Structure Analysis of Coke, Wood Charcoal and Bamboo Charcoal by Raman Spectroscopy and Their Reaction Rate with CO2

Abstract

In order to discuss the reactivity of carbonaceous materials with CO 2 , the Raman spectroscopy analysis was carried out. Nine kinds of materials were examined. The Raman spectra of ordered materials could be assigned to the graphite structure and its defect, but those of disordered materials could not. New parameters were derived to evaluate the structure of the latter. Using the parameters, the structure change was followed during high temperature heat treatment. The disordered material consists of random structure, graphite structure and its defects. The random structure changes to the graphite structure with many defects and the defects decrease with the heat treatment temperature. The reaction rate constant is evaluated. It increases when the structure changes from the random structure to the graphite structure with many defects. After the change, it decreases with decreasing the defects in graphite structure. Thus, the most reactive material should consist of the graphite structure with many defects.KEY WORDS: natural and synthetic graphite; coke; wood charcoal; bamboo charcoal; Raman spectroscopy; reactivity with CO 2 ; new parameters to evaluate structure; structure change during heat treatment; highly reactive material.

Characterization of Thermal Annealing Effects on the Evolution of Coke Carbon Structure Using Raman Spectroscopy and X-ray Diffraction

“…At 2 073 K, the G* band peak was split remarkably into two peaks while at 2 473 K, the spectrum became similar to that of synthetic graphite. 1) Several approaches have been used to characterize carbon structure of graphite like materials with Raman spectrum analysis, namely, peak intensity ratio, 5) peak area ratio 6) and peak half width. 7) The peak ratio of D band peak to G band peak is called R ratio, RϭI D /I G .…”

“…Masahiro KAWAKAMI, 1) Haruki KANBA, 1) Kazunori SATO, 1) Toshihide TAKENAKA, 1) Sushil GUPTA, 2) R. CHANDRATILLEKE 2) and Veena SAHAJWALLA (Received on February 9, 2006; accepted on May 12, 2006 ) An experimental study was conducted to monitor the evolution of coke carbon structure during thermal annealing in a temperature range from 1 273 to 2 473 K in a bench-scale reactor. Coke carbon structure was characterized by using Raman Spectroscopy and the X-ray Diffraction.…”

“…Even though many studies have been reported to use Raman spectroscopic analysis to understand the structure analysis of carbonaceous materials, the understanding of modification of coke carbon structure with increasing temperature is still far from complete particularly the interpretation of Raman analysis. [1][2][3][4][5][6][7][8][9][10][11][12][13] Raman peak of the graphite like materials is well known to appear at 1 580 cm…”

“…But only two broad peaks appeared near 1 600 cm Ϫ1 and 1 360 cm Ϫ1 for coke. 1) The peaks are designated as G* band peak and D* band peak, respectively. It may be noted this designation does not physically mean the graphite and its defect structure.…”

Effect of Carbon Structure Crystallinity on Initial Stage of Iron Carburization

“…It has been reported that the carbon structure has strong effect on gasification of carbonaceous material. 7,8) From the point of view of carburization reaction, there are several studies. Wu and Sahajwalla studied its structure effect on carbon dissolution into iron bath.…”