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Inhibition Effect of Ca2+ Ions on Sucrose Hydrolysis Using Invertase Hargono Hargono; Bakti Jos; Abdullah Abdullah; Teguh Riyanto
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 3 Year 2019 (December 2019)
Publisher : Department of Chemical Engineering - Diponegoro University

Fermentable sugar for bioethanol production can be produced from molasses due to its high sucrose content but Ca2+ ions found in the molasses may affect the hydrolysis. Therefore, this paper was focused to study the effect of Ca2+ ions as CaO on sucrose hydrolysis using invertase and to obtain the kinetic parameters. The kinetic parameters (KM and Vmax) were obtained using a Lineweaver-Burk plot. The value of KM and Vmax parameters were 36.181 g/L and 21.322 g/L.h, respectively. The Ca2+ ions act as competitive inhibitor in sucrose hydrolysis using invertase. Therefore, the inhibition mechanism was followed the competitive inhibition mechanism. The value of inhibition constant was 0.833 g/g. These parameters were obtained from the non-substrate inhibition process because this study used the low substrate concentrations which means the fermentable sugar production was low. Hence, there were still more challenges to studying the simultaneous effect of substrate and Ca2+ on sucrose hydrolysis to produce high fermentable sugar.

Effects of Ion Exchange Process on Catalyst Activity and Plasma-Assisted Reactor Toward Cracking of Palm Oil into Biofuels Istadi Istadi; Luqman Buchori; Didi Dwi Anggoro; Teguh Riyanto; Anindita Indriana; Chusnul Khotimah; Fachmy Adji Pangestu Setiawan
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 2 Year 2019 (August 2019)
Publisher : Department of Chemical Engineering - Diponegoro University

Biofuels can be produced through a conventional catalytic cracking system and/or a hybrid catalytic-plasma cracking system. This paper was focused on studying effect of Na+ ion exchange to HY-Zeolite catalyst on catalyst performance to convert palm oil into biofuels over a conventional continuous fixed bed catalytic cracking reactor and comparing the catalytic cracking performance when carried out in a continuous hybrid catalytic-plasma reactor. The catalysts were characterized by X-ray Diffraction (XRD) and Bruneuer-Emmet-Teller (BET) surface area methods. The biofuels product were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) to determine the hydrocarbons composition of biofuels product. From the results, ion exchange process of Na+ into HY-Zeolite catalyst decreases the catalyst activity due to decreasing the number of active sites caused by blocking of Na+ ion. The selectivity to gasoline ranges achieved 34.25% with 99.11% total conversion when using HY catalyst over conventional continuous fixed bed reactor system. Unfortunately, the selectivity to gasoline ranges decreased to 13.96% and the total conversion decrease slightly to 98.06% when using NaY-Zeolite catalyst. As comparison when the cracking reaction was carried out in a hybrid catalytic-plasma reactor using a spent residual catalytic cracking (RCC) catalyst, the high energetics electron from plasma can improve the reactor performance, where the conversion and yield were increased and the selectivity to lower ranges of hydrocarbons was increased. However, the last results were potential to be intensively studied with respect to relation between reactor temperature and plasma-assisted catalytic reactor parameters. Copyright © 2019 BCREC Group. All rights reserved

Sequential Microwave-Ultrasound Assisted Extraction of Flavonoid from Moringa oleifera: Product Characteristic, Antioxidant and Antibacterial Activity Aji Prasetyaningrum; Bakti Jos; Ratnawati Ratnawati; Nur Rokhati; Teguh Riyanto; Gian Restu Prinanda
Indonesian Journal of Chemistry Vol 22, No 2 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.65252

Moringa oleifera leaves contain secondary metabolites in flavonoid compounds known to prevent several diseases. Therefore, appropriate extraction methods are required to produce extracts with a high yield of flavonoids from Moringa. In this study, the extraction from Moringa leaves was carried out using the sequential microwave/ultrasound-assisted extraction (MUAE) method compared with sequential ultrasound/microwave (UMAE), microwave (MAE), ultrasound (UAE), and maceration (ME). The effects of the time, temperature, and percentage of ethanol were studied on total flavonoid content using AlCl3 colorimetric assay. The extracts were analyzed by Scanning Electron Microscopy (SEM), Fourier Transforms Infrared Spectrophotometry (FTIR), and High-Performance Liquid Chromatography (HPLC). The antioxidant and antibacterial activities were tested using DPPH-scavenging and disc diffusion methods. The results of SEM surface analysis on various extraction methods show differences on each surface. The FTIR spectrum showed the presence of flavonoid O–H at 3200 cm–1, C=O at 1621 cm–1, and C–O at 1019 cm–1. In the results of HPLC, MUAE extracts 16.70 mg/ 100 g flavonoid quercetin at the retention time of 4.5 min, with the highest total flavonoids (2.89 mg QE/g), the highest antioxidant activity (IC50 72.31 µg/mL), and highest antibacterial activity (S. aureus 7 mm, E. coli 2 mm).

Bifunctional CaCO3/HY Catalyst in the Simultaneous Cracking-Deoxygenation of Palm Oil to Diesel-Range Hydrocarbons Rosyad Adrian Febriansyar; Teguh Riyanto; I. Istadi; Didi D. Anggoro; Bunjerd Jongsomjit
Indonesian Journal of Science and Technology Vol 8, No 2 (2023): (ONLINE FIRST) IJOST: September 2023
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v8i2.55494

Palm oil is a promising raw material for biofuel production using the simultaneous catalytic mechanism of the bifunctional cracking-deoxygenation reactions. Through the cracking-deoxygenation process, the chains of palmitic acid and oleic acid in the palm oil were converted to diesel-range hydrocarbons. The combination effects of CaCO3 and HY zeolite enhanced the bifunctional catalytic cracking-deoxygenation of palm oil into biofuel, because of the increasing acid and basic sites in the catalysts due to the synergistic roles of CaCO3 and HY. The introduction of CaCO3 on HY zeolite generated both a strong acid and strong basic sites simultaneously on the designed catalyst, which supports the bifunctional mechanisms of hybrid cracking-deoxygenation, respectively. The CaCO3 impregnated on the HY catalyst has a synergistic and bifunctional effect on the catalyst supporting cracking-deoxygenation reaction mechanisms as mentioned previously. The deoxygenation reaction required the bifunctional strong acid and strong basic sites on the CaCO3/HY catalyst through decarboxylation, decarbonylation, and hydrodeoxygenation reaction mechanisms. Meanwhile, the cracking reaction pathway was supported by the strong acid sites generated on the CaCO3/HY catalyst. In other words, the high acidity strength promotes diesel selectivity, whereas the high strength of basicity leads to the deoxygenation reaction.

High Acidity and Low Carbon-Coke Formation Affinity of Co-Ni/ZSM-5 Catalyst for Renewable Liquid Fuels Production through Simultaneous Cracking-Deoxygenation of Palm Oil Istadi Istadi; Teguh Riyanto; Didi Dwi Anggoro; Cokorda Satrya Pramana; Amalia Rizqi Ramadhani
Bulletin of Chemical Reaction Engineering & Catalysis 2023: BCREC Volume 18 Issue 2 Year 2023 (July 2023, Issue in Progress)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.17974

This study investigates the effect of chemically doped Co and Ni metals on ZSM-5 catalyst with respect to the catalysts’ characteristics and performance for palm oil cracking. Some characterization methods have been conducted to identify the physicochemical properties of the synthesized catalysts, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), N2-physisorption, NH3- and CO2-probed Temperature Programmed Desorption (NH3-TPD and CO2-TPD) methods. The deposited carbon-coke on the spent catalysts is analysed using simultaneous thermal gravimetric – differential scanning calorimetry (TG-DTG-DSC) analysis. The performance of catalysts was evaluated on palm oil cracking process in a continuous fixed-bed catalytic reactor at 450 °C. To determine the liquid product composition functional group and components, we used Attenuated Total Reflectance Fourier-transform Infrared Spectroscopy (ATR-FTIR) and batch distillation methods, respectively. We found that the Co metal chemically-doped on Ni/SM-5 catalyst, resulting the increase in the catalysts acidity and the decrease in catalysts basicity. The conversion of palm oil increases as the increase of the ratio of catalysts’ acidity to basicity. The highest triglyceride conversion (76.5%) was obtained on the 3Co-Ni/ZSM-5 with the yield of gasoline, kerosene, and diesel of 2.61%, 4.38%, and 61.75%, respectively. It was also found that the chemically doping Co metal on Ni/ZSM-5 catalyst decreased carbon-coke formation due to the low catalysts’ basicity. Overall, it is proven that the combination of Co and Ni, which chemically doped, on ZSM-5 catalyst has a good activity in palm oil conversion with low carbon-coke formation affinity and high acidity of catalyst.

Biofuels Production from Catalytic Cracking of Palm Oil Using Modified HY Zeolite Catalysts over A Continuous Fixed Bed Catalytic Reactor I. Istadi; Teguh Riyanto; Luqman Buchori; Didi D. Anggoro; Andre W. S. Pakpahan; Agnes J. Pakpahan
International Journal of Renewable Energy Development Vol 10, No 1 (2021): February 2021
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2021.33281

The increase in energy demand led to the challenging of alternative fuel development. Biofuels from palm oil through catalytic cracking appear as a promising alternative fuel. In this study, biofuel was produced from palm oil through catalytic cracking using the modified HY zeolite catalysts. The Ni and Co metals were impregnated on the HY catalyst through the wet-impregnation method. The catalysts were characterized using X-ray fluorescence, X-ray diffraction, Brunauer–Emmett–Teller (BET), Pyridine-probed Fourier-transform infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM) methods. The biofuels product obtained was analyzed using a gas chromatography-mass spectrometry (GC-MS) method to determine its composition. The metal impregnation on the HY catalyst could modify the acid site composition (Lewis and Brønsted acid sites), which had significant roles in the palm oil cracking to biofuels. Ni impregnation on HY zeolite led to the high cracking activity, while the Co impregnation led to the high deoxygenation activity. Interestingly, the co-impregnation of Ni and Co on HY catalyst could increase the catalyst activity in cracking and deoxygenation reactions. The yield of biofuels could be increased from 37.32% to 40.00% by using the modified HY catalyst. Furthermore, the selectivity of gasoline could be achieved up to 11.79%. The Ni and Co metals impregnation on HY zeolite has a promising result on both the cracking and deoxygenation process of palm oil to biofuels due to the role of each metal. This finding is valuable for further catalyst development, especially on bifunctional catalyst development for palm oil conversion to biofuels.

High Acidity and Low Carbon-Coke Formation Affinity of Co-Ni/ZSM-5 Catalyst for Renewable Liquid Fuels Production through Simultaneous Cracking-Deoxygenation of Palm Oil Istadi Istadi; Teguh Riyanto; Didi Dwi Anggoro; Cokorda Satrya Pramana; Amalia Rizqi Ramadhani
Bulletin of Chemical Reaction Engineering & Catalysis 2023: BCREC Volume 18 Issue 2 Year 2023 (August 2023)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.17974

This study investigates the effect of chemically doped Co and Ni metals on ZSM-5 catalyst with respect to the catalysts’ characteristics and performance for palm oil cracking. Some characterization methods have been conducted to identify the physicochemical properties of the synthesized catalysts, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), N2-physisorption, NH3- and CO2-probed Temperature Programmed Desorption (NH3-TPD and CO2-TPD) methods. The deposited carbon-coke on the spent catalysts is analysed using simultaneous thermal gravimetric – differential scanning calorimetry (TG-DTG-DSC) analysis. The performance of catalysts was evaluated on palm oil cracking process in a continuous fixed-bed catalytic reactor at 450 °C. To determine the liquid product composition functional group and components, we used Attenuated Total Reflectance Fourier-transform Infrared Spectroscopy (ATR-FTIR) and batch distillation methods, respectively. We found that the Co metal chemically-doped on Ni/SM-5 catalyst, resulting the increase in the catalysts acidity and the decrease in catalysts basicity. The conversion of palm oil increases as the increase of the ratio of catalysts’ acidity to basicity. The highest triglyceride conversion (76.5%) was obtained on the 3Co-Ni/ZSM-5 with the yield of gasoline, kerosene, and diesel of 2.61%, 4.38%, and 61.75%, respectively. It was also found that the chemically doping Co metal on Ni/ZSM-5 catalyst decreased carbon-coke formation due to the low catalysts’ basicity. Overall, it is proven that the combination of Co and Ni, which chemically doped, on ZSM-5 catalyst has a good activity in palm oil conversion with low carbon-coke formation affinity and high acidity of catalyst.

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