Modeling Effects of Operating Conditions on Biomass Fast Pyrolysis in Bubbling Fluidized Bed Reactors

2013 ◽  
Vol 27 (10) ◽  
pp. 5948-5956 ◽  
Author(s):  
Qingang Xiong ◽  
Soroush Aramideh ◽  
Song-Charng Kong
Fuel ◽  
2017 ◽  
Vol 210 ◽  
pp. 625-638 ◽  
Author(s):  
Johnny Matta ◽  
Benjamin Bronson ◽  
Peter E.G. Gogolek ◽  
Dillon Mazerolle ◽  
Jules Thibault ◽  
...  

Author(s):  
Robert Macias ◽  
Juan Maya ◽  
Farid Chejne ◽  
Carlos Londoño ◽  
Javier De La Cruz

This work proposes a new strategy for the scaling of bubbling fluidized bed reactors. This strategy is based on the bubble size distribution, bubble coalescence phenomenon, and the chemical reactivity, allowing to deduct the dimensionless number Chejne-Macias-Maya that must remain constant at different scales to guarantee the fluidization regime. The proposed strategy is validated from computational simulations carried out at different operating conditions. Additionally, limits for the validity of this scaling strategy were determined, which agrees with those reported in the literature.


Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1407
Author(s):  
Jong Hyeon Ha ◽  
In-Gu Lee

A critical issue in the design of bubbling fluidized bed reactors for biomass fast pyrolysis is to maintain the bed at a constant level to ensure stable operation. In this work, a bubbling fluidized bed reactor was investigated to deal with this issue. The reactor consists of inner and outer tubes and enables in situ control of the fluidized-bed level in the inner-tube reactor with a mechanical method during biomass fast pyrolysis. The significant fraction of biochar produced from the fast pyrolysis in the inner-tube reactor was automatically removed through the annulus between the inner and outer tubes. The effect of pyrolysis temperature (426–528 °C) and feeding rate (0.8–1.8 kg/h) on the yield and characteristics of bio-oil, biochar, and gaseous products were examined at a 15 L/min nitrogen carrier gas flow rate for wood sawdust with a 0.5–1.0 mm particle size range as a feed. The bio-oil reached a maximum yield of 62.4 wt% on a dry basis at 440 °C, and then slowly decreased with increasing temperature. At least 79 wt% of bio-char byproduct was removed through the annulus and was found in the reactor bottom collector. The GC-MS analysis found phenolics to be more than 40% of the bio-oil products.


Fuel ◽  
2012 ◽  
Vol 97 ◽  
pp. 757-769 ◽  
Author(s):  
Q. Xue ◽  
D. Dalluge ◽  
T.J. Heindel ◽  
R.O. Fox ◽  
R.C. Brown

2010 ◽  
Vol 33 (12) ◽  
pp. 2021-2028 ◽  
Author(s):  
P. Lan ◽  
Q. Xu ◽  
M. Zhou ◽  
L. Lan ◽  
S. Zhang ◽  
...  

2014 ◽  
Vol 12 (1) ◽  
pp. 441-449 ◽  
Author(s):  
Zhonglin Zhang ◽  
Daoyin Liu ◽  
Yaming Zhuang ◽  
Qingmin Meng ◽  
Xiaoping Chen

Abstract This paper describes a CFD-DEM modeling of CO2 capture using K2CO3 solid sorbents in a bubbling fluidized bed, which takes into heat transfer, hydrodynamics, and chemical reactions. Shrinking core model is applied in reaction kinetics. Simulation and experiment results of bed pressure drop and CO2 concentration in the reactor exit agree well. Instantaneous dynamics as well as time-averaged profiles indicate detailed characteristics of gas flow, particle motion, and chemical reaction processes. The simulation results show an obvious core-annular flow and strong back-mixing flow pattern. CO2 concentration decreases gradually along the bed height, while regards on the lateral distribution CO2 concentration near the wall is lower than that in the middle zone where gas passes through faster. The effect of bubbles on CO2 reaction is two-sided: it can promote mixing which strengthens reaction, while it can be a short pass of gas which is not beneficial to reaction. The simulation is helpful for further understanding and optimal design of fluidized bed reactors of CO2 capture.


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