The swirl and pyrolysis reaction synergistically enhance solid-solid heat transfer and product separation in cyclone pyrolyzer

Autor: Niu, Haorui, Yang, Jingxuan, Lian, Wenhao, Zhang, Nan, Li, Yongguo, Ren, Hongzheng, Hao, Xiaogang, Guan, Guoqing
Zdroj: Particuology; 20240101, Issue: Preprints
Abstrakt: Cyclone pyrolyzer is a novel type of downer that combines centrifugal force field and double-layer cyclone vortex. Research on transfer behavior is helpful to optimize the pyrolyzer to meet the needs of pyrolysis. In this study, the Computational Particle Fluid Dynamics (CPFD) model is used to analyze the transfer behavior of binary particles, and finds that the swirl and reaction have a synergistic effect. This effect can increase the heating rate of the particles to the range of flash pyrolysis, and its mechanism lies in the flow field structure of the pyrolyzer. Due to the centrifugal force field, the particles gather to the near wall. The rapid swirl, which facilitates intense gas-solid heat transfer, leads to the rapid heating and pyrolysis of biomass particles. As the pyrolysis proceeds, the mass of the biomass particles becomes smaller and they are more easily affected by the gas flow in pyrolyzer. Under the action of gas flow, char particles serve as new heat carrier to form the inner cycle of particles, which strengthens the heating process. The pyrolysis products are discharged from the exhaust port in time with the flow field of the pyrolyzer to achieve separation from the heat carrier and inhibit the occurrence of secondary reactions.
Databáze: Supplemental Index