Synthesis of Moringa Oleifera (Kelor) Leaves Ash Catalyst for Transesterification of Low-Grade Malapari Oil into Biodiesel

Serisya Inier Aksanti, Prof. Triyono, SU; Prof. Wega Trisunaryanti M.S., Ph.D.Eng

2023 | Skripsi | KIMIA

Telah dilakukan penelitian Sintesis Katalis Abu Daun kelor (Moringa Oleifera) untuk transesterifikasi minyak Malapari Bali kualitas rendah menjadi biodiesel. Penelitian ini bertujuan untuk mempelajari pengaruh suhu pengabuan daun kelor terhadap oksida logam dan uji aktivitas katalis abu daun kelor terhadap produk cair biodiesel, mempelajari aktivitas dan selektivitas katalis abu daun kelor dalam transesterifikasi minyak Malapari untuk menghasilkan biodiesel dengan variasi berat katalis, suhu reaksi, rasio mol minyak terhadap metanol, dan waktu reaksi serta mempelajari kegunaan katalis terbaik dalam transesterifikasi minyak Malapari.

Sintesis katalis heterogen berbasis ekstrak daun kelor diperoleh dari hasil pre-treatment berupa penggilingan daun kelor yang dikalsinasi pada suhu 700,800, dan 900 derajat Celcius selama 3 jam. Katalis heterogen kemudian dikarakterisasi dengan menggunakan XRF, FTIR, XRD, dan SEM-EDX. Pre-treatment minyak Malapari Bali kualitas rendah (LMO) dilakukan melalui proses degumming dengan memanaskan larutan H3PO4 85%. Minyak yang diperoleh kemudian diesterifikasi dengan metode refluks menggunakan metanol dan larutan H2SO4 pekat. Aplikasi abu daun kelor sebagai katalis dalam pembuatan biodiesel dari minyak Malapari dilakukan dengan variabel berat katalis (3, 6, dan 9 % (b/b)), suhu reaksi (55, 60 dan 65 derajat Celcius), perbandingan mol minyak : metanol (1:3, 1:6 dan 1:9) dan waktu reaksi (60, 90, 120 dan 150 menit), serta menganalisis penggunaan katalis abu daun kelor secara berulang pada proses transesterifikasi Malapari minyak dengan metode refluks untuk menghasilkan produk metil ester. Produk biodiesel yang diperoleh dari proses transesterifikasi kemudian dianalisis menggunakan FTIR dan GC-MS.

Hasil karakterisasi katalis dengan menggunakan XRF, FTIR, XRD, dan SEM-EDX menunjukkan bahwa MA-700, MA-800, dan MA-900 mengandung CaO, K2O dan MgO sebagai tiga senyawa utama dari abu daun kelor. MA-900 digunakan sebagai katalis karena mengandung CaO paling tinggi sebagai senyawa utama katalis karena CaO meningkat dengan meningkatnya suhu kalsinasi. Analisis GC-MS pada metil ester diperoleh komponen yang terdiri dari metil oleat (41,58 %), metil palmitat (24,73 %), metil stearat (12,17 %), dan metil behenat (16,31%). Konversi metil ester optimum diperoleh pada kondisi berat katalis 3 %, suhu reaksi 60 derajat Celcius, rasio mol minyak:metanol 1:6, dan waktu reaksi 120 menit dengan rendemen biodiesel tingkat tinggi sebesar 82,65%. Hasil penggunaan berulang katalis MA-900 sebanyak 3 kali diperoleh konversi metil ester sebesar 82,65 %, 82.04%, dan 80,37%. Katalis abu daun kelor memiliki kegunaan yang menjanjikan.

Synthesis of Moringa Oleifera (Kelor) Leaves Ash Catalyst for Transesterification of Low-Grade Bali Malapari Oil into Biodiesel has been studied. The objectives of this research were to study the effect of the ashing temperature of Moringa leaves ash on the metal oxide and catalyst activity of moringa leaves ash toward biodiesel liquid products, study the activity and selectivity of Moringa leaves ash catalyst in transesterification of Malapari oil to produce biodiesel under variation of weight catalyst, reaction temperature, mole ratio oil to methanol, reaction time, and study the usability of the best catalyst in transesterification of Malapari oil.

The synthesis of heterogeneous catalysts based on Moringa leaves extract obtained from pre-treatment results in the form of grinding Moringa leaves which were calcined at a temperature of 700 degree Celcius (MA-700), 800 degree Celcius (MA-800), and 900 degree Celcius (MA-900) for 3 hours. The best catalysts were then characterized by using XRF, FTIR, XRD, and SEM-EDX. The pre-treatment of low-grade Bali Malapari oil (LMO) was done through a degumming process by heating an 85 % H3PO4 solution (DMO). The obtained oil was then esterified with the reflux method using methanol, and concentrated H2SO4 solution (EDMO). The application of MA-900 in biodiesel production was carried out with a catalyst-weight variables (3, 6, and 9 % (w/w)), reaction temperature (55, 60, and 65 degree Celcius), oil: methanol mole ratio (1:3, 1:6, and 1:9), and reaction times (60, 90, 120, and 150 minutes), as well as analyzing the repeated use of moringa leaves ash catalyst in the transesterification process of Malapari oil with the reflux method to produce methyl ester products. The biodiesel products obtained from the transesterification process were then analyzed using FTIR and GC-MS.

The results of catalyst characterization by using XRF, FTIR, XRD, and SEM-EDX indicated that MA-700, MA-800, and MA-900 contain CaO, K2O, and MgO as three main compounds of Moringa Ash. MA-900 was used as catalyst because it contained the highest CaO as the main compound of catalyst due to CaO increases by increasing the calcination temperature.GC-MS analysis on methyl ester obtained components consisting of methyl oleate (41.58%), methyl palmitate (24.73%), methyl stearate (12.17%), and methyl behenate (16.31%). The optimum methyl ester conversion was obtained under conditions of catalyst weight of 3%, reaction temperature of 60 degree Celcius, oil: methanol mole ratio 1:6, and reaction time of 120 minutes with a yield high-rank biodiesel of 82.65%. The results of repeated use of MA-900 catalyst 3 times obtained a methyl ester conversion of 82.65%, 82.04%, and 80.37%. Moringa leaves ash catalyst has promising usability.

Kata Kunci : Key words: biodiesel, Moringa (kelor) leaves, Malapari oil, transesterification