Pengaruh Kondisi Reaksi dan Jumlah Logam Co Terhadap Aktivitas dan Selektivitas Katalis Co/Lumpur Lapindo pada Hydrotreatment Minyak Sawit Bekas Menjadi Biofuel

Novia Cahya Ningrum, Prof. Dra. Wega Trisunaryanti, M.S., Ph.D.Eng; Akhmad Syoufian, Ph.D.

2023 | Skripsi | KIMIA

Telah dilakukan sintesis dan karakterisasi katalis Co/Lumpur Lapindo dari lumpur Lapindo untuk hydrotreatment minyak sawit bekas menjadi biofuel. Tujuan penelitian ini untuk menyelidiki pengaruh kondisi reaksi dan jumlah logam kobalt terhadap aktivitas dan selektivitas katalis Co/LL. Katalis dipreparasi melalui impregnasi basah menggunakan garam prekursor CoCl6.H2O, dengan variasi konsentrasi awal Co terhadap lumpur Lapindo yaitu 2, 6, dan 10% untuk menghasilkan katalis Co(a)/LL, Co(b)/LL, dan Co(c)/LL. Katalis dikalsinasi dengan gas N2 dan direduksi dengan gas H2 masing-masing pada suhu 500?C selama 3 jam. Katalis dikarakterisasi dengan FT-IR, XRD, SEM-EDX, BET/BJH dan uji keasaman dengan gravimetri. Uji hidrotermal dilakukan pada umpan minyak sawit bekas sebanyak 10g dengan suhu 450, 475, dan 500?C. Proses hydrotreatment dilakukan pada suhu optimum hidrotermal yang menghasilkan fraksi cair tertinggi pada variasi rasio berat umpan/katalis 1:50; 1:75; dan 1:100 menggunakan katalis Co(a)/LL. Proses hydrotreatment dilanjutkan dengan suhu dan rasio berat umpan/katalis optimum pada katalis Co(b)/LL dan Co(c)/LL. Variasi katalis yang menghasilkan fraksi cair tertinggi digunakan untuk uji masa pakai. Produk cair hasil hydrotreatment dianalisis GC-MS.

Hasil penelitian menunjukkan bahwa pada katalis Co(a)/LL, Co(b)/LL, dan Co(c)/LL kandungan Co yang berhasil diembankan masing-masing sebesar  6, 18, dan 36 %b/b; area permukaan spesifik (m2/g) dan diameter pori (nm) masing-masing 4,55 dan 7,72; 10,62 dan 9,41; 13,84 dan 8,61; dengan nilai keasaman masing-masing 1,7854; 2,7133; dan 3,1679 mmol/g. Suhu dan rasio berat katalis/umpan yang menghasilkan fraksi cair tertinggi adalah 450?C and 1:100. Katalis Co(c)/LL memiliki hasil terbaik pada selektivitas terhadap biofuel sebanyak 56,67 %b/b. Fraksi cair tertinggi (91,07 %b/b) dihasilkan oleh Co(b)/LL yang kemudian digunakan untuk uji masa pakai.

Kata kunci: katalis, kobalt, hydrotreatment, lumpur Lapindo, dan minyak sawit bekas.

ABSTRACT

The synthesis and characterization of Co/Lumpur Lapindo (Co/LL) catalysts from Lapindo mud for the hydrotreatment of used palm oil into biofuel has been conducted. The purpose of this research is to investigate the effect of reaction conditions and cobalt content towards activity and selectivity of Co/LL catalysts. The catalysts were prepared by wet impregnation method using salt precursor CoCl6.H2O, under variation of initially Co content of 2, 6, 10 wt?sed on the LL weight to produce Co(a)/LL, Co(b)/LL, and Co(c)/LL catalyst, respectively. The catalysts were calcined with N2 gas and reduced with H¬2 gas each at 500?C for 3 h. The catalysts were then characterized by FT-IR, XRD, SEM-EDX, BET/BJH, and acidity test by gravimetric method. Hydrothermal test was carried out for 10g used palm oil on temperature of 450, 475, and 500?C. Hydrotreatment was carried out at the optimum hydrothermal temperature which produced the highest liquid fraction on the variation of catalyst/feed weight ratio 1:50; 1:75; 1:100 using Co(a)/LL catalyst. Hydrotreatment was then carried out under optimum temperature and catalyst/feed weight ratio using the Co(b)/LL and Co(c)/LL. Catalyst that produce the highest liquid fraction was then tested for the usability. The liquid products were analyzed by GC-MS.

The results showed that Co(a)/LL, Co(b)/LL, and Co(c)/LL catalyst consisted of Co metal 6, 18, and 36 wt.%, respectively; the specific surface area (m2/g) and pore diameter (nm) 4.55 and 7.728, 10.616 and 9.408, 13.836 and 8.609, respectively; the acidity  1.7854, 2.7133, and 3.1679 mmol/g, respectively. The temperature and catalyst/feed weight ratio that produced the highest liquid fraction was 450?C and 1:100. The Co(c)/LL catalyst showed the best performance in selectivity towards biofuels of 52,67 wt %. The highest liquid fraction (91.07 wt%) was produced by Co(b)/LL which then tested for the usability.  

Keywords: catalyst, cobalt, hydrotreatment, lapindo mud, and used palm oil.

Kata Kunci : katalis, kobalt, hydrotreatment, lumpur Lapindo, minyak sawit bekas