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This study aims to produce diisopropyl ether (DIPE) via isopropanol dehydration using cobalt-phosphate-supported natural zeolite catalysts. The catalytic activities of the zeolite/CoO and zeolite/Co(H2PO4)2 were compared. The as-prepared catalysts were assessed using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, and N2 adsorption-desorption. Surface acidity was determined using the gravimetric method with pyridine as the probe. The results of this study showed that natural zeolite was favorably impregnated by CoO and Co(H2PO4)2 species. The impregnation process affected the textural and acidic features of the catalysts. The zeolite/Co(H2PO4)2 catalyst with a loading of 8 mEq.g-1 exhibited the highest surface acidity of 1.827 mmol.g-1. This catalyst also promoted the highest catalytic activity towards isopropanol dehydration, with an isopropanol conversion of 66.19%, DIPE selectivity, and yield of 46.72% and 34.99%, respectively. The cobalt phosphate species promoted higher catalytic activity for isopropanol dehydration than the CoO species. This study demonstrated the potential of cobalt phosphate-supported natural zeolite catalysts for DIPE production with adequate performance. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

In this paper, the catalysts (Nano-HZSM-5 and Fe-La/nano HZSM-5) were prepared with incipient wetness impregnation and applied for hydrocracking of Sunan candlenut oil. The hydrocracking process was conducted in a batch reactor with a pressure of 20-30 bar H2 gas for 2 h under various temperatures. The results demonstrated that hydrocracking of Sunan candlenut oil using nano HZSM-5 and Fe-La/NHZ catalysts could be converted into aromatic hydrocarbons, and the reaction temperature affected hydrocarbon production. The aromatic compounds, such as propyl-benzene, 1-ethyl-3-methylbenzene, heptyl-benzene, 2-ethyl-naphthalene, etc., reached 35.51% over the Fe-La/NHZ_2 catalyst. In all cases, the zeolite-based catalysts are the most suitable to produce aromatic hydrocarbons. Metal impregnated (Fe and La) on nano HZSM-5 catalyst could improve the aromatics compounds due to increased metal and acid sites. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Esterification is the reaction of the formation of an ester compound by reacting an alcohol compound and carboxylic acid. In this study, the performance of zeolite-based catalysts has been studied for esterification reactions. Modification of zeolite pore size was done to be hierarchical zeolite, with the aim of increasing the catalytic properties of zeolite. The modification was carried out by desilication by sodium hydroxide treatment with a variation of 0.1; 0.3; 0.5 M. The resulting catalyst was then characterized using BET and XRD. Furthermore, the catalyst was tested for activity for esterification of fatty acids and glycerol and the product was analyzed using GC-MS. Zeolite modification with sodium hydroxide has been proven to improve catalyst performance, without changing their crystal structure. The best catalytic activity was obtained on the catalyst with sodium hydroxide treatment of 0.3 M, resulting glycerol conversion of 92% and selectivity to monoglycerides of 74%.

UTILIZATION OF PRETREATMENT WASTE DURING PRODUCTION OF BIOETHANOL FROM LIGNOCELLULOSIC MATERIALS FOR RECOVERY FINE CHEMICALS BY PYROLYSIS. In production of second generation bioethanol by utilizing lignocelluloses as raw material, black liquor was produced from its pretreatment process. As waste of pretreatment process, the black liquor was rich in lignin. Therefore, the black liquor has potential to be proceeded to produce fine chemicals. In this study, black liquor powder was pyrolyzed at 450-600°C for 15 minutes using a fixed bed type reactor. Pyrolysis process produced four types of products thal called as liquid tar, heavy tar, char and gas. Liquid tar was condensable volatile product in condenser and uncondensable ones was called gas. Heavy tar was heavier volatile product that stick to reactor wall on bed of feed and unable to enter a condenser. Whereas, char was deposited carbon left in the pyrolizer. The liquid tar consisted of several chemical compounds that classified into groups of chemicals based on similar functional groups. In a range of temperatures process, higher yield of liquid tar was produced after treated at 550°C compared to other conditions. The main chemical compounds in the liquid tar were phenol, alcohols and alkyl phenols that mainly predicted derived from decomposition of lignin and represented as the fine chemicals from black liquor powder. Keywords: bioethanol; black liquor powder; fine chemicals; lignocelluloses; pyrolysis Abstrak Dalam produksi bioetanol generasi kedua dengan memanfaatkan lignocellulosa sebagai bahan baku, akan menghasilkan black liquor pada saat proses pretreatment. Sebagai limbah proses pretreatment, black liquor ini kaya akan lignin. Oleh karena itu, black liquor berpotensi diolah untuk menghasilkan fine chemicals. Pada penelitian ini, bubuk black liquor diproses secara pirolisa pada suhu 450-600°C selama 15 menit menggunakan reaktor jenis fixed bed. Proses pirolisa menghasilkan produk yang dapat digolongkan menjadi empat jenis yaitu liquid tar, heavy tar, char dan gas. Liquid tar merupakan volatile product yang terkondensasi di kondensor dan yang tidak dapat terkondensasi disebut sebagai gas. Heavy tar adalah volatile product yang lebih berat dan terlebih dahulu menempel di dinding reaktor pirolisa di atas bed umpan dan tidak sampai masuk ke kondensor. Sementara char adalah deposit karbon yang tertinggal di dalam reaktor pirolisa. Liquid tar tersusun oleh berbagai macam senyawa kimia yang bisa dikelompokkan menjadi grup-grup berdasarkan kesamaan gugus fungsi. Dari rentang suhu proses tersebut, liquid tar paling banyak dihasilkan pada suhu 550°C. Liquid tar tersebut banyak mengandung fenol, alkohol dan alkil fenol yang diprediksi umumnya berasal dari dekomposisi lignin dan menjadi fine chemicals yang dapat di-recovery dari bubuk black liquor Kata kunci: bioetanol; bubuk black liquor; fine chemicals; lignoselulosa; pirolisa .