Computational Design of a Proposed Plasma Cracker for Disposal of Municipal Solid Waste

Plasma gasification is an advanced thermal process that converts Municipal Solid Waste (MSW) into syngas and useful byproducts with high efficiency. In this study, a 3 kW plasma gasifier was numerically modeled using ANSYS FLUENT, incorporating modules for MagnetoHydroDynamics (MHD), electric potential to simulate plasma ionization, and combustion dynamics. The PISO algorithm was employed for pressure – velocity coupling under compressible flow conditions, while turbulence effects were resolved through the Large Eddy Simulation (LES) method. A Eulerian – Lagrangian framework was utilized to capture gas – solid phase interactions, with reaction continuity maintained across 10 discrete particle injection steps. Combustion and gasification processes were simulated using the Flamelet model, and radiative heat transfer was analyzed via the Discrete Ordinates (DO) radiation model. The numerical analysis focused on the thermochemical and fluid dynamic behavior within the gasifier, particularly the distribution and transformation of CH₄, CO, CO₂, H₂, and O₂. Syngas properties such as density, pressure, temperature, and velocity were evaluated across the reactor's vertical (XY mid-plane) and radial (XZ bottom-plane) sections. Simulation results revealed that the formation of CH₄ and CO is strongly influenced by temperature gradients, while CO₂ undergoes reduction into CO and H₂, enhancing syngas quality. Hydrogen concentration increased with reactor height due to steam reforming and water-gas shift reactions, whereas oxygen was efficiently consumed during the process. The proposed plasma gasifier achieved an efficiency of 90.48% at an operational temperature of 3000 K, demonstrating strong potential for sustainable MSW management and high-quality syngas production.