Catalysis and degradation of phenol in coking wastewater during low-rank coal coke gasification

Abstract

The thermochemical-reaction characteristics of different concentrations of phenol water and gasification-coke at 1000 °C in a thermochemical reactor were experimentally studied. The effect of phenol water on the thermochemical-reaction products and gasification-coke thermochemical reactivity, and the evolution of carbon crystalline structures of gasification-coke during the reaction were analyzed. Experimental results show that compared with pure water, when 1000 and 2000 mg L⁻¹ of phenol water reacted with gasification-coke, the yield of syngas increased by 2.2% and 4.9%, and the heating value increased by 1.4% and 5.8%, respectively. The degradation rates of the phenol and COD_Cr in the condensate could reach 96% and 92%, respectively. Gasification-coke pore walls became thinner or even damaged, and the carbon skeleton structure was eroded after the thermochemical reaction with phenol water. An increasing phenol water concentration was favorable for the thermochemical-reaction activity of gasification-coke, and the carbon conversion increase resulted in a more ordered carbon crystalline structure of gasification-coke. A comparison between pure water and phenol water revealed that the evolution of d₀₀₂ and L_c was approximately the same, with the major difference being in the evolution of L_a during the thermochemical reaction.