The usefulness of walnut shells as waste biomass fuels in direct carbon solid oxide fuel cells

Materials Selection and Construction Development for Ensuring the Availability and Durability of the Molten Hydroxide Electrolyte Direct Carbon Fuel Cell (MH-MCFC)

“…Furthermore, the fuel for the DCFC does not require any sophisticated preparation, since the solid carbon can be easily obtained from various resources [ 1 , 2 ] such as coal, petroleum coke, charred biomass (e.g., grass, woods, nut shells, corn husks), or even organic garbage. There are four basic types of direct carbon fuel cells under development, which generally differ with respect to electrolyte types, which can be either molten carbonates [ 3 , 4 ], solid oxygen ion conducting ceramics [ 5 , 6 , 7 , 8 ], or aqueous [ 9 ] or molten hydroxides [ 10 ]. Composite electrolytes (so-called hybrid electrolytes) are also widely used in DCFC prototypes [ 11 , 12 , 13 ].…”

Lignocellulose, Cellulose and Lignin as Renewable Alternative Fuels for Direct Biomass Fuel Cells

“…Molten hydroxide fuel cells were not used as DBFCs, because their operating temperature is too low to allow a suitable internal biomass pyrolysis. The most common type of fuel cell using raw biomass as the fuel was the solid oxide direct biomass fuel cell (SO‐DBFC) [125–131] . Compared to the other types of fuel cells, SO‐DCFCs present some benefits, such as all solid state components, resulting in a high safety of the system, enough stable performance and no need of purging gas.…”

“…The most common type of fuel cell using raw biomass as the fuel was the solid oxide direct biomass fuel cell (SO-DBFC). [125][126][127][128][129][130][131] Compared to the other types of fuel cells, SO-DCFCs present some benefits, such as all solid state components, resulting in a high safety of the system, enough stable performance and no need of purging gas. However, SO-DCFCs present some drawbacks, such as unsatisfactory long-term durability, carbon refilling and low performance at temperatures < 800°C.…”

“…Promising Ni/YSZ alternatives as anode catalysts are perovskite materials based on strontium titanates and lanthanum chromite, such as Sr 1-x La x TiO 3 (0 � x � 0.5) and La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3 (LSCM). [134] In all SO-DBFCs [125][126][127][128][129][130][131] YSZ was used as the electrolyte material, and in almost all SO-DBFCs [125][126][127][128][129] LSM was utilized as and the cathode material, except two works, [130,131] in which La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 (LSCF) was used. Ni-based materials such as Ni/ceria cermet (Ni/CeO 2 ), [125] Ni/YSZ [126,127,130] and Ni/ceria-gadolinia cermet (Ni/GDC) [128,131] were used, with one exception, [129] as SO-DBFC anode catalysts.…”

A Microtubular Direct Carbon Solid Oxide Fuel Cell Operated on the Biochar Derived from Pepper Straw

“…However, there are still several barriers remaining to be overcome for the performance improvement and widespread application of DC‐SOFCs. Currently, many types of biomass derived from crop residues, such as corn cob char, leaf char, wheat straw, bagasse, pomelo peel char, and walnut shells, have been adopted as carbon fuels to improve the cell performance due to the naturally existing catalysts of the reverse Boudouard reaction. Cai et al developed an electrolyte‐supported solid oxide fuel cell (SOFC), which yielded a maximum power density of 197 mW cm −2 at 800 °C using wheat straw as fuel.…”