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Title: Predictive Model for Particle Residence Time Distributions in Riser Reactors. Part 1: Model Development and Validation

Abstract

Here in this computational study, we model the mixing of biomass pyrolysis vapor with solid catalyst in circulating riser reactors with a focus on the determination of solid catalyst residence time distributions (RTDs). A comprehensive set of 2D and 3D simulations were conducted for a pilot-scale riser using the Eulerian-Eulerian two-fluid modeling framework with and without sub-grid-scale models for the gas-solids interaction. A validation test case was also simulated and compared to experiments, showing agreement in the pressure gradient and RTD mean and spread. For simulation cases, it was found that for accurate RTD prediction, the Johnson and Jackson partial slip solids boundary condition was required for all models and a sub-grid model is useful so that ultra high resolutions grids that are very computationally intensive are not required. Finally, we discovered a 2/3 scaling relation for the RTD mean and spread when comparing resolved 2D simulations to validated unresolved 3D sub-grid-scale model simulations.

Authors:
ORCiD logo [1];  [1];  [2]; ORCiD logo [1];  [1];  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States). National Bioenergy Center
  2. SABIC Americas, Sugar Land, TX (United States). Corporate Research and Development
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies Office (EE-3B)
OSTI Identifier:
1351161
Report Number(s):
NREL/JA-5100-67640
Journal ID: ISSN 2168-0485
Grant/Contract Number:
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
ACS Sustainable Chemistry & Engineering
Additional Journal Information:
Journal Volume: 5; Journal Issue: 4; Journal ID: ISSN 2168-0485
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 59 BASIC BIOLOGICAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; biomass pyrolysis; catalytic upgrading; riser reactor; multiphase flow simulation; catalyst residence time distribution

Citation Formats

Foust, Thomas D., Ziegler, Jack L., Pannala, Sreekanth, Ciesielski, Peter, Nimlos, Mark R., and Robichaud, David J. Predictive Model for Particle Residence Time Distributions in Riser Reactors. Part 1: Model Development and Validation. United States: N. p., 2017. Web. doi:10.1021/acssuschemeng.6b02384.
Foust, Thomas D., Ziegler, Jack L., Pannala, Sreekanth, Ciesielski, Peter, Nimlos, Mark R., & Robichaud, David J. Predictive Model for Particle Residence Time Distributions in Riser Reactors. Part 1: Model Development and Validation. United States. doi:10.1021/acssuschemeng.6b02384.
Foust, Thomas D., Ziegler, Jack L., Pannala, Sreekanth, Ciesielski, Peter, Nimlos, Mark R., and Robichaud, David J. Tue . "Predictive Model for Particle Residence Time Distributions in Riser Reactors. Part 1: Model Development and Validation". United States. doi:10.1021/acssuschemeng.6b02384. https://www.osti.gov/servlets/purl/1351161.
@article{osti_1351161,
title = {Predictive Model for Particle Residence Time Distributions in Riser Reactors. Part 1: Model Development and Validation},
author = {Foust, Thomas D. and Ziegler, Jack L. and Pannala, Sreekanth and Ciesielski, Peter and Nimlos, Mark R. and Robichaud, David J.},
abstractNote = {Here in this computational study, we model the mixing of biomass pyrolysis vapor with solid catalyst in circulating riser reactors with a focus on the determination of solid catalyst residence time distributions (RTDs). A comprehensive set of 2D and 3D simulations were conducted for a pilot-scale riser using the Eulerian-Eulerian two-fluid modeling framework with and without sub-grid-scale models for the gas-solids interaction. A validation test case was also simulated and compared to experiments, showing agreement in the pressure gradient and RTD mean and spread. For simulation cases, it was found that for accurate RTD prediction, the Johnson and Jackson partial slip solids boundary condition was required for all models and a sub-grid model is useful so that ultra high resolutions grids that are very computationally intensive are not required. Finally, we discovered a 2/3 scaling relation for the RTD mean and spread when comparing resolved 2D simulations to validated unresolved 3D sub-grid-scale model simulations.},
doi = {10.1021/acssuschemeng.6b02384},
journal = {ACS Sustainable Chemistry & Engineering},
number = 4,
volume = 5,
place = {United States},
year = {Tue Feb 28 00:00:00 EST 2017},
month = {Tue Feb 28 00:00:00 EST 2017}
}

Journal Article:
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  • Here, wsing the validated simulation model developed in part one of this study for biomass catalytic fast pyrolysis (CFP), we assess the functional utility of using this validated model to assist in the development of CFP processes in fluidized catalytic cracking (FCC) reactors to a commercially viable state. Specifically, we examine the effects of mass flow rates, boundary conditions (BCs), pyrolysis vapor molecular weight variation, and the impact of the chemical cracking kinetics on the catalyst residence times. The factors that had the largest impact on the catalyst residence time included the feed stock molecular weight and the degree ofmore » chemical cracking as controlled by the catalyst activity. Lastly, because FCC reactors have primarily been developed and utilized for petroleum cracking, we perform a comparison analysis of CFP with petroleum and show the operating regimes are fundamentally different.« less
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