Pengaruh perlakuan daun dan suhu terhadap waktu distilasi pada isolasi minyak cengkeh menggunakan super-steam distillation

The effects of leaves treatment and temperature to distillation times in clove oil isolation using super steam distillation Clove oil was generally obtained from clove leaves by using steam distillation. Distillation time was the most important factors in steam distillation as it was proportional to energy cost. In this work, the use of high boiling compound to accelerate steam distillation was studied in which steam distillation was conducted using temperature greater than 100oC. High temperature saturated steam could be obtained by boiling glycerol–water mixture. Glycerol was selected due to its properties in which it was completely water-soluble and high boiling compound. High temperature increased mass transfer of oil in the water within cell tissue of clove leaves, and hence shortened the distillation time. In this work, glycerol concentrations of 0, 10, 25, 50 and 75% by volume were used. The treatment of clove leaves was also investigated. The results showed that glycerol concentration of 10-75% by volum resulted in distillation time reduction of 46–72% compared to conventional steam distillation. For natural clove leaves without treatment, the convective mass transfer coefficient and effective molecular diffusivity were obtained to be 2x10-4 second-1 and 3,6x10-4 m2/second, whereas for chopped leaves these were 8,3x10-3 second-1 and 5,8x10-4 m2/second, respectively.Keywords: Isolation, Clove Oil, Super-Steam Distillation, Glycerol. Abstrak Minyak cengkeh umumnya diproduksi oleh para petani dari daun cengkeh dengan metode steam distillation. Parameter yang paling berpengaruh pada biaya distilasi adalah waktu distilasi, karena waktu distilasi akan berbanding lurus dengan biaya bahan bakar. Penelitian ini bertujuan untuk mempelajari pemakaian super-steam distillation dimana uap air jenuh yang digunakan untuk mendistilasi minyak cengkeh bersuhu lebih tinggi dari titik didih normal air (100oC). Uap jenuh bersuhu tinggi dapat diperoleh dengan mendidihkan campuran air dan gliserol atau pelarut lainnya yang bertitik didih tinggi dan larut sempurna dalam air. Pemakaian uap jenuh bersuhu tinggi akan meningkatkan difusitivitas efektif minyak cengkeh dalam jaringan sel tumbuhan, sehingga akan mempercepat waktu distilasi. Pada penelitian ini digunakan variasi konsentrasi gliserol 0, 10, 25, 50 dan 75% volume. Selain itu juga dipelajari pengaruh pencacahan daun cengkeh sebelum didistilasi. Hasil penelitian menunjukkan bahwa super-steam distillation dengan campuran gliserol dan air dengan perbandingan volum 10-75% mampu memperpendek waktu distilasi sebesar 46-72%. Besarnya nilai koefisien transfer massa dan diffusivitas efektif rerata untuk daun cengkeh tanpa perlakuan adalah 2x10-4 detik-1 dan 3,6x10-4 m2/detik, sedangkan untuk daun dengan pencacahan adalah 8,3x10-3 detik-1 dan 5,8x10-4 m2/detik.Kata Kunci: Isolasi, Minyak Cengkeh, Super-Steam Distillation, Gliserol.