Thermodynamic equilibrium model and second law analysis of a downdraft waste gasifier

Jarungthammachote, Sompop; Dutta, Animesh

doi:10.1016/j.energy.2007.01.010

Cited by 404 publications

(263 citation statements)

References 11 publications

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“…Several authors have recently investigated the thermodynamic and exergetic performance of gasification Jarungthammachote and Dutta, 2007;Prins et al, 2007) and gasification systems for the production of power (Brown et al, 2009;Prins et al, 2007;Fryda et al, 2008) and fuels (Ptasinski, 2008). Apart from (Brown et al, 2009), however, all these studies disregard or discuss the effects of process integration only very briefly, and lack a systematic approach as provided by pinch analysis techniques.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic comparison of the FICFB and Viking gasification concepts

Gassner

Maréchal

2009

Energy

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Two biomass gasification concepts, i.e. indirectly heated, fast internally circulating fluidised bed (FICFB) gasification with steam as gasifying agent and two-stage, directly heated, fixed bed Viking gasification are compared with respect to their performance as gas generators. Based on adjusted equilibrium equations, the gas composition and the energy requirements for gasification are accurately modelled. Overall energy balances are assessed by an energy integration with the heat cascade concept and considering energy recovery in a steam Rankine cycle. A detailed inventory of energy and exergy losses of the different process sections is presented and potential process improvements due to a better utility choice or feed pretreatment like drying or pyrolysis are discussed. While Viking gasification performs better as an isolated gas generator than state-of-the-art FICFB gasification, there is large potential for improvement of the FICFB system. Furthermore, a concluding analysis of the gasification systems in an integrated plant for synthetic natural gas production shows that FICFB gasification is more suitable overall due to a more advantageous energy conversion related to the producer gas composition.

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Section: Introductionmentioning

confidence: 99%

Thermodynamic comparison of the FICFB and Viking gasification concepts

Gassner

Maréchal

2009

Energy

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“…La validez del modelo se determinó mediante la Desviación Media Cuadrada (RMSD) y el Error Relativo (RE). Estos parámetros se determinan mediante las Ecuaciones 4 y 5, que han sido utilizadas para estimar la calidad de los resultados en trabajos de simulación previos [12,39,40]. Donde representa los valores experimentales reportados por los autores para cada variable respuesta y representa los Tabla 3.…”

Section: Parámetro Valorunclassified

Gasificación de madera para la obtención de un syngas útil en la producción de biocombustibles y/o productos químicos

Hernández

Bayer

Zapata

2017

rev.ion

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ResumenEn el presente trabajo se desarrolló un modelo en equilibrio que permite simular el proceso de producción de un syngas útil para la obtención de biocombustibles líquidos y/o productos químicos mediante gasificación en lecho arrastrado. El proceso fue modelado mediante el software Aspen Plus, considerando las etapas de pretratamiento y acondicionamiento de la biomasa (secado, torrefacción y molienda), gasificación en lecho arrastrado, limpieza y acondicionamiento del syngas producido, y ajuste de la relación H 2 /CO, adicionalmente se modela la Unidad de Separación de Aire (ASU) para la producción de oxígeno como agente gasificante. La validación del modelo se realizó a partir de datos experimentales reportados en la literatura, mediante el análisis de los errores relativos para las variables de interés: relación H 2 /CO, poder calorífico inferior (LHV, de sus siglas en inglés Lower Heating Value) y eficiencia en frío, obteniendo errores de 7,8%, 11,8% y 8,8%, respectivamente. Adicionalmente, se evaluó la sensibilidad del modelo para predecir el efecto de variables de proceso como la temperatura de torrefacción y la relación equivalente sobre las variables respuesta H 2 /CO y LHV, obteniendo con el modelo tendencias similares a las reportadas en la literatura bajo diferentes condiciones de operación, lo cual muestra que el modelo es sensible a cambios en los parámetros del proceso. Por tanto, se considera que el modelo desarrollado es una herramienta computacional útil para realizar análisis de sensibilidad en procesos de producción de biocombustibles líquidos y/o productos químicos a partir de gasificación de biomasa en lecho arrastrado. Palabras clave: gasificación en lecho arrastrado, Aspen Plus, biocombustibles líquidos, biomasa, syngas.Abstract A model to simulate the entrained flow gasification process to produce a syngas useful in the synthesis of liquid biofuels and/or chemicals was developed. The model is simulated in Aspen Plus and includes the stages of: pretreatment and conditioning of biomass (drying, torrefaction and grinding), entrained flow gasification, cleaning and conditioning of syngas produced, adjustment of H 2 /CO relation, and an Air Separation Unit (ASU) for oxygen production as gasifying agent. The model validation was performed from experimental data reported in the literature, by analyzing the relative errors for the interest variables: H 2 /CO, lower heating value and cold gas efficiency, founding errors of 7.8%, 11.8% and 8.8% respectively. Additionally, the sensibility of the model to predict the effect of process variables as torrefaction temperature and equivalence ratio on response variables, showed similar tendencies to those found Cita: Suárez L, Pérez JF, Barrera R. Gasificación de madera para la obtención de un syngas útil en la producción de biocombustibles y/o productos químicos. rev.ion. 2017;30(1):57-71.

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“…The enthalpy h and entropy s values for the medium, air (gas from the recuperator), and gas mixture are temperature dependent, and the values used in this study are based on the work from [11] and the JANAF thermodynamics tables as reported by [12]. The temperature of the hot gas from the recuperator was varied from 800…”

Section: Exergy Efficienciesmentioning

confidence: 99%

Modeling Performance of High-Temperature Biomass Gasification Process

Mhilu

2012

ISRN Chemical Engineering

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Biomass utilization is becoming a subject of increasing interest as an alternative to clean fuel. A novel gasification process using highly preheated air gasifier using agricultural residue such as sugar bagasse, rice husks, and palm stem widely available in Tanzania is presented. The study examines, irreversibilities making the gasifier the least efficient unit in the gasification process employing a thermodynamic equilibrium model allowing predicting the main product gas composition CO, CO 2 , H 2 , and CH 4 . The derived model equations are computed using the MAPLE process simulation code in MATLAB. The gasification regime is investigated at temperatures ranging from 800 K to 1400 K and at equivalence ratio (ER) values between 0.3 and 0.4. The results obtained conform to the second law efficiency based on chemical exergy yielding maximum values for the types of biomass materials used. These results indicate that the application of preheated air has an effect on the increase of the chemical exergy efficiency of the product gas, hence reducing the level of irreversibility. Similarly, these results show that the combined efficiency based on physical and chemical exergy is low, suggesting that higher irreversibilities are encountered, since the exergy present in the form of physical exergy is utilized to heat the reactants. Such exergy losses can be minimized by altering the ratio of physical and chemical exergy in the syngas production.

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Thermodynamic equilibrium model and second law analysis of a downdraft waste gasifier

Cited by 404 publications

References 11 publications

Thermodynamic comparison of the FICFB and Viking gasification concepts

Thermodynamic comparison of the FICFB and Viking gasification concepts

Gasificación de madera para la obtención de un syngas útil en la producción de biocombustibles y/o productos químicos

Modeling Performance of High-Temperature Biomass Gasification Process

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