(682b) Hydrogen Rich Syngas Production through Synergistic Methane Activated Catalytic Biomass Gasification

Hydrogen Rich
Syngas Production through Synergistic Methane Activated Catalytic Biomass
Gasification

Amoolya Lalsare^a,
Yuxin Wang^a,
Qingyuan Li^a, Ali Sivri^b, Roman
J. Vukmanovich^a, Cosmin E. Dumitrescu^b, Jianli Hu^a*

^aDepartment of Chemical and Biomedical Engineering

^bDepartment of Mechanical and Aerospace
Engineering

West
Virginia University, Morgantown, West Virginia, 26506, USA

Synergistic
natural gas – biomass gasification process is being developed at West Virginia
University for controllable H₂/CO ratio syngas production. Gasification
tests were performed at 850^oC and 950^oC using two
different catalyst systems: Fe-Mo promoted ZSM-5 and Mo-Fe supported on carbon
nanofiber structure. During co-gasification of methane and biomass, H₂/CO
ratio ranged from 3.5 to 7 at different reaction conditions. However, in the
absence of methane, H₂/CO ratio from biomass gasification varied
from 0.8 to 1.3 with very high CH₄ concentration between 55 to 63
mole%. Experimental results showed that when methane was introduced into
biomass gasification, steam methane reforming occurred simultaneously with biomass
gasification utilizing oxygenate available in biomass in the form of C=O and
C-OH functional moieties. In-situ tar reforming also contributed to the high H₂/CO
ratio.   The extreme high temperature (850^oC,
950^oC) caused irreversible deactivation of Fe-Mo/ZSM-5. In contrast,
carbon nanofiber based catalyst is found regenerative in nature and has been
shown to retain activity for multiple cycles. Introduction of methane in oxygen
rich lignocellulosic hardwood biomass gasification increases the overall
hydrogen to carbon ratio thus allowing for effective hydrogen transfer between
methane and biomass. High hydrogen production in methane activated biomass
gasification is attributed to simultaneous steam methane reforming (SMR) and
standard gasification reactions producing high H₂/CO ratio of 3.5 to
7. Attempt was made to elucidate the synergistic effect observed in
co-gasification of methane and biomass. It is postulated that reaction
mechanism involves hydrodeoxygentation of phenolic,
carbonyl, and carboxyl oxygen adsorbed on the oxophilic
Fe and Mo active sites to form H₂O adsorbate leading to SMR. This
reaction mechanism is being validated using first principle based density
functional theory to calculate binding energies of phenolic oxygen and methane
on the active sites, study thermodynamic feasibility of the proposed mechanism,
identify reaction intermediates, and exact pathway of the overall reaction.

Keywords:
biomass gasification, co-gasification of biomass and methane, FeMo/ZSM-5 catalyst

*Corresponding
Author Email: john.hu@mail.wvu.edu