Seminar Nasional Teknik Kimia Kejuangan
Not a member yet
523 research outputs found
Sort by
Pengawetan Ekstrak Pewarna Alami dari Daun dan Kulit Buah Kakao (Theobroma cacao L.)
Full text linkIndonesia has abundant natural resources that are very potential and prospective as raw materials for natural dyes, one of which is the leaves and skins of cocoa pods (Theobroma cacao L.). The purpose of this study is to determine the concentration of preservatives that can effectively inhibit the biodegradation reaction of natural dyes in the extract of leaves and skins of cocoa pods. Extracts of natural dyes that have been centrifuged and preservatives was added, then stored in a closed reactor. The preservatives used are benzoic acid and chitosan. Extraction is carried out for 20 days. Every 2 days, extract was analyzed from the reactor to determine the colorant concentration using gravimetric method. Besides benzoic acid, the same experiments was also carried out on another chitosan dissolved in 2% acetic acid solution. The results showed that the addition of benzoic acid and chitosan dissolved in 2% acetic acid solution can inhibit the biodegradation of leaves and skins of cocoa pods extract. Preservative concentrations of 0.50% benzoic acid and 0.25% chitosan are effective preservatives to inhibit the biodegradation reactio
Karakteristik Morfologi dari Formulasi Pupuk NPK Coated dengan Enkapsulasi Starch-PVA-Glycerol
Full text linkIn modern agriculture, the application of NPK fertilizer plays an important role in food security. However, most commercial uncoated fertilizers have low nutrient absorption efficiency with 30-70% nutrient loss, advances to financial losses for farmers and causing environmental issues. Slow-release fertilizer (SRF) is the best solution to decrease loss rate, supplying nutrients sustainably, and reduces potential negative environmental effects. These fertilizers are made by physically encapsulating NPK fertilizer with organic hydrophobic materials (starch-polyvinyl alcohol (PVA)-glycerol). Double layered encapsulation is formulated by in-situ copolymerization of starch with vinyl acetate monomer from PVA in different ratios. Glycerol is added to increase the film compatibility. Scanning Electron Microscope (SEM) followed by Energy Dispersive X-ray (EDX) analysis reveals the morphological characteristic of uncoated and coated NPK samples. The surface micrograph of uncoated NPK exhibits fine spire crystals that are intensely cemented on to the surface with some bigger crystals of potassium chloride. The gaps and pores are also visible. The SEM micrographs of coated NPK depict layering and agglomeration that is a clear indication of the coating. A higher ratio of PVA increases agglomeration on the surface of coated NPK, representing dense and complete coverage with less pores and cavities occur
The Effect of Complexity of Fuel Oil Composition Compounds on Desulphurization Degrees in Oxidative Desulphurization Processes
Full text linkOxidative Desulfurization is an alternative process to reduce sulfur content in fuel. ODS is an oxidation reaction of sulfur compounds in fuel, which contains various hydrocarbon compounds, using an oxidizing agent with the help of a catalyst. The polarity of fuel, sulfur compounds and catalysts is a critical success factor for ODS. This study aims to determine the effect of the complexity of the model fuel used in the ODS process on the degree of sulfur reduction. The complexity variable is considered by polarity, which is determined based on the dielectric constant of the compound using the mixed concentration average of the dielectric constant of the pure compound. The model fuel used in this study is a mixture of hydrocarbon compounds having 6 C atoms in the form of n-hexane, cyclohexane, and benzene. Dibenzothiophena is used as a representative of sulfur compounds with an initial concentration of 300 ppm in each sample. The independent variables that were varied were the composition of the model fuel and the ODS reaction time. Sulfur content in model fuel before and after ODS was analyzed using UV-Vis. Meanwhile, the dielectric constants of fuel and catalyst are determined using empirical equations. The results showed that the polarity of the model fuel changed depending on the composition of the constituent compounds. The ODS process resulted a decrease in DBT levels as a function of increasing the time reaction of ODS. Changes in the polarity of the model fuel solvent give different desulphurization results. The highest degree of desulphurization was obtained at 21% with the use of model fuel with a catalyst which had a dielectrict constant of 1.995
Production of Magnesium Silicate from Rice Husk with Variation of NaOH Concentration and Reaction Time Length Using Sol-gel Method
Full text linkRice husk is a by-product of rice production where as much as 9.9 million tons become organic waste. Rice husk ash, which is rich in silica, can be processed into materials that have high selling value. Magnesium silicate is one of the silica-based composite materials with the chemical formula MgSiO3 with an example of its application as a material in the manufacture of magnesium cement. The manufacture of magnesium silicate is done by sol-gel method with NaOH solvent where this method is relatively easy and uses simple equipment. This study was conducted to know the best NaOH concentration and length of reaction time to produce optimal magnesium silicate. The NaOH concentration variables used were 3 M, 5 M, 7 M, and 9 M, while the variable length of reaction time was 90 minutes and 150 minutes. The best NaOH concentration is 7M with 90 minutes of reaction time. This variable gave 49,9% yield of magnesium silicate compared to 3M with 90 minutes reaction time where it gave 17,4% yield. The analytical tests carried out were FITR where this test was carried out to confirm the formation of magnesium silicat
Studi Perancangan Material Komposit Berbahan Dasar Kitosan dan Selulosa Sebagai Langkah Pengendalian Limbah Tekstil Methylene Blue
Full text linkThe amount of methylene blue (MB) in water bodies is one of the environmental issues that still need to be considered. The vast concentration of MB may increase the chemical oxygen demand level, so it has the potential to disrupt aquatic ecosystems. On the other hand, the adsorption process is one of the best methods that functionalizes as a utility for dye removal. This research studied the MB adsorption characteristic using cellulose-based adsorbent from banana fronds. Adsorbents were synthesized and modified using chitosan, bentonite, and acid addition. The adsorption process occurred at various concentrations of MB (40, 60, 80, 100, and 120 ppm) then the result will be proved and calculated by analysis using UV Vis and FTIR Spectrophotometer. The result showed that the bentonite addition could not increase the adsorption capacity optimally due to fluctuating spectrum of UV-Vis. In conclusion, the adsorbent can absorb MB in wastewater which is the optimal condition at 80 ppm for 24 hours
Pengaruh Kosentrasi Pencampuran Tepung Bonggol Pisang Termodifikasi untuk Pembuatan Mie Basah
Full text linkBanana tuber flour is a type of non-wheat flour which has a high carbohydrate content so it has the potential to be processed into noodles. However, due to the low protein content and immature physicochemical properties, it is necessary to modify it enzymatically and mix it with wheat flour to obtain good quality noodles. This study aims to obtain enzymatically modified banana tuber flour with suitable characteristics for application in the manufacture of wet noodle products, as well as to obtain a formula (comparison of modified banana tuber flour and wheat flour) which can produce wet noodles that meet the SNI quality requirements. The treatment tested was enzymatically modified banana tuber flour substitution 10%, 20%, 30%, 40% and 0% were used as control variables. Wet noodle products were tested for water content and noodle organoleptic (smell, color and texture) according to SNI 2987:2015 wet noodle quality requirements. The results showed that the level of wet noodles met SNI standards, namely below 65%. The organoleptic test results showed that the best quality wet noodles were obtained from a combination of 10% modified banana tuber flour and 90% wheat flour with a concentration ratio of -amylase enzyme of 10%. The aroma test obtained a combination of 10% modified banana tuber flour and 90% wheat flour with a concentration ratio of -amylase enzyme of 40%
Thermal Stability Test and Formulation of Sodium Lignosulfonate with Isoamyl Alcohol as EOR Surfactant
Full text linkSodium lignosulfonate (SLS) is a promising low-cost surfactant that can be prepared from biomass. There has been large interest to utilize SLS as a chemical Enhanced Oil Recovery (EOR) surfactant. For that purpose, SLS is often mixed with other chemicals such as alcohols. The aim of this study was to find the best formulation of mixed-surfactant and to perform its thermal stability. The resulting mixed-surfactant was then characterized with variety of tests: aqueous stability, phase behavior, and IFT values. We found that a mixture that consists of 50 wt.% SLS, 30 wt.% Isoamyl Alcohol, and 20 wt.% of Palm Fatty Acid Distillate (PFAD) soap gave ultralow IFT at 1.864 × 10-3 mN/m. Phase behavior test shows that 1 wt% of mixed-surfactant formed a Winsor Type III. Subsequently, thermal stability test was conducted at 70°C for 90 days. The results showed that the IFT value fluctuates within the range of 10-3 mN/m for the first three weeks. After three weeks, the IFT values tend to increase to 10-2 mN/m until the end of the test. Hence, although ultralow IFT was achieved in the beginning of the test, further study is needed to improve the long-term stability of the present mixed-surfactan
Prediksi Kesetimbangan Cair-Cair pada Sistem Air + Asam Format + Pelarut Organik dengan Model UNIFAC
Full text linkFormic acid can be produced by a fermentation process, producing an aqueous solution in the form of a fermentation broth. The separation of formic acid from water is challenging due to the presence of an azeotropic mixture. The aim of this research is to predict the liquid-liquid equilibrium data using the universal functional activity coefficient (UNIFAC) model for formic acid + organic solvent + water systems at 298.15 and 323.15 K and atmospheric pressure (101.3 kPa). The liquid-liquid equilibrium data are required as a reference for optimal design of formic acid extraction process. This research also introduces new two-phase systems for the separation of formic acid from aqueous solution and expands the scope of thermodynamic studies on formic acid extraction. The extraction performance was in the order of MIPK > 2-hexanone > MIBK. The temperature has no significant influence on the extraction performance. The prediction of formic acid + water + MIBK system at 298,15 K and atmospheric pressure (101.3 kPa) was also compared with the experimental data with the RMSD 9,76 %. This result represented that UNIFAC was a reliable model for the prediction of liquid-liquid equilibria of system involving formic acid
Prediksi Data Kesetimbangan Cair-cair Pada Sistem Terner Air + Asam Laktat + Pelarut Menggunakan Model UNIFAC-DMD
Full text linkIndustrial lactic acid can be produced via chemical synthesis and fermentative production. However, due to the environmental issue and consumer preference, fermentative production of lactic acid is preferable. Lactic acid is used in many industries, including food processing, pharmaceutical, chemical and cosmetic industries. Various methods have been developed for separating lactic acid from its aqueous solution, and liquid-liquid extraction is considered as the most promising and efficient method. Liquid-liquid equilibrium data provide the basis for a rational design and optimal extraction operation. The objective of this study is to predict the liquid-liquid equilibria in the ternary systems of water+ lactic acid + solvent (MIBK, 2-pentanol, 1-hexanol) at temperatures of 303.15 K and 313.15 K and atmospheric pressure (101.3 kPa) using the UNIFAC-Dortmund (DMD) model. The distribution coefficients and separation factors were determined to evaluate the extraction performance of lactic acid. The extraction performance was in the order of MIBK > 1-hexanol > 2-pentanol. The prediction of lactic acid + water + MIBK system at 303,15 K was also compared with the experimental data with the RMSD 2,5 %. This result represented that UNIFAC-DMD was a reliable model for the prediction of liquid-liquid equilibria of system involving lactic acid