Open Access

ARTICLE

Three-Dimensional Simulation of Hydrodynamic Mechanism of Fluidized Bed Methanation

by Xiaojia Wang^1,*, Danyang Shao¹, Delu Chen¹, Yutong Gong¹, Fengxia An^1,2

1 Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy & Environment, Southeast University, Nanjing, 210096, China
2 State Key Laboratory of Clean and Efficient Coal-Fired Power Generation and Pollutant Control, China Energy Science and Technology Research Institute Co., Ltd., Nanjing, 210023, China

* Corresponding Author: Xiaojia Wang. Email:

Journal of Renewable Materials 2023, 11(7), 3155-3175. https://doi.org/10.32604/jrm.2023.027535

Received 03 November 2022; Accepted 15 December 2022; Issue published 05 June 2023

Abstract

Organic solid waste (OSW) contains many renewable materials. The pyrolysis and gasification of OSW can realize resource utilization, and its products can be used for methanation reaction to produce synthetic natural gas in the specific reactor. In order to understand the dynamic characteristics of the reactor, a three-dimensional numerical model has been established by the method of Computational Fluid Dynamics (CFD). Along the height of the reactor, the particle distribution in the bed becomes thinner and the mean solid volume fraction decreases from 4.18% to 0.37%. Meanwhile, the pressure fluctuation range decreased from 398.76 Pa at the entrance to a much lower value of 74.47 Pa at the exit. In this simulation, three parameters of gas inlet velocity, operating temperature and solid particle diameter are changed to explore their influences on gas-solid multiphase flow. The results show that gas velocity has a great influence on particle distribution. When the gas inlet velocity decreases from 6.51 to 1.98 m/s, the minimum height that particles can reach decreases from 169 to 100 mm. Additionally, as the operating temperature increases, the particle holdup inside the reactor changes from 0.843% to 0.700%. This indicates that the particle residence time reduces, which is not conducive to the follow-up reaction. Moreover, with the increase of particle size, the fluctuation range of the pressure at the bottom of the reactor increases, and its standard deviation increases from 55.34 to 1266.37 Pa.

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Graphic Abstract

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