Modifikasi dan Karakterisasi Zeolit Alam Sarulla Sebagai Katalis dan Uji Aktivitasnya pada Reaksi Catalytic Hydrocracking Minyak Biji Karet (Havea Brasiliensies SP)

Abstract

The study of modification and characterization of natural zeolite sarulla (SNZ) as a catalyst material and its activity test in the reaction of rubber seed oil catalytic hydrocracking was carried out. SNZ modification through the stages of 3M HCL activation at 90oC for 30 minutes using reflux to obtain SNZ-AA followed by calcination at 500oC with nitrogen gas flow and obtained SNZ-Cal. The next step is the process of impregnating Ni, Co and a combination of Ni-Mo and Co-Mo metals with wet impregnation method using precursor salt solutions (Ni (NO3)2.6H2O, Co (NO3)2 and (NH4)6Mo7O24.4H2O. This step continued with reflux process at 80oC for 5 hours, then evaporated and dried at 120oC. The sample of catalyst was then oxidized at 500oC for 2 hours under O2 gas flow, followed by a reduction process with H2 gas flow at 500oC for 2 hours (obtained Ni / SNZ-Cal catalyst, NiMo / SNZ-Cal, Co / SNZ-Cal and CoMo / SNZ -Cal). The Catalyst characterization were using FT-IR, XRD, XRF, SEM, and for determination of surface area by BET method using gas sorption analyzer. The activity test of each catalyst was carried out in the rubber seed oil hydrocracking reaction in a fixed bed reactor system made of stainless steel with variations in the feed catalyst ratio (1: 2; 1: 4 and 1: 6) and temperature variations (400oC, 450oC and 500oC). Liquid products from hydrocracking were analyzed by GC and GC-MS. The results of FT-IR analysis show that activation with acidification formed in dealumination so that the framework of tetrahedal zeolite was more effective than The results of XRD analysis also showed that the process of acid activation and calcination did not damage the crystal structure of zeolites and the results of BET analysis showed that the process of acid activation and calcination was able to increase the SNZ-Cal catalyst with specific surface area by 107,297 m2 / g. The process of developing Ni, Co and the combination of Ni-Mo and Co-Mo metals in the SNZ-Cal carrier generally shows a decrease in specific surface area and has a greater pore radius. The results of the XRD analysis showed that metal development in the SNZ-Cal carrier results in a decrease in the intensity of the diffractogram peak, but generally does not damage the zeolite crystal structure. Products produced from MEFA hydrocracking rubber seed oil are liquid products, coke and gas. Liquid products consist of gasoline fraction (C6-C12), diesel (C13- C20) and heavy oil (> C20). The optimum liquid product conversion of SNZ-Cal catalyst is 80.60% at catalyst: feed ratio 1: 2 (500oC), with selectivity to biogasoline fraction which is 37.31%. The Ni / SNZ-Cal catalyst produced the highest selectivity to the biogasoline fraction of 86.25%, followed by Co / SNZ-Cal catalyst, Ni-Mo / SNZ-Cal and Co-Mo / SNZ-Cal with a value of 83.19%; 81.86%; and 78.96%.

Penelitian modifikasi dan karakterisasi zeolit alam sarulla (SNZ) sebagai material katalis dan uji aktivitasnya pada reaksi catalytic hydrocracking minyak biji karet telah dilakukan. Modifikasi SNZ melalui tahapan proses aktivasi HCL 3M pada suhu 90oC selama 30 menit menggunakan refluks hingga diperoleh SNZ-AA diikuti proses kalsinasi pada suhu 500oC dengan aliran gas nitrogen dan diperoleh SNZ-Cal. Tahap selanjutnya yaitu proses pengembanan logam Ni, Co dan kombinasi logam Ni-Mo dan Co-Mo dengan metode impregnasi basah menggunakan larutan garam prekursor (Ni(NO3)2.6H2O, Co(NO3)2 dan (NH4)6Mo7O24.4H2O. Selanjutnya direfluks pada 80oC selama 5 jam, kemudian diuapkan dan dikeringkan pada 120oC. Katalis sampel kemudian dioksidasi pada 500oC selama 2 jam dibawah aliran gas O2, dilanjutkan proses reduksi dengan aliran gas H2 pada 500oC selama 2 jam (diperoleh katalis Ni/SNZ-Cal, Ni-Mo/SNZ-Cal, Co/SNZ-Cal dan Co-Mo/SNZ-Cal). Karakterisasi katalis menggunakan spektroskopi FTIR, XRD, XRF, SEM/ SEM-Map, dan penentuan luas permukaan dengan metode BET menggunakan gas sorption analyzer. Uji aktivitas dari masing-masing katalis dilakukan pada reaksi hydrocracking minyak biji karet dalam sistem reaktor fixed bed yang terbuat dari stainless steel dengan variasi rasio katalis umpan (1:2; 1:4 dan 1:6) dan variasi suhu 400oC, 450oC dan 500oC. Produk cair hasil hydrocracking dianalisis dengan GC dan GCMS. Hasil analisis FT-IR menunjukkan aktivasi dengan pengasaman mengakibatkan terjadinya dealuminasi sehingga kerangka tetrahedal zeolit lebih efektif. Difraktogram XRD menunjukkan bahwa proses aktivasi asam dan kalsinasi dari zeolit dan hasil analisis BET meperlihatkan bahwa proses aktivasi asam dan kalsinasi mampu meningkatkan luas permukaan spesifik katalis SNZ-AA sebesar 121,152 m2/g dan SNZ-Cal sebesar 107,297 m2/g. Proses pengembanan logam Ni, Co dan kombinasi logam Ni-Mo dan Co-Mo pada pengemban SNZ-Cal secara umum memperlihatkan penurunan luas permukaan spesifik katalis dan memiliki rerata jejari pori yang lebih besar dan mengakibatkan penurunan intensitas puncak difraktogram, namun secara umum tidak merusak struktur kristal zeolit. Produk yang dihasilkan dari hydrocracking MEFA minyak biji karet berupa produk cair, kokas dan gas. Produk cair terdiri dari fraksi bensin (C6-C12), diesel (C13-C20) dan minyak berat (>C20). Konversi produk cair optimum dihasilkan katalis SNZ-Cal sebesar 80,60% pada rasio katalis:umpan 1:2 dan temperature 500oC, dengan selektivitas terhadap fraksi bensin yaitu 37,31%. Katalis Ni/SNZ-Cal menghasilkan selektivitas terhadap fraksi bensin tertinggi yaitu sebesar 86,25%, diikuti oleh katalis Co/SNZ-Cal, NiMo/SNZ-Cal dan CoMo/SNZ-Cal dengan nilai masing-masing sebesar 83,19%; 81,86%; dan 78,96%.