Gas phase equilibria for dibenzo-p-dioxin, dibenzo-p-furan and biphenyl in the C-H-O system

The gas phase equilibrium calculation for the C-H-O system at atmospheric pressure and temperature from 773 to 1773 K at intervals of 250 K was performed to understand the generation and decomposition behavior of dibenzo-p-dioxin (DD), dibenzo-p-furan (DF) and biphenyl (BP) in relation to the existing oxygen potential. It is possible to categorize these results into three regions from the viewpoint of this potential: region (A), region (B) and region (C) are that of the higher, modest and lower oxygen potential, respectively. In region (A), the equilibrium amounts of DD, DF and BP are nearly zero. In region (B), they increase once and then decrease with rise in temperature. In the most characteristic region (C), they increase uniformly with rise in temperature.