Mass transfer limitation in thermogravimetry of biomass gasification

Nowak, Benedikt; Kärlstrom, Oskar; Backman, Peter; Brink, Anders; Zevenhoven, Maria; Voglsam, S.; Winter, Franz; Hupa, Mikko

doi:10.1007/s10973-012-2400-9

Cited by 42 publications

(13 citation statements)

References 16 publications

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“…The concentration of K in the spruce bark is 1830 mg K/kg dry bark, and Cl was below the detection limit of 500 mg Cl/kg, dry bark. 21 The same fuel has been studied previously, and its fuel analysis is presented elsewhere. 21 The release histories and the visually determined phases of combustion are presented in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Higher levels of K were released from spruce, beech, and bark 5 when the samples were first pyrolyzed and then heated and burned for up to 1 h. The measured chloride concentration for this bark was <500 mg/kg in dry bark. 21 Assuming the chloride in the KCl represents 100% of the chloride in the fuel, the concentration of chloride in the fuel would be 212 mg Cl/kg dry bark based on the results at 950 °C, 10% O 2. The first part of chloride release can occur during heating before decomposition of KCl begins.…”

Section: Resultsmentioning

confidence: 99%

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In Situ Measurement Technique for Simultaneous Detection of K, KCl, and KOH Vapors Released during Combustion of Solid Biomass Fuel in a Single Particle Reactor

et al. 2014

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A quantitative and simultaneous measurement of K, KCl, and KOH vapors from a burning fuel sample combusted in a single particle reactor was performed using collinear photofragmentation and atomic absorption spectroscopy (CPFAAS) with a time resolution of 0.2 s. The previously presented CPFAAS technique was extended in this work to cover two consecutive fragmentation pulses for the photofragmentation of KCl and KOH. The spectral overlapping of the fragmentation spectra of KCl and KOH is discussed, and a linear equation system for the correction of the spectral interference is introduced. The detection limits for KCl, KOH, and K with the presented measurement arrangement and with 1 cm sample length were 0.5, 0.1, and 0.001 parts per million, respectively. The experimental setup was applied to analyze K, KCl, and KOH release from 10 mg spruce bark samples combusted at the temperatures of 850, 950, and 1050 °C with 10% of O2. The combustion experiments provided data on the form of K vapors and their release during different combustion phases and at different temperatures. The measured release histories agreed with earlier studies of K release. The simultaneous direct measurement of atomic K, KCl, and KOH will help in the impact of both the form of K in the biomass and fuel variables, such as particle size, on the release of K from biomass fuels.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

In Situ Measurement Technique for Simultaneous Detection of K, KCl, and KOH Vapors Released during Combustion of Solid Biomass Fuel in a Single Particle Reactor

et al. 2014

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“…TGA is one of the most frequently used techniques for solid characterization in an inert or oxidative atmosphere [29,30]. In this work, experiments were performed using a TG SDT Q600-TA instruments analyzer (TA Instruments, New Castle, DE, USA).…”

Section: Thermogravimetric Experimentsmentioning

confidence: 99%

“…The set of four points delimited in Figure 4b for each sample represents the evolution of the different parameters (T i , T f , T max , r max , and ∆t) with the heating rate (10,20,30, and 40 • C·min −1 ) (the evolution of the temperature T f with the heating rate is shown in Figure 4b, as an example).…”

Section: Principal Component Analysismentioning

confidence: 99%

Combustion of Flax Shives, Beech Wood, Pure Woody Pseudo-Components and Their Chars: A Thermal and Kinetic Study

et al. 2018

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Thermogravimetric analysis was employed to investigate the combustion characteristics of flax shives, beech wood, hemicellulose, cellulose, lignin, and their chars. The chars were prepared from raw materials in a fixed-bed reactor at 850 • C. In this study, the thermal behavior based on characteristic temperatures (ignition, maximum, and final temperatures), burnout time and maximum rate was investigated. The kinetic parameters for the combustion of different materials were determined based on the Coats-Redfern approach. The results of our study revealed that the combustion of pure pseudo-components behaved differently from that of biomass. Indeed, principal component analysis showed that the thermal behavior of both biomasses was generally similar to that of pure hemicellulose. However, pure cellulose and lignin showed different behaviors compared to flax shives, beech wood, and hemicellulose. Hemicellulose and cellulose chars had almost the same behaviors, while being different from biomass and lignin chars. Despite the difference between flax shives and beech wood, they showed almost the same thermal characteristics and apparent activation energies. Also, the combustion of the hemicellulose and cellulose chars showed that they have almost the same structure. Their overall thermal and kinetic behavior remained between that of biomass and lignin.

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“…Other works describe the characteristics of heavy crude oils [10], biodiesel, palm oil and mineral diesel. Taking into consideration wood biofuels, thermogravimetric and kinetic analyses are reported concerning poplar wood and beech [11], populous and paulownia [12] and fir trees [13,14]. But to our knowledge, a full picture of thermogravimetric and kinetic research of different wood biofuels has not yet been presented.…”

Section: Introductionmentioning

confidence: 99%

Investigation of thermal degradation of different wood-based biofuels of the northwest region of the Russian Federation

Maryandyshev

Chernov

Lyubov

et al. 2015

J Therm Anal Calorim

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The thermal degradation of different wood biofuels collected in the Arkhangelsk region (northwest of the Russian Federation) was investigated in order to extract their kinetic parameters. Thermogravimetric analysis was carried out for small samples under inert atmosphere or air. These samples were heated from 20 to 1300°C under three heating rates of 5, 10 or 20°C min -1 . The mass loss rates were measured during the drying, devolatilization and char combustion processes. Average values of the activation energies were determined using Friedman's and OzawaFlynn-Wall's methods under inert atmosphere and air. The morphological analysis of raw samples and of the corresponding chars was also performed. Pore development presents an effective impact on char reactivity. These experimental results and the kinetic data obtained in this work should be considered for the simulation of the pyrolysis and combustion processes of different biofuels in industrial devices.Keywords Wood biofuel Á Pyrolysis Á Thermogravimetric analysis under inert atmosphere or air Á Morphological analysis Á Kinetic analysis of thermal degradation List of symbols aConversion rate of biofuel m(0) Initial mass of the sample (kg) m(t) Sample mass at time t (kg) m f Sample mass after the thermal decomposition of biofuels (kg) kKinetic constant (s -1 ) k 0Pre-exponential factor (s -1 ) E Activation energy (J mol -1 ) N Reaction order R Ideal gas constant (J mol -1 K -1 ) T Temperature (K)

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Mass transfer limitation in thermogravimetry of biomass gasification

Cited by 42 publications

References 16 publications

In Situ Measurement Technique for Simultaneous Detection of K, KCl, and KOH Vapors Released during Combustion of Solid Biomass Fuel in a Single Particle Reactor

In Situ Measurement Technique for Simultaneous Detection of K, KCl, and KOH Vapors Released during Combustion of Solid Biomass Fuel in a Single Particle Reactor

Combustion of Flax Shives, Beech Wood, Pure Woody Pseudo-Components and Their Chars: A Thermal and Kinetic Study

Investigation of thermal degradation of different wood-based biofuels of the northwest region of the Russian Federation

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