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Title: Bed Agglomeration During the Steam Gasification of a High Lignin Corn Stover Simultaneous Saccharification and Fermentation (SSF) Digester Residue

Abstract

This research investigates the bed agglomeration phenomena during the steam gasification of a high lignin residue produced from the simultaneous saccharification and fermentation (SSF) of corn stover in a bubbling fluidized bed. The studies were conducted at 895°C using alumina as bed material. Biomass was fed at 1.5 kg/hr, while steam was fed to give a velocity equal to 2.5 times the minimum fluidization velocity, with a steam/carbon ratio of 0.9. The pelletized feedstock was co-fed with a cooling nitrogen stream to mitigate feed line plugging issues. Tar production was high at 50.3 g/Nm3, and the fraction of C10+ compounds was greater than that seen in the gasification of traditional lignocellulosic feedstocks. Carbon closures over 94 % were achieved for all experiments. Bed agglomeration was found to be problematic, indicated by pressure drop increases observed below the bed and upstream of the feed line. Two size categories of solids were recovered from the reactor, +60 mesh and -60 mesh. After a 2.75-hour experiment, 61.7 wt % was recovered as -60 mesh particles and 38.2 wt% of the recovered reactor solids were +60 mesh. A sizeable percentage, 31.8 wt%, was +20 mesh. The -60 mesh particles were mainly formed by themore » initial bed material (Al2O3). Almost 50 wt. % of the + 20 mesh particles was found to be formed by organics. The unreacted carbon remaining in the reactor resulted in a low conversion rate to product gas. ICP-AES, SEM, SEM-EDS, and XRD confirmed that the large agglomerates (+ 20 mesh) were not encapsulated bed material but rather un-gasified feedstock pellets with sand particles attached to it.« less

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1252850
Report Number(s):
PNNL-SA-112332
Journal ID: ISSN 0887-0624; BM0101010
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Energy and Fuels
Additional Journal Information:
Journal Volume: 29; Journal Issue: 12; Journal ID: ISSN 0887-0624
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
Simultaneous saccharification and fermentation digester residue, thermochemical conversions; gasification; lignin, integrated biorefinery; renewable energy; biofuels; bioenergy

Citation Formats

Howe, Daniel T., Taasevigen, Danny J., Gerber, Mark A., Gray, Michel J., Fernandez, Carlos A., Saraf, Laxmikant, Garcia-Perez, Manuel, and Wolcott, Michael P. Bed Agglomeration During the Steam Gasification of a High Lignin Corn Stover Simultaneous Saccharification and Fermentation (SSF) Digester Residue. United States: N. p., 2015. Web. doi:10.1021/acs.energyfuels.5b01808.
Howe, Daniel T., Taasevigen, Danny J., Gerber, Mark A., Gray, Michel J., Fernandez, Carlos A., Saraf, Laxmikant, Garcia-Perez, Manuel, & Wolcott, Michael P. Bed Agglomeration During the Steam Gasification of a High Lignin Corn Stover Simultaneous Saccharification and Fermentation (SSF) Digester Residue. United States. https://doi.org/10.1021/acs.energyfuels.5b01808
Howe, Daniel T., Taasevigen, Danny J., Gerber, Mark A., Gray, Michel J., Fernandez, Carlos A., Saraf, Laxmikant, Garcia-Perez, Manuel, and Wolcott, Michael P. Fri . "Bed Agglomeration During the Steam Gasification of a High Lignin Corn Stover Simultaneous Saccharification and Fermentation (SSF) Digester Residue". United States. https://doi.org/10.1021/acs.energyfuels.5b01808.
@article{osti_1252850,
title = {Bed Agglomeration During the Steam Gasification of a High Lignin Corn Stover Simultaneous Saccharification and Fermentation (SSF) Digester Residue},
author = {Howe, Daniel T. and Taasevigen, Danny J. and Gerber, Mark A. and Gray, Michel J. and Fernandez, Carlos A. and Saraf, Laxmikant and Garcia-Perez, Manuel and Wolcott, Michael P.},
abstractNote = {This research investigates the bed agglomeration phenomena during the steam gasification of a high lignin residue produced from the simultaneous saccharification and fermentation (SSF) of corn stover in a bubbling fluidized bed. The studies were conducted at 895°C using alumina as bed material. Biomass was fed at 1.5 kg/hr, while steam was fed to give a velocity equal to 2.5 times the minimum fluidization velocity, with a steam/carbon ratio of 0.9. The pelletized feedstock was co-fed with a cooling nitrogen stream to mitigate feed line plugging issues. Tar production was high at 50.3 g/Nm3, and the fraction of C10+ compounds was greater than that seen in the gasification of traditional lignocellulosic feedstocks. Carbon closures over 94 % were achieved for all experiments. Bed agglomeration was found to be problematic, indicated by pressure drop increases observed below the bed and upstream of the feed line. Two size categories of solids were recovered from the reactor, +60 mesh and -60 mesh. After a 2.75-hour experiment, 61.7 wt % was recovered as -60 mesh particles and 38.2 wt% of the recovered reactor solids were +60 mesh. A sizeable percentage, 31.8 wt%, was +20 mesh. The -60 mesh particles were mainly formed by the initial bed material (Al2O3). Almost 50 wt. % of the + 20 mesh particles was found to be formed by organics. The unreacted carbon remaining in the reactor resulted in a low conversion rate to product gas. ICP-AES, SEM, SEM-EDS, and XRD confirmed that the large agglomerates (+ 20 mesh) were not encapsulated bed material but rather un-gasified feedstock pellets with sand particles attached to it.},
doi = {10.1021/acs.energyfuels.5b01808},
url = {https://www.osti.gov/biblio/1252850}, journal = {Energy and Fuels},
issn = {0887-0624},
number = 12,
volume = 29,
place = {United States},
year = {2015},
month = {11}
}