EFFECTIVELY METHOXY FORMATION IN TRANSESTHERIFICATION REACTION USING MIXTURE OF IRON, ZEOLITE AND NAOH CATALYST

• Main Author: (NIM : 20510001); Pembimbing I : Prof. Dr. Euis Holisotan Hakim; Pembimbing II : Dra. Rita A, HANDI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/15840
• Institution: Institut Teknologi Bandung

Transestherification reaction is a classic organic reaction that is widely used in organic synthesis (synthesis of ester) both in the laboratory and in industry. Transestherification reaction is usually performed using classical homogeneous catalyst system, which uses alkaline NaOH or KOH as base source of OH-, generally followed by side reaction hydrolysis called saponification, which in its application in industries, such as the manufacture of biodiesel, cause many problems. To overcome the problems faced by the industry associated with this process, especially in the last decade, much research is directed to use the baseheterogeneous catalysis systems. For this reason various possible uses of heterogeneous bases catalytic system has been widely studied. However, the <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> results showed weaknesses in these system of catalysis studied which limit the effectiveness of the reaction: Among the difficulties are the need for a high molar <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> ratio between alcohol and ester used, the need for higher temperatures, and the need for activation of the catalyst which usually requires energy (high temperatures). In this research, transestherification reactions of benzyl benzoate <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> with methanol were carried out using a catalyst mixture of iron, natural zeolite from Sukabumi, and NaOH in the range of some various combination. Reactions in each system were carried out at room temperature for 8 hours. Iron is used as a catalyst in the form of pure iron, reduced iron, ferrous sulphate , and iron from the crushed wastes lathe workshop. Preliminary analysis to detect the formation of <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> products was carried out using thin layer chromatography (TLC) method with 3 eluents system. In general, chromatogram of GCMS analysis showed four major <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> peaks that indicate methyl benzoate and benzyl alcohol as the product of transestherification , benzyl ether as side products and benzyl benzoate left over. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> Based on the results obtained by GCMS analysis, the result of classic transestherification reaction (using a homogeneous catalyst NaOH) showed that conversion benzyl benzoate into methyl benzoate was 41.89%. Whereas the <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> transestherification reaction using mixture of pure iron and NaOH was 89,90%. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> Futhermore in transestherifications reaction using mixture zeolite-NaOH and zeolite-iron-NaOH was 87,70% and 87,67% respectively. Transestherification reaction system which is not using NaOH showed no reaction. pH measurements performed every hour during the reaction. In the transestherification reaction system which contained no zeolite a change in pH was not observed, whereas a decrease in pH were observed in the reaction systems when zeolite was used. Decrease in pH observed in any system containing zeolite is expected due to the exchange of Na+ cations in the reaction system with the Brönsted acid in zeolite. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> KSCN’s test on the filtrate obtained in each experiment showed negative results. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> The results of KSCN’s test indicated there were no free iron(III) at the end of the reaction . Transestherfication reaction product in the reaction system using mixture iron- NaOH- zeolite gave strong evidence of effective formation of methoxy, CH3O-, as intermediete which can be seen in the amount of product in the reactions using a mixture of catalyst-NaOH of iron-zeolite, a situation that is very subtle compared with the results seen in the classic transesterification reaction using NaOH.