Direct Electricity Generation from Dissolved Cellulosic Biomass in an Alkaline Fuel Cell

Abstract

Cellulose, which accounts for more than half of the carbon content in plants, has become a popular feedstock for biofuel production. In this work, direct electricity generation from dissolved cellulosic biomass in an alkaline fuel cell is explored without energy‐intensive process. The effect of different cellulose dissolution solvents on the electricity production is investigated. Results show dissolution treatment can remarkably affect the fuel cell performance. When NaOH/urea/thiourea is chosen as a solvent, the specific capacity of cellulose is about sixfold higher than that using only NaOH as solvent. The limiting current density and the maximum power density reach 0.85 mA cm−2 and 0.07 mW cm−2, respectively. This power density surpasses those of any existing biotic or abiotic designs. Electrochemical characterizations demonstrate that the remarkable activity improvement towards the cellulose oxidation reaction in NaOH/urea/thiourea aqueous solution is due to the lower charger transfer resistance and higher energy transfer efficiency.

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

“…As can be seen in the histogram in Figure 5, the MPD of various low temperature abiotic direct cellulose fuel cells operating at room temperature (RT) goes from 0.0044 mW cm −2 for an AFC, [74] to 0.045 mW cm −2 for an AFC with MV as redox mediator, [75] to 0.07 mW cm −2 for a PEMFC with a composite anode, [28] to 0.7 mW cm −2 for a HFFC [87] and a RFFC [96] …”

“…Single chamber fuel cells working in batch mode were used as direct biomass alkaline fuel cells (DBAFCs). The chamber of the fuel cell was filled with the electrolyte (NaOH), containing the biomass, commonly commercial microcrystalline cellulose [72–74] . While in MFCs insoluble cellulose is commonly used without any pretreatment, before its use in AFCs cellulose must be pretreated to make it soluble in alkaline media.…”

“…dissolved pure cellulose powder in an alkaline solution by a freezing/thawing process, then used it as the fuel in an alkaline direct cellulose fuel cell with gold and platinum as anode and cathode, respectively, generating a power density of 0.0044 mW cm −2 . Later, single chamber AFCs operating at room temperature (RT) in a batch mode with methyl viologen (MV) as an electron transfer catalyst (redox mediator) were fueled with pretreated biomass compounds [73,74,77] . Viologens, derivatives of 4,4′‐bipyridine, have highly reversible redox reactions, and are relatively inexpensive among redox‐active organic compounds.…”

“…The chamber of the fuel cell was filled with the electrolyte (NaOH), containing the biomass, commonly commercial microcrystalline cellulose. [72][73][74] While in MFCs insoluble cellulose is commonly used without any pretreatment, before its use in AFCs cellulose must be pretreated to make it soluble in alkaline media. Previous studies indicate that the structural parameters of the cellulose, mainly its degree of polymerization (DP) and its crystallinity, affect its solubility and reactivity.…”

“…Later, single chamber AFCs operating at room temperature (RT) in a batch mode with methyl viologen (MV) as an electron transfer catalyst (redox mediator) were fueled with pretreated biomass compounds. [73,74,77] Viologens, derivatives of 4,4'-bipyridine, have highly reversible redox reactions, and are relatively inexpensive among redox-active organic compounds. Viologens can oxidize glucose and other carbohydrates in an alkaline solution, making them as suitable catalysts in direct carbohydrate fuel cells.…”