1985 Volume 18 Issue 2 Pages 131-136
Activated carbon produced from lignite char was impregnated with potassium carbonate and gasified with steam in an H2O-H2-CO mixture gas at total pressure of 1.5 MPa and in the range of temperatures from 973 to 1073 K.
The gasification rate changed with the progress of carbon conversion and showed a maximum value at a carbon conversion around 0.3-0.4. The ratio of the gasification rate at any conversion to the initial rate could be correlated with the extent of carbon conversion by a relation which took into account the structural change of pores constructed in char filled with catalyst. The initial rate of gasification could be represented by a Langmuir-Hinshelwood type equation of single site mechanism including adsorption terms of H2O and H2. The rate constant was found to be roughly proportional to the atomic ratio of potassium to carbon. The apparent activation energy was 97.8kJ/mol, independently of the potassium content and carbon conversion.
