Telah dilakukan preparasi katalis berbasis zeolit alam yang dimodifikasi dengan logam Ni dan Cr untuk perengkahan limbah plastik jenis polipropilena (PP) menjadi fraksi bensin. Zeolit alam diaktivasi terlebih dahulu, kemudian diimpregnasi dengan logam Ni konsentrasi tetap 4% (b/b) dan logam Cr dengan konsentrasi bervariasi, yaitu 4% (katalis A), 6% (katalis B), dan 8% (katalis C), secara bersamaan (koimpregnasi). Hasil preparasi dikarakterisasi dengan XRD, AAS, BET, dan metode adsorpsi amonia. Difraktogram katalis menunjukkan spesi NiO (2 = 44°) dan Cr2O3 (2 = 33° dan 54°) memiliki intensitas yang cukup signifikan dan semakin meningkat seiring dengan kandungan logam Cr yang terimpregnasi. Luas permukaan dan total volume pori katalis memiliki tren menurun, sedangkan rata-rata diameter pori memiliki tren meningkat seiring dengan semakin banyaknya logam yang terimpregnasi. Kandungan total logam pada katalis A sebesar 1,81% Ni - 1,32% Cr, pada katalis B sebesar 1,80% Ni - 1,91% Cr, dan pada katalis C sebesar 2,37% Ni - 2,38% Cr dimana total keasaman katalis meningkat dengan semakin besarnya kandungan total logam. Uji aktivitas katalis dilakukan pada suhu 400°C dan 450°C menunjukkan bahwa hasil konversi pada fraksi bensin C3-C14 lebih besar sekitar 10-23% dibandingkan dengan hasil perengkahan termal (tanpa katalis). Hasil konversi terbesar diperoleh dengan pengunaan katalis B sebesar 86,91% pada suhu 450°C.
Catalyst was prepared by modifying natural zeolite with Ni and Cr metals and was used for the cracking of polypropylene (PP) waste into gasoline fractions. The natural zeolite was first activated and then was loaded simultaneously with a fixed Ni-metal of 4 wt.% and Cr-metal of varied concentrations of 4 wt.% (namely catalyst A), 6 wt.% (namely catalyst B), and 8 wt.% (namely catalyst C). The catalysts were characterized by XRD, AAS, BET, and ammonia adsorption method. The catalysts difractograms showed peaks of NiO species (2 = 44 °) and Cr2O3 species (2 = 33 ° and 54 °) which showed an increase intensities with the increased Cr-loading. BET surface area measurement showed a decreased surface area and total pore volume with the increased metals loading, meanwhile the pore diameters were increased. Analysis by AAS method showed the total metals content in catalyst A were 1,81% Ni - 1,32% Cr, in catalyst B were 1,80% Ni - 1,91% Cr, and in catalyst C were 2,37% Ni - 2,38% Cr whereas the catalysts acidity were increased with the total metals loading. The studies on catalysts activities were conducted at 400 °C and 450 °C, which showed the conversion results on gasoline fraction C3-C14 around 10-23 % more than thermal cracking (48,51 %). The highest results of conversion was obtained using catalyst B which was 86.91% at 450 ° C. |
