Economic considerations for industrial firing of coal-oil mixtures

Industrial users of oil and gas face an uncertain future with respect to fuel availability and economics. Direct conversion to coal may be beyond the physical-technical capabilities of a large segment of the industrial community. Conversion to COM (coal-oil mixtures) offers an intermediate, near-term solution which could reduce oil consumption by as much as 40 to 45%. In many cases, COM could be utilized in existing steam-raising equipment without a significant derating. In this paper key economic and technical considerations associated with the conversion of existing clean-fuel-burning industrial boilers to COM-firing are explored. The costs incurred in converting No. 6-oil-fired boilers to COM (50% coal) firing were ascertained for two units with steam capacities of 100,000 lb/hr and 500,000 lb/hr. Based on a discounted cash flow analysis, the fuel savings ensuing from COM substitution are of sufficient magnitude to warrant modifying a substantial number of industrial boilers to COM-firing. With Eastern bituminous coal priced at $1.05/10/sup 6/ Btu and 1% S No. 6 residual oil priced at $2.16/10/sup 6/ Btu, COM appears attractive for immediate consideration as an industrial boiler fuel, based purely on the profit motive. The concept of a commercial COM/coal preparation complex, producing low-ash and low-sulfur coal for established local markets and/or a premium low-sulfur COM fuel was also examined.