Modelling of a rotary kiln for the pyrolysis of aluminium waste

Marías, Fréderic; Roustan, Hervé; Pichat, A.

doi:10.1016/j.ces.2005.03.025

Cited by 38 publications

(11 citation statements)

References 24 publications

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“…If it is considered that the coal used for the process being modeled behaves in the same way as the subbituminous coal used by Nelson, which produces a char the same as the one shown in Figure 2 named ''char G,'' giving a g value of 0.65. The inclusion of NOx modeling to predict the pollutant behavior in co-combustion processes for rotary kilns represents an important improvement when compared to previous numerical models of similar systems, such as the models developed by Mastorakos et al (1999), Martins et al (2001), and Marias et al (2005) for rotary kilns and Fidaros et al (2007) for a calciner. According to the specific characteristics of the processes modeled by these authors, the use of gas phase conservation equations, chemical-turbulence interaction models, and kinetic= diffusion solid fuel reaction mechanisms can be found; however, none of them evaluates the pollutant formation of NOx formation for any of the three different mechanisms considered in this research.…”

Section: Coal and Natural Gas Co-combustion In Rotary Kiln 31mentioning

confidence: 99%

Modeling and Numerical Solution of Coal and Natural Gas Co-Combustion in a Rotary Kiln

Barraza

Bula

Palencia

2012

Combustion Science and Technology

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Due to the great importance of rotary kilns in the cement industry and the fact that these systems are known to be high energy consumers, a model was developed for one of the most important phenomena occurring inside of such kilns, i.e., combustion. This model and its numerical solution allow for carrying out process optimization techniques in order to reduce the use of the fuel required, emissions, and operation costs. Furthermore, this model permits geometrical modifications in the burner as well as variations in operational conditions, i.e., flow rates, temperatures, and concentrations. The process studied here is carried out inside a tubular rotary kiln, which has a burner of concentric tubes that allows the combustion of two fuels in different phases, in this case, coal and natural gas. The modeling accounts for phenomena such as the turbulence produced due the high Reynolds number in the feed streams; the convective heat loss from the shell to the environment; and a three-step and two-step eddy brake-up combustion model for natural gas and volatiles. The model is developed from Lagrangian-Eulerian multiphase flow, taking into consideration coal solid particles in the gaseous stream, devolatilization rate of coal, heterogeneous burnout of char, and NOx generation. Finally, velocity, temperature, and concentration fields were analyzed to evaluate dragging, reactions conversion, and pollutants formation in the process.

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Section: Coal and Natural Gas Co-combustion In Rotary Kiln 31mentioning

confidence: 99%

Modeling and Numerical Solution of Coal and Natural Gas Co-Combustion in a Rotary Kiln

Barraza

Bula

Palencia

2012

Combustion Science and Technology

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“…The transport of material through the rotary kiln is specified by equation (6), which is commonly known as Kramers equation [5].…”

Section: Modeling Of the Bed Phasementioning

confidence: 99%

“…Computational fluid dynamics (CFD) is a widely accepted tool for the detailed description of gaseous combustion phenomena occurring within a rotary kiln [6], [3]. Unfortunately, it does neither allow for the modeling of transport of the solid bed nor for the theoretical description of the chemical reactions therein.…”

Section: Comparison To Cfd Simulationsmentioning

confidence: 99%

Modeling of Rotary Kilns and Application to Limestone Calcination

Küssel¹,

Abel²,

Schumacher³

et al. 2009

Linköping Electronic Conference Proceedings

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This paper presents the one dimensional modeling of rotary kilns used for energy intensive production processes. Raw material is fed into an inclined rotating kiln and heated by counter current gas flow. Chemical reactions take place in the bed of raw material as well as in the gas phase. Heat and mass transfer between the bed and the gas phase are implemented. Also the heat transfer to the environment is taken into account. As a benchmark, the process of limestone calcination is chosen. Results are compared with computational fluid dynamic simulations.

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“…They are a key element in the production processes of cement (Mujumdar and Ranade, 2006), lime and pigments (titanium dioxide calcination) and in extractive metallurgy for the reduction of ore (Boateng, 2008). Rotary kilns are well suited for the conversion of coal and coke (Lebas et al, 1995), for drying (Shahhosseini et al, 2000), for the pyrolysis of solid waste (Descoins et al, 2005;Marias et al, 2005), and are also used for several conversions in the manufacture of nuclear fuel (Debacq, 2001;Thammavong et al, 2011). Rotary kilns used for the conversion of enriched or depleted uranium are equipped with lifters and are externally and electrically heated, but they differ in size and nominal operating conditions, as can be seen in Table 1: the type of rotary kiln used for depleted uranium conversion is henceforth named "kiln #1"; the type of conversion kiln used for enriched uranium is named "kiln #2".…”

Section: Introductionmentioning

confidence: 99%

A hydrodynamic model for flighted rotary kilns used for the conversion of cohesive uranium powders

Debacq

Thammavong

Vitu

et al. 2013

Chemical Engineering Science

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The axial and transverse solid distribution of a cohesive powder in flighted rotary kilns was calculated from an original method based on the lifter discharge law previously determined, geometrical calculations and supplementary measurements (in particular the fall velocity of the powder at high temperature). At a given axial position, the quantity of powder falling through the gas, the total quantity of flighted powder as well as the quantity remaining in the bulk are thus calculated; the axial bed depth profile is obtained from the Saeman-Kramers-Afacan model. Highlights ► Transverse flow of cohesive powder in flighted rotary kiln was modelled. ► Axial bed depth profile was calculated from Saeman-Kramers-Afacan model. ► Solid distribution was calculated from geometrical calculations and measurements. ► The fall velocity of the cohesive powder was measured at high temperature. ► The 'snapshot' obtained allows to calculate thermal transfer areas and mass transfer.

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Modelling of a rotary kiln for the pyrolysis of aluminium waste

Cited by 38 publications

References 24 publications

Modeling and Numerical Solution of Coal and Natural Gas Co-Combustion in a Rotary Kiln

Modeling and Numerical Solution of Coal and Natural Gas Co-Combustion in a Rotary Kiln

Modeling of Rotary Kilns and Application to Limestone Calcination

A hydrodynamic model for flighted rotary kilns used for the conversion of cohesive uranium powders

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