High‐Intensity Microwave‐Assisted Pyrolysis Liquid Subjected to Supercritical Fluid Extraction with Carbon Dioxide (Case Study: Bio‐phenol)

Abstract

AbstractA crude bio‐oil from high‐intensity microwave‐assisted pyrolysis of oil palm shell was subjected to an attractive, environmentally friendly separation process, namely supercritical fluid extraction with carbon dioxide (scCO2), to study the value‐added chemicals such as bio‐phenol. The operating parameters temperature and pressure were examined above the critical point of carbon dioxide. The yield of scCO2‐oil extract tended to increase significantly with these two parameters according to one‐way ANOVA. The extract yield was within 63.09–67.72 %. The scCO2‐oils were characterized for value‐added chemical components by GC‐MS and compared with the crude bio‐oil. Acids, as the dominant group of chemicals, were enriched by scCO2, and included dodecanoic acid, n‐hexadecanoic acid, and octadecanoic acid. The thermal behavior of scCO2‐oil was studied by thermogravimetry. The production cost of bio‐phenol extracted from scCO2‐oil was estimated and compared with a commercial phenol product.