ASEAN Journal of Chemical Engineering

Effects of Tricalcium Phosphate Addition as A Filler on The Properties of Chitosan Based Adhesive

David Bennet Imanuel — 2025-04-29

Interest in medical bioadhesives, such as wound closing and tissue repair, has increased in recent decades because of its advantages. Chitosan has been investigated in several studies and can become a bioadhesive. In this study, fillers and photoinitiators were added to the chitosan based bioadhesive, and the mechanical properties of the bioadhesive were analyzed. The fillers were added into bioadhesive at concentrations of 0.25, 0.5, and 1 %w/v. The photoinitiator was added into bioadhesive at 0, 0.05, 0.1, and 0.2%w/v concentrations. The results of SEM, FTIR, and DSC were analyzed. The analysis results show that the filler concentration of 1% w/v has mechanical properties near optimal, where the viscosity is 62.54 cP, solid content 12.1%, and tensile strength is 34 kPa. The SEM results show that adding filler will increase the homogeneity and quality of the bioadhesive. The FTIR results show that the bioadhesive has amine and alcohol groups with and without filler in the adhesive. Adding a photoinitiator to the bioadhesive, which was analyzed using DSC, showed that it would slightly speed up the adhesive reaction time and increase the material’s melting point. The increase in filler concentration will also increase the viscosity and solids content of the bioadhesive. The best adhesive combination is the TCP filler concentration 1%w/v and photoinitiator BPO 0.05%w/v. In the future, bioadhesives in medical treatment can be a potential. This research will be a benchmark for applying bioadhesives in medical treatment.

A One-Pot Method for The Synthesis of Nanocellulose from Palm Oil Empty Bunches Using Fe-Cr Combination Catalyst

Irwan Hidayatulloh — 2025-04-29

Oil Palm Empty Fruit Bunches (OPEFB) are one of the byproducts of Crude Palm Oil (CPO) production. Due to its high cellulose content, OPEFB can be processed into nanocellulose, one of its applications. The objective of this study was to determine the procedure for synthesizing nanocellulose from OPEFB using the one-pot method with a combination of Fe and Cr catalysts, as well as the properties and effect of the catalyst composition on the nanocellulose synthesized from OPEFB. In this investigation, OPEFB was processed into nanocellulose in a single vessel. The delignification step was conducted at 90^oC for 5 hours with 30%-w/v H₂O₂, and the acid hydrolysis phase was conducted at 75^oC for 1 hour with an 8%-w H₂SO₄ solution and Fe(NO₃)₃.9H₂O and Cr(NO₃)₃.9H₂O catalysts. The independent variables were the catalyst composition (3-7%-w/w) and Fe/Cr catalyst weight ratio (0-1). Based on the results, the highest nanocellulose yield was 37%-w, obtained with a catalyst concentration of 5%-w/w with a 0:1 Fe-Cr catalyst ratio. At the same time, the smallest lignin content was 1.711%-wt. which was obtained with a catalyst concentration of 3%-w/w with a Fe-Cr catalyst ratio of 0.5:0.5. Statistical analysis obtained an optimum variable of one-pot method at a catalyst concentration of 3%-w/w with a Fe-Cr catalyst ratio of 0:1. Nanocellulose yield obtained of 30.146%-w and lignin content of 1.610%-w. Meanwhile, from the experimental results at a catalyst concentration of 3%-w/w and a catalyst ratio of Fe-Cr 0:1, a nanocellulose yield of 29.616%-w and a lignin content of 1.799%-w was obtained. Nanocellulose was characterized by PSA, FTIR, TEM, and XRD analyses.

Investigation of Drying Behavior of Glutinous Rice (Oryza Sativa Var. Glutinosa) in a Fixed-Bed Dryer

Sangitha Bathumaly — 2025-04-29

Small-scale glutinous rice processing facilities often rely on manual drying methods, with drying conditions typically determined by experience. Establishing an accurate drying profile of glutinous rice allows for optimal selection of drying conditions. This contribution investigated glutinous rice drying behaviors in fixed bed dryers at temperatures 40°C, 50°C, and 60°C. The Page model was determined to be the best-fit thin layer model for describing glutinous rice drying with R² of 0.953 (50°C). Experimentally determined drying information was fed into the Aspen Plus V14 simulator to produce a digital version of glutinous rice drying process. A combined constant and falling rate mass transfer coefficient specified in the process simulator produced a simulation output close to that of the Page model with an R² of 0.9843. Modeling and digitalization of glutinous rice drying in this work are instrumental to accurately predict the drying performance of glutinous rice or other food grains.

Modelling and Simulation of Benzene Production from Biogas using Zeolite Catalyst

Samuel Pangeran Aletheia — 2025-04-29

Biogas has emerged as a promising sustainable resource due to its abundant methane content, which can be converted into valuable chemicals. This study investigates benzene production from biogas using a Mo/HZSM-5 catalyst in a packed bed reactor, aiming to provide an alternative feedstock for the petrochemical industry. A process model was developed using DWSim software to simulate and optimize the benzene production process. The simulation demonstrated that with a biogas feed of 7.5 kiloton/year, benzene production reached 1.2 kiloton/year, yielding 0.16% with a reactor conversion efficiency of 43.89%. Key process parameters were analyzed to ensure feasibility and sustainability, including energy consumption (0.6 MW heating, 0.8 MW cooling, and 0.2 MW electricity). The separation of CO₂ and light gases was achieved using a mixed-matrix membrane, followed by benzene purification through absorption and distillation, achieving a final purity of over 98%-mol. Compared to conventional benzene production methods from shale gas or LPG, this process offers lower energy requirements and improved yield, making it a viable approach for industrial implementation. This study not only presents a detailed simulation but also highlights the potential of biogas as a renewable feedstock for benzene synthesis, contributing to sustainable chemical production. Further techno-economic analysis and experimental validation are recommended to assess scalability and commercial feasibility.

Efficacy of Chitosan Derived from Tahong (Perna viridis) Shells in Treating Swine Biogas Digester Effluent

Engr. Rejie C. Magnaye — 2025-04-29

Chitosan, a natural linear biopolyaminosaccharide, is a non-toxic and environmentally friendly coagulant derived through the deacetylation of chitin, a major component of Tahong (Perna viridis) shells. This study evaluates the efficacy of chitosan in modifying the physicochemical properties of treated swine biogas digester effluent under varying chitosan dosages (8 g/L and 10 g/L) and agitation speeds (30 rpm and 50 rpm). The extracted chitosan powder exhibited high deacetylation, quantified at 74.65%. The untreated swine biogas digester effluent displayed the following properties: pH 7.34, COD 704 mg/L, BOD 338 mg/L, phosphate 81.54 mg/L, nitrate 138.75 mg/L, TDS 2027 mg/L, and TSS 2355 mg/L. Optimal treatment conditions were observed at a dosage of 8 g/L and an agitation speed of 30 rpm, yielding effluent properties of pH 8.30, COD 1499.00 mg/L, BOD 348.33 mg/L, phosphate 2.28 mg/L, nitrate 64.93 mg/L, TDS 2950.67 mg/L, and TSS 25.33 mg/L. Comparative analysis against the Department of Environment and Natural Resources (DENR) Class C water standards revealed significant improvements in BOD, phosphate, and nitrate levels, with p-values of 0.000. Conversely, the differences in pH and TSS were not statistically significant, with p-values of 0.141 and 0.199, respectively.

Recovery of glucose and acetic acid from Piper betle Linn leaves by subcritical water hydrolysis

Nur Lailatul Rahmah — 2025-04-29

Piper betle Linn (PBL) leaves contain high carbohydrate, which can be hydrolysed into glucose and acetic acid by hydrolysis method. Subcritical water hydrolysis (SWH) is an environmentally friendly method that uses water as a solvent and is suitable for the hydrolysis process. Thus, the aim of this study is to evaluate the glucose and acetic acid recovered from PBLleaves using SWH. SWH was performed under different process conditions (temperature range from 100 to 275°C and time range from 5 to 30 min) using a factorial design. Glucose and acetic acid were determined using high performance liquid chromatography (HPLC) with a refractive index (RI) detector. The ANOVA results show that temperature, time, and the interaction of temperature and time have a significant impact on the yield of glucose and the acetic acid concentration. The yield of glucose and acetic acid show opposite trend, with glucose degrading to acetic acid. The highest glucose concentration was obtained at two different conditions of SWH at 175°C for 30 min (6.237 mg/g extract) and 200°C for 5 min (6.143 mg/g extract), while the highest acetic acid concentration was obtained at 275°C for 15 min (2.536 mg/g extract).

Synthesis of Polylactic Acid from Apple, Pineapple, and Potato Residues

Nur Muhammad Firdaus Bin Ahmad Tagudin — 2025-04-29

Polylactic acid (PLA), a recyclable and biodegradable polymer, is essential for bioplastic production. Driven by the growing need for sustainable alternatives to petroleum-based plastics and the pressing issue of global food waste, PLA emerges as a promising biodegradable polymer derived from renewable resources such as sugarcane, corn, and biomass. Food waste presents a significant opportunity to produce PLA. While the conversion of food waste into lactic acid (LA), the PLA precursor, has been extensively studied, the subsequent transformation into PLA remains relatively unexplored. This research gap underscores the need for comprehensive investigations to understand the properties, production efficiency, and overall feasibility of producing PLA from food waste. This study aimed to produce PLA from food waste-derived LA. Apple, pineapple, and potato residues, rich in carbohydrates, served as substrates for LA fermentation using Lactobacillus Casei. The resulting LA was polymerized into PLA via ring-opening polymerization (ROP) using zinc oxide and tin (II) 2-ethylhexanoate as catalysts. Fourier Transform Infrared Chromatography (FTIR) confirmed the presence of LA in the fermentation broth, with the carbonyl and hydroxyl groups detected and LA appearing at peak 2.45 minutes in High-Performance Liquid Chromatography (HPLC). Apple residue yielded the highest LA percentage (31.36%), followed by pineapple (23.41%) and potato (20.81%). FTIR also indicated PLA formation due to the carbonyl group being slightly higher and the hydroxyl group being slightly lower than LA. Gel Permeation Chromatography (GPC) results showed potato residue produced PLA with a significantly higher molecular weight (12,662) compared to apple (543). Notably, apple residue PLA exhibited desirable monodisperse properties, which are advantageous for food packaging applications. This study demonstrates the potential of transforming food waste into valuable bioplastics, contributing to waste reduction and environmental sustainability.

Techno-economic Analysis of Biomass Co-firing Application on Indonesia 660 MW Class Subcritical Coal-Fired Power Plant

Alfian Muhammad Reza — 2025-04-29

Following the publication of the Ministerial of Energy and Mineral Resources of Indonesia Decree number 14.K/TL.04/MEM.L/2023 regarding the greenhouse gas (GHG) emission cap for coal-fired power plant (CFPP), PLN, the electricity company owned by Indonesia, is attempting the GHG reduction of its CFPPs at certain levels through several decarbonization programs, with biomass co-firing on its existing CFPP as the first step. The CFPP that becomes the object of this study is 660 MW class subcritical, Suralaya units 5-7, with a net capacity of 643.09 MW per unit. The biomass used is sawdust that was taken from local suppliers. The existing power plant has a carbon emission intensity of 1.03 Ton/MWh, higher than that of the carbon cap (0.911 Ton/MWh). Therefore, it should pay a carbon tax at a certain value. The biomass co-firing implementation can reduce its intensity depending on the ratio. The biomass implementation would probably require an upgrade investment. The other cost-effect factors are fuel cost and carbon tax. The degradation of CFPP performance can impact on fuel costs. Then, the biomass co-firing implementation can reduce or even prevent a power plant from paying the carbon tax. The best option regarding the financial calculation result is a 5% ratio. It potentially reduces the levelized cost of electricity (LCOE) by 0.36 IDR/kWh. However, a higher biomass ratio will probably increase the power plant LCOE. Implementing a higher biomass co-firing ratio does not always result in better financial aspects. The decision to implement shall consider the valid regulation comprehensively.

Municipal Solid Waste Potential for Indonesian Electrical Energy Sharing: Process Simulation Study

Maulana Gilar Nugraha — 2025-04-29

Indonesia’s growing energy demand and increasing municipal solid waste (MSW), projected to reach 48.19 million tons by 2027, present significant challenges and opportunities for sustainable energy solutions. This study investigates the conversion of MSW to electricity using validated Aspen Plus® simulations calibrated against real-world operations with one MSW based power plant located in Indonesia. The study evaluated four technologies—air gasification, steam gasification, plasma gasification, and incineration—to assess their electricity generation potential and pollutant emissions. Gasification technologies outperformed incineration, generating 15–27 MW of electricity, with gas engines demonstrating superior efficiency compared to steam turbines due to fewer energy conversion stages. Air gasification increased electricity production with reduced air input but resulted in elevated pollutant emissions, including NH₃ (up to 8 ppm), H₂S (up to 210 ppm), and HCl (up to 1052 ppm). Steam gasification enhanced hydrogen production at optimal steam levels; however, excessive steam inputs reduced efficiency and increased pollutant concentrations, such as NH₃ (14 ppm), H₂S (369 ppm), and HCl (1846 ppm). Plasma gasification maintained stable CO₂ concentrations (~14% vol) but experienced diminishing electricity returns with higher heat inputs. This study also highlights the inefficiency of incineration technology since it produced lower NH₃ and H₂S emissions but notable levels of NOₓ, SOₓ, and HCl, emphasizing the importance of advanced emission control systems. This study provides valuable insights for optimizing waste-to-energy processes, supporting industrial adoption, and informing sustainable waste management strategies to enhance Indonesia’s energy security and environmental sustainability.

Investigating the Kinetics of Tannin Removal in Sorghum [Sorghum Bicolor (L.) Moench] Grains through a Soaking Process

Zuhriyan Ash Shiddieqy Bahlawan — 2025-04-29

Sorghum (Sorghum bicolor (L.) Moench) grains contain tannins that significantly affect their nutritional value and potential utilizations in food product development. This study aims to investigate the kinetics of tannin removal during the soaking process and to optimize the operating condition. To achieve the goals, sorghum grains were subjected to various soaking durations, temperatures, and soaking solution concentrations. The soaking process employed potassium hydroxide and calcium hydroxide solutions at concentrations ranging from 0.05% to 0.15%; soaking temperatures were varied at 30°C, 40°C, and 50°C. Soaking was performed for 8 hours, with samples withdrawn every hour. The dissolved tannin was analyzed for its concentration, and the data were fitted to first-order rate equation kinetic models to determine the rate constants associated with tannin reduction. This study provides valuable insights into the soaking kinetics of sorghum grains, highlighting the potential for improving sorghum-based products’ nutritional quality through optimized soaking treatments. From the investigation results, the type and concentration of the solvent, as well as the soaking temperature, affected the tannins removal rate from sorghum grains. The highest dissolution rate and constant (k) were obtained during soaking in 0.15% calcium hydroxide solution at 50°C, with values of 0.436 ppm. min⁻¹ and 0.00616 min⁻¹, respectively. The average percentage error of the first-order reaction kinetics model was below 0.2%, which suggested its high suitability for application in the soaking process of sorghum grains using an alkaline solvent. The findings can guide food processors in developing more efficient methods for tannin reduction, enhancing the utilization of sorghum as both a staple food and food ingredient.

Comparison of Furfural Production from Corn Waste and Empty Fruit Bunch (EFB): Effect of Time, Temperature, and Solvent

Muryanto — 2025-04-29

Furfural is a compound derived from xylose, a building block material. Sources of furfural can come from various corn industry wastes such as corn cobs and corn husks, and palm oil industry wastes like Empty Fruit Bunch (EFB). This study aims to compare the potential of furfural production from corn industry waste and palm oil industry waste. The research method involves the hydrolysis and dehydration of hemicellulose using two types of solvents, sulfuric acid (SA) and Deep Eutectic Solvents (DES), at varying temperatures (160 °C, 170 °C, and 180 °C) and reaction times (60, 120, and 180 minutes). The highest furfural yield from corn cobs, 7.69 g/L, was obtained using 1 M sulfuric acid solvent at 160 °C for 60 minutes. The optimal condition for producing a high concentration of furfural from corn cobs was achieved using DES at 170°C for 60 minutes, yielding approximately 13.18 g/L. In contrast, furfural production from EFB resulted in a concentration of 4.70 g/L.

Utilization of Epoxidized Palm Oil as A Plasticizer in Synthetic Leather

Andri Saputra — 2025-04-29

Substituting petroleum-based plasticizers in the synthetic leather industry with renewable resources, such as epoxidized palm oil (EPO), will mitigate environmental pollution. This study aims to produce synthetic leather using EPO and compare its characteristics to those of synthetic leather using commercial plasticizers. Raw materials were compounded, coated on embossed paper, covered with reinforcing fabric, and cured in an oven at 180 ^oC for 1 minute. Control leather (CoL) was produced using diisononyl phthalate (DINP) and epoxidized soybean oil (ESBO), A leather (AL) was produced using DINP and EPO, B leather (BL) was produced only using EPO, and C leather (CL) was produced using EPO and ESBO. Synthetic leather was characterized for mechanical properties (SNI 1294:2009), glossiness (gloss meter), surface morphology (digital microscope), thermal properties (DSC), and functional groups (FTIR). The synthetic leather characteristics show that the thickness of AL and CL was close to CoL. The longitudinal tensile strength of BL (186.52 N) was not significantly different from CoL (191.41 N) and AL (190.06 N), whereas its transversal tensile strength (44.13 N) was not significantly different from CL (42.37 N). Both the longitudinal and transversal tear strengths of BL were not significantly different from those of AL. Furthermore, the glossiness of BL (4.37 GU) was not significantly different from CoL (4.22 GU) and AL (4.32 GU). Unlike CoL, EPO produces a smooth surface morphology (in AL, BL, CL) and eliminates pinhole defects. CoL, AL, BL, and CL exhibit similar functional groups. DSC analysis shows that BL exhibits thermal stability identical to CoL, AL, and CL. Our findings indicate that EPO could be a promising plasticizer for producing synthetic leather.

Changes in Dissolved Organic Matter by Fluorescence Excitation-Emission Matrix Analysis during Palm Oil Mill Effluent Treatment Using Dielectric Barrier Discharge

Reni Desmiarti — 2025-04-29

This study explored the treatability of dissolved organic matter (DOM) in palm oil mill effluent (POME) by dielectric barrier discharge (DBD) treatment under aerated and non-aerated conditions at different electric voltages of 15, 20, and 25 kV. The DOM composition was monitored by fluorescence excitation-emission matrix (EEM) analysis, and tryptophan-like Peak 2 and humic-like Peak 5 were dominant in POME. Chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total solids (TS) were significantly removed by DBD treatment under aerated and non-aerated conditions by 93–98%, 96–98%, and 78–83%, respectively. The relative changes Peak 3/Peak 2 revealed the DOM treatability by DBD treatment, where more protein-like substances were reduced than humic-like substances, owing to the different composition interaction against the oxidation reaction performed by reactive species (O₃, •OH, H₂O₂) generated from the DBD reactor. In contrast, humic-like substances increased after DBD treatment under aerated and non-aerated conditions. Fluorescence indices demonstrated that DBD treatment caused significant changes in the fluorescence index (FI), while no significant changes were observed in the humification index (HIX) and biological index (BIX). This study provides useful information on the changes in DOM from POME after DBD treatment, evaluated by fluorescence EEM analysis.

Review and Improvement of Learning Outcomes of Undergraduate Chemical Engineering Program: Curriculum 2024 Case Study

Tjokorde Walmiki Samadhi — 2025-04-29

Institut Teknologi Bandung (ITB) has mandated several key changes in the general design framework of the Curriculum 2024. Several institution-wide mandatory courses centered around SDG & Industry 4.0 issues were implemented as a part of the 2025-2050 ITB Development Master Plan. This paper describes the review and improvement processes undertaken by the Chemical Engineering Undergraduate Program at ITB of its Program Educational Objectives (PEO) and its entire hierarchical learning outcomes. This review was undertaken in 2023-2024 both as a part of periodic outcomes assessment and evaluation (bottom-up approach), and to define the articulation of new mandatory courses and Program offering variations required by ITB (top-down approach). The current PEO resulted from the latest revision during the Curriculum 2019 development and were deemed to be still relevant for the next 5-10 years. Direct and indirect assessments of graduate learning outcomes (CPL) since 2019 indicated a satisfactory overall attainment by the graduates and their relevance to the needs of graduates’ employers. The Program-level outcomes were also deemed to be sufficiently flexible to accommodate ITB's current policies for the new curriculum. Minor revisions were undertaken on Graduate Sub-Learning Outcomes (Sub-CPL) to better align with modern computational skillset requirements of the industry.

Hydrothermal ZnO Photocatalysis for Efficient Removal of Tetracycline from Wastewater

Wan Nuraishah Wan Ishak — 2025-04-29

Tetracycline (TC), a widely used antibiotic, is increasingly detected in wastewater, posing a significant environmental and health risk. Zinc oxide nanoparticles are emerging as a promising photocatalyst for TC photodegradation due to their low cost and superior light absorption capabilities at room temperature compared to the widely used titanium dioxide (TiO₂). This study explores the efficacy of hydrothermally synthesized ZnO nanoparticles in degrading TC. The photocatalytic degradation efficiency of ZnO was examined under controlled batch conditions by varying parameters like ZnO dosage (0.5-2.5 g/L), TC concentration (5-25 ppm), and light source (solar, visible, and UV). The result showed that the highest TC removal efficiency (70.17%) was achieved under UV light with 1 g/L ZnO for a 5 ppm TC solution. The synthesized ZnO nanoparticles showed excellent reusability, highlighting their potential as a cost-effective and sustainable approach for TC degradation in wastewater treatment applications.