Macroscopic modeling of plasma effects on heat and fluid flow in a dielectric barrier discharge based process for biosolid stabilization

This work presents a simple, easily applicable macroscopic model for the simulation of the plasma effect on the fluid flow and the heat transfer, in a Dielectric Barrier Discharge (DBD) reactor used for environmental applications, such as soil remediation and biosolid stabilization. The model uses inputs that are easy to obtain experimentally, such as the inlet flow rate, electric power consumption, and reduction in the moisture of the treated specimen, in order to provide information on features that are difficult to measure, such as the temperature distribution in the plasma region and inside the specimen. The model is presented here through the simulation of a floating-electrode DBD process, and the results are compared with experimental data. For the simulation, the reactor's exact geometry is reconstructed in the computational domain, conjugate heat transfer is considered between the flowing air and the solid components, and the treated biosolid is modeled as a porous material. The findings show that, within the selected operating window, the temperature increase in the plasma area and inside the biosolid does not exceed 100 K. Such information is crucial for the assessment of the physicochemical modification of the specimen under treatment and the suitability of the treatment procedure for targeted applications.