Chapter 3 - Characteristics of Alternative Fuels

Abstract

Opportunity fuels or combustible resources that are outside the mainstream of commercial fuels can be used productively in the generation of electricity or the raising of process steam and space heat in industrial and commercial applications. Under certain circumstances, materials once defined as opportunity fuels can emerge as mainstream and highly popular energy resources. Because opportunity fuels are outside the mainstream of fuels of commerce, the most common types are residues or low-value products from other processes. This chapter focuses on four of the most commonly used alternative fuels in industry: petroleum coke, wood wastes, tire-derived fuel, and herbaceous crops. Of the entire range of fuels, petroleum coke and wood wastes are the most widely used opportunity fuels, with the wood fuels alone supplying about 3 EJ (or quads) to the U.S. economy and about 20 EJ worldwide. Numerous process industries consume their own residuals as opportunity fuels. Many additional industries consume opportunity fuels in their production process. the use of opportunity fuels in standalone operations, however, the most common use—and the most promising use—remains in cofiring applications. This results from the number of coal-fired boilers in the existing fleet of units; the potential benefits of fuel costs, emissions management, and other technical improvements resulting from cofiring wood waste; and the ability to manage the risk of using opportunity fuels by firing them in situations in which they can be removed if problems occur.