Development of a co-firing fuel from biomass-derived binder and crushed coal

The focus of this work was the development of a co-firing boiler fuel for use in the coal power plant industry. This fuel, known as co-fire pellets, is a densified product comprised of crushed coal and a renewable binder derived from the liquid product of the fast pyrolysis of lignocellulosic biomass. The co-fire pellets can help meet certain state and federal regulations related to electricity production. A central composite design of experiments was used to evaluate properties of the co-fire pellets based on four factors relating to the makeup of the pellets. These factors are coal particle size, coal moisture content, binder percentage, and pellet cure time. Properties of the pellets were investigated using the following tests: higher heating value, proximate analysis, ultimate analysis, mass density, particle density, indirect tensile strength, impact resistance, and abrasion resistance. The experimental data was modeled using linear regression techniques. The pyrolyzed biomass binder fraction had the largest impact on pellet properties, while cure temperature was determined to be a nonessential treatment.