Electronic Theses and Dissertation

Biodiesel merupakan bahan bakar nabati yang ramah lingkungan yang dikembangkan sebagai pengganti diesel komersial. Proses produksi menggunakan reaksi transesterifikasi antara minyak nabati dan metanol dengan menggunakan katalis heterogen bonggol dan kulit pisang yang dikalsinasi. Dimana kandungan Kalium 37,3 % - 60% pada kulit dan 22.62- 57,4 % pada bonggol. Keberadaan kalium dalam katalis berperan aktif dalam meningkatkan aktifitas dan kristalinasi katalis yang tinggi Penelitian ini bertujaun mengkaji pengaruh temperatur kalsinasi dan waktu kalsinasi terhadap produksi biodiesel, menganalisa karakteristik katalis dan mengkaji pengaruh waktu reaksi, perbandingan mol metanol minyak dan berat katalis terhadap perolehan produk biodiesel serta mengevaluasi optimasi proses produksi biodiesel menggunakan metode permukaan respons yaitu Response Surface Metodology (RSM). Tahapan penelitian terdiri tiga tahapan yaitu tahap preparasi katalis bonggol pisang dan kulit pisang yang dikalsinasi pada suhu 600oC dan 700oC. waktu (4 dan 6 jam ).dan, Katalis dikarakterisasi dengan analisis Brunauer- Emmett- Teller (BET) surface analyzer untuk mengukur luas permukaan pori katalis, X-Ray Diffractometer (XRD) untuk mengkaji kristalinitas katalis, Scanning Electron Microscopy (SEM) untuk mengevaluasi morfologi katalis, Energy Dispersive X-ray (EDX) untuk menganalisa atom dan karakterisasi kimia katalis. Tahap kedua yaitu reaksi transesterifikasi dari hasil katalis yang terbaik Proses reaksi transesterifikasi dilakukan dengan perbandingan mol minyak metanol (1:4, 1:6 , 1:8, 1;10. dan 1:12), waktu reaksi 60, 90 dan 120 menit. Berat katalis yang ditambahkan yaitu 2%, 4% dan 6%. Produk biodiesel yang dihasilkan dianalisis kandungan komposisi metil ester dengan menggunakan Gas Chromatography-Mass Spectroscopy (GC-MS) dan dianalisa karakteristik kandungan produk yaitu densitas, viscositas, yield dan bilangan setana untuk mencapai kondisi standar biodiesel. Tahap yang ketiga adalah mencari kondisi yang optimal untuk berbagai kondisi operasi dengan pendekatan Response Surface Metodology (RSM). Hasil penelitian katalis bonggol pisang berdasarkan analisa TEM diperoleh ukuran pori dalam kisaran 20-100 nm yaitu sebesar 48.3 nm pada kalsinasi 700oC suhu 6 jam. Hasil Analisa SEM Katalis yang di dapatkan dalam bentuk partikel teraglomerisasi dengan ukuran 3.2 μm - 4.0 μm untuk suhu 600oC , waktu 4 jam dan 5,3- 7,3 μm pada suhu suhu 600 oC dan waktu 6 jam Untuk suhu 700oC waktu 4 memiliki ukuran partikel 2 - 9,3 µm, pada waktu 6 jam dan 6 - 9,3 µm. Yield tertinggi 99,845% dengan rasio mol minyak 1:6 waktu reaksi 120 menit dan massa katalis 2 %, Bilangan setana 63.6, Nilai kalor 39,96 mj/kg, Viscositas 3,26 cSt dan densitas 866 kg/m3. Untuk katalis kulit pisang berdasarkan analisa BET luas permukaan 1,577 m2/g, ukuran pori 12.2674 nm, yield tertinggi 98,064% pada rasio mol minyal 1:8.

Biodiesel is an environmentally friendly plant-based fuel developed as a substitute for commercial diesel. The production process involves a transesterification reaction between vegetable oil and methanol using a heterogeneous catalyst made from calcined banana stems and peels. The potassium content ranges from 37.3% to 60% in the peels and from 22.62% to 57.4% in the stems. The presence of potassium in the catalyst plays an active role in enhancing the catalyst’s activity and promoting high crystallization. This study aims to examine the effects of calcination temperature and calcination time on biodiesel production, analyze the catalyst characteristics, and investigate the effects of reaction time, the molar ratio of methanol to oil and the catalyst weight on biodiesel yield, and to evaluate the optimization of the biodiesel production process using the Response Surface Methodology (RSM). The research consisted of three stages: the preparation of banana stem and banana peel catalysts, which were calcined at temperatures of 600°C and 700°C for 4 and 6 hours, respectively; characterization of the catalysts using Brunauer-Emmett analysis; -Teller (BET) surface analyzer to measure the catalyst’s pore surface area; X-ray diffractometry (XRD) to assess the catalyst’s crystallinity; scanning electron microscopy (SEM) to evaluate the catalyst’s morphology; and energy-dispersive X-ray spectroscopy (EDX) to analyze the catalyst’s atomic composition and chemical characterization. The second stage involved the transesterification reaction using the best catalyst. The transesterification reaction was carried out with molar ratios of oil to methanol of 1:4, 1:6, 1:8, 1:10, and 1:12, and reaction times of 60, 90, and 120 minutes. The catalyst loadings were 2%, 4%, and 6%. The produced biodiesel was analyzed for its methyl ester composition using Gas Chromatography-Mass Spectrometry (GC-MS), and its characteristics—including density, viscosity, yield, and cetane number—were analyzed to meet biodiesel standards. The third stage involved determining the optimal conditions for various operating conditions using the Response Surface Methodology (RSM) approach. The results of the banana stem catalyst study, based on TEM analysis, showed pore sizes in the range of 20–100 nm, with an average of 48.3 nm following calcination at 700°C for 6 hours. SEM analysis of the catalyst revealed agglomerated particles with a size of 3.2 μm – 4.0 μm at 600°C for 4 hours, and 5.3–7.3 μm at 600°C for 6 hours. At 700°C for 4 hours, the particle size was 2–9.3 μm, and at 6 hours, it was 6–9.3 μm. The highest yield was 99.845% with an oil-to-catalyst molar ratio of 1:6, a reaction time of 120 minutes, and a catalyst mass of 2%; the octane number was 63.6, the calorific value was 39.96 MJ/kg, the viscosity was 3.26 cSt, and the density was 866 kg/m³. For the banana peel catalyst, based on BET analysis, the surface area was 1.577 m²/g, the pore size was 12.2674 nm, and the highest yield was 98.064% at an oil-to-catalyst molar ratio of 1:8.