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Exergy evaluation of biomass steam gasification via interconnected fluidized beds
Author(s) -
Song Guohui,
Chen Lulu,
Xiao Jun,
Shen Laihong
Publication year - 2013
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.2987
Subject(s) - syngas , exergy , biomass (ecology) , exergy efficiency , fluidized bed , yield (engineering) , waste management , heat of combustion , chemistry , pulp and paper industry , environmental science , materials science , combustion , engineering , organic chemistry , metallurgy , catalysis , geology , oceanography
SUMMARY This paper presents the thermodynamic assessment of biomass steam gasification via interconnected fluidized beds (IFB) system. The performance examined included the composition, yield and higher heating value (HHV) of dry syngas, and exergy efficiencies of the process. Two exergy efficiencies were calculated for the cases with and without heat recovery, respectively. The effects of steam‐to‐biomass ratio ( S/B ), gasification temperature, and pressure on the thermodynamic performances were investigated based on a modified modeling of the IFB system. The results showed that at given gasification temperature and pressure, the exergy efficiencies and dry syngas yield reached the maximums when S/B was at the corresponding carbon boundary point ( S/B CBP ). The HHV of the dry syngas continuously decreased with the increase of S/B . Moreover, the exergy efficiency with heat recovery was averagely a dozen percentage points higher than that without heat recovery. Under atmospheric conditions, lower gasification temperature favored the yield and HHV of dry syngas at various S/B . In addition, it also favored the exergy efficiencies of the process when S/B is approximately larger than 0.75. Under pressurized conditions, higher gasification pressure favored both the yield and HHV of dry syngas, as well as the exergy efficiencies at different S/B . Copyright © 2013 John Wiley & Sons, Ltd.