Relative combustion efficiency of composite fuels based on of wood processing and oil production wastes

Highlights: • Sawdust can be used as main and additional components of waste derived fuel. • Composite fuels are attractive compared with coal and fuel oil. • Relative efficiency of composite fuels based on sawdust and oil may amount to 0.3–12.9 • Relative efficiency is maximum for the fuel: 50% sawdust, 25% oil component, 25% water. • Even a small addition of water significantly decrease emissions from fuel combustion. -- Abstract: This paper presents the results of an experimental study that explores the ignition and combustion of composite fuels based on wood processing and oil production wastes. By the example of a typical developed industrial region, it is shown how numerous of wood processing wastes (sawdust) and oil production wastes (sludge) may be effectively recovered. We study the main time characteristics (ignition delay and combustion duration) of fuel combustion, heat release, anthropogenic emissions. The values of relative efficiency (taking into account energy, environmental and economic indicators) of waste-derived composite fuels are defined in comparison with fuel oil and coal. The optimal concentration of components – 50% of sawdust, 25% of oil component, and 25% of water – allows the maximum efficiency of fuel combustion. In terms of minimizing the cost of ignition, the best is the mixture of 30% of sawdust and 70% of heavy oil. The research findings illustrate the great prospects for the large-scale involvement of numerous wastes in the fuel and energy cycle of any industrially developed region of the world.