Sintesa Mentol Dari Sitronelal Dalam Proses Satu Tahap Dengan Katalis Dwifungsi

Abstract

Menthol is one of volatile compound which gives cooling effect if it is consumed. Since long time ago, menthol has used in medical field as a medicines treating sore throats and mouth irritations. It has also used in treatments for analgesics and decongestants. In the 1920 and 1930, menthol has used as flavoring and reducing for irritation, especially to the throat (Cotton, 2007). Menthol is obtained by separation of natural sources (natural menthol) and by organic synthesis. Natural menthol is obtained by extraction from mint plants such as Mentha piperita and Mentha arvensis. One of organic synthesis of menthol is obtained from citronellal. Citronellal is one of compound citronella oil which is obtained by fractionation. Generally, the synthesis of menthol from citronellal has carried out through two-step process; there have cyclization and hydrogenation. The aim of this research is to synthesize menthol from citronellal oil fractionate product through one-step process over catalyst, which can be performed to isomerate citronellal to the cylic alcohol (isopulegol) and to hydrogenate isopulegol into menthol (bifunctional catalyst). The parameters that has used in this research are the temperature of cyclization, time process, hydrogenation’s temperature, pressure, dan the kind of catalyst. This research has used the variation for temperature of cyclization at 100 °C and 150 °C. The variation for time process has used 20 hours (10 hours for cylization and 10 hours for hydrogenation) and 6 hours (3 hours for cylization and 6 hours for hydrogenation). The variation for hydrogenation’s temperature has used 70 °C, 100 °C and 150 °C. The variation for pressure has used 5 bar, 10 bar, and 15 bar. The condition process has determinated over Ni/Sulfated-Bentonite 5 % has used to determinate the condition process. The best condition process will has used at Ni/Sulfated-Bentonite, Ni/Sulfated-Bentonite with ball mill preparation, and Ni/Sulfated-Titanium. Based on Gas Chromatography can be known that the best conditions process for synthesis of menthol are cyclization’s temperature at 100 °C, 6 hours for the time process, hydrogenation’s temperature at 100 °C, 5 bar for the pressure. The catalyst of Ni/Sulfated-Bentonite has produced menthol 0.85 percent. Ni/Sulfated- Bentonite has produced menthol 2.38 percent. In this research, Ni/Sulfated-Titanium Dioxide has produced menthol that has the highest percentage about 3.12 percent.