Fast pyrolysis multiphase CFD-kinetics model in a drop tube reactor

Tobo, Yohannis; Lotfi, A.; Virla, Luis D.; Mahinpey, Nader

doi:10.1016/j.fuel.2023.127524

Cited by 6 publications

(4 citation statements)

References 30 publications

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“…The molecular dynamics of the oxidation processes of polymers mixtures with cellulose and coals were investigated in [166,167]. Numerical tools based on computational fluid dynamics (CFD) for reacting waste and plastic particles (for laboratory drop tube reactor conditions) were proposed in [168][169][170].…”

Section: Mathematical Modelling 41 Numerical Models Of Combustion And...mentioning

confidence: 99%

Particle Agglomeration of Biomass and Plastic Waste during Their Thermochemical Fixed-Bed Conversion

Donskoy

2023

Energies

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The article provides state-of-the-art research on agglomeration processes during fixed-bed combustion and gasification of low-grade fuels such as biomass and waste (primarily plastic-containing waste). Such fuels demonstrate complex thermal behaviour: their decomposition and combustion are multistage, accompanied by phase transitions, and may lead to fixed-bed mechanical instability and the non-uniformity of air distribution over the cross-section. To clarify the role of physicochemical factors (fuel composition and properties, reactor conditions), data from different sources are compared. The review shows that the fixed-bed agglomeration regimes can, in a rough approximation, be classified by the sintering mechanism (due to the melting of the mineral part or the organic part), with the following search for each mechanism realisation conditions by comparing the fuel properties and characteristic temperatures. Attempts to theoretically describe and numerically simulate the agglomeration phenomenon as a change in the structure of a reacting dispersed medium are also considered: the main directions in which such approaches can be developed are indicated.

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Section: Mathematical Modelling 41 Numerical Models Of Combustion And...mentioning

confidence: 99%

Particle Agglomeration of Biomass and Plastic Waste during Their Thermochemical Fixed-Bed Conversion

Donskoy

2023

Energies

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“…applied a granular multiphase flow model to examine the chemical kinetics of the pyrolysis process using a drop tube reactor. At a reactor wall temperature of 773 K, the numerical solution provided a gas yield of 25%, whereas, on a mass basis, the water and biochar obtained were 10% and 20%, respectively 10 …”

Section: Introductionmentioning

confidence: 99%

“…At a reactor wall temperature of 773 K, the numerical solution provided a gas yield of 25%, whereas, on a mass basis, the water and biochar obtained were 10% and 20%, respectively. 10 Apart from the chemistry of pyrolysis, it is necessary to discuss the mode of heat transfer and the heating rate. So far, the heat transfer to feedstock was provided either by furnace, 11,12 steam, 13,14 heating cable, 15,16 or microwave, 17,18 so the design parameter plays a pivotal role in obtaining the maximum cold or hot efficiencies.…”

Section: Introductionmentioning

confidence: 99%

Thermo‐economic assessment of a bench‐scale pyrolysis unit through a process simulator

Dhaundiyal,

Toth

2023

Biofuels Bioprod Bioref

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This article focuses on the holistic appraisal of a pilot‐scale updraft reactor (E1) powered by the processed residue of forest waste (W1) and hog fuel (W2). The detailed analysis of the up‐draft unit includes the availability of energy, economic evaluation, and the determination of the lignocellulose content of the pine waste. The reformed structure of the pine pellet was used for gas, bio‐oil, and char generation. The Aspen HYSYS process simulator was used for simulation purposes and the results were validated with the solution obtained experimentally. For the measurement of the constituent contents of the pine needles, the National Renewable Energy Laboratory (NREL) procedure was adopted. To investigate the similitude of the packed bed reactor, the Soave–Redlich–Kwong model was considered. For comparison of the given prototype, five different reactor types – conversion (R1), equilibrium (R2), Gibbs (R3), continuous stir tank (CST) (R4) and plug flow (R5) – were juxtaposed and their thermodynamic behavior was evaluated. From structural composition, it was noticed that the cellulose and hemicellulose(s) content dropped by 24.95% and 37.37%, respectively, whereas a rise of 23.33% was seen in the acid‐insoluble lignin (AIL) fraction of forest waste after the torrefaction process. Irrespective of the fuel type, the unconsumed fuel percentage was the same for both wood and processed residue pellets for R5. The relative percentage of methane increased by 1% for processed forest residue. The CO2 emission was estimated to be maximum for reactors R3 and R4. The O2 gain was absent in the R2 reactor. Concomitantly, it gained momentum in R1, R3, and R4. The simulated polytropic equations of state for W1 and W2 were PV1.083 = C and PV1.092 = C, respectively. The levelized cost of energy dropped by 12.50% while scaling up a pyrolysis unit.

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“…88,89 Mathematical models of tar condensation in tubes and ducts were proposed. [90][91][92] Kinetic models of biomass pyrolysis and gasification processes taking into account multi-component tar formation were also proposed; [93][94][95] : however, their use is computationally expensive and requires a lot of input coefficients with significant uncertainty.…”

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confidence: 99%

Mathematical modeling of tar conversion on downdraft biomass gasification processes

Donskoy

2023

Biofuels Bioprod Bioref

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The article concerns some problems associated with the use of low‐grade fuels for the production of syngas in fixed‐bed gasifiers. Syngas is typically used to feed internal combustion engines in small power systems. Gas quality can be understood as its various characteristics, such as calorific value, the content of individual components (for example, hydrogen), low tar and soot content, and so forth. Achieving these quality criteria often requires specific conditions for the gasification process, in addition, some of them may be limited by additional requirements that are associated with thermal stability or fuel conversion requirements. When evaluating the technical and economic characteristics of gasification‐based power plants, the optimal efficiency does not always correspond to the higher efficiency of the gasification process and the quality of producer gas. In this regard, the aim is to develop optimization methods for different criteria and to create regime maps that cover physically achievable options. Novel mathematical models of tar conversion are proposed, allowing investigation of the dependencies of tar yield on gasification conditions, including the addition of catalysts or staged air supply. Computational tools based on thermodynamic and kinetic models make it possible to solve some of these problems, first of all, to consider and compare the efficiency of various methods for reducing tar content in producer gas (staged gasification, fuel mixing, thermal, and catalytic methods of tar elimination). The choice of relatively simple mathematical models allows us to conduct numerical calculations in a wide range of conditions and to optimize the parameters of biofuel conversion plants. This approach allows a more flexible choice of gasifier operating conditions, including its work as a part of a power unit. Optimal parameters are calculated for specific conditions: secondary air ratio (1–20%) and fraction of catalytic material (5–10%). The results may be used in the analysis and choice of biofuel gasification conditions at small power plants.

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Fast pyrolysis multiphase CFD-kinetics model in a drop tube reactor

Cited by 6 publications

References 30 publications

Particle Agglomeration of Biomass and Plastic Waste during Their Thermochemical Fixed-Bed Conversion

Particle Agglomeration of Biomass and Plastic Waste during Their Thermochemical Fixed-Bed Conversion

Thermo‐economic assessment of a bench‐scale pyrolysis unit through a process simulator

Mathematical modeling of tar conversion on downdraft biomass gasification processes

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