SynopsisHeat of reaction and kinetic parameters were determined by differential scanning calorimetry for decomposition of hydrogen peroxide, reaction of hydrogen peroxide with lignocellulosic materials, glucose and pinitol, and for the reaction of the same materials with produced or introduced oxygen. The heat of decomposition of hydrogen peroxide obtained in N2 (720 cal/g H202) was in fair agreement with literature data, considering the different temperature and pressure conditions. The heats of reaction of hydrogen peroxide and lignocelluloses were higher when determined in N 2 (1670-2500 cal/g H202) than in 0 2 (1450-2020 cal/g H202) atmosphere. The activation energy for decomposition of hydrogen peroxide amounted to 20.3 kcal/mol in N2 and 15.9 kcal/mol in 0 2 with frequency factors of 5.7 X lo9 and 3.7 X lo7 min-I, respectively. The activation energies for the reaction of hydrogen peroxide and lignocellulosic materials tested were similar and not influenced by the atmospheric composition, ranging overall between 19.7 and 22.4 kcal/mol. The corresponding frequency factors ranged between 2.77 X lo9 and 2.23 X 10".