Sintesis dan Karakterisasi Biodiesel dari Minyak Curah dengan Katalis Heterogen Sabut Kelapa-K2CO3

Abstract

Penelitian ini bertujuan menganalisis pengaruh suhu kalsinasi katalis sabut kelapa-K2CO3 dan suhu transesterifikasi terhadap mutu biodiesel dari minyak curah. Katalis disintesis melalui karbonisasi sabut kelapa, impregnasi K2CO3 20 wt%, dan kalsinasi pada suhu 500, 600, 700 °C. Biodiesel diproduksi menggunakan rasio molar metanol:minyak 9:1 dan katalis 5 wt% pada suhu reaksi 50, 60, dan 70 °C. Karakterisasi dilakukan menggunakan XRD, FTIR, SEM, dan BET. Hasil penelitian menunjukkan bahwa peningkatan suhu kalsinasi memengaruhi pembentukan fase aktif K2O dan K2CO3, perubahan gugus fungsi, morfologi permukaan, serta karakteristik pori katalis. Variasi suhu kalsinasi dan suhu transesterifikasi memberikan nilai p-value <0,05 terhadap rendemen biodiesel, sedangkan terhadap densitas dan bilangan asam diperoleh nilai p-value >0,05. Kondisi optimum diperoleh pada suhu kalsinasi 600 °C dan suhu transesterifikasi 70 °C dengan rendemen 87,50%, densitas 858,782 kg/m³,dan bilangan asam 0,361 mg KOH/g. Seluruh biodiesel memenuhi persyaratan SNI 7182:2015.

This research aims to analyze the effect of coconut husk-K2CO3 catalyst calcination temperature and transesterification temperature on the quality of biodiesel produced from bulk cooking oil. The catalyst was synthesized through the carbonization of coconut husk, followed by impregnation with 20 wt% K2CO3 and calcination at temperatures of 500, 600, and 700 °C. Catalyst characterization was carried out using XRD, FTIR, SEM, and BET analyses. The results showed that increasing the calcination temperature affected the formation of the active K2O and K2CO3 phases, functional group composition, surface morphology, and pore characteristics of the catalyst. Statistical analysis indicated that the variations in calcination and transesterification temperatures resulted in p-values < 0.05 for biodiesel yield, whereas p-values > 0.05 were obtained for density and acid value. The optimum conditions were achieved at a calcination temperature of 600 °C and a transesterification temperature of 70 °C, producing a biodiesel yield of 87.50%, a density of 858.782 kg/m³, and an acid value of 0.361 mg KOH/g. All biodiesel samples complied with the requirements of SNI 7182:2015.