Combustion of calcium-exchanged coals

The combustion of calcium-exchanged coals was studied in a laminar flow reactor under strongly fuel-lean conditions. The aim was to study the nature of release and capture of sulphur oxides in the presence of finely dispersed calcium oxide and explore the effectiveness of calcium-exchange pretreatment for sulphur emission control in coal combustion. The experimental variables were residence time, oxygen concentration, reactor temperature and amount of calcium additive. A Texas lignite and an Indiana high volatile B bituminous coal were used. Analysis of the experimental data indicated that sulphur capture increased with residence time and oxygen concentration. The results also showed that sulphur capture was approximately proportional to the Ca/S ratio of the coals.