Research in Chemical Engineering

Physical Properties of Biofoam from Cassava Starch: An Environmentally Friendly Alternative to Conventional Styrofoam

Zulaikha Al-Qordhiyah — 2026-04-14

A study has been conducted on the manufacture of biofoam from cassava starch extract with the addition of peanut shell powder. There were 3 samples made in this study by heating using an oven (120°C, 140°C, 160°C) with the addition of magnesium stearate and ZnO. The quality characteristics of the synthesized biofoam were tested through water absorption tests, water content tests, leakage tests and biodegradable tests. The results of the water absorption test analysis obtained the percentage of each sample of 17.409%, 12.081%, and 4.049%. From these results, the temperature of 160°C which meets the SNI standard is 11.8682%. In the water content test, the percentage of each sample was 30.290%, 15.884%, and 9.615%. From these results, it has met the SNI standard of 26.12% except at a temperature of 120°C. In the leakage test, the results were obtained in the form of leaking samples on days 1, 2, and 4. In the biodegradable test, the percentage of each sample decomposed was 96%, 97%, and 100%, in the seventh week. Based on the biodegradable test, all samples can decompose well in a relatively fast time span and meet SNI, which is 100% for 60 days.

Particle Micronization of Medicinal Plants Extract using Electrospraying

Nadya Rizkita — 2026-04-14

Phytochemical compounds are non-nutritive plant bioactive components
that contribute to disease prevention through their antioxidant and antiinflammatory
activities. In this study, particles of polyvinylpyrrolidone (PVP),
chitosan, and starch-containing phytochemical compounds from medicinal
plant extracts were prepared through an electrospray process. This method
is used to increase the bioavailability of phytochemical compounds as well
as to facilitate the storage process and durability. The effect of process
parameters in this study was investigated, the type of polymers (medicinal
plant extract/PVP, chitosan, and starch) and the electric voltage used.
Particle characterization and phytochemical properties were evaluated using
FTIR, total phenolic content (TPC), total flavonoid content (TFC), and
antioxidant activity analyses. The results showed that PVP exhibited the best
performance in binding phytochemical compounds from medicinal plants.
This was exemplified by the O. aristatus/PVP at an applied voltage of 16 kV,
which resulted in the highest total phenolic and flavonoid contents of 0.5816
mg GAE/g sample and 0.7638 mg CE/g sample, respectively. Antioxidant
activity, evaluated using antioxidant efficiency (AE), also showed the highest
value for the O. aristatus/PVP at 18 kV, reaching 0.8511 min⁻¹. FTIR analysis
indicated that PVP was able to physically interact with phytochemical
compounds, as evidenced by the overlap between the polymer and extract
spectra. In contrast, chitosan and starch exhibited relatively weaker
interactions, leading to more limited encapsulation capability and
consequently lower retention of phytochemical compounds within the
particles.

Application of Sol-Gel Synthesized Cu-TiO₂/ZnO Photocatalyst for Textile Dye Wastewater Treatment

David Kevin — 2026-04-14

The textile dyeing industry is the second largest water polluter in the world, with the industry generating 20% of the world's total wastewater effluent. Methylene blue is one of the most commonly used textile dyes, causing degradation of aquatic ecosystem quality. A new method that can help in the treatment process of liquid waste that has a relatively low cost, one of which is a photocatalyst using material and using the sol gel method. This photocatalyst was tested by characterization using SEM, UV-Vis DRS, and UV-Vis Spectrometer. The results of SEM characteristics show that the particles are spherical with varying particle sizes. The UV-Vis DRS results show that the Eg values obtained are 3.186 eV for TiO₂/ZnO, 2.296 eV for Cu(5%)-TiO₂/ZnO, and 2.162 eV for Cu(8%)-TiO₂/ZnO. The concentration of methylene blue affects the effectiveness of degradation with the highest degradation at 5 ppm of 77.51%, at 10 ppm of 67.02% and 15 ppm of 54.30%. In conclusion, the sol-gel synthesized Cu-TiO₂/ZnO photocatalyst demonstrates promising effectiveness for textile dye wastewater treatment, with optimized Cu doping significantly enhancing visible-light absorption and degradation efficiency of methylene blue.

Simulation of Performance of Heater Treater Using MATLAB

Erwan Adi Saputro — 2026-04-14

This study presents a comprehensive performance evaluation of Heater Treater operating at oil and gas Field, The unit’s performance was assessed through analytical modeling and MATLAB simulation using field operating data to determine three key parameters: effective length, retention time, and heat duty. The analysis employed established correlations for gravitational settling, residence time, and thermal requirements to compare actual operating conditions with design specifications. The results show that the unit currently operates beyond its design capacity at a throughput of 5600 bbl/day, leading to excessive heat duty (3.9 MMBtu/h > 2.2 MMBtu/h design), insufficient retention time (~20 min), and inadequate effective length for complete oil–water separation. Optimal performance was achieved only within the flowrate range of 1100–2900 bbl/day, where all parameters remain within safe and efficient limits. The findings indicate that reactivating the preheater and maintaining the optimal operating window would significantly improve dehydration efficiency, reduce thermal load, and extend equipment life.

Project-Based Learning Approach for Teaching Life Cycle Assessment in an Industrial Pollution Control Engineering Master’s Program

Rio Aryapratama — 2026-04-14

Addressing the complex challenges of climate change requires analytical tools that enables evaluation of the environmental performance of industrial activities. Life Cycle Assessment (LCA) has emerged as one such key tool, providing a science-based framework to quantify environmental impacts across product and process life cycles. In Indonesia, LCA has gained increasing attention through policy initiatives such as the Ministry of Environment’s PROPER program, which mandates LCA assessments for certain performance ratings. To address the growing demand for LCA applications, higher education must ensure that graduates possess adequate methodological understanding and practical skills to apply LCA effectively in real-world contexts. This study evaluates the effectiveness of teaching LCA through a project-based learning (PBL) framework in the Industrial Pollution Control Engineering Master’s Program at Universitas Gadjah Mada (UGM). Survey data from three student cohorts (2023–2025) were used to assess students’ perceived learning outcomes, learning experiences, challenges, and post-course application of LCA. The results show that students developed strong conceptual understanding and practical competence in LCA, with high satisfaction regarding theory–practice alignment and instructor feedback. However, several challenges were identified, particularly regarding the transition from simplified exercises to more complex, data-intensive case studies, especially related to software use and inventory development. Importantly, large number of students reported continued interest or intended use of LCA in their academic or professional activities after completing the course. Overall, the findings indicate that a project-based learning approach effectively supports the development of applied LCA competencies and promote sustained participants’ engagement with life cycle thinking.

Literature Review: Effects of Palm Oil Fuel Ash Adsorbent Mass Variation on Adsorption Process Efficiency in Water Treatment

Vania Talitha Ananta — 2026-04-14

Palm Oil Fuel Ash (POFA) has excellent potential as an adsorbent for heavy metals, especially zinc (Zn), because it is able to provide a high absorption percentage. The purpose of this literature study is to systematically examine the effect of variations in the mass of Palm Oil Fuel Ash (POFA) adsorbent on the efficiency of the heavy metal adsorption process in water treatment, as well as to identify the most effective activator for POFA-based adsorbents based on the results of previous studies. The literature study method was carried out by reviewing and comparing relevant national and international scientific articles through Google Scholar, Garuda, and SINTA-accredited journal databases, with a focus on the relationship between POFA adsorbent mass and adsorption efficiency. Commonly used activators include NH₄Cl, HCl, NaOH, and KOH, with the best results varying for each type of POFA modification. Unmodified POFA showed optimum performance when activated using NH₄Cl, with an adsorption percentage reaching 98.65% at a mass of 10 grams, while zeolite POFA gave the highest results with HCl activator, namely 98.77% with a mass of only 2 grams. In contrast, silica POFA showed a lower adsorption capacity, with an adsorption percentage of 44.50% at a mass of 25 grams. Overall, these results indicate that POFA zeolite is the most effective adsorbent in the adsorption of zinc metal compared to unmodified POFA and silica POFA because it is able to achieve high efficiency with the use of less adsorbent mass.

A Review on Valorization of Coal Fly Ash into High-Purity Silica: Extraction Methods, Applications, and Future Perspectives

Devi Lestari — 2026-04-14

Coal fly ash (CFA), a by-product of coal combustion, contains high silica (SiO₂) content and is continuously generated, making it a promising secondary source of silica. Efficient extraction of silica from CFA can support sustainable material utilization, reduce industrial waste, and align with circular economy principles. This review analyzes recent advances in CFA-derived silica, focusing on extraction techniques, structural characteristics, applications, sustainability, and future prospects. Techniques examined include alkaline leaching, acid dissolution, alkali fusion, sol–gel processing, hydrothermal activation, and emerging biological and process-intensified methods such as ultrasonic treatment and ZnO sintering. Key factors such as CFA composition, Si/Al ratio, and amorphous content are discussed for their influence on extraction efficiency. Recovery efficiencies of CFA-derived silica vary from 38% to over 93%, with cascaded processes achieving purities up to 99%. Structural forms range from amorphous nanoparticles to ordered mesoporous frameworks, enabling applications in construction, catalysis, environmental remediation, energy storage, and biomedicine. Life cycle assessments show that CFA valorization significantly reduces CO₂ emissions compared to conventional quartz-based silica production. Limitations include feedstock heterogeneity, reagent consumption, and economic feasibility. CFA-derived silica offers a sustainable route for industrial waste mitigation while providing high-purity silica for advanced applications. Future research should focus on greener hybrid extraction methods, process standardization, and application-driven material design, supported by regulatory and cross-sector collaboration.

The Effect of Combining Coffee Grounds Charcoal on The Quality of Rice Husk Briquettes With Varying Amounts of Molasses Adhesive

Mochammad Agung Indra Iswara — 2026-04-14

Energy demands are increasing although fossil fuel resources are decreasing. Charcoal briquettes are used as an alternative renewable energy source, producing heat from biomass derived from agricultural waste. This study is aimed at a) determine the composition ratio of a waste combination including coffee grounds and rice husk charcoal as a carbon source, and b) evaluate the amount of molasses applied as an adhesive in briquette production to yield briquettes of optimal quality. The briquette production process consists of three stages: the preparation of materials by drying, followed by carbonization, then briquetting, and finally, the analytical testing of the resulting briquette products. The best briquettes produced in accordance with SNI standards from this study contain 3% adhesive, comprising 40 grams of coffee grounds charcoal and 60 grams of rice husk charcoal, with an ash content of 0.18%, a moisture content of 5%, a density of 0.97 g/cm³, and a calorific value of 5335.80 Cal/gram.

Effect of Chitosan Content and Freezing Temperature on The Properties of Freeze-Thawed Hydrogels

Haryanto — 2026-04-14

Climate change characterized by increasing temperatures and drought frequency has led to decreased agricultural land productivity, especially in areas with limited water availability. One alternative to overcome this problem is the use of hydrogel as a soil moisture retention material which is able to absorb and store water. This study aims to determine the effect of chitosan concentration (1%, 2%, and 3%) and freezing temperatures (–20°C, –30°C, and –40°C) on the physical characteristics of Polyvinyl alcohol (PVA)-chitosan-based hydrogels synthesized using the freeze–thaw method. The parameters analyzed include gel fraction, swelling ratio, and compressive strength. The results showed that most treatments did not have a significant effect on the physical properties of the hydrogel, especially on the gel fraction and compressive strength. The gel fraction values ranged from 8.42% to 23.55% and the compressive strength ranged from 0.0031 MPa to 0.009 MPa. However, variations in temperature and chitosan concentration affect the swelling ratio. The swelling ratio ranged from 12.98% to 27.90%. PVA-chitosan hydrogels composition and a freezing temperature of –20°C showed the highest potential for water retention despite limited mechanical strength. Therefore, this hydrogel still has potential as an alternative planting medium, especially for maintaining soil moisture in dry areas, with the limitation that the formulation and synthesis process need to be further refined.