Search

This paper presents analysis of pine and sunflower husk pellet combustion and their co-combustion with oats in a domestic biomass boiler. Selected physical and chemical properties of the studied biomass pellets were determined. Thermal analysis (TGA) of the analyzed biomass in air atmosphere was carried out. The concentrations of CO, CO 2 , NO and NO 2 in the exhaust gases were also examined. The obtained experiment results were compared with the numerical calculations using CHEMKIN-PRO. The best convergence of the experiment results with the calculations was obtained for a residence time of 2 s and temperature of 650 °C. The experiment and calculated results show that the co-combustion of pellets with oats contributes to reducing the CO and CO 2 concentrations in the flue gas. • Pine and sunflower husk pellets were combusted and co-combusted with oat in a domestic biomass boiler. • Selected physical and chemical properties, of the studied biomass pellets were determined. • Thermal analysis (TGA) of the analyzed biomass in air atmosphere was carried out. • The concentrations of CO, CO 2 , NO and NO 2 were examined and compared with the numerical calculations. [ABSTRACT FROM AUTHOR]

Sida hermaphrodita is one of the energy crops with high potential for energy conversion technologies. In this study the torrefaction of Sida hermaphrodita was carried out at the specially constructed test bench simulating industrial like process operating conditions. The torrefaction temperature was in the range from 250 to 350 °C. The obtained solid products (biochars) were characterized in terms of its proximate and ultimate properties. The chemical analysis of liquid phase was also performed. The combustion process of obtained biochars was examined by Simultaneous Thermal Analysis (STA) through dynamic runs at 10 °C/min heating rate from RT to 700 °C. The structural changes during the torrefaction were studied using scanning electron microscope technique. The fibre analysis was performed to determine structural composition (the content of hemicellulose, cellulose and lignin). Results from analyses significantly contributed to extending databases in the field of plant torrefaction. The results confirmed positive features of obtained biochars comparing to raw biomass material. It was concluded, that the optimal process temperature for Sida hermaphrodita should not exceed 400 °C. Additionally, the mineral matter was investigated using X-ray Fluorescence (XRF) to study the influence of torrefaction on chemical composition of the ash. Only some differences in ash compounds were observed. • Sida Hermaphrodita torrefaction process were conducted at specified temperatures. • Increasing process temperature leads to enhance energy properties of obtained biochar. • The fibre and structural analyses confirmed the changes in morphology structure. • Condensates of torrefaction contained high amount of organics. [ABSTRACT FROM AUTHOR]

A novel approach, linking both experiments and modelling, was applied to obtain a better understanding of combustion characteristics of torrefied biomass. Therefore, Pine, Acacia and Miscanthus giganteus have been investigated under 260 °C, 1 h residence time and argon atmosphere. A higher heating value and carbon content corresponding to a higher fixed carbon, lower volatile matter, moisture content, and ratio O/C were obtained for all torrefied biomass. TGA analysis was used in order to proceed with the kinetics study and Chemkin calculations. The kinetics analysis demonstrated that the torrefaction process led to a decrease in Ea compared to raw biomass. The average Ea of pine using the KAS method changed from 169.42 to 122.88 kJ/mol. The changes in gaseous products of combustion were calculated by Chemkin, which corresponded with the TGA results. The general conclusion based on these investigations is that torrefaction improves the physical and chemical properties of biomass. [ABSTRACT FROM AUTHOR]