Electronic Theses and Dissertation

ABSTRAK
Penelitian ini difokuskan pada pemanfaatan batu kapur (limestone) dari Lhoknga, kabupaten Aceh Besar, Indonesia, sebagai bahan baku katalis heterogen anorganik serta uji aktivitas katalitiknya pada reaksi transesterifikasi minyak kelapa sawit untuk sintesis biodiesel. Pada penelitian ini, katalis dipreparasi melalui proses kalsinasi pada suhu 900oC selama 5 jam dan dilanjutkan dengan modifikasi ion logam Ni(NO3)2 dan NaNO3 dengan variasi konsentrasi 1%, 3% dan 5% (b/b). Selanjutnya, katalis yang dipreparasi dikarakterisasi menggunakan X-Ray Diffractions (XRD), Fourier Transform Infrared (FTIR) dan Scanning Electron Microscope-Energy Dispersive X-Ray Spectroscopy (SEM-EDS). Berdasarkan difraktogram XRD, katalis didominasi oleh kristal CaO dan CaCO3, sedangkan Al2O3 ditemukan sebagai senyawa minor. Hasil karakterisasi menggunakan SEM-EDS menunjukkan bahwa katalis yang dimodifikasi menggunakan ion logam memiliki morfologi permukaan yang homogen dan distribusi ukuran partikel yang homogen. Berdasarkan kromatogram GC-MS, biodiesel telah berhasil disintesis menggunakan katalis yang dipreparasi pada penelitian ini dengan persentase yield lebih dari 60%. Biodiesel hasil sintesis memiliki nilai massa jenis, viskositas, bilangan asam dan warna yang memenuhi Standard Nasional Indonesia (SNI).

Kata kunci : Katalis heterogen, Batu kapur Lhoknga, Provinsi Aceh, sintesis biodiesel

ABSTRACT This study is focused on the utilization of limestone from Lhoknga, Aceh Besar district, Indonesia, as a raw material for inorganic heterogeneous catalysts and studies its catalytic activity in the transesterification reaction of palm oil for biodiesel synthesis. In this study, the catalyst was prepared through a calcination process at a temperature of 900oC for 5 hours and continued with the modification of metal ions Ni(NO3)2 and NaNO3 with varying concentrations of 1%, 3%, and 5% (w/w). Furthermore, the prepared catalyst was characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), and Scanning Electron Microscope-Energy Dispersive X-Ray Spectroscopy (SEM-EDS). Based on the XRD diffractogram, the catalyst was dominated by crystals of CaO and CaCO3, whereas Al2O3 was found as a minor compound. The results of characterization using SEM-EDS showed that the catalyst modified using metal ions had a homogeneous surface morphology, and uniform particle size distribution. Based on the GC-MS chromatogram, biodiesel has been successfully synthesized using the catalyst prepared in this study with a yield of more than 60%. The synthesized biodiesel has density, viscosity, acid number, and colour values that are suitable for the Indonesian National Standard (SNI). Keywords : Heterogeneous catalyst, Lhoknga limestone, Aceh Province, biodiesel synthesis