Zeolites as Adsorbent Materials for Decolorization of Crude Terpineol

Abstract

Zeolites are microporous crystalline aluminosilicates extensively used as adsorbents, catalysts, and ion exchange beds. The adsorption property of zeolite is expected to be applied as a decolorization agent for terpineol. Terpineol is an alcohol compound derived from turpentine oil and widely used as an active ingredient for disinfectants, cleansers, perfumes, and pharmaceutical purposes. Industrial-scale of terpineol production used two stages of reaction: the first stage is hydration of turpentine into terpin hydrate and the second stage is dehydration of terpin hydrate to terpineol. However, as terpin hydrate is easily oxidized, the product color will change from clear into dark solution and make the price of product cheaper. This study aims to increase terpineol selling price by removing unreacted terpin hydrate (decolorization) from crude terpineol. Zeolite is the main absorbent used in this study along with other similar materials i.e. activated carbon and silica gel. Performances of the adsorbent are indicated by its adsorption capacity and color clarity analysis. The results would be analyzed using GC-MS. Based on the experiment, it can be concluded that the best adsorbent is zeolite activated by acetic acid with 8-15 mg/g adsorption capacity and producing a terpineol purity of 83.5%. This activated zeolite was able to remove terpin hydrate from 9.41% to 0% and other impurities from 14.06% to 6.78%.