Assessment of biochar as feedstock in a direct carbon solid oxide fuel cell

Abstract

The feasibility of employing biochar as a fuel in a direct carbon fuel cell (DCFC) or a hybrid carbon fuel cell (HCFC) is investigated in the present study, by utilizing bare biochar or biochar/carbonate mixture as feedstock, respectively. Three different types of biochars, i.e., pistachio shells (PI), pecan shells (PE) and sawdust (SD) are used as feedstock in a solid oxide fuel cell (SOFC) of a type: Biochar|Co-CeO 2 /YSZ/Ag|Air. All samples were characterized by means of chemical composition (ultimate/proximate analysis), thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), to obtain a close correlation between cell performance and biochar characteristics. The electrochemical measurements reveal that the optimum performance, in terms of maximum power density (P max ), is obtained for the PI biochar, which demonstrated a power output of 15.5 mW/cm 2 at 800 o C, compared to 14 and 10 mW/cm 2 for PE and SD biochars, respectively. The obtained cell performance results are interpreted on the basis of biochar physicochemical characteristics and AC impedance spectroscopy studies. The superior performance of PI biochar is attributed to a synergistic effect of several physicochemical characteristics, involving the porosity, the acidity, the volatile matter, the carbon and hydrogen content as well as the population of oxygenated surface functionalities.

The combined impact of carbon type and catalyst-aided gasification process on the performance of a Direct Carbon Solid Oxide Fuel Cell

“…AC sample shows the lowest BET area (3.0 m 2 /g) and available porosity (0.01 cm 3 /g), whilst the PCC sample possesses the highest area (11.0 m 2 /g) and pore volume (0.05 cm 3 /g). BC presented intermediate values with BET area and porosity equal to 4.0 m 2 /g and 0.02 cm 3 /g, respectively [35].…”

“…been demonstrated that the electrochemical performance is strongly affected by their composition and physicochemical properties [12,[29][30][31][32][33][34]. In view of this fact we recently investigated the impact of various carbons [29] and biochars [35] on the DCFC performance. The results revealed that fuel physicochemical characteristics, such as volatile matter, structure disorder and sulfur content, notably affect the DCFC performance [29,35].…”

“…In view of this fact we recently investigated the impact of various carbons [29] and biochars [35] on the DCFC performance. The results revealed that fuel physicochemical characteristics, such as volatile matter, structure disorder and sulfur content, notably affect the DCFC performance [29,35].…”

“…The electrochemical cell used in the experiments has been described in detail elsewhere [29,35]. Chromatograph (SRI 8610B) equipped with a Molecular Sieve 5A and Porapak Q columns.…”

Biosynthesis of Ag/almond shell nanocomposite as a cost-effective and efficient catalyst for degradation of 4-nitrophenol and organic dyes

“…8 The bands observed at around 1600 cm À1 are due to the aromatic C]O ring stretching (possibly COOH) or C]C stretching of aromatic groups in lignin, implying the presence of lignin. 28 The broad peak in the 1040-1070 cm À1 region may be due to C-OH stretching vibration of alcoholic groups and carboxylic acids.…”