Ahmad, Sharizan

Assim, Zaini

Hussein, Mohd Zobir

Ibrahim, Ramli

Zainal, Zulkarnain

Universiti Putra Malaysia Institutional Repository

FOR Category F11200: Material SciencesPREPARATION,CH'ARACTERISATION ANDAPPLICATION OF ACTIVATED CARBON FROMINDUSTRIAL BY-PRODUCTRamli Ibrahim, Zulkarnain Zainal, Mohd ZobirHussein, Zaini Assim and Sharizan AhmadFaculty of Science and Environmental StudiesUniversiti Putra Malaysia, 43400 UPM, Serdang, Selangor,MalaysiaKeywords: activated carbon, surface area, porosity,chemical impregnation, adsorption.IntroductionActivated carbon is a processed carbonaceous material con-sisting of pores of various sizes and having large surface area(usually in range of 500 to 1500 m2/g). It is an excellent ad-sorbent and is widely used in the purification of chemicalproducts, pharmaceuticals, food industries, drinking water,controlling environmental pollution and recently in themanufacturing of electronic component. It can be preparedfrom various lignocellulosic materials. The focus of the studywas to prepare activated carbon from the by-product of localagricultural industries. Two main industries were identifiednamely, oil palm and sago industries. Oil palm industry aloneis producing millions of tonnes of mesocarp fibre, palmshells, empty fruit bunches and palm trunks annually. Theseby-products have been proven to be potential raw materialsfor the activated carbon. On the other hand local sago indus-try is generating thousands of tonnes of waste each year,which create environmental problems to the nearby rivers.In this abstract the preparation and characterisation of acti-vated carbon from sago waste is presented.Materials and MethodsSago waste obtained from a local sago industry was initiallydried under sunlight before being dried in an oven at 120°Cfor a week. Elemental analysis of C, H and N was usuallycarried out on the raw material. This was followed by ther-mal analysis to determine its thermal stability. The prepara-tion was carried out with and without chemical impregnation.About 109 of the dried raw material was impregnated withdifferent amount of ZnCl2 (5 - 40 %). The impregnation wascarried out at 70°C with constant shaking until almost all thewater had evaporated. Further drying was carried out in anoven at 120°C for a week. The dried impregnated samplewas heated at 400 - 800 "C in a quartz tube, which was in-serted horizontally into a tubular furnace. The heating proc-ess was carried out for a total of 4 hours, with a constant flowof N2 and CO2 for 3 and 1 hour respectively. The resultingactivated carbon was repeatedly washed in 1 M HCI orRN03 followed by distilled water to remove the ZnClz.Results and DiscussionElemental analysis of the raw material showed that the car-bon content was about 39%. This is considered sufficientlyhigh and suitable for the preparation of activated carbon.Apart from other major elements neutron activation analysisshowed that sago waste also contained significant amount oftrace elements such as Ca, P and Si. Thermal analysis indi-cated a change in weight at the temperature around 260-390"C presumably due to carbonisation process. Removal ofnon-carbon elements as volatile matter occurred in this tem-perature range followed by formation of elementary graphiticcrystallites (Wigmans, 1989). Thus the preparation of acti-vated carbon may be carried out at temperature as low as 392QC.The quality of the product was found to be related to theamount of the chemical impregnation of the raw material.The carbon content of unimpregnated sample prepared at 500o~ was around 63% and increased to 75% at 15% impregna-tion. The surface area increased with increasing amount ofZnClz for every heating temperature up to 15% impregnationwhere a maximum was reached. Further increase in the im-pregnation has no effect on the surface area. This trend wassimilar to previous findings in the preparation of activatedcarbon from oil palm trunk (Hussein et. al. 1995) and oilpalm shell (Hussein et. al. 1996) where the amount of ZnCl2adsorbed by the raw material reached a saturation at about15% impregnation. The heating temperature of around 400-500 °c was found to give relatively high surface area. Poreformation was also found to be affected by the amount ofZnClz impregnated in the precursor. The average pore sizewas in the micropore region at low level impregnation (lessthan 5%). As the level of impregnation increased the averagepore size increased which might be due to the formation ofmore mesopores. The iodine adsorption analysis was alsoperformed and was found to follow the same trend as the sur-face area. The iodine numbers were usually lower comparedto the value of the surface area. This analysis was sometimesused as an alternative method to analyse the surface areawhen the N2 adsorption method was not possible. Activatedcarbon from sago waste was found to be very effective inremoving organic substance from water. The test was carriedout using phenol.ConclusionsSago waste is a valuable raw material for the preparation ofactivated carbon. High quality activated carbon can be ob-tain~ from this source with surface area of over 1500 m2/g.Optimum preparation condition was at 15 % impregnation ofZnCl2 and combustion of 500 QC.The activated carbon ob-tained also has sufficiently high carbon content and effectivein removing organics and colours from water.ReferencesHussein, M.Z., Zainal, z., Ibrahim. R., Kheong, K.K. andMuhammad, B. 1995. The Preparation of Activated Carbon from.Chips of Oil Palm Trunk Catalysed by ZnCI2lC02: Surface Areaand Porosity Studies. Journal of Chemical Technology and Bio-technology. 64: 35-40.Hussein. M.Z., Tarrnizi, R.S.H.• Zainal, Z. and Ibrahim, R. 1996.Preparation and Characterisation of Active Carbons from OilPalm Shells. Carbon. 34(11): 1447-1454Wigmans, T. 1989. Industrial Aspects of Production and Use of Ac-tivated Carbons. Carbon. 27(1): 13-22.Supported by IRPA Grant 09-02-04-0028299

Preparation, characterisation and application of activated carbon from industrial by-product

http://psasir.upm.edu.my/42955/1/Preparation%2C%20characterisation%20and%20application%20of%20activated%20carbon%20from%20industrial%20by-product.pdf

Preparation, characterisation and application of activated carbon from industrial by-product

Abstract

Similar works

Full text

Available Versions

Universiti Putra Malaysia Institutional Repository