Thermogravimetric kinetic study of solid recovered fuels pyrolysis

Abstract

In the Republic of Serbia there are significant quantities of coffee and tire wastes that can be utilized as Solid Recovered Fuel (SRF) and used as an additional fuel for co?combustion with coal and biomass in energy production and cement industry sectors. Differences between SRF and base fuel are a cause of numerous problems in design of burners. The objective of this study was to determine the kinetic parameters for the thermochemical conversion of selected SRF using Simultaneous Thermal Analysis (STA). Samples of coffee and tire waste were used for the experimental tests. Thermal analysis was carried out in nitrogen atmosphere at three different heating rates 10, 15 and 20 K/min for each sample, while it was heated from room temperature up to 900?C. Two sample sizes x <0.25 mm and 0.25 < x <0.5 mm of each SRF were used in experiments, in order to obtain reliable Thermal Gravimetric Analysis (TGA) data for estimation of kinetic parameters for SRF pyrolysis. Experimental results were used for determination of pre-exponential factor and activation energy according to methods presented in the literature. Presented research provides valuable data of coffee and tire waste that can be used for the burners design.

Effect of autohydrolysis on hemicellulose extraction and pyrolytic hydrogen production from Eucalyptus urograndis

“…To calculate the kinetic parameters in the "model fitting" technique, it must be supposed that the shape of the degradation equation must be assumed in the calculations. Then, it is difficult to obtain results in a suitable form and Radojevic et al [33] offers this reason for the production of unknown values of kinetic parameters with the "model fitting" methodology. For the "model free" methodology, an isoconversional method can be the more suitable to the pyrolysis kinetic studies because it is a single-step kinetic like the "model free" methods.…”

Comparing different reaction models for combustion kinetics of solid recovered fuel

“…The decomposition of solid waste-derived fuels was investigated quite thoroughly in the past few years [1][2][3][4][5][6][7], but the reaction kinetics were covered only a few times. To acquire the parameters describing the kinetic behavior, different methods are available, which could be categorized as model-free and model-fitting methods.…”

“…Acceptable results were achieved by all methods with some limitations, which shows that there is no obviously best way to handle mixed solid fuels; every case needs special attention and thorough investigation. The three most commonly used model-free methods were applied for two kind of solid wastes by Radojevic et al [2] in nitrogen atmosphere. A more advanced model-fitting method was applied by Conesa et al [3].…”

“…Identifying the origin of these is quite challenging for these complex samples. In the literature, it is common to relate them to the major waste components, which are cellulosic materials like paper, textiles and sometimes biomasses, and plastics [1][2][3][4][5][6][7]. For combustion, this means three main reaction groups, two of which are responsible for the volatile releases at around 300°C and 470°C.…”

“…The first one describes the pyrolysis of all cellulosic materials, and the second shows the decomposition of the plastics. The third reaction takes place between 600 and 700°C; it is related to the combustion of all remaining char, mostly from the cellulosic components [1][2][3][4][5][6][7].…”