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Analysis Of Recent Research In Solketal Synthesis Toward Circular Economy : A Review Adna Ivan Ardian; Tamaratritania Citta Trisnantari; Dennis Farina Nury; Rizky Ibnufaatih Arvianto; Suhirman Suhirman
Equilibrium Journal of Chemical Engineering Vol 10, No 1 (2026): Volume 10, No 1 July 2026 (First Online)
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v10i1.113030

Abstract

Indonesia’s growing biodiesel production has caused a large surplus of crude glycerol, which becomes both an economic and environmental problem. The study present a systematic chemical engineering perspective on how glycerol can be transformed into solketal, a compound that can act as a biofuel additive and green solvent. The discussion is based on a systematic reading method of twelve research papers published between 2018 and 2024, specifically discuss the development of catalysts related to this process. The contrasting performance between catalyst efficiency and its industrial implementation become a concern. It shows Zeolites and MOF catalyst exceed other types of catalysts by using process intensification in laboratory. But in contrast, their stability lower when associated with impurities found in feedstock, followed by heat-related problems. On the other side, simple and cheaper catalysts such as acid-treated clays still show steady activity even in less clean feedstocks, making them more realistic for larger scale operation. The review also points out that improving catalyst lifetime and using new process approaches like microwave heating are important to make the process more economical. Overall, this study suggests that creating catalysts which can resist impurities together with better process design is necessary to make glycerol utilization more sustainable and in line with Indonesia’s circular economy plan.
Gamma Spectrometric Analysis of Natural Radionuclides and Radiological Hazards in Ilmenite Sand Esther Mutiara Santallum Ekklesia Tibalia; Farida Diyah Hapsari; Tamaratritania Citta Trisnantari; Geraldi Rahanra; Muhammad Ikhsan Taipabu
Equilibrium Journal of Chemical Engineering Vol 10, No 1 (2026): Volume 10, No 1 July 2026 (First Online)
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v10i1.116251

Abstract

Ilmenite sand, categorized as Naturally Occurring Radioactive Material (NORM), contains radionuclides derived from the uranium and thorium decay series. The present work investigates radionuclide concentrations in ilmenite sand collected from a mineral processing facility to evaluate associated radiological hazards using gamma spectrometry. Activity measurements were performed with a gamma spectrometry system calibrated for energy and efficiency using a Eu-152 reference source. Environmental background radiation was measured separately to correct spectral data during analysis. Prior to measurement, samples were dried, homogenized, and sealed in airtight containers to establish radioactive equilibrium between parent radionuclides and their progeny. Radionuclide activities were quantified based on characteristic gamma-ray peak energies. The measured activity concentrations were 472.98 Bq/kg for Ra-226, 302.20 Bq/kg for Th-232, and 10.68 Bq/kg for K-40. Radiological hazard parameters, including radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), and absorbed dose rate, were subsequently calculated. The estimated annual effective dose was 0.492 mSv/year, remaining below the recommended public exposure limit of 1 mSv/year. These findings indicate that, despite relatively elevated radionuclide activities, the resulting radiation exposure levels remain within acceptable safety limits. Overall, gamma spectrometry demonstrates reliable capability for radionuclide identification and radiological risk assessment in mineral-based materials.
Proses Ekstraksi Antioksidan dari Daun Kalanchoe pinnata: Studi Pengaruh Ukuran Partikel dan Kinetika Maserasi Sabrianah Badaruddin; Alif Nur Laili Rachmah; Ratih C F Ratumanan; Ronald Darlly Hukubun; Tamaratritania Citta Trisnantari
INSOLOGI: Jurnal Sains dan Teknologi Vol. 4 No. 4 (2025): Agustus 2025
Publisher : Yayasan Literasi Sains Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55123/insologi.v4i4.6183

Abstract

Kalanchoe pinnata leaves are rich in bioactive compounds, including flavonoids and phenolic constituents, which exhibit notable antioxidant properties. However, the efficiency of extraction processes is highly influenced by operational variables such as the type of physical pre-treatment and maceration duration. This study aims to evaluate the effect of three physical pre-treatment methods (manual grinding, chopping, and blending) and maceration periods ranging from 3 to 5 days on the antioxidant activity of K. pinnata leaf extracts using the DPPH radical scavenging assay. Results indicate that the grinding method combined with five days of maceration yields the highest antioxidant activity (95.04%), while blending leads to the lowest activity (81.78%), presumably due to heat-induced degradation of active compounds. Kinetic observations show that antioxidant activity tends to plateau on day five, particularly in ground samples. These findings highlight the critical influence of particle size reduction and solvent–solid contact time on mass transfer efficiency during extraction. This preliminary investigation provides a scientific basis for further research on the optimization of natural antioxidant extraction processes and the development of functional herbal formulations derived from K. pinnata leaves.