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Equilibrium Journal of Chemical Engineering
Published by Universitas Sebelas Maret
ISSN : -     EISSN : 26223430     DOI : https://dx.doi.org/10.20961/equilibrium.v4i1.42852
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Engineering Materials Science & Nanotechnology
Equilibrium Journal of Chemical Engineering (EJChE) publishes communication articles, original research articles and review articles in :. Material Development Biochemical Process Exploration and Optimization Chemical Education Chemical Reaction Kinetics and Catalysis Designing, Modeling, and Process Optimization Energy and Conversion Technology Thermodynamics Process System Engineering and products Membrane Technology Food Technology Bioprocess Technology Chemurgy Technology Waste Treatment Technology Separation and Purification Technology Natural Dyes Technology
Arjuna Subject : Teknik Kimia (semua kategori) - Kimia Proses dan Teknologi
Articles 122 Documents
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Optimization of Bio-lubricant Produced from Non-edible Jatropha curcas Seed Oil David Emoefe Rockson-itiveh; alexander Oghenereke Efih; Mabel Keke; Fabian Chidiebere Ozioko
Equilibrium Journal of Chemical Engineering Vol 8, No 2 (2024): Volume 8, No 2 December 2024--Online First
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i2.86674

Abstract

Abstract. This paper presents the production and optimization of a bio-lubricant derived from non-edible Jatropha plant seed oil. Plant oil-based lubricants offer significant environmental benefits and are derived from renewable sources, making them an attractive alternative to conventional lubricants. They provide a potential solution for sustainable and low-cost feedstock for fuel oil and its derivatives without competing with food uses, as Jatropha oil contains toxic esters unsuitable for human consumption. Jatropha seed oil was extracted using a Soxhlet apparatus fitted with a heating mantle. A total of 500 g of the extracted oil was esterified in a round-bottom flask glass reactor with 25 wt% methanol and 1.0 wt% H₂SO₄ as a catalyst, reducing free fatty acids (FFA) to approximately 1%. The esterified oil was then subjected to transesterification in a reactor preheated to 60°C. A mixture of 1.0 wt% NaOH and methanol at a 6:1 ratio was added while stirring at 300 rpm for a reaction time of 90 minutes. The transesterification process was optimized using a 23 response surface methodology (RSM) experimental design. This design evaluated the effects of temperature (112.16°C to 160.00°C), reaction time (1.81 to 5.00 hours), and catalyst concentration (0.73% to 1.73% w/w) at a constant mole ratio of JME to TMP of 3.9:1 under vacuum conditions. The results revealed that the optimal conditions for bio-lubricant synthesis were a temperature of 130°C, a reaction time of 3 hours, and a catalyst concentration of 0.8% w/w. A second-order quadratic model was developed to predict the yield of Jatropha curcas bio lubricant based on the process variables. The model predicted a yield of 88.74% with a desirability of 0.9739 and demonstrated a high coefficient of determination (R²) of 0.9739, indicating strong predictive accuracy Keywords:Bio-lubricant, Jatropha, Esterification, Seed Oil
Glucose Syrup from Purple Sweet Potatoes (Ipomoea batatas L. Poir) using Acid Hydrolysis Method Esa Nur Shohih; Dendi Sri Sulistyantoro; Vira Mawardha Putri
Equilibrium Journal of Chemical Engineering Vol 8, No 1 (2024): Volume 8, No 1 July 2024
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i1.87411

Abstract

Abstract. The making of glucose syrup from purple sweet potatoes is motivated by the high demand for alternative sugar in Indonesia. Through the processes that have been carried out and the results of previous studies, the potential of purple sweet potatoes to be processed into glucose syrup has been produced. This experiment was conducted to determine whether purple sweet potatoes can be processed into glucose syrup and to determine the suitability of the product to the standard. To convert purple sweet potatoes into glucose syrup, it is necessary to first extract the starch content in purple sweet potatoes and go through the process of making glucose syrup by the acid hydrolysis method using citric acid of various concentrations (0.2, 0.4, 0.6, 1 N). For the feasibility of consuming glucose syrup from purple sweet potatoes, a toxicity test was carried out using the Brine Shrimp Lethality Test (BSLT) method. Tests were also carried out on water, ash, reducing sugar, and starch content to then be compared with the Indonesian glucose syrup standard (SNI 01-2978-1992). The results showed that the reducing sugar content of purple sweet potato glucose syrup followed the glucose syrup quality standard, which was 43.31%, the lowest water content was 18.35%, the lowest ash content was 7.95% and there was no starch content in purple sweet potato liquid sugar. The aroma of the glucose syrup produced was following the Indonesian National Standard, but the color and taste produced were not yet in accordance. The toxicity test of purple sweet potato liquid sugar showed a lethal concentration value of LC50 >1,000 ppm, which means that purple sweet potato liquid sugar has no toxic potential so it is safe for consumption.Keywords:Purple Sweet Potatoes, Liquid Sugar, Acid Hydrolysis
The Effect of HCl Activator on PET Adsorbent to Reduce Phosphate Content in Laundry Waste Lutfi Wahidatur Rizky; Iskandar Zulkarnain; Ismadi Raharjo; Yeni Ria Wulandari
Equilibrium Journal of Chemical Engineering Vol 8, No 1 (2024): Volume 8, No 1 July 2024
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i1.84179

Abstract

Plastic waste is waste that cannot be decomposed so it will cause serious problems to the environment. The National Waste Management Information System (SIPSN) reported that in 2020 plastic waste was found to be 17.2% of the total waste collected. Several types of plastic can become porous charcoal through the heating process in a furnace so that it can be used as an adsorbent for liquid waste from the laundry industry. Laundry liquid waste containing excess phosphate will disrupt the environment such as eutrophication. This research aims to determine the effect of the HCl activator on carbon from polyethylene terephthalate (PET) plastic bottle waste to reduce phosphate levels in liquid laundry waste. This research uses varying concentrations of HCl as a carbon activator, namely 1M, 5M, and 10M. The activated carbon is added to the liquid laundry waste and stirred at a speed of 100 rpm. Phosphate content analysis was carried out using a spectrophotometer in liquid laundry waste before and after the adsorption process and BET (Brunauer-Emmet-Teller) analysis on activated carbon with activator HCl 10 M. The greatest decrease in phosphate levels was 10 M HCl concentration of 52.87%, with a carbon surface area of 203.1222 m²/g and a particle size of 29.53 nm. The adsorption capacity of activated carbon with a 10 M activator is 0.1499 mg/g. Keywords:PET, Adsorbent, HCl, Laundry Waste, Phosphate 
Study of The Effect of Temperature On The Desorption Efficiency of Precious Metals In The Elution Process Using Anglo American Research Laboratories (AARL) Method Frideni Yushandiana Putri G.F.; Mei Iftita Mawarda'; Sulaeman - -; Riria Zendy Mirahati; Shofa Rijalul Haq
Equilibrium Journal of Chemical Engineering Vol 8, No 2 (2024): Volume 8, No 2 December 2024--Online First
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i2.89289

Abstract

The elution process, known as the desorption of gold from carbon into solution, uses high temperature and pressure. Activated carbon is used as an adsorbent in the precious metal adsorption process. PT Indo Muro Kencana uses the Anglo American Research Laboratories (AARL) method to desorb valuable metals from the activated carbon of the Carbon In Pulp (CIP) process. The elution process of this research involves 9 stages: Pre-heat, Pre-soak 1, Pre-soak Circulation, Lean 1, Presoak 2, Lean 2, Water Elution 1, Water Elution 2, and Cooling. This study found that copper (Cu) metal desorbed from carbon first, followed by silver (Ag) metal, with the desorption of gold (Au) metal occurring last due to the influence of the stability value of metal cyanide complexes. High cyanide concentrations (~ 10% CN-) were given in Pre-soak 1, Pre-soak Circulation, and Pre-soak 2. The elution process is significantly affected by high process temperatures, particularly 123°C in the Lean 2 stage, which effectively desorbs gold (Au) at its optimal point. The solution product that only contains copper from the initial 60 minutes of the Pre-heat and Pre-soak 1 processes was transferred to the tailings tank to improve the efficiency of the refining process. The total recoveries for gold (Au), silver (Ag), and copper (Cu) were 93.1%, 95%, and 94.7%, respectively.
The Impact of pH And Temperature on the Crystallization Process of Coconut Palm Sugar Aulia Bunga Kencana; Erwana Dewi; Muhammad Taufik
Equilibrium Journal of Chemical Engineering Vol 7, No 2 (2023): Volume 7, No 2 December 2023
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v7i2.79964

Abstract

Abstract. This experiment concerns the optimization of coconut sugar production by using innovative processing methods. The raw material, coconut sap, is systematically collected through tapping coconut flowers to ensure consistency. Focusing on the process of coconut sap into coconut sugar in a convenient powdered form emphasizes a systematic approach. The research utilizes a controlled heating method with a crystallizer, introducing variations in pH and temperature. This research was to determine the best temperature and ph to produce coconut palm sugar products that comply with several SNI 3743: 2021 standards. To solve the problems associated with traditional palm sugar production emphasizes the need for innovative and efficient approaches. The results  show that quality of palm sugar: sucrose content of 86.93%, moisture content of 1.03%, ash content of 1.65% and Pb content according to Indonesian Nasional Standard of palm sugar SNI 3743:2021. This systematic and innovative approach aligns coconut sugar with the quality standards specified in SNI 3743:2021, offering a high-quality and marketable formKeywords:Coconut Nira, Palm Sugar, Volume, pH
Application of Subcritical Water Hydrolysis (SCW) in Producing Reducing Sugar for Biofuel Production Dian Ranggina; Maria Assumpta Nogo Olea; Hanny F. Sangian; Arief Widjaja; Hijrah Amaliah Azis
Equilibrium Journal of Chemical Engineering Vol 8, No 2 (2024): Volume 8, No 2 December 2024--Online First
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i2.86196

Abstract

Abstract. This work aimed to produce reducing sugar from coconut husk using subcritical water hydrolysis. Coconut husk contains cellulose and hemicellulose that can be converted into reducing sugars and then fermented into biofuel. In this study, the subcritical water hydrolysis was carried out in a batch reactor at  temperatures 120-260 oC and pressures, 40, 80, and 160 bar for 1 h. Subcritical water method obtained two products, namely (a) liquid containing sugar and (b) solid containing cellulose, hemicellulose and lignin. The liquid sugars were analyzed by HPLC and DNS, while crystal structure was characterized by XRD and SEM. The highest yield of reducing sugar obtained was 0.25 g/g cellulose+ hemicellulose at 150 oC and 80 bar.Keywords: Biofuel, Coconut husk, Lignocellulose, Reducing sugar, Subcritical water
Simulation of Gas Sweetening Process using Extended NRTL and Stages Efficiency as Modeling Approach Aditya Kurniawan; Yusmardhany Yusuf; Ahnaf Hazimizzufar; Wildan Zanuar Herviansyah
Equilibrium Journal of Chemical Engineering Vol 8, No 1 (2024): Volume 8, No 1 July 2024
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i1.88301

Abstract

Gas sweetening is a process to remove CO₂ and H₂S from natural gas. The current established technology is by using Amine contactor where the solvent used is in form of Amine solution. To simulate the effect of different solvent, electrolyte-NRTL is used to model the equilibrium, and mass transfer-kinetic is used to model the rate-based processes. This modeling approach is rather complex and available only in commercial and proprietary process simulation software. Therefore we propose an alternative modeling approach where we use extended NRTL and stage efficiency to model the acid gas absorption processes. We find that this approach is quite good to describe CO₂ absorption, yet unsuccessful to calculate the H₂S absorption. Inadequate vapor liquid equilibrium parameter regression for H₂S, specifically at low partial pressure might cause the problem. However the stage efficiency approach shows good result where it is comparable to rate-based model and corresponds to current understanding of physico-chemical phenomenon of acid gas absorption. Keywords:Gas sweetening, Unisim design, Simulation, NRTL, Stage efficiency
Calcination Temperature Effect on Characteristic Properties of Na2/3[Fe1/2Mn1/2]O2 Synthesized by Sol-Gel Reaction Diah Agustina Puspitasari; Supriyono Supriyono; Christina Wahyu Kartikowati; Mar’atul Fauziyah; Femiana Gapsari; Vania Mitha Pratiwi; Devina Annora H Br Butar-Butar; Ira Marisa D.N; Rashieka Putri Maghfiroh; Yudha Bhakti Prasetia; Rivanda Adi I. R; Irginata Aqil H; Roihan Rajabi; Umar Khalid Zaki Abdul
Equilibrium Journal of Chemical Engineering Vol 8, No 1 (2024): Volume 8, No 1 July 2024
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i1.80464

Abstract

Abstract. Recently, Na2/3[Fe1/2Mn1/2]O2 has received attention as a potential candidate material for cathode sodium-ion batteries. However, this material was synthesized by a solid-state process, resulting in larger particle size and nonuniform morphology. The larger particle size will sluggish the Na ion diffusion. Here we report the synthesis of Na2/3[Fe1/2Mn1/2]O2 using a simple sol-gel process. The X-ray diffraction revealed that the sample was identified as Na2/3[Fe1/2Mn1/2]O2 with a hexagonal crystal structure. However, the impurities are formed at diffraction angles of 36.28°, 45.03°, and 51.23°. Calcination temperature affects the formation of the crystal phase, grain growth, morphology, and particle size. Our findings provide valuable insight into the development of Na2/3[Fe1/2Mn1/2]O2  material with desirable properties. Keywords:Sol-Gel, Solid State, Grain Growth, Calcination, Na2/3[Fe1/2Mn1/2]O2 
Study of the Effect of Dissolved Oxygen Concentration on Gold Recovery Leaching at PT Indo Muro Kencana Frideni Yushandiana Putri GF; Wilson Pauru'; Sulaeman .
Equilibrium Journal of Chemical Engineering Vol 8, No 1 (2024): Volume 8, No 1 July 2024
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i1.78333

Abstract

Gold is a very important metal in human life. Most gold is processed using the sodium cyanide (NaCN) leaching method. Maximizing the leaching recovery can be done by optimizing the leaching process parameters, one of which varies the concentration of dissolved oxygen (DO). Oxygen is added to oxidize gold atoms (Au) into cations (Au+) which will then react with cyanide ions (CN-) to form the aurocyanid complex anion Au(CN)2- dissolved in cyanide solution. This study aims to investigate the best method between the use of O2, H2O2, and Aachen reactor in generating dissolved oxygen concentration to oxidize valuable metals. From the experimental results, which method can produce higher leaching recovery will be seen. Based on this study, the dissolved oxygen variation derived from oxygen injection (O2) obtained a percent recovery of 92.5% Au and 80.5% Ag, hydrogen peroxide (H2O2) achieved a percent recovery of 92.5% Au and 79.9% Ag, and Aachen sheared (Aachen reactor) with a percent recovery of 95% Au and 81.9% Ag.Keywords:Gold, Leaching, Dissolved Oxygen, Percent Recovery, Aachen Reactor
Making Natural Dye Powder from Miana Leaves (Coleus scutellarioides (L) Benth) Using the Foam Mat Drying Method Sri Wahyuni; Sirajuddin Sirajuddin; Fitriyana Fitriyana
Equilibrium Journal of Chemical Engineering Vol 8, No 2 (2024): Volume 8, No 2 December 2024--Online First
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v8i2.89241

Abstract

Abstract. Food color is one of the things that consumers consider when choosing and sorting food. So the use of coloring in food seems to be a necessity for every food producer. The health impact of using synthetic dyes is a reason for us to go back to nature by using natural dyes. Natural dyes can be an alternative dye that is non-toxic, renewable and environmentally friendly. Miana (Coleous scutellarioides (L) Benth) is a tropical plant that grows wild in Indonesia. This plant contains anthocyanins which have potential as natural dyes. This research aims to determine the effect of maceration time on total anthocyanin coloring powder from miana leaves as a source of natural coloring substances using the foam mat drying method. The research began with preparing the ingredients, then macerating 25 grams of miana leaves using 250 mL of distilled water with varying times of 6, 12, 18, 24, 30 and 36 hours. The maceration results are then filtered and centrifuged. In the foam mat drying method, maltodextrin filler is added with a concentration of 8% and egg white foaming agent with a concentration of 5%. Based on the research results, the best conditions were obtained at a maceration time of 36 hours. The analysis results showed that the dye powder yield was 57.643%, the water content was 2.237%, the solubility was 97.711% and the total anthocyanin concentration was 217.09 mg/L. Keywords:Coleous scutellarioides (L) Benth, Natural Dyes, Foam Mat Drying, Maltodextrin, Egg White

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