SINTESIS SILIKA MESOPORI DARI LUMPUR LAPINDO TERIMPREGNASI LOGAM Pd SEBAGAI KATALIS HIDRORENGKAH MINYAK SAWIT BEKAS MENJADI BIOFUEL

RIZQI MUHAMAD RESA, Prof. Dra. Wega Trisunaryanti, M.Si., Ph.D. Eng.; Prof. Dr. Triyono, SU

2021 | Skripsi | S1 KIMIA

Telah dilakukan sintesis silika mesopori (SM) dari lumpur lapindo terimpregnasi logam Pd (Pd/SM) sebagai katalis untuk hidrorengkah minyak sawit bekas menjadi biofuel. Tujuan penelitian ini adalah mempelajari karakter katalis SM dan Pd/SM pada hidrorengkah minyak sawit bekas menjadi biofuel. Ekstraksi silika dari lumpur Lapindo dilakukan melalui relfuks menggunakan HCl 6 M dan dilanjutkan dengan NaOH 6 M. Silika yang diperoleh kemudian dilakukan proses templating dengan surfaktan cetyltrimethylammonium bromide (CTAB) dengan rasio berat silika:CTAB = 1:0,65 menghasilkan SM. Logam Pd diimpregnasi ke dalam SM dengan metode impregnasi basah menggunakan larutan prekursor PdCl2, kemudian dikalsinasi pada suhu 550 °C dengan aliran gas N2 dilanjutkan reduksi dengan aliran gas H2 masing-masing dengan laju alir gas 20 mL/menit selama 3 jam. Katalis SM dan Pd/SM yang telah disintesis dilakukan uji keasaman melalui adsorpsi gas NH3 dengan metode gravimetri, dikarakterisasi dengan Fourier Transform Infrared (FTIR), Surface Area Analyzer (SAA), X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), dan Transmission Electron Microscopy (TEM). Hasil hidrorengkah minyak sawit bekas berupa fraksi cair dianalisis menggunakan Gas Chromatography-Mass Spectrometry (GC-MS). Hasil ekstraksi silika dari lumpur Lapindo, diperoleh kemurnian SiO2 sebesar 81,55%. Luas permukaan spesifik SiO2 sebesar 88,052 m2/g dan diameter pori rerata dari material SiO2 sebesar 10,752 nm. SM memiliki luas permukaan spesifik sebesar 521,511 m2/g dan diameter pori rerata sebesar 4,781 nm. Pd/SM menunjukkan luas permukaan spesifik dan rerata diameter pori sebesar 580,074 m2/g dan 4,729 nm. Penambahan logam Pd pada silika mesopori (SM) meningkatkan nilai keasaman katalis dari 9,942 menjadi 10,726 mmol/g. Produk cair terbanyak hasil hidrorengkah minyak sawit bekas dicapai dengan menggunakan katalis Pd/SM (66,60% b/b) dengan selektivitas terhadap biofuel dalam bentuk senyawa hidrokarbon sebesar 53,53% b/b. Hasil penggunaan berulang katalis Pd/SM sebanyak 3 kali diperoleh selektivitas senyawa hidrokarbon dalam fraksi cair berturut-turut sebanyak 53,53; 63,24; dan 61,42% b/b. Katalis Pd/SM memiliki kegunaan kembali (re-useability) yang menjanjikan.

Synthesis of mesoporous silica (SM) from lapindo mud impregnated by Pd metal as a catalyst for hydrocracking of waste palm oil into biofuel has been conducted. The purpose of this research was to learn characters of SM and Pd/SM as catalysts in hydrocracking of waste palm oil into biofuel. The Silica extraction from Lapindo mud was done by reflux using HCl 6 M and followed by NaOH 6 M. Silica from the exctraction process was templated by CTAB surfactant with weight ratio silica:CTAB equal to 1:0,65. The Pd metal was impregnated into the mesoporous silica (SM) using the wet impregnation method with PdCl2 solution as a precursor, followed by the calcination at 550 °C with N2 gas and reduction process with H2 gas for each under gas flow rate of 20 cc/minute in 3 h. Synthesized SM and Pd/SM catalyst was tested for the acidity value through gravimetry method using ammonia gas (NH3) and characterized by Fourier Transform Infrared (FTIR), Surface Area Analyzer (SAA), X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), dan Transmission Electron Microscopy (TEM). The liquid product after the hydrocracking process was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The extraction result of silica from Lapindo mud resulted in a purity of 81.55%. The specific surface area of SiO2 was 88.052 m2/g and the average pore diameter was 10.752 nm. SM has the specific surface area of 521.511 m2/g and average pore diameter of 4.781 nm. Pd/SM showed the specific surface area and the average pore diameter of 580.074 m2/g and 4.729 nm. The addition of Pd metal to the mesoporous silica (SM) increased the acidity value from 9.942 to 10.726 mmol/g. The largest liquid product from hydrocracking of waste palm oil was obtained by Pd/SM catalyst (66.60 wt%) with selectivity for biofuel in the form of hydrocarbon compound was 53.53 wt%. The results of the 3 times re-utilization of Pd/SM catalyst has the selectivity towards hydrocarbon compounds of 53.53, 63.24, and 61.42 wt%, respectively. The Pd/SM catalyst has a promising re-useability performance.

Kata Kunci : biofuel, hydrocracking, impregnation, mesoporous silica.