Energetic use of solid products of pyrolysis technology

Abstract

At the present time there has been a serious question of non-renewable energy resources substitution that is why solved problem has worldwide meaning within high increase of fuels consumption from renewable energy resources. The aim of this paper is definition of other possibilities and limits for energetic utilization of solid biomass modified by pyrolysis technology to biochar.

Analyzed samples are processed into the form of pellets in diameter 8 mm made from rape straw. There is used laboratory pyrolysis unit working on the principle of slow pyrolysis reaction which processes samples at the temperature of 400 °C and taking 220 minutes in reactor filled by nitrogen medium. The experimental part of the work is based on elemental and stoichiometric analysis. The thermal-emission properties are determined on the combustion furnace device with lower fuel supply for the samples analyzed before and after the pyrolysis process. The resulting values ​​are evaluated by statistical regression analysis.

The results show that the analyzed biofuels samples have not large concentration differences of sulfur, nitrogen and chlorine after pyrolysis processing. The great advantage of pyrolysis processing is the fact that the calorific value of examined samples almost doubled (26.22 MJ/kg). The pyrolysis fuel processing of selected samples significantly reduces the proportion of volatile matter and oxygen. For energy use of these processed samples is necessary to pay attention to these indicators. The results of biofuel stoichiometric properties and the resulting values of thermal-emission concentrations (T_flue-gas, CO, CO₂ a NO_x) depending on excess air coefficient show the final energy use of pyrolysis solid samples which differs in their properties significantly from the original samples. For energy use of assessed samples is limiting value the excess air coefficient which significantly influenced course of the experimental tests.