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Saint-Sauveur-en-Rue, France

Fourcault A.,Laboratoire Thermique Energetique et Procedes | Marias F.,Laboratoire Thermique Energetique et Procedes | Michon U.,EUROPLASMA
Biomass and Bioenergy | Year: 2010

The thermal degradation of tars in a chamber fed by a non-transferred plasma torch is theoretically examined in this study. The input of this reactor is a product gas coming from a gasification unit with a temperature of about 800°C. According to literature, naphthalene and toluene are chosen as model compounds to represent the behaviour of their classes. According to this choice and to the data available in the literature, a reaction pathway for the thermal degradation of tars and its associated kinetics are proposed in this study. This mechanism is introduced in a CSTR model in order to check the influence of the operating parameters of the reactor on the degradation efficiency. These computations clearly show that a complete conversion of toluene (>99.9%) and an important conversion of naphthalene (96.7%) can be reached in the reactor, with concentration levels compatible with the further use of gas engines for electricity production. This theoretical study requires to be validated by comparison with experimental results. © 2010 Elsevier Ltd.


Bernada P.,University of Pau and Pays de lAdour | Marias F.,University of Pau and Pays de lAdour | Deydier A.,University of Pau and Pays de lAdour | Couture F.,University of Pau and Pays de lAdour | Fourcault A.,EUROPLASMA
Waste and Biomass Valorization | Year: 2012

This work deals with the modelling of a travelling bed waste gasifier. This gasifier is a part of a more general process devoted to the production of electricity from waste and refused derived fuel. In a first stage the load is dried and gasified in a travelling bed gasifier using air with an equivalence ratio of 0.3. This product gas contains light hydrocarbons as well as tars. It is converted into a syngas free from tars in a specific reformer (Turboplasma ©) that uses plasma technology in order to raise the temperature of the incoming gas to a value compatible with thermal cracking of tars. The model of the travelling bed gasifier is based on the coupling between a software devoted to the description of the chemical and physical processes occurring within the travelling bed, and a CFD package (FluentTM) that allows for the description of the homogenous gas reaction and radiation occurring within the freeboard of the bed. The first software is a ''home made'' software based on the conservation equations of the solid, liquid and gas phases as well as of the energy. The balance equations are firstly written at the ''phase scale'', and then, using a homogenisation technique (volume averaging) balance equations are derived at a representative volume scale. In this first work, this model is written using a one dimensional formalism along the axis of the travelling bed. Wood is used as a case study material with a pyrolysis mechanism that uses three parallel reactions leading to the formation of gas, tars and char. The gas and tars produced during the pyrolysis step can be converted within the bed itself but also over the freeboard of the bed. Hence, the free board of the bed is used as a boundary condition of the CFD domain, with known local mass flowrate, composition and temperature. This study allows for a complete and precise description of the processes occurring within the gasifier under consideration. © Springer Science+Business Media B.V. 2012.


Patent
Europlasma | Date: 2012-02-08

Treating a synthesis gas includes generating a plasma jet from a non-transferred arc torch having a main axis, the jet having a propagation axis substantially collinear with the torch main axis. The plasma torch is mounted on a feed enclosure. The syngas is received at an inlet port of the feed enclosure, downstream from the plasma torch and feeding the syngas so the flow encounters the plasma jet to mix the syngas and plasma jet in a distribution chamber. The mixture is propagated in a reactor downstream from the feed enclosure to convert the syngas into an outlet gas. The reactor is in communication in its upstream portion with the feed enclosure through a flared segment, and has a longitudinal axis that is substantially collinear with the propagation axis of the plasma jet. The outlet gas is extracted via an outlet port and particles are captured by a submerged conveyor.


Deydier A.,EUROPLASMA | Deydier A.,Laboratoire Of Thermique Energetique Et Procedes | Marias F.,Laboratoire Of Thermique Energetique Et Procedes | Bernada P.,Laboratoire Of Thermique Energetique Et Procedes | And 2 more authors.
Biomass and Bioenergy | Year: 2011

A mathematical model describing a gasification process composed of a dryer section and of a gasification section is presented in this work. This model is based on the equilibrium assumption within both sections. The whole set of assumptions used in the model are presented in the paper as well as the derivation of the corresponding equations. The temperature of both sections is computed using energy balances. The numerical predictions of the model are compared to available data describing the gasification of coal, wood and grass. The influence of two operating parameters of the system is investigated in the study. The first one is the ratio of air supplied to the dryer to the biomass fed to this section. Our computation clearly shows the existence of an optimal value for this parameter. In the same manner, the influence of the ratio of air supplied to the gasifying section to the incoming biomass is investigated. Once again, this parameter shows an optimal value. © 2010 Elsevier Ltd.


Marias F.,University of Pau and Pays de lAdour | Bernada P.,University of Pau and Pays de lAdour | Couture F.,University of Pau and Pays de lAdour | Robert Arnouil J.P.,EUROPLASMA | Lamande A.,EUROPLASMA
3rd International Conference on Computational Methods for Thermal Problems, ThermaComp 2014 | Year: 2014

This work deals with the modelling of a travelling bed biomass gasifier. This gasifier is a part of a more general process devoted to the production of electricity from biomass. In a first stage biomass is dried and gasified in a travelling bed gasifier using air with an equivalence ratio of 0.3. This product gas contains light hydrocarbons as well as tars. It is converted into a syngas free from tars in a specific reformer (Turboplasma©) that uses plasma technology in order to raise the temperature of the incoming gas to a value compatible with thermal cracking of tars. The overall process. The model of the travelling bed gasifier is based on the coupling between a software devoted to the description of the chemical and physical processes occurring within the travelling bed, and a CFD package (Fluent™) that allows for the description of the homogenous gas reaction and radiation occurring within the freeboard of the bed. The first software is a "home made" software based on the conservation equations of the solid, liquid and gas phases as well as of the energy. The balance equations are firstly written at the "phase scale", and then, using a homogenisation technique (volume averaging) balance equations are derived at a representative volume scale. In this first work, this model is written using a one dimensional formalism along the axis of the travelling bed. Wood is used as a case study material with a pyrolysis mechanism that uses three parallel reactions leading to the formation of gas, tars and char. The gas and tars produced during the pyrolysis step can be converted within the bed itself but also over the freeboard of the bed. Hence, the free board of the bed is used as a boundary condition of the CFD domain, with known local mass flow-rate, composition and temperature. This study allows for a complete and precise description of the processes occurring within the gasifier under consideration.

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