Optimizing the preparation of activated carbon from lugi pressurized gasifier (LPG) slag by microwave-assisted potassium hydroxide activation

Abstract

Activated carbon (AC) was prepared from the carbon residue of Lugi pressurized gasifier (LPG) slag with a microwave-assisted activation process using potassium hydroxide (KOH) as the activating agent. The effects of various factors such as the heating behavior of the microwave, power of the microwave, activation time and ratio between LPG slag and KOH on the activation have been studied. The surface property of the AC was characterized by BET. The optimal activation conditions were 900 W of microwave power, 9 min of radiation time and 1:1 ratio of KOH and carbon. The surface area of prepared AC was 1061 m2.g-1, and a carbon yield of 42% could be reached. The iodine value was 1082.2 mg g-1. When compared with the traditional method, the microwave-assisted activation process demonstrated faster rate of activation and higher carbon yield. Microwave-assisted AC removed phenols and chromaticity from the wastewater obtained from the Coking Plant in Kunming efficiently.