A Study on the catalytic pyrolysis and combustion characteristics of Turkish lignite and co-processing effects with biomass under various ambient conditions

Abbasi Atibeh, Ehsan
In this study the catalytic pyrolysis and combustion characteristics of Turkish coal samples in O2/N2 and O2/CO2 (oxy-fuel conditions) ambient conditions were explored and the evolution of emissions during these tests was investigated using non-isothermal Thermo-gravimetric Analysis (TGA) technique combined with Fourier Transform Infrared (FTIR) spectroscopy. Potassium carbonate (K2CO3), calcium hydroxide (Ca(OH)2), iron (III) oxide (Fe2O3) and iron (III) chloride (FeCl3) were employed as precursors of catalysts to investigate the effects of potassium (K), calcium (Ca) and iron (Fe). Furthermore the effects of these catalysts on calorimetric tests of Turkish coal samples were investigated. TGA-FTIR pyrolysis tests were carried out in 100 % N2 and 100 % CO2 ambient conditions which are the main diluting gases in air and oxy-fuel conditions. Lignite pyrolysis tests revealed that the major difference between pyrolysis in these two ambient conditions was observed beyond 720 ˚C and Derivative Thermogravimetric (DTG) profiles experienced sharp peaks at 785 ˚C in pure CO2 cases which can be attributed to char-CO2 gasification reaction. Furthermore K2CO3 found to be the most effective catalyst in lignite char gasification reaction during pyrolysis tests in 100 % CO2. Combustion experiments were carried out in various oxygen concentrations from 21 % to 35 % in N2 and CO2 ambient conditions. Lignite combustion tests carried out in CO2 ambient revealed that in 30 % and 35 % oxygen concentrations, the relative active sequence of catalysts to the reaction rates of devolatilization can be described as Fe˃˃ K˃ Ca˃ Raw-form and Fe˃ Ca˃ Raw-form˃˃ K respectively. Furthermore K-based catalyst showed the best char reactivity due to its much higher reaction rates in all the oxygen concentrations. Emission profiles of CO2, CO, H2O, CH4, SOx, COS, NH3, NO and HCl evolved species were analyzed using Fourier Transform Infrared spectroscopy (FTIR) method for pyrolysis and combustion tests in both N2 and CO2 ambient conditions. A good correlation was seen in most of the combustion tests between the T2max (temperature of the maximum rate of weight loss in the devolatalization region of combustion) and TFG-max (temperature of the maximum flue gas emission) and also between


A study on the effects of catalysts on pyrolysis and combustion characteristics of Turkish lignite in oxy-fuel conditions
ABBASI-ATIBEH, Ehsan; Yozgatlıgil, Ahmet (Elsevier BV, 2014-01-01)
The catalytic pyrolysis and combustion characteristics of low calorific value Turkish lignite in various ambient conditions were explored and the evolution of gases during pyrolysis tests was examined using a Thermogravimetric Analyzer coupled with a Fourier Transform Infrared spectrometer (TGA-FTIR). Potassium carbonate (K2CO3), calcium hydroxide (Ca(OH)(2)) and iron (III) oxide (Fe2O3) were employed as precursors of the catalysts and compared to the Raw-form (no catalyst added) to investigate the effects ...
An investigation into the combustion curves of lignites
Kök, Mustafa Verşan (2001-01-01)
In this research, combustion curves of seventeen lignite samples from the Thrace basin (Turkey) were analysed using thermal analysis (TG/DTG) techniques. A comparative analysis was performed considering the relationship between peak temperature, burn-out temperature, moisture content, ash, volatile matter, fixed carbon and calorific values of the samples studied and the results are discussed.
Combustion behavior and kinetics of a Turkish lignite blended with biomass/magnesite dust
Yousefzad Farrokhi, Farshid; Kazanç Özerinç, Feyza; Department of Mechanical Engineering (2017)
This study investigated the effect of blending on the combustion behavior of Turkish lignite blended with biomass or magnesite dust using a thermogravimetric analyzer (TGA) under air atmosphere. The lignite used in this study is Tunçbilek lignite (TL), which is blended with the biomass types; olive residue (OR) and almond shell (AS), and the inorganic industrial waste, magnesite dust (MD). The blends are composed of various weight fractions of fuels, with a constant weight fraction of molasses (10 wt. %) as...
An investigation into the thermal behavior of coals
Kök, Mustafa Verşan (2002-10-01)
The thermal behavior of 4 coal samples was investigated using simultaneous thermogravimetry (TG/DTG) and differential thermal analysis (DTA) methods. Upon heating the coals in an inert atmosphere up to 800degreesC, 31.44-43.82% weight loss occurs. The 2 temperature regions of increased chemical reactivity are evident in the coal samples studied Two different models determined kinetic analysis of the samples, and the results are discussed.
Investigation of alternative biomass fuels and Turkish lignites at high heating rate pyrolysis and combustion conditions
Magalhaes, Duarte; Kazanç Özerinç, Feyza; Yozgatlıgil, Ahmet; Department of Mechanical Engineering (2021-2-12)
The objective of this work was to investigate alternative Turkish fuels fortheir ignition, combustion, pyrolysis, and gasification behavior and to select alternative fuels for co-firing, co-pyrolysis, and co-gasification applications based on low and high heating rate experimental results. Agricultural biomass (olive residue, almond shell, and hazelnut shell)and Turkish lignites (Tunçbilek, and Soma) were chosen as the feedstocks. Severalexperimental rigs used such as thermogravi...
Citation Formats
E. Abbasi Atibeh, “A Study on the catalytic pyrolysis and combustion characteristics of Turkish lignite and co-processing effects with biomass under various ambient conditions,” M.S. - Master of Science, Middle East Technical University, 2012.