Experiments and modeling of single plastic particle conversion in suspension

Abstract

 Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

CPFD simulation of petcoke and SRF co–firing in a full–scale cement calciner

“…The particles are considered as isothermal with constant sphericity and emissivity throughout the conversion process. It is reported that in calciner operating conditions and for plastic particles lighter than 1000 mg, the total conversion time predicted using an isothermal model is within ±30% of the value predicted by a detailed non-isothermal model [56].…”

“…It is assumed that the plastic particles constitute moisture, volatile, and ash contents. The plastic particles in SRF are assumed to go through moisture evaporation [78], melting and decomposition processes [56]. The particles are considered as isothermal with constant sphericity and emissivity throughout the conversion process.…”

“…The original heats of melting and decomposition for plastic particles are 207 and 365 kJ/kg, respectively [56,79]. In the present study, for plastic conversion, it is assumed that: CH 4 is the only product of decomposition, the specific heat capacities of solid and liquid phases change with temperature and are equal to the gaseous CH 4 specific heat capacity, and the heats of melting and decomposition are modified in a way that the total thermal energy required for complete particle heating, melting, and decomposition would be the same compared to a plastic particle with original heats of melting and decomposition and specific heat capacity.…”

“…In the CPFD model, solid particles are tracked in a Lagrangian frame using the MP-PIC approach. The sub-models used for conversion of different SRF particle types are previously developed and validated [55,56]. Finally, predictions from the CFD simulations and the measurements are compared throughout the calciner, and suggestions for improving the accuracy of the simulation are provided.…”

Multi-Scale Modeling of Plastic Waste Gasification: Opportunities and Challenges

“…Internal transport limitations can affect the rate of transfer of heat and mass to different layers and locations. This can be a reason for non-uniform but shell-progressive melting of the particle [38]. Non-uniform temperature/concentration profiles, as well as the presence of bubbles as the result of evaporation, can also be seen in this figure . Considering the whole process, reactor scale phenomena are crucial in determining the hydrodynamic behavior and temperature/product distribution of the gasifier.…”