RESEARCH OF POSSIBILITY OF PROCESSING PETROLEUM COKE WITH INCREASED VOLATILE SUBSTANCES INTO ACTIVATED CARBONS

Abstract

In present work, study to obtain granulated active carbon based on industrial petroleum coke of the CEL grade (coke with an increased content of volatile substances) produced in delayed coking unit have been conducted. The production of activated carbons was carried out by preliminary carbonization of coke at a temperature of 500-800 °C, followed by activation in a water vapor atmosphere at a temperature of 850-900 °C. In addition, tests were carried out on the effect of impregnation of the initial coke with aqueous solutions of chemical activators (sodium hydroxide, potassium carbonate, phosphoric acid) on the efficiency of heat treatment and characteristics of the porous structure of the resulting sorbent. The use of sodium hydroxide as an activating agent increases the reactivity of the sample, but the microporous structure does not develop. Using potassium carbonate as the activating solution and increasing the carbonization temperature to 800 °C causes an increase in the degree of burning from 28 to 44 %. However, activation of the resulting carbonizates with superheated steam leads to a 97-98 % burn-out of the samples due to a sharp increase in reactivity. It was shown that activated carbon obtained on the base of petroleum coke with an increased content of volatile substances by preliminary impregnation with an aqueous solution of phosphoric acid (concentration 17 wt.%), filtration and drying, followed by carbonization at a temperature of 800 °C in an inert atmosphere and activation in water vapor medium at a temperature of 850-900 °С has a sufficiently high specific surface of micropores (up to 430 m2/g) and other characteristics of the porous structure. Thus, the proposed method can serve as one of the ways to expand the qualified use of petroleum coke.