Electrical and Physical Properties of Carbonized Charcoals

Abstract

Because coal does not conduct electricity and graphite is costly and inert, little attention has been given to the development of a carbon fuel cell (i.e., a battery that utilizes a consumable carbon anode to generate electrical power). In this work we show that a packed bed of carbonized charcoal particles subject to a compressive pressure (ca. 8 MPa) can be a good electrical conductor (σ < 0.2 Ω‚cm). Low electrical resistivities σ are manifest by many different charcoals after carbonization at a heat treatment temperature (HTT) of 950 °C. The 5 orders of magnitude decrease in the electrical resistivity of charcoal with increasing HTT from 650 to 1050 °C is not associated with any dramatic change in the carbons' X-ray diffraction spectrum, its Fourier transform infrared spectrum, or its elemental analysis. Our findings cause us to visualize carbonized charcoal to be a macromolecular, cross-linked, three-dimensional, aromatic structure replete with conjugation and π bonds that facilitate the movement of electrons, as well as nanopores, and micromolecular cracks. Because charcoal powder is competitive in price with fossil fuels and because carbonized charcoal is extremely reactive with a volumetric energy density (in a compacted packed bed) comparable to conventional liquid fuels, compact packed beds of carbonized charcoal hold promise for use as electrodes and consumable anodes in fuel cells. The packed-bed apparatus we describe is a prototype anode for use in a biocarbon fuel cell.

Homogeneously Dispersed Zerovalent Iron Nanoparticles Supported on Hydrochar-Derived Porous Carbon: Simple, in Situ Synthesis and Use for Dechlorination of PCBs

“…The deviation of the baseline at small angles (<30°) in the XRD pattern originated from the amorphous carbonaceous structure of HC-800. 26 All of the above observations indicate clearly that the transformation of carbon from amorphous phase to graphitic structure was catalyzed by in situ formation of NZVI, which is highly dependent on temperature.…”

Nano-zerovalent iron contained porous carbons developed from waste biomass for the adsorption and dechlorination of PCBs

“…The estimated size of ZVI from the 1 1 0 plane diffraction was 27 nm in A800. As for P800, the XRD pattern was simple, and the broad weak bands around 2h = 22°together with the deviation of the baseline between 20°and 30°indicated the amorphous carbonaceous structure of organic matrix (Mochidzuki et al, 2003).…”

Fundamental aspects of biomass carbonisation

“…Mochidzuki et al [16] determined the physical and electrical properties of charcoal materials produced under laboratory conditions. They found predominantly alkyl aromatic structures with oxygen enriched C-O-H, C O and C-O-C functional groups.…”