Impregnasi CaO Pada SiO2 Termodifikasi Material Magnetik Alam Untuk Katalis Transesterifikasi Minyak Sawit Mentah Menjadi Metil Ester

Fitricia Nisa Indriani, Prof. Dr.rer.nat. Nuryono, M.S. ; Prof. Indriana Kartini, S.Si., M.Si., Ph.D.

2026 | Skripsi | KIMIA

Katalis kalsium oksida terimpregnasi pada silika yang termodifikasi material magnetik alam (MM-SiO2/CaO) telah berhasil disintesis, dikarakterisasi, dan diaplikasikan pada reaksi transesterifikasi minyak sawit mentah (MSM) menjadi metil ester (ME). Tahap pertama adalah sintesis material magnetik-termodifikasi silika (MM-SiO2) melalui metode sol-gel menggunakan prekursor tetraetoksisilan (TEOS) dan templat setiltrimetilamonium bromida (CTAB), dilanjutkan dengan impregnasi basah CaO dengan variasi persentase MM-SiO2 10, 20, dan 30%, sehingga diperoleh katalis 10% MM-SiO2/CaO, 20% MM-SiO2/CaO, dan 30% MM-SiO2/CaO. Katalis yang telah dihasilkan kemudian dikarakterisasi dengan instrumen XRD, FTIR, SAA, dan SEM-EDX Mapping. Transesterifikasi dengan tiga jenis katalis MM-SiO2/CaO dioptimasi dengan memvariasi rasio mol minyak:metanol, berat katalis, dan waktu reaksi.

Hasil penelitian menunjukkan bahwa katalis 10% MM-SiO2/CaO, 20% MM-SiO2/CaO, dan 30% MM-SiO2/CaO memiliki luas permukaan spesifik secara berturut turut yaitu 7,60; 11,68; dan 12,91 m²/g dengan volume pori total 0,0527; 0,0608; dan 0,1189 cm3/g serta diameter pori-pori katalis sebesar 27,77; 20,81; dan 36,83 nm yang menunjukkan terbentuknya struktur mesopori. Katalis 20% MM-SiO?/CaO menunjukkan performa katalitik paling baik dibandingkan katalis cangkang telur ayam, CaO, MM-SiO2, 10% MM-SiO2/CaO, dan 30% MM-SiO2/CaO. Katalis MM-SiO2/CaO pada kondisi optimum (rasio mol minyak:metanol 1:21, berat katalis 3%, dan waktu reaksi 3 jam), 20% MM-SiO2/CaO mampu menghasilkan metil ester sebesar 84,88%. Uji stabilitas katalis diperoleh 20% MM-SiO2/CaO memiliki stabilitas yang baik, hingga siklus ketiga terjadi penurunan aktivitas menjadi 62,04%. Secara keseluruhan, hasil penelitian ini menunjukkan bahwa katalis MM-SiO2/CaO memiliki potensi yang baik sebagai katalis basa heterogen dalam reaksi transesterifikasi MSM.

Kata kunci: kalsium oksida, metil ester, minyak sawit, silika, transesterifikasi

Calcium oxide catalyst impregnated on silica modified with natural magnetic material (MM-SiO2/CaO) was successfully synthesized, characterized, and applied to the transesterification reaction of crude palm oil (CPO) into methyl ester (ME). The first stage involved the synthesis of magnetic material-modified silica (MM-SiO2) through the sol-gel method using tetraethyl orthosilicate (TEOS) as the precursor and cetyltrimethylammonium bromide (CTAB) as the template. This was followed by the wet impregnation of CaO with MM-SiO2/CaO at 10, 20, and 30%, resulting in catalyst 10% MM-SiO2/CaO, 20% MM-SiO2/CaO, and 30% MM-SiO2/CaO. The synthesized catalyst was systematically characterized using XRD, FTIR, SAA, and SEM-EDX Mapping. The transesterification reaction using the three types of MM-SiO2/CaO catalysts was optimized by varying the oil:methanol molar ration, catalyst weight, and reaction time. 

The results indicated that the 10% MM-SiO2/CaO, 20% MM-SiO2/CaO, and 30% MM-SiO2/CaO catalysts exhibited specific surface areas of 7.60; 11.68; and 12.91 m²/g, respectively, with total pore volume of 0.0527; 0.0608; and 0.1189 cm3/g, and pore diameters of 27.77; 20.81; and 36.83 nm, confirming the formation of a mesoporous structure. The 20% MM-SiO2/CaO catalyst showed better performance than eggshell-derived catalyst, pure CaO, MM-SiO?, 10% MM-SiO2/CaO, and 30% MM-SiO2/CaO. At the optimum conditions (oil:methanol molar ratio 1:21, weight of catalyst 3%, reaction time 3 hours), the 20% MM-SiO2/CaO produced a methyl esters yield of 84.88%. Stability tests revealed that the 20% MM-SiO2/CaO catalyst showed good stability, although its activity decreased to 62.04% by the third cycle. Overall, is study showed that the MM-SiO2/CaO catalyst has significant potential as a heterogeneous base catalyst for the transesterification of crude palm oil. 

Keywords: calcium oxide, crude palm oil, methyl ester, silica, transesterification

Kata Kunci : Kata kunci: kalsium oksida, metil ester, minyak sawit, silika, transesterifikasi