TITLE:
Co-Gasification of Mesquite and Coal Blend in an Updraft Fixed Bed Gasifier
AUTHORS:
Wei Chen, Siva Sankar Thanapal, Kalyan Annamalai, Robert James Ansley, Mustafa Mirik
KEYWORDS:
Gasification; Bioenergy; Coal; Heating Value; Sustainability
JOURNAL NAME:
Journal of Sustainable Bioenergy Systems,
Vol.3 No.3,
September
24,
2013
ABSTRACT: In order to reduce the emission of NOx, SOx,
and CO2 and mitigate the dependence on the fossil fuel, the use of renewable energy,
especially the biomass energy, has been explored. Since most biomass fuels are
hard to grind to the very fine size, gasification is the preferred
technology of energy conversion. Updraft fixed bed gasification using
partial oxidation process is adopted where air less than the stoichiometric
quantity is admitted to oxidize the char to CO. The temperature profile within
the bed reveals a characteristic temperature peak. The results reveal a
correlation between the higher heating value (HHV) of producer gas and the peak
gasification temperature (Tpeak). Coal with higher char content (~45%) is
blended with biomass of low char content (~20%) in order to produce high
quality gas. In this study, the Texas-based mesquite fuel was blended with
Wyoming Power River Basin (PRB) coal with mass ratios of 100:0, 90:10, and
80:20 and fired downward into the gasifier. It was found that at a given
mesquite to the coal mass ratio, the peak gasification temperature decreased with
the increase in ER. With the increase of the coal ratio in the mesquite: coal
blend and the peak temperature increased significantly; more combustible
gases such as CO, CH4 were generated at the end of product
gas, and the HHV of the product gas increased by 10%-20%.