Determination of coal gasification kinetics from integral drop tube furnace experiments with steam and CO2

Keller, Florian; Küster, Felix; Meyer, Bernd

doi:10.1016/j.fuel.2017.11.120

Cited by 23 publications

(10 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, it was suggested to adjust all the kinetic rates proportionally to the rate of the CO desorption (C (O) → CO) to obtain the most accurate match with experiments. As a result, instead of applying Equation 8, the frequency factor was scaled on the basis of the char conversion experiment of the Illinois coal [58], which is close to that analyzed in the present study of Utah coal, was based on the Van Krevelen diagram (Figure 4). As regards the optimization of the gasification step, the first phase in the optimization process required proper estimation of the frequency factor for surface oxide desorption in the CBK/G model [21].…”

Section: Optimization Procedures Resultsmentioning

confidence: 99%

“…As a result, instead of applying Equation 8, the frequency factor was scaled on the basis of the char conversion experiment of the Illinois coal [58], which is close to that analyzed in the present study of Utah coal, was based on the Van Krevelen diagram (Figure 4). 8, and with the adjusted frequency factor on the basis of the experimental data [58]. Judging by the results, the modified frequency factor will be further incorporated in the calculations.…”

Section: Optimization Procedures Resultsmentioning

confidence: 99%

“…Judging by the results, the modified frequency factor will be further incorporated in the calculations. 8, and with the adjusted frequency factor on the basis of the experimental data [58]. Judging by the results, the modified frequency factor will be further incorporated in the calculations.…”

Section: Optimization Procedures Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Entrained-Flow Coal Gasification Process Simulation with the Emphasis on Empirical Char Conversion Models Optimization Procedure

Mularski

Modliński

2021

Energies

View full text Add to dashboard Cite

Computational fluid dynamics (CFD) modeling of an entrained-flow reactor is demonstrated and compared with experimental data. The study is focused on char conversion modeling and its impact on gasification simulation results. An innovative procedure of optimizing input data to empirical char conversion kinetic-diffusion model is investigated, based on the complex carbon burnout kinetic model for oxidation (CBK/E) and gasification (CBK/G). The kinetics of the CBK/G model is determined using the data from char gasification experiments in a drop tube reactor. CFD simulations are performed for the laboratory-scale entrained-flow reactor at Brigham Young University for the bituminous coal. A substantial impact of applied kinetic parameters on the in-reactor gas composition and char conversion factor was observed. The effect was most considerable for the reduction zone, where gasification reactions dominate, although a non-negligible impact could also be observed in the flame zone. Based on the quantitative assessment of the incorporated optimization procedure, its application allowed to obtain one of the lowest errors of CO, H2, CO2, and H2O axial distribution with respect to the experimental data. The maximum errors for these species were equal to 18.48, 7.95, 10.15, and 20.22%, respectively, whereas the average errors were equal to 4.82, 5.47, 4.72, and 9.58%, respectively.

show abstract

Section: Optimization Procedures Resultsmentioning

confidence: 99%

Section: Optimization Procedures Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Entrained-Flow Coal Gasification Process Simulation with the Emphasis on Empirical Char Conversion Models Optimization Procedure

Mularski

Modliński

2021

Energies

View full text Add to dashboard Cite

show abstract

“…The process can be described by various global or intrinsic reaction models such as the apparent rate model, shrinking core model (SCM), random pore model (RPM), Umemoto et al’s model, char burnout kinetics/gasification (CBK/G) model, char conversion kinetics (CCK). − These models express the reaction rate as a product of kinetic rate (in a single Arrhenius rate or a Langmuir–Hinshelwood form) and surface area (as a function of carbon conversion). In particular, RPM has been regarded as a suitable model for char gasification, ,, which considers the intraparticle pore development to describe an initial increase in reactive surface area. However, Mahinpey and Gomez suggested that the maximum gasification rate is not a consequence of surface area increase but of separation in pyrolysis and gasification in most fundamental experiments.…”

Section: Introductionmentioning

confidence: 99%

Determination of Effective Reaction Conditions for Char Gasification in an Entrained Flow Reactor

Sohn

Ryu

et al. 2018

Energy Fuels

View full text Add to dashboard Cite

The entrained flow reactor (EFR) is frequently applied to analyze the reactivity of pulverized coal char under controlled atmospheres of temperature and partial pressure. The rate constants for a specific char gasification model derived from EFR tests may be subject to errors due to the differences between the target and actual conditions caused by (i) the shorter reaction time because of the thermal entry region if not preheated to the target temperature, (ii) lower particle temperatures because of endothermic reactions, and (iii) lower partial pressure of reactants consumed. In this study, coal char was gasified using CO2 and H2O in a pressurized EFR, and the validity of the rate constants for a char conversion model based on the target reaction conditions was assessed using computational fluid dynamics (CFD). Then, an analytical method was proposed to determine the effective reaction time, particle temperature, and reactant partial pressure for derivation of rate constants only using the experimental data. The predicted char conversion ratios adopting the modified rate constants showed good agreement with the measured data under various conditions. The method can be applied to deriving rate constants for a particular char conversion model and to estimating the uncertainties of a particular EFR design and test conditions.

show abstract

“…The kinetic constant k is described by the well-known Arrhenius' equation given in Eq. 9 [24][25][26][27][28][29][30][31];…”

mentioning

confidence: 99%

Experimental Analysis and Kinetic Modelling for Steam Gasification of the Turkish Lignites

Güney

Koyun

2020

Journal of Thermal Engineering

View full text Add to dashboard Cite

During the last decades, the importance of structural parameters has been increased because the models which have been developed using structural parameter can define the gasification process effectively. In this study, structural parameters, rates of conversion and activation energies of Zonguldak coal and Beypazari lignite have obtained. The samples of Zonguldak coal and Beypazari lignite used in this study have different characteristics. Pore dimensions, distribution of pores and surface areas were used as structural parameters. Suitable kinetic parameters were determined by fitting the gasification model to experimental data. The random pore model was used to define these kinetic parameters. The data were taken from experiments of Balci and Durusoy and the results obtained from Zonguldak coal and Beypazarı lignite pyrolysed in a vertical tube heated from outside by an inert gas and gasified with steam at elevated temperatures (between 700 °C and 1000 °C) were used in the model.

show abstract

Determination of coal gasification kinetics from integral drop tube furnace experiments with steam and CO2

Cited by 23 publications

References 31 publications

Entrained-Flow Coal Gasification Process Simulation with the Emphasis on Empirical Char Conversion Models Optimization Procedure

Entrained-Flow Coal Gasification Process Simulation with the Emphasis on Empirical Char Conversion Models Optimization Procedure

Determination of Effective Reaction Conditions for Char Gasification in an Entrained Flow Reactor

Experimental Analysis and Kinetic Modelling for Steam Gasification of the Turkish Lignites

Contact Info

Product

Resources

About