Overview of Solid Fuels, Characteristics and Origin

Abstract

Abstract This chapter is concerned with the origin, properties and characteristics of coals, cokes, different biomass, and peat. The first section gives a brief overview of the formation of coal, and defines coal rank and coal type, the sources of biomass and peat and some of their properties. The availability of the fossil and biomass fuels is estimated in the second section. This is followed in Section 1.3 by an overview of the principal standard test methods for chemical and physical properties of coal and biomass. Section 1.4, the major part of this chapter, gives useful reference data, containing typical chemical and physical measurement test results for the common coal types, a selection of biomass and also for the lesser used fuels such as peat and waste materials. The significance of ash composition in boiler performance is outlined, and typical ash properties are also listed for several coals and biomass fuels. Trace elements can be problematic for certain types of waste fuels in particular. This section also discusses approaches to classifying solid fuels, and examines how some properties interrelate. Section 1.4 also discusses the factors that influence the reactivity of solid fuels and how thermogravimetric analysis may be applied to compare and quantify these differences. Finally, Section 1.5 outlines solid fuel preparation methods, drying, and milling and an emerging pre‐treatment method in the case of biomass, namely, torrefaction.