PREPARASI KATALIS γ-Al2O3, MORDENIT, DAN ZEOLIT ALAM AKTIF TEREMBAN NIKEL UNTUK HIDRORENGKAH POLIETILENA

WIWIN SRININGSIH, Prof. Dra. Wega Trisunaryanti, M.S., M.Eng., Ph.D.

2014 | Skripsi | KIMIA

Telah dilakukan preparasi katalis γ-Al2O3, Mordenit, dan zeolit alam aktif teremban nikel untuk hidrorengkah polietilena. Penelitian diawali dengan aktivasi zeolit alam (ZA) dari Sukabumi dengan perlakuan HCl 6 N selama 30 menit, dilanjutkan perendaman dengan NH4Cl 1 N selama 1 minggu sehingga dihasilkan zeolit alam aktif (ZAA). Preparasi katalis dilakukan dengan pengembanan logam nikel pada pengemban γ-Al2O3, Mordenit, dan ZAA menggunakan prekursor logam Ni(NO3)2·6H2O dengan metode impregnasi basah, dilanjutkan kalsinasi menggunakan microwave 450 watt selama 30 menit, dan reduksi dengan gas H2 pada 400 °C selama 3 jam sehingga dihasilkan katalis Ni/γ-Al2O3, Ni/Mordenit, dan Ni/ZAA. Karakterisasi katalis dilakukan dengan metode difraksi sinar-X (XRD), spektrometri inframerah (FT-IR), dan spektroskopi serapan atom (AAS). Keasaman ditentukan dengan metode gravimetri menggunakan uap basa amoniak dan piridin. Uji aktivitas katalis dilakukan melalui reaksi hidrorengkah plastik polietilena jenis LDPE (Low Density Polyethylene) menggunakan katalis-katalis tersebut dengan variasi temperatur 350, 400, dan 450 °C, serta dialiri gas H2 dengan laju alir 20 mL/menit selama 1 jam, perbandingan umpan : katalis = 5. Produk cair hidrorengkah dianalisis menggunakan kromatografi gas (GC) dan kromatografi gas-spektrometer massa (GC-MS). Hasil analisis XRD menunjukkan bahwa perlakuan asam terhadap ZA maupun pengembanan logam nikel pada γ-Al2O3, Mordenit, dan ZAA tidak merusak kristalinitas katalis secara signifikan. Berdasarkan spektrum FTIR, perlakuan asam terhadap ZA menyebabkan dealuminasi dan hilangnya pengotor kristalin maupun amorpus sehingga meningkatkan rasio Si/Al secara kualitatif. Perlakuan asam dan pengembanan logam nikel mampu meningkatkan jumlah situs asam katalis. Konversi produk cair tertinggi dihasilkan oleh katalis Ni/Mordenit pada temperatur 400 °C sebesar 63,62% b/b dengan konversi total fraksi bensin dan diesel sebesar 42,32% b/b dan 21,30% b/b yang tersusun atas isoparafin, naften, dan olefin.

, Mordenite Preparation of γ-Al2O3 , and activated natural zeolite catalysts supported by nickel for hydrocracking of polyethylene has been carried out. This study was begun by activation of natural zeolite (ZA) from Sukabumi by treatment of HCl 6 N for 30 min, followed by immersion with NH4Cl 1 N for a week, produced activated natural zeolite (ZAA). The catalysts were prepared by loading nickel metal onto γ-Al2O3, Mordenite, and ZAA using the precursor of Ni(NO3)2·6H2O by wet impregnation method, followed by calcination with microwave at 450 watt for 30 min, and reduction by H2 gas at 400 °C for 3 h, obtained Ni/γ-Al2O3, Ni/Mordenite, and Ni/ZAA catalysts. Characterization of the catalysts has been conducted by X-ray diffraction (XRD), infrared spectrometry (FT-IR), and atomic absorption spectroscopy (AAS) methods. Catalysts acidity was determined by gravimetric method using ammonia and pyridine base vapor. Activity test of catalysts has been performed through hydrocracking process of polyethylene plastic type LDPE (Low Density Polyethylene) over these catalysts with various temperatures of 350, 400, and 450 °C under operation condition of hydrogen flow rate of 20 mL/min for an hour, feed/catalyst ratio of 5. The liquid yield of hydrocracking was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometer (GC-MS). , Mordenite, and ZAA The XRD results showed that acid treatment toward ZA and loading of nickel metal onto γ-Al2O3 did not ruin the crystalinity of catalysts significantly. According to FTIR spectrum, the acid treatment toward ZA sample caused dealumination and loss of cristalline and amorpous impurities so that increased Si/Al ratio qualitatively. The acid treatment and loading of nickel metal also increased the acid amount of catalysts. The highest conversion of liquid yield was obtained by Ni/Mordenite catalyst at 400 °C as much as 63.62 wt% with the total conversion of gasoline and diesel fractions as much as 42.32 wt% and 21.30 wt% that consisted of isoparaffins, naphthenes, and oleffins.

Kata Kunci : γ-Al2O3, Mordenit, zeolit alam, polietilena (LDPE), hidrorengkah