Combustion and gasification of coal and straw under pressurized conditions. Task 2: Determination of kinetic parameters in PTGA

The reactivities of pulverized coal and straw fuels were investigated regarding pyrolysis, combustion and gasification with CO_2 and H_2O by thermogravimetric analysis under pressurized conditions. The fuels were a Colombian coal, pulverized to 45-90 #mu#m particles, and wheat straw pulverized to 0-200 #mu#m particles.

The pyrolysis studies were performed at 150-1000 deg. C in pure N_2 at 1.5 to 40 bar. The combustion studies were performed at 300-550 deg. C, 1.5-40 bar total pressure with 0.08-0.8 bar of O_2 partial pressure. The CO_2 gasification studies were performed at 850-1200 deg. C, 4-40 bar of total pressure with 0.7-4 bar of CO_2 partial pressure, also including studies with CO in combination with CO_2.

A minor H_2O gasification study with straw was performed at 900-1050 deg. C at 1.5-2.0 bar of total pressure in an atmosphere containing partial pressures up to 0.32 bar of H_2O, o.2 bar of CO_2, 0.28 bar of CO and 0.12 bar of H_2. For combustion and CO_2 gasification the results were analyzed with regard to reaction kinetics, and kinetic parameters that represent the experimental results were found. (AU) 11 tabs., 26 ills., 10 refs..