Study of the reactivities of chars from sulfur rich Spanish coals

Abstract

Large coal reserves in Spain are an important source of energy. Their mediterranean coals are characterized by a high sulfur content. Thus, the combustion of these coals can cause serious environmental effects due to the release of SO x . Coal gasification with advanced technologies has the potential to provide a clean fuel that produces electric power while minimizing the emission of air pollutants. The measurement of char reactivity associated with coals is essential when the gasifier design and fuel efficiency has to be optimized in the industrial process. In this paper we use a procedure (particle size ca. 500 μm, sample mass 15.5 mg, CO 2 and air reactant gases, near isothermal conditions) to determinate the reactivity of chars from Utrillas subbituminous coal, Calaf and Mequinenza lignites by thermogravimetry at 900 °C. The procedure also provides proximate analysis information which allows to establish the suitability of these coals for the gasification process and affords a quick comparison between different coal types. This paper presents the results of the reactivities of chars from three coals from Spain and describes the main properties of these coals which influence the gasification process.