Carbonization of Carbohydrates in an Atmosphere of Argon and under the Action of Calcium and Iron Chlorides

Abstract

The carbonization of carbohydrates (glucose, sucrose, and starch) in an inert gas atmosphere of argon and under the action of calcium chloride and iron(III) chloride additives was studied. It was established that the addition of calcium and iron(III) chlorides exerted a peculiar catalytic effect on the carbonization process. Carbon production can be carried out at lower temperatures to 200°С. In traditional methods of synthesis, carbonization upon the decomposition of carbohydrates occurs at temperatures of 300–800°C. It was found that the process of carbon production was accompanied by the release of heat, which was confirmed by thermodynamic calculations of the chemical reaction of carbon production and experimental studies of the carbonization of carbohydrates by differential scanning calorimetry. A regular decrease in the yield of carbon, as compared to a maximum theoretically possible one, was observed in the order glucose sucrose starch. It was established that the heat of combustion of carbon obtained upon the carbonization of carbohydrates under the action calcium and iron chlorides reached 34 MJ/kg or more due to the presence of structural fragments that do not occupy energetically favorable positions compared to the graphite structure. The presence of the structural fragments of carbon was established by X-ray phase analysis of powder diffraction patterns.