Desulphurization of low-rank coals by low-temperature carbonization

A lignite sample from the Istanbul region with 14.18% inherent moisture, 11.01% ash, 1.86% total sulphur, 47.24% volatile matter, 41.75% fixed carbon and 5590 kcal kg^-1 calorific value as dried basis has been subjected to a set of systematic low-temperature carbonization tests. The tests have been carried out as a function of particle size, temperature and heating time. A semicoke product containing 15.22% volatile matter, 16.67% ash, 68.04% fixed carbon contents with 63% desulphurization on the basis of total sulphur has been obtained under the optimum conditions of 650°C temperature and 50 minutes of heating time. The product has a calorific value of 6403 kcal kg^-1 but does not have enough strength for use as a fuel and thus needs to be improved by briquetting.