TRANSESTERIFIKASI MINYAK NYAMPLUNG MENJADI BIODIESEL MENGGUNAKAN KATALIS ABU DAUN KELOR: PENGARUH KONDISI REAKSI TERHADAP KONVERSI BIODIESEL

DESTANIA AYU R, Prof. Dra. Wega Trisunaryanti, M.S., Ph.D., Eng.

2022 | Skripsi | S1 KIMIA

Penelitian transesterifikasi minyak nyamplung menjadi biodiesel (metil ester) menggunakan katalis abu daun kelor (AK900-3) dengan variasi kondisi reaksi telah dilakukan. Penelitian ini bertujuan untuk mempelajari karakter, uji aktivitas, dan selektivitas katalis AK900-3 pada transesterifikasi minyak nyamplung menjadi biodiesel melalui variasi berat katalis, temperatur reaksi, rasio mol minyak:metanol, dan waktu reaksi. Katalis AK900-3 diperoleh dengan cara grinding daun kelor tua kemudian dikalsinasi pada temperatur 900 °C selama 3 jam. Katalis AK900-3 kemudian dikarakterisasi menggunakan FTIR, XRD, dan SEM-EDX. Crude minyak nyamplung dilakukan degumming dengan pemanasan menggunakan larutan H3PO4 85% (MD). Minyak MD diesterifikasi menggunakan metode refluks dengan rasio mol minyak:metanol 1:40, volume katalis H2SO4 98% sebanyak 13 % (v/v), temperatur reaksi 60 °C, dan waktu reaksi 60 menit (MDE). Transesterifikasi MDE dilakukan menggunakan katalis AK900-3 dalam larutan metanol 97% dengan variasi berat katalis (3, 6, dan 9% (b/b)), temperatur reaksi (55, 60, dan 65 °C), rasio mol minyal:metanol (1:3, 1:6, dan 1:9), dan waktu reaksi (60, 90, 120, dan 150 menit). Katalis AK900-3 diuji usability (masa pakai) sebanyak 3 kali pada kondisi reaksi optimum proses transesterifikasi MDE. Pada produk cair transesterifikasi ditentukan konversi metil ester berdasarkan data GC-MS dan dianalisis menggunakan FTIR. Proses transesterifikasi juga dilakukan pada prosedur yang sama menggunakan katalis CaO sebagai pembanding. Hasil karakterisasi katalis AK900-3 menggunakan FTIR, XRD, dan SEM-EDX mengindikasikan bahwa AK900-3 mengandung Ca sebesar 52,91%. Reaksi esterifikasi dapat menurunkan kadar FFA hingga 89,82%, yaitu dari 19,46% menjadi 1,98%. Transesterifikasi MDE menggunakan katalis AK900-3 diperoleh kondisi reaksi optimum dengan berat katalis 3%, temperatur reaksi 60 °C, rasio mol minyak: metanol 1:9, dan waktu reaksi 120 menit menghasilkan produk cair transesterifikasi sebesar 80,00% (b/b) dengan selektivitas terhadap biodiesel dalam bentuk senyawa metil ester sebesar 76,17% (b/b). Uji usability katalis AK900-3 pada kondisi reaksi optimum transesterifikasi MDE untuk run ke 1, 2, dan 3 diperoleh konversi metil ester berturut-turut sebesar 76,17; 76,49, dan 71,65%. Transesterifikasi MDE menggunakan katalis CaO menghasilkan konversi metil ester sebesar 73,08% pada berat katalis 3%, temperatur reaksi 60 °C, rasio mol minyak: metanol 1:6, dan waktu reaksi 120 menit.

Research on the transesterification of nyamplung oil into biodiesel (methyl ester) using a moringa leaf ash (AK900-3) catalyst has been conducted with various reaction conditions. This study aims to study the character, activity test, and selectivity of AK900-3 catalyst in the transesterification of nyamplung oil into biodiesel through variations in catalyst weight, reaction temperature, oil:methanol mole ratio, and reaction time. AK900-3 catalyst was obtained by grinding old moringa leaves and then calcined at a temperature of 900 °C for 3 hours. The AK900-3 catalyst was then characterized using FTIR, XRD, and SEM-EDX. The crude oil of nyamplung was degummed by heating using an 85% H3PO4 (MD) solution. MD oil was esterified using the reflux method with an oil:methanol mole ratio of 1:40, a volume of 98% H2SO4 catalyst as much as 13% (v/v), a reaction temperature of 60 °C, and a reaction time of 60 minutes (MDE). MDE transesterification was carried out using AK900-3 catalyst in 97% methanol solution with variations in catalyst weight (3, 6, and 9% (w/w)), reaction temperature (55, 60, and 65 °C), oil:methanol mole ratio (1:3, 1:6, and 1:9), and reaction time (60, 90, 120, and 150 minutes). The AK900-3 catalyst was tested for usability 3 times under the optimum reaction conditions for the MDE transesterification liquid product, methyl ester conversion was determined based on GC-MS data and analyzed using FTIR. The transesterification process was also carried out in the same procedure using a CaO catalyst as a comparison. The results of AK900-3 catalyst characterization using FTIR, XRD, and SEM-EDX indicated that AK900-3 contained 52.91% Ca. The esterification reaction can reduce FFA levels up to 89.82%, from 19.46% to 1.98%. Transesterification of MDE using AK900-3 catalyst obtained optimum reaction conditions with catalyst weight of 3%, reaction temperature of 60 °C, oil:methanol mole ratio of 1:9, and reaction time of 120 minutes to produce a liquid transesterification product of 80.00% (w/w) with selectivity for biodiesel in the form of methyl ester compounds of 76.17% (w/w). The usability test of the AK900-3 catalyst at the optimum reaction conditions for MDE transesterification for runs 1, 2, and 3 obtained methyl ester conversion of 76.17; 76.49; and 71.65. MDE transesterification using CaO catalyst resulted in methyl ester conversion of 73.08% at 3% catalyst weight, reaction temperature of 60 °C, oil:methanol mole ratio of 1:6, and reaction time of 120 minutes.

Kata Kunci : biodiesel, daun kelor, minyak nyamplung, transesterifikasi