PRODUCT DISTRIBUTION AND SULFUR FORMS IN THE LOW-TEMPERATURE PYROLYSIS OF A SPANISH SUBBITUMINOUS COAL

The product distribution from the low temperature pyrolysis of a high sulfur Utrillas coal is studied in the 350-600 degree C interval. Runs were carried out under helium (0. 1 MPa) in a horizontal fixed bed reactor with a heating rate of 7 degree C min** minus **1. Gases from pyrolysis were analyzed by gas chromatography and low temperature chars were characterized in terms of proximate and ultimate analyses, heating value and sulfur forms distribution. At 500 degree C and with a pyrolysis time of 1 hour the transformation of pyrite into pyrrhotite is almost complete. Organic sulfur tends to accumulate in higher temperature chars. A structural characterization of tars from different temperatures was made by FT-i. r. and **1H nmr spectroscopy.