Title: Experimental investigation of hardwood air gasification in a pilot scale bubbling fluidized bed reactor and CFD simulation of jet/grid and pressure conditions

Abstract

A pilot scale pressurized (50 psi) fluidized bed gasification was performed to investigate the effects of the jet/ grid air ratio (5:95–90:10) and equivalence ratio (ER = 0.23–0.45) on the gasification products such as syngas, tar, contaminant gas, and biochar. There was a noticeable effect of the jet/grid ratios on the syngas concentration. An increase in CO, CH₄, and C₂ gases was obtained at the condition closer to jet/grid = 50:50, whereas a higher jet/grid ratio favored water–gas shift reaction by increasing CO₂ and H₂ gases under the pressurized condition. The highest lower heating value (LHV) of 7.7 MJ/Nm³ was obtained at the lowest ER = 0.23. Both the jet/grid ratio and ER were important parameters in determining the H₂ concentration. The cold gasification and carbon conversion efficiencies were obtained as high as 66% and 94%, respectively. Also, higher temperature and ER promoted a reduction in contaminant gases as well as tar yield. Tar product yield was also reduced significantly after a wet scrubber, and the tar consisted of chemicals of a carbon number less than 13 (≤C₁₂). Here, the gasification biochar was also analyzed and showed an effective carbon sequestration property with a relatively higher surface area (105 m²/g).more » Furthermore, computational fluid dynamics simulation was performed to determine the effects of different jet/grid air ratio and pressure conditions on the hydrodynamics in the fluidized bed reactor.« less

Authors:

Nam, Hyungseok  ^[1];

• Search DOE PAGES for author "Nam, Hyungseok"
• Search DOE PAGES for ORCID "0000-0003-2334-7288"

Rodriguez-Alejandro, David Aaron ^[2]; Adhikari, Sushil  ^[3];

• Search DOE PAGES for author "Adhikari, Sushil"
• Search DOE PAGES for ORCID "0000-0001-7033-0230"

Brodbeck, Christian ^[3]; Taylor, Steven ^[3]; Johnson, James ^[3]

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+ Show Author Affiliations

1. Auburn University, AL (United States); Korea Institute of Energy Research (KIER), Daejeon (Korea)
2. University of Guanajuato (Mexico)
3. Auburn University, AL (United States)

Publication Date:

Fri May 25 00:00:00 EDT 2018

Research Org.:

Univ. of Tennessee, Knoxville, TN (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDA

OSTI Identifier:

1781056

Alternate Identifier(s):

OSTI ID: 1691726

Grant/Contract Number:  

EE0006639; 2015-67021-22842; ALA014-6-17027

Resource Type:

Accepted Manuscript

Journal Name:

Energy Conversion and Management

Additional Journal Information:

Journal Volume: 168; Journal ID: ISSN 0196-8904

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

30 DIRECT ENERGY CONVERSION; pressurized gasification; pilot scale fluidized bed; jet/grid ratio; CFD hydrodynamic analysis; tar; contaminant gas