This paper presents a procedure for exacly determination the conversion factor of fuel-bound nitrogen to nitrogen oxides in the combustion process of wet spruce wood in boiler grate furnaces with a heat input of 300 to 2,500 kW. They are referred to as fuel-bound nitrogen oxides, thermal nitrogen oxides, and immediate nitrogen oxides. The conversion rate of spruce wood fuel-bound nitrogen is determined based on an analysis of biofuel and emissions-technological measurements of nitrogen oxide concentrations in flue gases from the combustion process of biofuels. For combustion tests, wet spruce chips from 16 sites in Slovakia were used. The value of the conversion factor of spruce wood fuel-bound nitrogen is XNOₓ = 65.4±8.3%. The calculated value of the conversion factor of spruce wood fuel-bound nitrogen to NOₓ emissions can be considered fair value, both from the aspect of combustion conditions of spruce chips and made emissions-technology measurements and from the technical calculation itself. It is also declared by the following observations and statements.
Wood and other biomass have the great potential of decreasing carbon dioxide emissions to the atmosphere, or at least mitigating the speed of the increase in the concentration of carbon dioxide. This paper presents an analysis of the possible use of degraded land – thermal power plant ash ponds – for the growth of fast-growing trees for fuel wood and the subsequent utilization of this fuel wood by means ofa verified technique – co-combustion with coal, or a proposed technique – pyrolysis. Pyrolysis of wood with the combustion of pyrolysis gases and carbon sequestration would provide approximately 26% more favorable effects on climate change than the co-combustion of wood in a coal-fired boiler.