Đang chuẩn bị liên kết để tải về tài liệu:
Báo cáo vật lý: "PREPARATION OF SELENIUM-DOPED ACTIVATED CARBON AND ITS UTILIZATION FOR IMPROVING THE QUALITY OF USED COCONUT OIL"

Tuyển tập các báo cáo nghiên cứu khoa học trên tạp chí khoa học vật lý quốc tế đề tài: PREPARATION OF SELENIUM-DOPED ACTIVATED CARBON AND ITS UTILIZATION FOR IMPROVING THE QUALITY OF USED COCONUT OIL | Journal of Physical Science Vol. 18 1 11-21 2007 11 PREPARATION OF SELENIUM-DOPED ACTIVATED CARBON AND ITS UTILIZATION FOR IMPROVING THE QUALITY OF USED COCONUT OIL E. Kusrini A. Setyopratiwi and U.M. Yahya Faculty of Mathematic and Natural Sciences Gadjah Mada University Sekip Utara BLS 21 Yogyakarta 55281 Indonesia Corresponding author eny2kus@yahoo.com Present address School of Chemical Sciences Universiti Sains Malaysia 11800 USM Pulau Pinang Malaysia Abstract Activated carbon AC doped with Selenium Se element 2.5 w w was prepared by calcination oxidization and reduction processes. The modified activated carbon MAC material exhibited specific surface area and total pore volume of 889.43 m2 g and 486.35 cc g.10-3 respectively and these are higher than ordinary AC. The pore size determination showed a distribution of 63.88 mesopore and 36.12 micropore. Several key quality indicators of the oil were determined for the used coconut oil before and after being treated with the MAC and these were compared to those of fresh coconut oil. The prepared MAC shows promise as an effective material for the low cost regeneration of used coconut oil especially in reducing the level of peroxide value and free fatty acids. Keywords activated carbon selenium mesopore used coconut oil 1. INTRODUCTION Coconut oil comprises mainly lauric acid C11H23COOH 44.0 -52.0 which belongs to the saturated fatty acid SFA family. A small quantity of unsaturated fatty acids UFA namely oleic acid C17H33COOH linoleic acid C17H31COOH and palmitoleic acid C15H29COOH in the range of 0.0 -8.0 is also found.1 The small quantity of the UFA is responsible for the relatively high resistance of the oil to oxidation.2 The UFA easily form peroxides in the presence of oxygen UV light metallic ions and biological catalysts that induce the production of free radicals. These free radicals result in the breakdown of membrane phospholipids and initiate lipid peroxidation.3 The natural colour of the coconut oil is .