Reactivity and Kinetic Analysis of Biomass during Combustion

Wang, Qing; Zhao, Weizhen; Liu, Hongpeng; Jia, Chunxia; Xu, Hao

doi:10.1016/j.egypro.2012.02.181

Cited by 39 publications

(16 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Therefore samples with higher torrefaction temperatures have a higher ignition temperature and a shorter time of combustion. These results are in agreement with research conducted by Wang et al (2012).…”

Section: Cpeczasopismapanpl; Degruytercom/view/j/cpesupporting

confidence: 83%

Thermogravimetric and Kinetic Analysis of Raw and Torrefied Biomass Combustion

Kopczyński¹,

Plis²,

Zuwała³

2015

Chemical and Process Engineering

View full text Add to dashboard Cite

The use of torrefied biomass as a substitute for untreated biomass may decrease some technological barriers that exist in biomass co-firing technologies e.g. low grindability, high moisture content, low energy density and hydrophilic nature of raw biomass. In this study the TG-MS-FTIR analysis and kinetic analysis of willow (Salix viminalis L.) and samples torrefied at 200, 220, 240, 260, 280 and 300 o C (TSWE 200, 220, 240, 260, 280 and 300), were performed. The TG-DTG curves show that in the case of willow and torrefied samples TSWE 200, 220, 240 and 260 there are pyrolysis and combustion stages, while in the case of TSWE 280 and 300 samples the peak associated with the pyrolysis process is negligible, in contrast to the peak associated with the combustion process. Analysis of the TG-MS results shows m/z signals of 18, 28, 29 and 44, which probably represent H 2 O, CO and CO 2 . The gaseous products were generated in two distinct ranges of temperature. H 2 O, CO and CO 2 were produced in the 500 K to 650 K range with maximum yields at approximately 600 K. In the second range of temperature, 650 K to 800 K, only CO 2 was produced with maximum yields at approximately 710 K as a main product of combustion process. Analysis of the FTIR shows that the main gaseous products of the combustion process were H 2 O, CO 2 , CO and some organics including bonds: C=O (acids, aldehydes and ketones), C=C (alkenes, aromatics), C-O-C (ethers) and C-OH. Lignin mainly contributes hydrocarbons (3000-2800 cm ). Hydrocarbons, aldehydes, ketones and various acids were also generated from hemicellulose (1790-1650 cm −1). In the kinetic analysis, the two-steps first order model (F1F1) was assumed. Activation energy (E a ) values for the first stage (pyrolysis) increased with increasing torrefaction temperature from 93 to 133 kJ/mol, while for the second stage (combustion) it decreased from 146 to 109 kJ/mol for raw willow, as well as torrefied willow at the temperature range of 200-260°C. In the case of samples torrefied at 280 and 300°C, the E a values of the first and second stage were comparable to E a of untreated willow and torrefied at 200°C. It was also found that samples torrefied at a higher temperature, had a higher ignition point and also a shorter burning time.

show abstract

Section: Cpeczasopismapanpl; Degruytercom/view/j/cpesupporting

confidence: 83%

Thermogravimetric and Kinetic Analysis of Raw and Torrefied Biomass Combustion

Kopczyński¹,

Plis²,

Zuwała³

2015

Chemical and Process Engineering

View full text Add to dashboard Cite

show abstract

“…The hypothesis in present article is that the char obtained from confined chamber charring systems is inferior to the char obtained from unconfined chamber, due to the higher condensation of gaseous volatiles and moisture vapor on the char produced in confined charring systems. This article explains the validity of our hypothesis using thermogravimetric analysis (Ledakowicz and Stolarek, 2002;Wu et al, 2006;Lu et al, 2009;Abdullah et al, 2010;Damartzis et al, 2011;Vasile et al, 2011;White et al, 2011;Sait et al, 2012;Wang et al, 2012;Al-Wabel et al, 2013;Fang et al, 2013) of char obtained from these two types of system. For application of biochar in soil, the stability of char in soil environment is most critical.…”

Section: Introductionmentioning

confidence: 86%

“…The Coats-Redfern method (Lu et al, 2009;Damartzis et al, 2011;Vasile et al, 2011;White et al, 2011;Sait et al, 2012;Wang et al, 2012;Fang et al, 2013) was used for estimating the E (kJ/mole) for three types of biomaterials (raw pigeon pea stalk, char [confined system], and char [unconfined]) under study. This method can be expressed by the following formula:…”

Section: Methodsmentioning

confidence: 99%

Thermogravimetric Evidence for Better Thermal Stability in Char Produced Under Unconfined Conditions

Gangil

2014

Environmental Engineering Science

View full text Add to dashboard Cite

Thermogravimetric degradation of two kinds of char obtained from two different types of systems, confined and unconfined, was studied. In a confined system, charring was accomplished in a closed chamber in which vapors produced during the charring process were captured within the system and were forced to condense on the char being produced. In the unconfined charring system, a passage was available for the escape of gaseous substances evolved during the charring process; the presence of condensed volatiles in produced char was low. Using thermogravimetric analysis, differences between chars produced in these two systems were studied and it was proved that the char from the unconfined system showed a superior profile of apparent activation energy as compared with the char from the confined system due to higher presence of condensed vapors of volatiles in the char produced in confined conditions. A first-order derivative of thermogram of the char generated in the unconfined system showed a broad peak, at higher temperature segments, ascribed to the thermal decomposition of heavier volatiles and lignin. Activation energies for both types of char were determined and compared using the Coats-Redfern method. Char obtained from the unconfined system had higher thermal stability. This article recommends that for generation of more thermally stable char, unconfined charring chambers should be preferred. A new direct and simple method was used in this article to define the accelerating or retarding nature of thermal decomposition process using segmental analysis of conversion fraction.

show abstract

“…Consequently, there was limited time for the structure of particle to relax and respond to the thermal input, which did not support the release of the volatile matter. Furthermore, when there is less time to burn, at a given temperature, there is insufficient time to burn out the particle [50]. Conversely, at lower heating rate, there is sufficient time for the biomass particles to experience gradual heating that causes the improvement and more effective heat transfers to the inner portions and among particles.…”

Section: Thermal Analyses Resultsmentioning

confidence: 93%

Thermogravimetric kinetic analysis of Nannochloropsis oculata combustion in air atmosphere

et al. 2015

View full text Add to dashboard Cite

The thermal behavior of Nannochloropsis oculata combustion in air atmosphere were investigated by performing experiments on STA PT1600 Thermal Analyzer at heating rates of 10°C/min, 40°C/min and 70°C/min and range of temperatures from room temperature to 1200°C. The kinetic parameters were evaluated by using Kissinger and Ozawa methods. The result showed that Nannochloropsis oculata combustion occurred in five stages. Started with initial devolatilization, the main thermal decomposition and combustion process, transition stage, the combustion of char and the last stage was the slow burning reaction of residual char. In line with increasing heating rate, the mass loss rate increased as well, but it delayed the thermal decomposition processes toward higher temperatures. The average activation energy at the main thermal decomposition stage and the stage of char combustion were approximately 251 kJ/mol and 178 kJ/mol, respectively.

show abstract

Reactivity and Kinetic Analysis of Biomass during Combustion

Cited by 39 publications

References 9 publications

Thermogravimetric and Kinetic Analysis of Raw and Torrefied Biomass Combustion

Thermogravimetric and Kinetic Analysis of Raw and Torrefied Biomass Combustion

Thermogravimetric Evidence for Better Thermal Stability in Char Produced Under Unconfined Conditions

Thermogravimetric kinetic analysis of Nannochloropsis oculata combustion in air atmosphere

Contact Info

Product

Resources

About