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Title: Warm Cleanup of Coal-Derived Syngas: Multicontaminant Removal Process Demonstration

Abstract

Warm cleanup of coal- or biomass-derived syngas requires sorbent and catalytic beds to protect downstream processes and catalysts from fouling. Sulfur is particularly harmful because even parts-per-million amounts are sufficient to poison downstream synthesis catalysts. Zinc oxide (ZnO) is a conventional sorbent for sulfur removal; however, its operational performance using real gasifier-derived syngas and in an integrated warm cleanup process is not well reported. In this paper, we report the optimal temperature for bulk desulfurization to be 450oC, while removal of sulfur to parts-per-billion levels requires a lower temperature of approximately 350oC. Under these conditions, we found that sulfur in the form of both hydrogen sulfide and carbonyl sulfide could be absorbed equally well using ZnO. For long-term operation, sorbent regeneration is desirable to minimize process costs. Over the course of five sulfidation and regeneration cycles, a ZnO bed lost about a third of its initial sulfur capacity, however sorbent capacity stabilized. Here, we also demonstrate, at the bench-scale, a process and materials used for warm cleanup of coal-derived syngas using five operations: 1) Na2CO3 for HCl removal, 2) regenerable ZnO beds for bulk sulfur removal, 3) a second ZnO bed for trace sulfur removal, 4) a Ni-Cu/C sorbent formore » multi-contaminant inorganic removal, and 5) a Ir-Ni/MgAl2O4 catalyst employed for ammonia decomposition and tar and light hydrocarbon steam reforming. Syngas cleanup was demonstrated through successful long-term performance of a poison-sensitive, Cu-based, water-gas-shift catalyst placed downstream of the cleanup process train. The tar reformer is an important and necessary operation with this particular gasification system; its inclusion was the difference between deactivating the water-gas catalyst with carbon deposition and successful 100-hour testing using 1 LPM of coal-derived syngas.« less

Authors:
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Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE Office of Fossil Energy (FE)
OSTI Identifier:
1347855
Report Number(s):
PNNL-SA-120510
Journal ID: ISSN 0887-0624; BM0101010
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Energy and Fuels; Journal Volume: 31; Journal Issue: 3
Country of Publication:
United States
Language:
English

Citation Formats

Spies, Kurt A., Rainbolt, James E., Li, Xiaohong S., Braunberger, Beau, Li, Liyu, King, David L., and Dagle, Robert A. Warm Cleanup of Coal-Derived Syngas: Multicontaminant Removal Process Demonstration. United States: N. p., 2017. Web. doi:10.1021/acs.energyfuels.6b02568.
Spies, Kurt A., Rainbolt, James E., Li, Xiaohong S., Braunberger, Beau, Li, Liyu, King, David L., & Dagle, Robert A. Warm Cleanup of Coal-Derived Syngas: Multicontaminant Removal Process Demonstration. United States. doi:10.1021/acs.energyfuels.6b02568.
Spies, Kurt A., Rainbolt, James E., Li, Xiaohong S., Braunberger, Beau, Li, Liyu, King, David L., and Dagle, Robert A. Wed . "Warm Cleanup of Coal-Derived Syngas: Multicontaminant Removal Process Demonstration". United States. doi:10.1021/acs.energyfuels.6b02568.
@article{osti_1347855,
title = {Warm Cleanup of Coal-Derived Syngas: Multicontaminant Removal Process Demonstration},
author = {Spies, Kurt A. and Rainbolt, James E. and Li, Xiaohong S. and Braunberger, Beau and Li, Liyu and King, David L. and Dagle, Robert A.},
abstractNote = {Warm cleanup of coal- or biomass-derived syngas requires sorbent and catalytic beds to protect downstream processes and catalysts from fouling. Sulfur is particularly harmful because even parts-per-million amounts are sufficient to poison downstream synthesis catalysts. Zinc oxide (ZnO) is a conventional sorbent for sulfur removal; however, its operational performance using real gasifier-derived syngas and in an integrated warm cleanup process is not well reported. In this paper, we report the optimal temperature for bulk desulfurization to be 450oC, while removal of sulfur to parts-per-billion levels requires a lower temperature of approximately 350oC. Under these conditions, we found that sulfur in the form of both hydrogen sulfide and carbonyl sulfide could be absorbed equally well using ZnO. For long-term operation, sorbent regeneration is desirable to minimize process costs. Over the course of five sulfidation and regeneration cycles, a ZnO bed lost about a third of its initial sulfur capacity, however sorbent capacity stabilized. Here, we also demonstrate, at the bench-scale, a process and materials used for warm cleanup of coal-derived syngas using five operations: 1) Na2CO3 for HCl removal, 2) regenerable ZnO beds for bulk sulfur removal, 3) a second ZnO bed for trace sulfur removal, 4) a Ni-Cu/C sorbent for multi-contaminant inorganic removal, and 5) a Ir-Ni/MgAl2O4 catalyst employed for ammonia decomposition and tar and light hydrocarbon steam reforming. Syngas cleanup was demonstrated through successful long-term performance of a poison-sensitive, Cu-based, water-gas-shift catalyst placed downstream of the cleanup process train. The tar reformer is an important and necessary operation with this particular gasification system; its inclusion was the difference between deactivating the water-gas catalyst with carbon deposition and successful 100-hour testing using 1 LPM of coal-derived syngas.},
doi = {10.1021/acs.energyfuels.6b02568},
journal = {Energy and Fuels},
number = 3,
volume = 31,
place = {United States},
year = {Wed Feb 15 00:00:00 EST 2017},
month = {Wed Feb 15 00:00:00 EST 2017}
}