Session: 03-02 Advanced Modeling and Retrofit Techniques for Hydrogen and Mixed-Fuel Combustion Systems

Paper Number: 153953

Computational Fluid Dynamics Modeling of Steam Co-Gasification of Biochar and Waste Mixed Plastic in Downdraft Fixed Bed Reactor 

Energy demand is increasing exponentially due to technological advancements, but energy sources are depleted rapidly. According to EIA, only 6% of the total energy consumption in the USA in 2023 was generated from renewable sources. Of these renewable sources, 60% came from the gasification of biomass. The efficiency of the gasification process depends on multiple parameters. This research investigates the steam co-gasification of biochar and plastic using computational fluid dynamics. A 3-dimensional fixed bed downdraft gasifier is designed. Only steam is introduced alongside the particles for the reaction. To track the movement of the particles of biochar and plastic, Discrete Phase Modeling (DPM) is used. From the species transport model, finite-rate/eddy-dissipation is used for the chemical kinetics. Eleven reactions are employed, encompassing both homogeneous and heterogeneous types. The simulation is conducted under steady-state conditions and the turbulence k-epsilon model is used. To examine the impact of temperature and plastic-to-biochar ratio on syngas composition, these parameters are varied from 700ºC-1000ºC and 0.25, 0.5, 0.75, and 1. The particle sizes of biochar and plastic are also varied to assess their effect on the product gases. The plastic is divided into CH4, C2H4, and higher carbon by devolatilization. The primary products of the syngas are  CO, CO2, CH4, and H2 while the main goal of this research is to attain the maximum H2 synthesis. The simulation results are then further compared with the experimental results for a better comparative assessment.

Presenting Author: Md Mahmudul Hasan Georgia Southern University

Presenting Author Biography: Md Mahmudul Hasan is pursuing his Master of Science in Mechanical Engineering at Georgia Southern University. He is also working as a graduate research assistant under the supervision of Dr. Prakash Bhoi. He completed his Bachelor of Science in Mechanical Engineering from Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh. He worked in the Bangladesh Power Development Board for more than two years. He worked in the renewable energy research sector during his job and was also in charge of two 33/11Kv substations. His research interests include renewable energy, gasification processes, computational fluid dynamics, and machine learning.

Authors:

Md Mahmudul Hasan Georgia Southern University
Brandon O’ Brien Georgia Southern University
Prakash Bhoi Georgia Southern University