A Novel Method for Removal of Iron Ion Contamination in Patchouli Essential Oil

Nowadays, in the aromatic and cosmetics industries, as well as an additive for food flavoring, patchouli essential oil (PEO) is a significantly crucial raw material. This oil is extracted from Pogostemon cablin, a plant from the Lamiaceae family. The standard method to obtain this oil is steam distillation. However, applying this method, the oil has a relatively high iron content. A contaminated iron ion can arise in the PEO for some reasons, i.e., the distillation practice used in a non-stainless steel tank, the PEO stored in an iron drum, or even the water for steam production was not appropriately treated. Activated carbon adsorbents can be used to remove contaminants from liquids or gasses by adsorbing ions, complexes, and molecules from aqueous solutions. Although fine adsorbent particles offer advantages in terms of adsorption capacity and kinetics, the application of the adsorbent to remove iron ions contaminated in PEO is not simple work. It is because a problem with these particles is widely dispersed in the oil and challenging to recover and contaminates the final product of PEO. This study developed a novel method to remove iron ions contaminated in a PEO using a modified activated carbon, i.e., magnetic activated carbon (MAC). For practical applications, using MAC material will reduce operating costs and solve the problems related to the quality of the end product, i.e., contamination by the adsorbent. The result shows that the MAC material improved the quality of PEO by reducing iron ion concentration in the oil from the initial concentration of 194 mg/L to around 87 mg/L. As expected, the adsorbent allows rapid removal from the PEO by using a magnetic source. Based on this study, MAC material enables the reduction of iron ion contamination in PEO and produces a free-adsorbent in the final product.