Pyrolysis of Subbituminous New Mexico Coal

Abstract

Introduction Most previous studies on devolatilization have concentrated on the effects of temperature, heating rates, and pressure. Various correlations have resulted from these studies. However, the role of particle size in the devolatilization step has not been studied thoroughly. Since a larger particle size tends to slow down heat and mass-transfer rates, the overall reaction rate will be reduced and the quality and quantity of the product gas will be affected. This study is a preliminary investigation of single-particle devolatilization using 2.5-cm diameter San Juan subbituminous coal. The apparent devolatilization-rate constant and activation energy were determined by a least-squares fit of the initial rate data. Two distinct mathematical models are presented and used to investigate the particle-temperature curve and the weight-loss history. This equipment and system are described in further detail by Stoddart. Description of Equipment Our experimental work centered around a bench-scale single-particle reactor, whose internal conditions could be both controlled and monitored by a minicomputer. Supporting equipment included a carrier gas flow system and product collection and analysis systems. JPT