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INDONESIA
CHEMICA Jurnal Teknik Kimia
Published by Universitas Ahmad Dahlan
ISSN : 2355875X     EISSN : 23558776     DOI : 10.26555
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Energy
CHEMICA Jurnal Teknik Kimia ISSN, 2355-875X (print) 2355-8776 (online) is a journal that publishes manuscripts or scientific papers in Chemical Engineering. The scope of this journal covers chemical reaction techniques, separation, optimization, process control, process system engineering, waste treatment, food and material technology. Journals are published in print and online twice a year, in June and December by Chemical Engineering Program, Faculty of Industrial Technology, Universitas Ahmad Dahlan Yogyakarta.
Arjuna Subject : -
Articles 189 Documents
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Effect of Temperature, Concentration, and Type of Plasticizer on Edible Pectin Film Characteristics of Mango Peel (Mangifera indica L.) Eka Wahyu Asriyanti; Muna Munisah; Erlando Rizki Dewanto; Muhammad Mujiburohman
CHEMICA: Jurnal Teknik Kimia Vol 9, No 1 (2022): April 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i1.20540

Abstract

Plastic is a polymer product that is widely used by the community and is generally non-degradable. Its high usage makes plastic a source of waste that is difficult to decompose. It is important to transform the use of degradable materials as packaging by the community in an effort to overcome plastic waste. The edible film is an environmentally friendly packaging medium, which is generally synthesized from a mixture of pectin, plasticizer, and tapioca starch by heating and stirring. This study aims to study the effect of mixing temperature, pectin concentration, and type of plasticizer on the characteristics of the edible film. The temperature was varied at 70 oC, 80 oC, and 90 oC, with variations in pectin concentrations of 1%, 2%, and 3%. The types of plasticizers used were glycerol, sorbitol, and polyethylene glycol (PEG 400). The characteristics of the edible film were tested from thickness, tensile strength, elongation, and solubility. In the range of variables studied, the optimum conditions for producing the best edible film characteristics were 70 oC, 3% pectin, and the plasticizer of glycerol, giving solubility of 0.670 g water/g edible film, the thickness of 0.392 mm, the tensile strength of 3.200 MPa, and elongation of 0.134.
Yield and Physicochemical Properties of Candlenut Oil by Microwave Assisted Extraction Shintawati Shintawati; Yatim R Widodo
CHEMICA: Jurnal Teknik Kimia Vol 9, No 1 (2022): April 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i1.22228

Abstract

Candlenut (Aleurites moluccana L) is one of the native plants of Indonesia, used as a spice and in the cosmetic industry. Candlenut seeds contain high oil content with unstable properties at high temperatures. Generally, candlenut oil production is carried out by direct heating and on a laboratory, scale using Soxhlet extraction with chemical solvents. Microwave heating has been widely used to extract the active compounds in plant materials. The study of candlenut oil extraction with microwaves is still limited. This study aims to identify the physicochemical properties and yield of candlenut oil extracted using the Microwave Assisted Extraction (MAE) method and compare it with solvent extraction. This research was conducted by varying the extraction time of 35 minutes, 70 minutes and 105 minutes. The results showed that candlenut oil produced by the MAE method had a density, refractive index, ALB content and saponification number of 0.867 g/ml, 1.477, 2.8085% and 212.9764 mgKOH/g sample with a yield of 38.50%.
Effect of Hydrolysis Time and Sulfuric Acid Concentration on Reducing Sugar Content on Corn Cob Hydrolysis Anisah Nur Jannah; Ahmad M Fuadi
CHEMICA: Jurnal Teknik Kimia Vol 9, No 1 (2022): April 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i1.20637

Abstract

Energy demand in Indonesia continues to increase, while the source of petroleum energy is a non-renewable energy source. This problem encourages people to seek alternative renewable and environmentally friendly fuels. Bioethanol is an alternative to replace petroleum energy that is environmentally friendly because it can be made from organic waste. The utilization of corncobs waste currently is not optimal. Corncobs are known to contain lignocellulose compounds, namely cellulose, hemicellulose, and lignin which are suitable as raw materials for making bioethanol. One of the conversions of lignocellulose into bioethanol is through hydrolysis. So in this study, the effect of hydrolysis time and sulfuric acid concentration (H2SO4) will be analyzed on the reducing sugar levels that will be produced because high reducing sugars will produce more bioethanol. The method of determining reducing sugar used is Nelson - Somogyi. The independent variables used were hydrolysis times that is 45 minutes, 90 minutes, 135 minutes, and 180 minutes, and the acid concentrations that are 5%, 10%, 15%, and 20% (1:20 w/v). The fixed variables used were corncob mass and hydrolysis volume, while the dependent variable was the reducing sugar content.
Hazard Identification of Liquefied Natural Gas (LNG) Transportation and Storage in DKI Jakarta Province Sari Sekar Ningrum; Aidha Zulaika; Dody Guntama
CHEMICA: Jurnal Teknik Kimia Vol 9, No 2 (2022): August 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i2.22250

Abstract

LNG is an alternative fuel to replace diesel and gasoline. The use of LNG as a fuel has many advantages from various aspects. Besides having advantages, LNG also has disadvantages because it contains dangers in it. LNG is a volatile material that is easily flammable, which causes fires and explosions. Environmental Risk Assessment (ERA) is a systematic method used to measure the magnitude of the risk of a process and product that is a hazard to human health and ecology. By conducting an ERA, the risks and hazards of LNG are known. In carrying out the research, describing the LNG delivery system, identifying hazards in the event of LNG released from the carrier, making accident scenarios along with the outcome events that will occur, collecting data, calculating the frequency of accidents and their consequences, determining existing risks, and providing preventive actions, and mitigation. Hazard evaluation was determined using fault tree analysis (FTA) and event tree analysis (ETA). Based on identifying hazards to the storage and transportation of LNG, it is classified into category four and server (severe). Scenarios of releasing LNG into the environment in the process of transporting and storing LNG can be caused by several things, including external factors, failure in filling, and failure due to excess pressure so that it can cause fire pools/BLEVE events, cloud vapor explosions, flash fires, and cloud vapors. Based on the level of risk entered into, not tolerable action at the next opportunity.
Preparation and Characterization of Mangrove (Rizhopora Mucronata) Charcoal-Epoxy Polymer Composite Althaf Irfan Fachrezy; Ryan Sutedja; Sartika Selang; Aster Rahayu; Maryudi - Maryudi
CHEMICA: Jurnal Teknik Kimia Vol 9, No 1 (2022): April 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i1.24472

Abstract

Composite materials have been widely developed and applied for various purposes. Polymer composites have excellent properties on mechanical strength and chemical resistance. This study aims to determine the strength of composite made of mangrove charcoal and epoxy since mangrove charcoal has a good character and is abundantly available. The mangrove charcoal was added into the epoxy-hardener matrix with a volume fraction of 10%, 20%, and 30%. The charcoal size was 40, 60, and 100 mesh. The highest tensile strength was found with a volume fraction of 10% with an average of 19.33 N/mm2 at a size variation of 100 mesh mangrove charcoal. The highest elongation at break was found with a volume fraction of 10% with an average of 5.233% at 100 mesh mangrove charcoal size.
Biohydrometallurgy for Cobalt Recovery from Spent Li-ion Batteries using Acidophilic Bacteria Isolated from Acid Mine Drainage Asful Hariyadi; Umi Sholikah; Bangkit Gotama; Muhammad Abdul Ghony
CHEMICA: Jurnal Teknik Kimia Vol 9, No 2 (2022): August 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i2.22328

Abstract

Nowadays, recycling Li-ion batteries is an important thing to do to minimize the risk of exposure to this hazardous solid waste. On the other hand, extracting these materials can optimize the economic potential of valuable minerals in the active cathode. Bioleaching was developed as an environmentally friendly method to extract cobalt from the cathode by utilizing the metabolic activity of A. ferrooxidants cells. Microorganisms were isolated from Acid Mine Drainage in a 9K liquid medium at pH=2.5 and used as an inoculum. The Bioleaching process was carried out with various cell concentrations of 5, 10, and 20 %v/v. A positive response was shown by monitoring the microorganism activity through changes in physical appearance, decreasing the pH value, and increasing the Fe3+ concentration. The structural analysis of cathode by XRD and SEM has shown the effect of Co dissolution before and after bioleaching. Optimum recovery of cobalt was achieved up to 57.81% after 14 days of incubation.
Effects of Nutrients Ca and K on Anaerobic Digestion of Food Waste Firda Mahira Alfiata Chusna; Lukhi Mulia Sitophyta; Rachma Tia Evitasari
CHEMICA: Jurnal Teknik Kimia Vol 9, No 1 (2022): April 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i1.24538

Abstract

We often find food waste daily, especially on household and restaurant scales. Using food waste for helpful something, biogas is an alternative to reduce wasted waste and produce renewable energy. The anaerobic digestion process is a process that decomposes organic material into biogas with the help of microorganisms in conditions without oxygen. Adding nutrients in the anaerobic digestion process can positively affect biogas-producing microorganisms. One of the nutrients or nutrients studied this time is Ca and K. The provision of nutrient Ca has a positive effect, namely a significant increase in biogas production compared to without the addition of nutrients. However, adding K does not positively impact biogas production is inhibited. Excessive amounts of nutrient K can inhibit the process by inhibiting microorganisms in breaking down intermediate products into biogas. The largest volume of biogas produced for five days came from the reactor with the addition of nutrient Ca, which was 15072 cm3, while the control reactor and reactor with the addition of nutrient K produced biogas of 1648.5 cm3 and 15.7 cm3. The addition of nutrient Ca increases biogas production more than nine times.
The Effect of Operating Temperature on the Yield of Liquid Products in the Pyrolysis Process of Used Tires into Fuel Oil Muhammad Irsan B; Hasbi Assiddiq S.
CHEMICA: Jurnal Teknik Kimia Vol 9, No 2 (2022): August 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i2.22309

Abstract

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The Effect Of The Addition Of Polyvinyl Alcohol (PVA) Concentrations on the Characteristics of The Carboxymethyl Cellulose (CMC)-Poly (Acrylic Acid) Hydrogel Superabsorbent as a Planting Medium Rahma Falah Maulidina; Dwi Pujiani; Haryanto Haryanto
CHEMICA: Jurnal Teknik Kimia Vol 9, No 2 (2022): August 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i2.24428

Abstract

Superabsorbent hydrogel is a hydrophilic network which has the ability to absorb and bind large amounts of water, but is insoluble in water. Hydrogel can be applied in various fields including medical applications, planting medium and waste absorbers. One type of hydrogel that has been widely developed is Carboxymethyl Cellulose (CMC) based hydrogel. However, CMC-based hydrogels still have several shortcomings, namely mechanical properties and low water absorption. In this study, a superabsorbent hydrogel was synthesized from CMC and acrylic acid with the addition of PVA and citric acid as a crosslinking agent and ammonium persulfate as an initiator. This research was conducted to determine the effect of PVA on the characteristics of the CMC-Poly(Acrylic Acid) hydrogel. The variation of the concentration of PVA used was 0% to 2.5% (w/v). The analyzed characteristics include gel fraction, swelling ratio, mechanical properties (tensile strength and elongation). The results showed that the addition of PVA decreased gel fraction from 60.35% to 48.68% and increased the swelling ratio from 719% to 895%. The mechanical properties of hydrogel also increased by increasing the concentration of PVA as seen in the tensile strength value (0.365 MPa to 2.165 MPa) and the percent elongation (13.96% to 30.82%). The results of the FTIR spectrum showed the presence of the OH functional group at the absorption wave number 3284.42 cm-1 and a new absorption band appeared due to the cross-linking at the wave number 1303.88 cm-1 (C-C group).
Green Synthesis of Sulfonated Activated Carbon from Palm Kernel Shell as Potential Catalyst for Hydrolysis of Palm Bunch Cellulose Totok Eka Suharto; Cindy Wulandari; Dwita Oktiarni; Devi Ratnawati; Ibdal Satar
CHEMICA: Jurnal Teknik Kimia Vol 9, No 2 (2022): August 2022
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v9i2.24511

Abstract

Sulfonated activated carbon (SAC) is one of green catalysts that has been successfully synthesized from palm shell waste. The SAC catalysts have been tested in the hydrolysis of cellulose of palm bunch to simple sugar. The SAC catalysts were prepared from palm shell waste by converting to activated carbon followed by sulfonating step. The SAC catalysts were characterized by using XRD, SEM, FTIR and gravimetric methods. The SAC catalysts show as porous amorphous materials and have acidic properties, a prerequisite for good catalytic activity. Preliminary catalytic tests showed that the SAC catalysts can be used for the hydrolysis of cellulose from palm bunch waste that was shown by the existence of reducing sugar in the liquid product of hydrolysis.

Page 16 of 19 | Total Record : 189

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