S. Gil

Influence of pressure on the rate of nitric oxide reduction by char

Abstract The reduction of NO by char from sub-bituminous SIERSZA coal has been studied in a pressurized reactor at 1073 to 1373 K. It has been found that the reaction NO + C → 0.5 N2 + CO is controlled both by the chemical kinetics and diffusion of NO within the char particle’s pores. The rate constant of the above reaction was found to be independent of pressure within the examined range of 0.2 to 1 MPa.

Modelling of Nitric Oxide Formation During Liquid Fuel Combustion

A liquid fuel combustion process, being a source of many environmentally hazardous pollutants (e.g. nitric oxides, carbon monoxide, polycyclic aromatic hydrocarbons, soot and sulphur oxides), is a subject of extensive research aimed at reduction of their emissions. A high temperature of the combustion air tends to increase the content of NOX in exhaust gases. Based on the experimental data and literature as well as using the CFD tools, a model of light fuel oil combustion has been developed with an emphasis on nitric oxide formation. The model adequately reflects the impact of geometry changes in the flow of combustion substrates on concentrations of carbon monoxide and nitric oxides in the chamber. The quantitative results obtained are comparable to the experimental data.

Experimental Study of Hydrogasification of Lignite and Subbituminous Coal Chars

The experimental facility for pressure hydrogasification research was adapted to the pressure of 10 MPa and temperature of 1300 K, which ensured repeatability of results and hydrogen heating to the process temperature. A hydrogasification reaction of chars produced from two rank coals was investigated at temperatures up to 1173 K, pressures up to 8 MPa, and the gas flow rates of 0.5–5 dmn 3/min. Reactivity of the “Szczerców” lignite char was found to be slightly higher than that of the subbituminous “Janina” coal char produced under the same conditions. A high value of the char reactivity was observed to a certain carbon conversion degree, above which a sharp drop took place. It was shown that, to achieve proper carbon conversion, the hydrogasification reaction must proceed at a temperature above 1200 K.