A semi-empirical approach to the thermodynamic analysis of downdraft gasification

Svishchev, Denis; Козлов, А. Г.; Donskoy, Igor; Рыжков, А. Ф.

doi:10.1016/j.fuel.2015.11.066

Cited by 44 publications

(24 citation statements)

References 61 publications

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“…In a state of equilibrium, a thermodynamically stable solid carbon (or char) can be obtained. The gasification conditions can achieve the maximum energy efficiency of the process when the solid carbon fuel has completely reacted [55]. Hence, when the carbon content is high in a biomass, the experimental results of gasification are closer to the thermodynamic models.…”

Section: Model Validationmentioning

confidence: 80%

Development of a modified equilibrium model for biomass pilot-scale fluidized bed gasifier performance predictions

Alejandro

Nam

Maglinao

et al. 2016

Energy

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The objective of this work is to develop a thermodynamic model considering non-stoichiometric restrictions. The model validation was done from experimental works using a bench-scale fluidized bed gasifier with wood chips, dairy manure, and sorghum. The model was used for a further parametric study to predict the performance of a pilot-scale fluidized biomass gasifier. The Gibbs free energy minimization was applied to the modified equilibrium model considering a heat loss to the surroundings, carbon efficiency, and two non-equilibrium factors based on empirical correlations of ER and gasification temperature. The model was in a good agreement with RMS < 4 for the produced gas. The parametric study ranges were 0.01 < ER < 0.99 and 500 °C < T < 900 °C to predict syngas concentrations and its LHV (lower heating value) for the optimization. Higher aromatics in tar were contained in WC gasification compared to manure gasification. A wood gasification tar simulation was produced to predict the amount of tars at specific conditions. The operating conditions for the highest quality syngas were reconciled experimentally with three biomass wastes using a fluidized bed gasifier. The thermodynamic model was used to predict the gasification performance at conditions beyond the actual operation.

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Section: Model Validationmentioning

confidence: 80%

Development of a modified equilibrium model for biomass pilot-scale fluidized bed gasifier performance predictions

Alejandro

Nam

Maglinao

et al. 2016

Energy

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“…If moisture content is more than 20 %, it is necessary to maintain high air ratios to achieve high fuel conversion degree that leads to low cold gas efficiency. Lower limit of cold gas efficiency may be fixed at 60 % (allowable value in comparison with existing low-capacity gasifiers [6]). Then reasonable biomass fraction in fuels mixture will naturally decrease with moisture content: it is 50 % at 20 % of moisture in raw biomass; 15 % at 30 % moisture in raw biomass; and less than 5 % at 40 % of moisture in raw biomass.…”

Section: Modelling Resultsmentioning

confidence: 99%

Mathematical Modelling of the Fixed-Bed Biomass-Coal Co-Gasification Process

Donskoy

2016

MATEC Web Conf.

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“…A distinctive feature of this multistage process is an active use of the producer gas heat and exhaust gases of the internal combustion engine to heat the air blow and fuel in the screw pyrolyzer. Chemical efficiency of such an allo-autothermal process reaches 93%, whereas in the autothermal conditions it does not exceed 75-80% [9,10]. Moreover, the tar content in the unrefined gas is at the level of 15 mg/nm 3 .…”

Section: A Review Of Technologies For Multistage Solid Fuel Gasificationmentioning

confidence: 95%

Modeling of Pyrolysis in a Stage Scheme of Low‐Grade Solid Fuel Gasification

Козлов¹,

Levin²,

Svishchev³

et al. 2017

Pyrolysis

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This paper is concerned with the development of a model of wood pyrolysis in a screw reactor as the first stage of the multistage gasification process. In terms of design, the pilot pyrolyzer represents a recuperative heat exchanger where the heat carrier is represented by a mixture of exhaust and recirculation gases. To prevent clinkering of particles and thermal inhomogeneities, screw-type transportation is used to transport fuel. In order to describe kinetics of pyrolysis and transport of volatiles within the wood particles and their transition to the gas phase, we carried out the studies using a complex of synchronous thermal analysis. The original techniques for the interpretation of measurements were developed for this complex, including the techniques for technical analysis of fuels and identification of detailed kinetics and mechanism of pyrolysis. A detailed numerical modeling of pyrolyzer was performed using the Comsol Multiphysics software, which makes it possible to optimize the design and operating parameters of the pyrolysis process in a screw reactor.

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A semi-empirical approach to the thermodynamic analysis of downdraft gasification

Cited by 44 publications

References 61 publications

Development of a modified equilibrium model for biomass pilot-scale fluidized bed gasifier performance predictions

Development of a modified equilibrium model for biomass pilot-scale fluidized bed gasifier performance predictions

Mathematical Modelling of the Fixed-Bed Biomass-Coal Co-Gasification Process

Modeling of Pyrolysis in a Stage Scheme of Low‐Grade Solid Fuel Gasification

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