Evaluation and comparison of enrichment efficiency of physical/chemical activations and functionalized activated carbons derived from fluid petroleum coke for environmental applications

Abstract Activated carbons were produced from fluid petroleum coke using physical (steam and CO 2 ) and chemical (KOH and H 3 PO 4 ) activations. Effects of process parameters including activation temperature, activation time period and water flow rate on yield and BET surface area of steam-activated carbons were investigated and optimized. Steam activation improved BET surface area of the precursor more than 40 times at optimum operating conditions and KOH activation increased BET surface area from 11 to 692 m 2 /g. Properties of activated carbons were characterized by BET, SEM, CHSNO, FTIR, ICPMS and Boehm analysis techniques. The steam-activated carbons were treated with HNO 3 and H 2 O 2 separately to study the effects of acid treatments on surface chemistry, porous characteristics and environmental applications of activated carbons. Activated carbons produced in this study were used as adsorbent for ammonium ion (40.0 and 260.0 mg/L) in liquid phase and as catalyst for direct oxidation of H 2 S (10,000 ppm) in gas stream. Among all other samples HNO 3 and H 2 O 2 -treated samples showed the highest ammonium adsorption by 184.6 and 169.6 mg/g, respectively. The largest breakthrough time (320 min) among all samples was shown by KOH activated carbon. The SO 2 production was less than 5% of H 2 S fed to the reactor.