Promoting characteristics and mechanisms of phenol in coking wastewater on coke gasification

Coke gasification and coking wastewater treatment are the major concerns of the research community, both in the past and today. However, most researchers have not paid enough attention to the research that phenol in coking wastewater can promote coke gasification. The promoting characteristics of aqueous solution with phenol concentration of 1000 and 2000 mg/L on coke gasification were experimentally studied. The effects of the reaction temperature on coke gasification, phenol concentration in water on reaction kinetics, and phenol aqueous solutions on the coke structure during gasification reactions were explored. The morphological, physicochemical, and textural properties of coke were characterized using Raman spectroscopy, scanning electron microscopy, and N-2 low-temperature physical adsorption analyzer. Results show that with an increase in the reaction temperature from 900 degrees C to 1100 degrees C, the total syngas amount, low calorific value, carbon conversion, and reaction rate increased by 20.5%, 4.6%, 10.2%, and 1.2 times, respectively. The random pore model was the most suitable among the considered kinetic models. The apparent activation energy for the reaction of aqueous solution with phenol concentration of 1000 and 2000 mg/L reacted with gasification-coke was approximately 8.48% and 27.26% lower than that of pure water with coke, respectively. Compared with pure water, phenol aqueous solutions may preferentially consume the amorphous carbon structure and penetrate deeply into the carbon matrix of the gasification-coke to participate in the reaction. Phenol aqueous solutions can inhibit the sintering and aggregation of the ash phase in coke and improve its dispersibility on the coke surface. Moreover, it facilitates the development of the coke pore structure.