Oxidative Desulphurisation and Kinetics of Pyrite in Coal

Abstract

Removing sulphur from fuels (coal, petroleum etc) is one of the important subject in the area of environmental pollution control. This technique has various advantages over other desulphurisation methods as this method is cost effective and efficient results are obtained which are much more than other desulphurisation technique (mainly hydrodesulphurisation).

This paper reports oxidative desulphurisation of coal using hydrogen peroxide alone as well as in the presence of dilute sulphuric acid. The influence of various parameters like particle size, temperature, concentration of hydrogen peroxide and sulphuric acid was determined.

An increase in desulphurisation rate was witnessed with increase in temperature and hydrogen peroxide concentration which is 30.7%-45.6% and 17.9%-27.6% respectively. Also leaching with 25% hydrogen peroxide and varying concentration of sulphuric acid increased the desulphurisation  from 31.7%-47.9%  at 45°C.  Complete removal of  sulphate sulphur  was witnessed. Also up to 95% and 25.7% removal was witnessed in pyritic and organic sulphur respectively. The experimental data from the oxidation of pyritic sulphur correlated well with second order rate which was represented continuous reaction model. The activation energy for pyritic conversion is 19.92 J/kmol.

This method effectively removes sulphur from coal. The percentage sulphur removal is more than other methods of desulphurisation under normal conditions of temperature (30°C-50°C) and pressure (1atm).