Feasibility of Pine Bark Pellets and Their Pyrolyzed Biochar Pellets as Fuel Sources in Molten Hydroxide Direct Carbon Fuel Cells

Abstract

A comprehensive study was conducted on the fuel feasibility of forest-based biomass−pine bark pellets (BPs) and their pyrolyzed biochar pellets (BP800) using molten hydroxide direct carbon fuel cells (MH-DCFCs). The polarization behaviors of MH-DCFCs fed with BP and BP800 were Ohmic resistance-controlled in the low current density region, while mass-transfercontrolled polarization behavior was dominant in the high current density region. The achieved maximum current density and peak power density were 74.5 mA/cm 2 and 30.8 mW/cm 2 at 450 °C for BP and 110.4 mA/cm 2 and 45.0 mW/cm 2 at 450 °C for BP800, respectively. The fuel availability test revealed that the batch lives of BP-and BP800-fed cells are ∼19.0 and ∼15.7 h and the energy conversion efficiencies are 39.0 and 45.9%, respectively, indicating that the fuel performance of BP is comparable with that of the pyrolyzed biochar (BP800) thereof with regard to energy conversion efficiency and cell stability. The characterizations suggest that this can be largely attributed to the inherent ash components in BP and the water formation during the BP-fed cells' operation, which can suppress the carbonate ion accumulation at the anode. In conclusion, direct utilization of raw BP as the fuel is feasible to feed MH-DCFCs, and the thermal pretreatment might not be required for biomass to run MH-DCFCs.

Pellet Production from Pruning and Alternative Forest Biomass: A Review of the Most Recent Research Findings

“…Basically, pellets are mostly already produced from forest residues; in particular, with coniferous sawdust derived from sawmills. However, there has been great interest in recent years in producing pellets from alternative species, both from natural stands and from dedicated plantations, and from other types of forest residues, such as bark, cones, or material from low-diameter wood like branches [ 55 , 56 ].…”

Strong Metal–Support Interactions of Ni-CeO2 Effectively Improve the Performance of a Molten Hydroxide Direct Carbon Fuel Cell

“…The resultant peak power densities, P max , for ARP8, AC (C-3014), PP8, PB, and ARB were 273 mW (50.6 mW cm –2 ), 251 mW (46.5 mW cm –2 ), 198 mW (mW cm –2 ), 165 mW (30.6 mW cm –2 ), and 148 mW (27.4 mW cm –2 ), respectively. Hao et al 19 tested the feasibility of pine bark pellets and their pyrolyzed biochar pellets as fuel sources in the MHDCFC; the maximum power density of the cell was 45 mW cm –2 at 450 °C. However, we tried to add catalysts to improve the electrochemical performance of the MHDCFC.…”