Transesterifikasi minyak jelantah kelapa sawit menjadi Biodiesel menggunakan katalis NaOH tanpa proses esterifikasi dan katalis asam (H2SO4 dan Zeolit-Y) melalui proses esterifikasi
MASTUTIK, Diah, Dr. Wega Trisunaryanti, MS
2006 | Tesis | S2 Ilmu KimiaTelah dilakukan penelitian transesterifikasi minyak jelantah kelapa sawit menjadi biodiesel menggunakan katalis NaOH tanpa proses esterifikasi dan katalis asam (H2SO4 dan zeolit-Y) pada proses esterifikasi. Reaksi transesterifikasi dilakukan dengan menggunakan katalis basa NaOH 1% terhadap berat (minyak + metanol) dengan memvariasi rasio mol me tanol-minyak 6:1; 9:1 dan 12:1 pada temperatur 70°C. Dilakukan juga reaksi esterifikasi dengan katalis H2SO 4 1,25% terhadap berat (minyak + metanol) dilanjutkan reaksi transesterifikasi dengan katalis NaOH dalam media metanol pada temperatur 30°C, 45°C dan 70°C. Zeolit-Y digunakan sebagai katalis asam padat pada reaksi esterifikasi asam lemak bebas minyak jelantah kelapa sawit dalam media metanol dengan variasi konsentrasi katalis 1,25%; 2,50%; 3,75%; 5,00%; dan 6,00% terhadap berat (minyak + metanol) pada variasi temperatur 30°C, 45°C dan 70°C. Reaksi dilanjutkan dengan transesterifikasi trigliserida minyak jelantah kelapa sawit menggunakan katalis NaOH dalam media metanol. Karakterisasi zeolit-Y meliputi penentuan keasaman dengan metode gravimetri, luas permukaan spesifik, volume total pori dan rerata jejari pori dengan menggunakan metode BET. Produk metil ester (biodiesel) dianalisis dengan Gas Chromatography (GC), Gas Chromatography-Mass Spectroscopy (GC-MS). Karakter biodiesel dianalisis dengan metode uji ASTM (American Society for Testing Materials). Hasil penelitian menunjukkan bahwa keasaman katalis zeolit-Y 0,02 mmol/g, luas permukaan spesifik 475,94 m2/g, volume total pori 214,47 x 10-3 cc/g, dan rerata jejari pori 86,99 Å. Pada transesterifikasi menggunakan katalis NaOH tanpa perlakuan awal (proses esterifikasi), konversi biodiesel terbesar sebesar 63,19% (b/b) dicapai pada rasio mol metanol-minyak 9:1. Dengan katalis H2SO 4 1,25% pada temperatur 70°C diperoleh konversi biodiesel adalah 63,74% (b/b). Konversi biodiesel terbesar dicapai pada konsentrasi katalis zeolit-Y 3,75% pada temperatur 70°C sebesar 74,05% (b/b). Berdasarkan data ASTM, biodiesel yang diperoleh memiliki kualifikasi sebagai bakan bakar diesel dan memenuhi karakter minyak diesel otomotif.
A research on transesterification of used palm oil into biodiesel using NaOH catalyst without esterification process and acid (H2SO4 and Y-zeolite) catalyst through esterification process has been done. The transesterification without esterification process using NaOH catalyst 1 % from (oil + methanol) weight was also carried out by varying the methanol/oil mol ratio of 6:1, 9:1 and 12:1 under temperatur e of 70°C. The esterification reaction was also done using H2SO 4 catalyst of 1.25% from (oil + methanol) weight then continued by transesterification using NaOH catalyst in methanol media under temperature of 30, 45 dan 70°C. The Y-zeolite was used as solid acid catalyst in esterification process of free fatty acid of used palm oil in methanol media by varying catalyst concentration of 1.25, 2.50, 3.75, 5.00 and 6.00% from (oil + methanol) weight under temperature variation of 30, 45 and 70°C. The reaction was then followed by transesterification of used palm oil using NaOH catalyst in a methanol media. The characterization of Y-zeolite included the acidity was determined by a gravimetric method, specific surface area, total volume pore and average pore radius by using BET method. The biodiesel product was analyzed by Gas Chromatography (GC), and Gas Chromatography-Mass Spectro scopy (GC-MS). The characters of biodiesel were analy zed by ASTM testing method (American Society for Testing Materials). The research results showed that the acidity of Y-zeolite catalyst was 0. 02 mmol/g, the specific surface area was 475.94 m2/g, the total volume pore was 214.47 x 10-3 cc/g, and that the average pore radius was 86,99 Å. The transesterification using NaOH catalyst without esterification, produced the highest biodiesel conversion 63. 19 wt.% in 9:1 mol ratio of methanol/oil. Using 1.25% H2SO4 catalyst under temperature of 70°C resulted the highest biodiesel conversion of 63.74 wt.%. The highest conversion of biodiesel was 74.05 wt.% achieved by Y-zeolite catalyst under the concentration of 3.75% and temperature of 70°C. Based on the ASTM data, the biodiesel was qualified as diesel fuel and has characters of automotive diesel fuel.
Kata Kunci : Biodiesel,Katalis NaOH,Minyak Kelapa Sawit
