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Exploration of Novel Lipase from Plant Seeds and Plant Latexes Istyami, Astri Nur; Sari, Myra Wardati; Gultom, Cristy Hagi; Prakoso, Tirto; Soerawidjaja, Tatang Hernas
Indonesian Journal of Chemical Research Vol 12 No 1 (2024): Edition for May 2024
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2024.12-ist

Abstract

As the demand for fatty acids increases, the enzymatic process of triglyceride hydrolysis emerges as a promising technology. Compared to microbial lipase, utilization of plant lipase is more practical due to its ease of preparation and cost-efficiency. This work aimed to verify the degree of lipolysis of several novel lipase sources from plants. Novel lipase sources investigated were seeds of kapok (Ceiba pentandra), java almond (Sterculia foetida), pongam (Milletia pinnata), sea mango (Cerbera manghas), tamanu (Calophyllum inophyllum), latex of sea mango, aveloz (Euphorbia tirucalli), and jackfruit (Artocarpus heterophyllus). Several acknowledged plant lipase sources were also compared, i.e. seeds of castor bean (Ricinus communis), physic nut (Jatropha curcas), rice bran (Oryza sativa), latex of frangipani (Plumeria rubra) and papaya (Carica papaya). Plant lipase was utilized in the hydrolysis of olive oil at room temperature. Results for seed and latex lipase were compared and technical issues were reported. Several plant lipases are remarkably active and potential to compete with microorganism lipases in industrial applications.
The Study of Hydrothermal Carbonization and Activation Factors' Effect on Mesoporous Activated Carbon Production From Sargassum sp. Using a Multilevel Factorial Design Prakoso, Tirto; Rustamaji, Heri; Yonathan, Daniel; Devianto, Hary; Widiatmoko, Pramujo; Rizkiana, Jenny; Guan, Guoqing
Reaktor Volume 22 No.2 August 2022
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.22.2.59-69

Abstract

Seaweeds are large-scale multicellular marine algae categorized based on color as Chlorophyceae, Rhodophyceae, and Phaeophyceae. No information has been provided on the conditions affecting the production of mesoporous activated carbon from one member of the described aquatic plants, namely Sargassum sp. Therefore, this study aimed to determine the impact of the main factors and their interactions on Sargassum sp.-derived activated carbon manufactured (SAC) by hydrothermal carbonization and CO2 activation methods. A mathematical approach was employed using a multilevel factorial design with the main factors being the activator type (ZnCl2, CaCl2, & KOH), hydrothermal temperature (200, 225, & 250oC), and activator ratios (2 & 4). Meanwhile, the response variables were yield and BET surface area (SBET) of SAC. Morphological, functional, crystallographic, and porosity characterization was carried out on the samples. The SAC-Ca-200-2 sample had the highest yield, with the value being 26.5 percent of weight. The activators having the highest specific surface area (SBET) were SAC-Zn-250-4, SAC-Ca-225-2, and SAC-K-250-2, with 1552, 1368, and 1799 m2/g, respectively. The pore size distribution in SAC products ranged from 2.16 to 10 nm in diameter. The analysis conducted indicated the activator type and interaction with its ratio substantially impacted the SAC yield value; besides, only the activator type affects the formation of high surface area pores.
Synthesis of rubber seed shell-derived porous activated carbons for promising supercapacitor application Rustamaji, Heri; Prakoso, Tirto; Devianto, Hary; Widiatmoko, Pramujo; Febriyanto, Pramahadi; Ginting, Simparmin br; Darmansyah, Darmansyah
International Journal of Renewable Energy Development Vol 14, No 2 (2025): March 2025
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2025.60869

Abstract

This work investigates synthesizing activated carbon obtained from rubber seed shells utilizing several activating agents (KOH, CaCl2, and ZnCl2) for supercapacitor applications. Activated carbon was produced from a rubber seed shell using hydrothermal carbonization at 275 °C for 60 minutes and a 120-minute activation treatment at 800 °C. Various activating agents pronounced impacted the pore architecture, surface area, crystallinity, and level of graphitization, which collectively determined the electrochemical characteristics of the resulting materials. Incorporating activation agents enhances the specific surface area and influences the extent of graphitization of activated carbon. The specific surface area of activated carbon products ranges from 367 to 735.2 m² g⁻¹. Further investigation through electrochemical analysis, conducted with a carefully engineered two-electrode system, demonstrated a peak electrode capacitance value of 246 F g-1 at 50 mA g-1 for an ACZn-based supercapacitor. Supercapacitor cells’ energy and power densities reached significant levels, measuring 5.47 Wh kg-1 and 246 W kg-1, respectively. The RSS-derived activated carbon-based supercapacitor exhibited remarkable longevity in a 5000-cycle test, with consistent capacitance retention and coulombic efficiency of 100.11% and 100%, respectively. This work presents a sustainable pathway for producing activated carbon electrodes, contributing to the global circular economy and demonstrating considerable industrial potential.
Morphological and thermal stability analysis of Sn/C electrodes synthesized through impregnation and precipitation methods for CO2 electroreduction Eviani, Mitra; Prakoso, Tirto; Kusdiana, Dadan; Widiatmoko, Pramujo; Devianto, Hary
International Journal of Renewable Energy Development Vol 14, No 5 (2025): September 2025
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2025.61280

Abstract

This study investigates tin (Sn) based electrodes supported by graphite for the electrochemical reduction of carbon dioxide (ECO2R) to formic acid, comparing precipitation and impregnation synthesis methods. Electrodes were characterized using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Thermogravimetric Analysis (TGA), Cyclic Voltammetry (CV), Chronoamperometry, and Electrochemical Impedance Spectroscopy (EIS). The precipitation method yielded higher Sn content (91.22%) and superior thermal stability (3% mass loss at 1000°C vs. 45% for impregnation). Morphological analysis through SEM revealed precipitation-synthesized electrodes exhibited more uniform Sn particle distribution across the graphite surface, while impregnation resulted in larger Sn agglomerates with less homogeneous coverage, significantly influencing electroactive surface area and catalytic performance. The electrochemical performance of electrodes was tested using H-cell. CV showed decreased cathodic current for Sn/C electrodes compared to pure graphite in CO2-saturated electrolyte, while chronoamperometry indicated slightly better sustained performance for precipitation-synthesized electrodes with stabilized current densities after 3 hours of operation. EIS analysis suggested the precipitation method yields a marginally lower ohmic resistance (28.8 Ω vs. 29.8 Ω), resulting in a more favorable electrode structure for overall catalytic activity. Both methods showed lower ohmic resistance than that of pure graphite (38.1 Ω), the precipitation-synthesized Sn/C electrode emerged as the preferred selection for ECO2R to formic acid, balancing high Sn content, thermal stability, superior durability, and better Faradaic efficiency. The observed performance differences were attributed to distinct metal-support interactions formed during synthesis, with precipitation creating stronger metal-carbon bonds that enhance stability but potentially limit certain active sites necessary for optimal CO2 reduction kinetics. This comprehensive characterization revealed that the precipitation-synthesized electrode offers the most promising foundation for further development, potentially through process optimization, hybrid synthesis approaches, or targeted doping strategies to enhance catalytic activity while maintaining the advantageous stability characteristics.
Hematite-Gamma Alumina-based Solid Catalyst Development for Biodiesel Production from Palm Oil Rizkiana, Jenny; Bryan, Bryan; Gozali, Edbert; Bustomi, Agus Tendi Ahmad; Prakoso, Tirto
Journal of Engineering and Technological Sciences Vol. 56 No. 1 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.1.4

Abstract

This research investigated the performance of hematite-gamma alumina (Fe2O3/γ-Al2O3) catalyst in biodiesel production from palm oil. A full factorial experimental design was utilized to analyze the effect of hematite content, catalyst loading, and methanol-to-oil ratio on catalyst performance. From the experiment, biodiesel in the range of 73.6 to 87.6% FAME content was obtained. It was concluded that the catalyst composition, the methanol-to-oil ratio, and the catalyst loading have a significant effect on the FAME content of the biodiesel. Hematite has strong affinity for fatty acids, so a larger hematite surface area will result in a higher fatty acid absorption capacity. The addition of excess methanol can reduce the contact inhibition between the reactants and the active site of the catalyst, thereby increasing the conversion rate of the reaction. Moreover, a higher amount of catalyst loading can result in an increase in the FAME content when accompanied by an increase in the hematite content of the catalyst.