Effects of catalysts on combustion reactivity of anthracite and coal char with low combustibility at low/high heating rate

Zou, Chong; Zhao, Junxue; Li, Xiaoming; Shi, Rui

doi:10.1007/s10973-016-5806-y

Cited by 38 publications

(29 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…21 So this phenomenon is considered as an oxygen-absorption mass-gain process of char and carboxyl and carbonyl were determined as the key functional groups for coal oxidation mass gain. 20,21 As shown in Fig. 1, the curves of conversion versus temperature moved toward the right-hand side with an increase of heating rate.…”

Section: Thermogravimetric Analysismentioning

confidence: 72%

“…The furnace temperature was increased from 30 C to 850 C. All samples were tested at four different heating rates of 15,20,25, and 30 C min À1 , respectively.…”

Section: Sample Preparation and Analysismentioning

confidence: 99%

“…Some differential and integral forms of kinetic models used in solid-state kinetics are listed in Table 3, and these kinetic models are frequently used in reaction mechanism investigations of a solid-state process, especially the coal or char combustion process. 9,20 In this study, the difference between the theoretical and experimental values of y(a) is not obvious, so the z(a) master plots were used to determine the most appropriate kinetic model. The experimental and theoretical z(a) master plots for combustion of char under different heating rates are presented in Fig.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

Wang

Cheng

et al. 2018

RSC Adv.

View full text Add to dashboard Cite

In this paper, the combustion reaction kinetics of pyrolysis char of low-rank coal is studied by thermal analysis technology. For the combustion process of the char at different heating rates, the reaction kinetic parameters were calculated by three common mode-free methods (FWO method, KAS method , respectively, and the activation energy decreased with increasing conversion rates. There is a compensation effect between the activation energy and pre-exponential factor of char combustion. Results of the kinetic analysis by Malek method and Popescu method both indicated that the Avrami-Erofeev equation) controlled by nucleation and nuclei growth models is the most probable reaction model of char combustion.

show abstract

Section: Thermogravimetric Analysismentioning

confidence: 72%

“…The furnace temperature was increased from 30 C to 850 C. All samples were tested at four different heating rates of 15,20,25, and 30 C min À1 , respectively.…”

Section: Sample Preparation and Analysismentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

Wang

Cheng

et al. 2018

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…A comparative evaluation of coal reactivity during oxidation was carried out using the following parameters: temperature, time and oxidation rate, which were calculated by the graphical method (Zou et al 2016) using TG and DTG curves ( Fig. 1).…”

Section: Reactivity Parametersmentioning

confidence: 99%

Non-isothermal oxidation of coal with Ce(NO3)3 and Cu(NO3)2 additives

Ларионов

Gromov

2019

Int J Coal Sci Technol

View full text Add to dashboard Cite

Non-isothermal oxidation of brown coal with 5 wt% of Cu(NO 3) 2 , 5 wt% of Ce(NO 3) 3 and {2.5 wt% Cu(NO 3) 2 ? 2.5 wt% Ce(NO 3) 3 } additives was studied. The introduction of additives was carried out by an incipient wet impregnation method to ensure uniform distribution of cerium and copper nitrates within the structure of coal powdery samples (according to SEM and EDX mapping). The samples reactivity was studied in an isothermal oxidation regime at 200°C (1 h) and by DSC/TGA at 2.5°C/min heating rate. The additives implementation was found to reduce significantly the oxidation onset temperature (DT i = 20-55°C), the samples oxidation delay time (Dt i = 2-22 min) and overall duration of the oxidation process (Dt c = 8-16 min). The additives efficiency could be graded in accordance with the activation on the coal oxidation in the following row: Cu(NO 3) 2 [ {Cu(NO 3) 2 ? Ce(NO 3) 3 } [ Ce(NO 3) 3. According to the mass spectroscopy, the obtained row of activation correlates well with the initial temperature of the studied nitrate's decomposition (from 190 to 223°C). A presence of nitrates was found to change significantly the trend of heat release taking place during the oxidation of coal samples (according to DSC/TGA data). The influence of coal morphology and volatiles content in initial sample on the parameters of the oxidation process was studied as well. Activation energy (E a) of the coal oxidation was calculated using Coats-Redfern method. Maximum decrease in E a from 69 to 58 kJ/mol was observed for the samples with Cu(NO 3) 2 .

show abstract

“…Some authors [36,37] have also demonstrated the catalytic effect of ashes on char oxidation reactions. In our study, the yield of char from oxidative pyrolysis of ash-rich (herbaceous) biomass was shown to be higher than the yield of low-ash biomass.…”

Section: Yields and Composition Of The Char Condensates And Permanent Gasesmentioning

confidence: 99%

Oxidative pyrolysis of pine wood, wheat straw and miscanthus pellets in a fixed bed

Pham

Piriou

Salvador

et al. 2018

Fuel Processing Technology

View full text Add to dashboard Cite

Oxidative pyrolysis is a key step in the autothermal operation of many fixed-bed reactors for staged gasification and advanced carbonisation. In these reactors, biomass is converted into charcoal, condensates and permanent gases inside a moving Oxidation Zone (OZ) which also produces energy to self-sustain the process. Oxidative pyrolysis of three different biomass types: pine wood, miscanthus and wheat straw pellets, was performed in a batch 20 cm diameter fixed bed reactor. Results showed that the OZ consumed 11% to 14% of the stoichiometric air to self-sustain the process and reached a peak temperature around 720°C whatever the biomass. The propagation velocity and thickness of the OZ were inversely proportional to the ash content and to the bulk density of the biomass. Ash was also shown to influence the yield and composition of the resulting products due to a catalytic effect on primary and secondary pyrolysis reactions.

show abstract

Effects of catalysts on combustion reactivity of anthracite and coal char with low combustibility at low/high heating rate

Cited by 38 publications

References 29 publications

Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

Non-isothermal TGA study on the combustion reaction kinetics and mechanism of low-rank coal char

Non-isothermal oxidation of coal with Ce(NO3)3 and Cu(NO3)2 additives

Oxidative pyrolysis of pine wood, wheat straw and miscanthus pellets in a fixed bed

Contact Info

Product

Resources

About