Catalytic pyrolysis of waste epoxy resin using activated carbon to produce stable phenolic compounds

Epoxy resin (ER), renowned for its superior properties, is extensively applied in various engineering materials. However, the growing usage has led to substantial solid waste generation, highlighting the importance of developing ER recycling technologies. In this study, a method was proposed for the selective preparation of high-value-added monophenolic chemicals via the catalytic pyrolysis of ER using activated carbon (AC). The impacts of activation method (steam and KOH activation) in the preparation of AC and pyrolysis conditions (pyrolysis temperature and AC/ER ratio) on the yields and composition distributions of pyrolysis liquid products were thoroughly explored. The results indicated that KOH-activated AC exhibited a high specific surface area and abundant oxygen-containing functional groups, which could catalyze the pyrolysis of ER for the selective production of phenol and 4-isopropylphenol. At a pyrolysis temperature of 450°C and AC/ER ratio of 1, the total yield and selectivity of phenol and 4-isopropylphenol reached 30.09 wt% and 56.98 %, significantly higher than those of 12.00 wt% and 21.53 % obtained from direct pyrolysis of ER. This study provides guidance for achieving resource-efficient, and high-value recycling of ER-based waste.