Pengaruh Perbedaan Lokasi Tumbuh dan Konsentrasi Asam Sulfat (H?SO?) pada Proses Esterifikasi terhadap Kualitas Minyak Ester Nyamplung (Calophyllum inophyllum)

Lila Asfili, Ir. Sigit Sunarta, S. Hut., M. P., M. Sc., Ph. D., IPU ; Krisnawati, S. Hut., M. Sc

2026 | Skripsi | KEHUTANAN

Ketergantungan industri biodiesel nasional terhadap minyak kelapa sawit (CPO) sebagai bahan baku tunggal mendorong perlunya diversifikasi menuju sumber minyak nabati non-pangan, salah satunya minyak nyamplung (Calophyllum inophyllum). Karakteristik fisiko-kimia TCO diketahui dipengaruhi oleh asal-usul genetik dan lingkungan tumbuh tanaman, sehingga penelitian ini dilakukan untuk mengkaji sejauh mana perbedaan lokasi tumbuh nyamplung (Purworejo, Jawa Tengah dan Dompu, Nusa Tenggara Barat) serta variasi konsentrasi H?SO? pada tahap esterifikasi memengaruhi karakteristik minyak ester yang dihasilkan.

Metode yang digunakan adalah Rancangan Acak Lengkap (RAL) faktorial dua faktor: lokasi asal TCO (Purworejo, Dompu) dan konsentrasi H?SO? pada tiga taraf (1%, 2%, 3?ri berat minyak), dengan tiga ulangan per kombinasi perlakuan. Proses esterifikasi berlangsung 2 jam pada suhu 60–70°C menggunakan metanol 20%. Berdasarkan SNI 7182:2024 karakteristik minyak ester adalah massa jenis, viskositas kinematik, kadar air, dan angka asam, ditambah rendemen dan profil senyawa dari analisis GC-MS. Signifikansi pengaruh masing-masing faktor serta interaksinya diuji lewat ANOVA dua arah (taraf 5%), dilanjutkan uji lanjut Bonferroni.

Hasil penelitian diperoleh bahwa konsentrasi H?SO? memengaruhi secara nyata seluruh parameter yang diukur, sementara lokasi asal bahan baku berpengaruh nyata terhadap rendemen, massa jenis, viskositas, dan angka asam namun tidak terhadap kadar air. Interaksi antara kedua faktor memengaruhi rendemen, viskositas, dan kadar air secara nyata, tetapi tidak pada massa jenis maupun angka asam. Kombinasi TCO Dompu dengan konsentrasi H?SO? 3% menghasilkan rendemen tertinggi (92,67%) dan angka asam terendah (9,54 mg KOH/g) di antara seluruh perlakuan, meskipun pada kombinasi yang sama viskositasnya justru paling tinggi (43,08 cSt). Sementara itu, massa jenis tertinggi (0,978 g/mL) diperoleh dari TCO Purworejo pada konsentrasi H?SO? yang sama. Nilai massa jenis dan viskositas pada keseluruhan perlakuan masih jauh melampaui ambang mutu biodiesel menurut SNI 7182:2024, menandakan bahwa produk yang dihasilkan pada tahap ini merupakan minyak ester yang masih memerlukan tahap transesterifikasi lanjutan agar trigliserida yang tersisa dapat terkonversi sepenuhnya menjadi metil ester.

The dependence of the national biodiesel industry on palm oil (CPO) as a single feedstock has driven the need for diversification toward non-food vegetable oil sources, one of which is nyamplung oil (Calophyllum inophyllum L.). The physicochemical characteristics of TCO (Tamanu Crude Oil) are known to be influenced by the plant's genetic origin and growing environment; therefore, this study was conducted to examine the extent to which differences in the provenance of nyamplung (Purworejo, Central Java and Dompu, West Nusa Tenggara) and variations in H?SO? concentration during the esterification stage affect the characteristics of the resulting ester oil.

The method used was a two-factor factorial Completely Randomized Design (CRD): TCO provenance (Purworejo, Dompu) and H?SO? concentration at three levels (1%, 2%, 3% of oil weight), with three replications per treatment combination. The esterification process was carried out for 2 hours at a temperature of 60–70°C using 20% methanol. Based on SNI 7182:2024, the ester oil characteristics assessed were density, kinematic viscosity, water content, and acid value, in addition to yield and compound profiles obtained from GC-MS analysis. The significance of each factor's effect and their interaction was tested using two-way ANOVA (5% significance level), followed by Bonferroni post-hoc testing.

The results showed that H?SO? concentration significantly affected all measured parameters, while provenance significantly affected yield, density, viscosity, and acid value, but not water content. The interaction between the two factors significantly affected yield, viscosity, and water content, but not density or acid value. The combination of Dompu TCO with 3% H?SO? concentration produced the highest yield (92.67%) and the lowest acid value (9.54 mg KOH/g) among all treatments, although the same combination also produced the highest viscosity (43.08 cSt). Meanwhile, the highest density (0.978 g/mL) was obtained from Purworejo TCO at the same H?SO? concentration. The density and viscosity values across all treatments still far exceeded the biodiesel quality thresholds set by SNI 7182:2024, indicating that the product obtained at this stage is still ester oil that requires a further transesterification step so that the remaining triglycerides can be fully converted into methyl esters.

Kata Kunci : Minyak Nyamplung, Esterifikasi, Katalis Asam Sulfat, Lokasi Tumbuh, Karakteristik Minyak Ester