Kinetics of Irreversible Saponification Reactions in terms of changes in Reactant Concentration

Dwi Indah Lestari, Debi Anggun Sari, Zeolita Prabu Putri, Isma Uly Maranggi — Mon, 26 Jan 2026 00:00:00 +0000

This study aims to investigate the kinetics of the irreversible saponification reaction between triglycerides in cooking oil and sodium hydroxide (NaOH) by analyzing the changes in reactant concentrations over time. The reaction was carried out at 60 ^oC, and samples were collected every 5 minutes and analyzed by titration using 0.5 M HCl. The results showed that the concentration of NaOH decreased from 0.500 mol/L to 0.290 mol/L within 30 minutes, while triglycerides decreased from 0.203 mol/L to 0.133 mol/L. The kinetic data were evaluated using both second-order and pseudo first-order models to determine the most appropriate mechanism. The second-order model yielded an R² value of 0.9069 with a rate constant of 0.0125 L-mol^-1·min^-1, whereas the pseudo first-order model exhibited better linearity with an R² of 0.9296 and a rate constant of 0.0169 min^-1. These results indicate that although the reaction is mechanistically bimolecular, the experimental conditions particularly the relative excess of NaOH caused the reaction to behave in accordance with pseudo first-order kinetics. Thus, the observed kinetic behavior is more accurately described by the pseudo first-order model, in which the decrease in triglyceride concentration plays a dominant role in controlling the reaction rate. This study provides further insight into the kinetic characteristics of saponification under laboratory operating conditions.

Abstrak
Penelitian ini bertujuan untuk mempelajari kinetika reaksi saponifikasi irreversible antara trigliserida dalam minyak goreng dan natrium hidroksida (NaOH) melalui analisis perubahan konsentrasi reaktan terhadap waktu. Reaksi dijalankan pada suhu 60 ^oC, dan sampel diambil setiap 5 menit untuk dianalisis melalui titrasi menggunakan HCl 0,5 M. Hasil pengamatan menunjukkan bahwa konsentrasi NaOH menurun dari 0,500 mol/L menjadi 0,290 mol/L dalam 30 menit, sedangkan trigliserida turun dari 0,203 mol/L menjadi 0,133 mol/L. Data kemudian dianalisis menggunakan model kinetika orde dua dan pseudo first-order untuk menentukan mekanisme reaksi yang paling sesuai. Model orde dua memberikan nilai R² sebesar 0,9069 dengan konstanta laju 0,0125 L-mol^-1·min^-1, sedangkan model pseudo first-order menunjukkan linearitas lebih baik dengan R² 0,9296 dan konstanta laju 0,0169 min^-1. Perbedaan ini menunjukkan bahwa meskipun reaksi secara mekanistik bersifat bimolekuler, kelebihan relatif NaOH menyebabkan reaksi tampak mengikuti pola pseudo first-order. Dengan demikian, kinetika teramati lebih akurat dijelaskan oleh model pseudo first-order, dimana penurunan konsentrasi trigliserida menjadi faktor pengendali utama laju reaksi. Hasil penelitian ini memperkuat pemahaman mengenai perilaku kinetika saponifikasi pada kondisi operasi laboratorium.

Mediated Electrochemical Oxidation with Lead as Electrode for Organic Waste Treatment from Pulp Industry

Haryono, Juliandri, Atiek Rostika Noviyanti, Irwan Kurnia — Mon, 26 Jan 2026 00:00:00 +0000

The pulp industry is a type of industry based on natural materials, namely lignocellulose, which produces relatively large amounts of organic liquid waste. The use of various types of synthetic chemicals in the pulp production process results in waste from this industry being classified as hazardous and toxic waste. Various methods of liquid waste treatment can be applied, one of which is the Mediated Electrochemical Oxidation (MEO) method. The MEO method allows organic compounds in liquid waste to be oxidized into simple and relatively environmentally friendly inorganic compounds, such as carbon dioxide and water. The purpose of this study was to determine the effect of the potential difference between electrodes and time on the performance of the MEO method with lead electrodes in the treatment of organic liquid waste from the pulp industry. The potential difference between electrodes was studied at values of 3.0, 4.5 and 6.0 volts, while the electrolysis time in MEO was studied for 60, 90 and 120 minutes. The performance of the MEO method in the treatment of organic liquid waste was determined based on the degradation efficiency parameters. The results showed that the maximum degradation efficiency of organic waste was achieved when MEO was carried out at a potential difference between electrodes and an electrolysis time of 6.0 volts and 120 minutes. Under these MEO operating conditions, an organic waste degradation efficiency of 99.03% was achieved.

Abstrak
Industri pulp merupakan salah satu jenis industri berbasis bahan alam, yaitu lignoselulosa, yang menghasilkan limbah cair organik relatif banyak. Pemanfaatan berbagai jenis bahan kimia sintetik pada proses produksi pulp mengakibatkan limbah dari industri tersebut termasuk sebagai limbah berbahaya dan beracun. Berbagai metode pengolahan limbah cair dapat diterapkan, salah satunya adalah metode Oksidasi Elektrokimia Termediasi (OET). Metode OET memungkinkan senyawa organik pada limbah cair untuk dioksidasi menjadi senyawa anorganik sederhana dan relatif ramah lingkungan, seperti karbon dioksida dan air. Tujuan penelitian ini adalah menentukan pengaruh beda potensial antar elektroda dan waktu terhadap kinerja metode OET dengan elektroda timbal pada pengolahan limbah cair organik dari industri pulp. Beda potensial antar elektroda dipelajari pada nilai 3,0, 4,5 dan 6,0 volt, sedangkan waktu elektrolisis pada OET dipelajari selama 60, 90 dan 120 menit. Kinerja metode OET pada pengolahan limbah cair organik ditentukan berdasarkan parameter efisiensi degradasi. Hasil penelitian menunjukkan bahwa efisiensi degradasi limbah organik maksimum dicapai ketika OET dilakukan pada beda potensial antar elektroda dan waktu elektrolisis sebesar 6,0 volt dan 120 menit. Pada kondisi operasi OET tersebut dicapai efisiensi degradasi limbah organik sebesar 99,03%.

Jurnal Kimia dan Rekayasa

Kinetics of Irreversible Saponification Reactions in terms of changes in Reactant Concentration

Mediated Electrochemical Oxidation with Lead as Electrode for Organic Waste Treatment from Pulp Industry