PENGARUH VISKOSITAS DAN LAJU ALIR TERHADAP HIDRODINAMIKA DAN PERPINDAHAN MASSA DALAM PROSES PRODUKSI ASAM SITRAT DENGAN BIOREAKTOR AIR-LIFT DAN KAPANG Aspergilus Niger

• Main Authors: Kristinah Haryani, Widayat Widayat
• Format: Article
• Language: English
• Published: Diponegoro University 2012-04-01
• Series: Reaktor
• Subjects: reaktor airlift; asam sitrat; fermentasi; hidrodinamika dan perpindahan massa
• Online Access: http://ejournal.undip.ac.id/index.php/reaktor/article/view/3179
• ISSN: 0852-0798; 2407-5973

<p>&nbsp;</p><p><strong>EFFECT OF VISCOSITY AND FLOW RATE ON THE HYDRODYNAMICS AND MASS TRANSFER ON CITRIC ACID PRODUCTION USING <em>Aspergilus Niger</em> YEAST IN AN AIR-LIFT BIOREACTOR.</strong><em> Citric acid is an important organic acid that has many advantages used in foods, drinks, pharmaceuticals industries. Waste of pine apple (covers and core of the fruit) still have high contents of glucose and sucrose components, that these are potentially used as basic material for making citric acid by means of fermentation using Aspergillus niger. The reactor to do so is a reactor air-lift external loop with 88 cm in height, 45.41 cm² in riser area, and 2.01 cm² in downcomer area. This research is intended to study the influence of volumetric flow and viscosity upon mass transfer in the fermentation process of citric. The variable factors are concentration of total sugar (5 to 25%) and of volumetric flow of gas 9.4 to 23.3 cc/second. A dynamic method used to measure of the constants transfer&nbsp; of gas-fluid mass where oxygen concentration soluted is measured every 30 second using DO meter device. Result of this research shows that the increase of viscosity causes the decrease of hold up gas and fluid circulation speed of the fluid, and the decrease of the constants of mass transfer. The increase of air speed flow will cause the increase of hold up gas and fluid circulation speed, and constants of mass transfer. Relation of the constraints of mass transfer to volumetric flow and viscosity is formulated as follow </em><em>&nbsp;</em><em>&nbsp;</em><em>&nbsp;</em></p><em>Asam sitrat adalah asam organik penting yang sangat banyak kegunaannya seperti untuk industri makanan, minuman, farmasi, dan sebagainya. Limbah nanas (kulit dan bonggol) masih mengandung kadar glukosa dan sukrosa yang cukup tinggi, sehingga sangat potensial sebagai bahan baku pembuatan asam sitrat dengan cara fermentasi bantuan kapang Aspergillus niger. Reaktor yang digunakan adalah reactor air-lift external loop. Reaktor yang digunakan berdimensi tinggi 88 cm, luas daerah riser 46,41 cm², dan luas daerah downcomer 2,01 cm². Penelitian ini mempelajari pengaruh laju alir dan viskositas terhadap proses perpindahan massa dalam proses fermentasi asam sitrat. Variabel berubah adalah konsentrasi gula total (5-25%) dan laju alir gas 9,4-23,3 cc/detik. Metode untuk pengukuran konstanta perpindahan massa gas-cair dengan metode dinamik, dimana konsentrasi oksigen terlarut diukur tiap 30 detik menggunakan alat DO meter. </em><em>Hasil penelitian menunjukkan bahwa kenaikan viskositas mengakibatkan penurunan hold up gas dan laju sirkulasi cairan, juga penurunan konstanta perpindahan massa. Kenaikan laju alir udara akan mengakibatkan kenaikan hold up gas, laju sirkulasi cairan, konstanta perpindahan massa. Hubungan konstanta perpindahan massa terhadap laju alir dan viskositas diperoleh persamaan </em><strong><em></em></strong><strong><em></em></strong><strong><em></em></strong><em></em>