Experimental and theoretical investigation on unburned coal char burnout in a pilot-scale rotary kiln

Cangialosi, Federico; Canio, Francesco Di; Intini, Gianluca; Notarnicola, Michele; Liberti, L.; Belz, G.; Caramuscio, P.

doi:10.1016/j.fuel.2006.01.031

Cited by 6 publications

(2 citation statements)

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“…ADM equation with above boundary conditions is solved numerically [28,29], though the analytical solution can be found for Pe > 50 [30]. An implicit finite difference method was used to solve ADM according to the above boundary conditions.…”

Section: The Axial Dispersion Model (Adm)mentioning

confidence: 99%

Residence Time Distribution of Non-Spherical Particles in a Continuous Rotary Drum

et al. 2022

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The motion of non-spherical particles with sharp edges, as they are commonly involved in practice, was characterized by residence time distribution (RTD) measurement in a continuous drum. Particles with two sizes, 6 and 10 mm, and two densities, 750 and 2085 kg/m3, were used in the experiments. The effects of rotation speed (3–11 rpm), incline angle (2–4°), feed rate, and mixture composition were investigated and compared to the results of other researchers on particles without sharp edges. We also fitted the RTD with an axial dispersion model to obtain a better insight into the flow behavior. MRT of non-spherical particles with sharp edges depends on ω−α similar to other shapes, while the value of alpha is higher for particles with sharp edges (0.9 < α < 1.24), especially at high incline angles. The MRT depends on incline angle, β−b, where b varies between 0.81 (at low ω) and 1.34 (at high ω), while it is close to 1 for other shapes. Feed rate has a slight effect on the MRT of particles with sharp edges and the effect of particle size diminishes when rotation speed increases. The MRT linearly increases with volume fraction of light particles in a mixture of light and heavy particles (from pure heavy to pure light particles).

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Section: The Axial Dispersion Model (Adm)mentioning

confidence: 99%

Residence Time Distribution of Non-Spherical Particles in a Continuous Rotary Drum

et al. 2022

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“…Conventionally, when coal reactions are investigated, one is able to use a drop-tube furnace (DTF), 13 a wire-mesh reactor (WMR) 14 or thermogravimetry (TG) 15 to explore the reaction mechanisms and thermal properties of the fuel. In a DTF, the heating rate of the fuel is usually around 10 4 to10 5 K/sec; hence it can be used to simulate the situation of fuel particles suddenly exposed to a combustor or a high-temperature environment.…”

Section: Technical Papermentioning

confidence: 99%

Formation Characteristics of Aerosol Particles from Pulverized Coal Pyrolysis in High-Temperature Environments

Chen

Yang

et al. 2008

Journal of the Air & Waste Management Association

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Carbons

Schlögl

2008

Handbook of Heterogeneous Catalysis

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The element carbon plays a multiple role in heterogeneous catalysis. In homogeneous catalysis it occurs of course as the most prominent constituent of ligand systems and will be treated as such there. Carbon-containing molecules are, in most catalytic applications, the substrates of the process under consideration. Deposits and polymers of carbon often occur as poisons on catalysts. Carbon deposition is the most severe problem in certain zeolite applications. In hydrogenation reactions carbon deposits are thought to act as modifiers for the activity of the catalyst and to provide selectivity by controlling the hydrogenationdehydrogenation activity of the metal part of the catalyst. Carbon deposits are even thought to constitute part of the active sites in some cases. Carbon is a prominent catalyst support material as it allows the anchoring of metal particles on a substrate which does not exhibit solid acid-base properties. Carbon is finally a catalyst in its own right allowing the activation of oxygen and chlorine for selective oxidation, chlorination and de-chlorination reactions. These multiple roles of the element carbon are in parallel with a complex structural chemistry giving rise to families of chemically vastly different modifications of the element. It is a special characteristic of carbon chemistry that many of these modifications cannot be obtained as phase-pure materials. This limits the exact knowledge of physical and chemical properties to a few archetype modifications, namely graphite and diamond. The reason for this poor definition of materials is found in the process of its formation. This is comprised of difficult to control polymerisation reactions. Such reactions will occur also in catalytic reactions with small organic molecules. The nature of carbon deposits will therefore reflect all the complexity of the bulk carbon materials. It is one aim of this article to describe the structural and chemical complexity of "carbon" or "soot" in order to provide an understanding of the frequently observed complexity of the chemical reactivity (e.g. in re-activation processes aiming at an oxidative removal of deposits). The surface chemistry of carbon which determines its interfacial properties is a rich field as a wide variety of surface functional groups are known to exist on carbon. The by far most important family of surface functional groups are those involving oxygen. Other prominent heteroatoms on the surface are hydrogen and nitrogen. This article focusses on the description and characterisation of oxygen surface functional groups. In the final section, selected case studies of carbon chemistry in catalysis will be discussed in order to illustrate characteristic properties of carbon materials as wanted or unwanted components in catalytic systems. Regarding the literature on basic properties of carbon materials, the reader is referred to the extensive collection of review papers published in the series Chemistry and Physics of Carbon. Editors P.L.

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Experimental and theoretical investigation on unburned coal char burnout in a pilot-scale rotary kiln

Cited by 6 publications

References 10 publications

Residence Time Distribution of Non-Spherical Particles in a Continuous Rotary Drum

Residence Time Distribution of Non-Spherical Particles in a Continuous Rotary Drum

Formation Characteristics of Aerosol Particles from Pulverized Coal Pyrolysis in High-Temperature Environments

Carbons

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