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Articles 349 Documents

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PEMANFAATAN EKSTRAK DAUN SAMBUNG NYAWA (Gynura Procumbens [Lour].Merr) SEBAGAI ANTIOKSIDAN PADA MINYAK KELAPA MENGGUNAKAN PELARUT METANOL Mersi Suriani Sinaga, Putri Defriska Siagian, Rika Ariska
Jurnal Teknik Kimia USU Vol 6, No 2 (2017)
Publisher : Universitas Sumatera Utara

Sambung Nyawa leaves (Gynura Procumbens [Lour].Merr) have been used as a traditional medicine. Sambung Nyawa leaves contain flavonoid compounds, its functional as a natural antioxidant. The aim of this study was to analyze the effect of Sambung Nyawa leaves extract addition as an antioxidant and ability to preserve the quality of coconut oil. Firstly, flavonoids were extracted from Sambung Nyawa leaves with combination of raw material to solvent ratio (w/v) and extraction temperature. The extracts which gave the highest total flavonoids contents were mixed into the coconut oil for 3 days, 6 days, 9 days, 12 days, and 15 days. Total flavonoids contents of Sambung Nyawa leaves extracts were analyzed by UV-Vis spectrophotometry. The analyses for coconut oil were the value of acid, iod, and peroxide number. The results showed that the highest total flavonoids contents of 1,32 % be obtained with raw material to solvent ratio of 1:10 (w/v) and extraction temperature of 55 oC. The lowest acid number of 0.45%, the highest iod number of 7.90 gr I2/100 gr, and the lowest peroxide number of 4.40 mg O2/100 gr be obtained with stored time of 3 days for coconut oil which mixed with the Sambung Nyawa leaves extracts.

OPTIMASI SINTESIS BIOSURFAKTAN KARBOHIDRAT ESTER DARI ASAM PALMITAT DAN FRUKTOSA MENGGUNAKAN ENZIM LIPASE TERIMOBILISASI Hiskia Arapenta Ginting, Zuhrina Masyithah, Tjahjono Herawan, Denny Samuel Silaen
Jurnal Teknik Kimia USU Vol 6, No 2 (2017)
Publisher : Universitas Sumatera Utara

Carbohydrate ester is one of many needed nonionic surfactant groups and has the potential to be an environmental friendly surfactant. The principal problem in the synthesis of carbohydrate ester is to obtain the optimum conversion of palmitic acid from temperature influence, the amount of biocatalyst and reaction time. The optimization of carbohydrate ester synthesis is carried out on three variables that influence the esterification reaction. Therefore, the esterification process is carried out by reacting directly the palmitic acid and fructose using a Novozyme®435 an immobilized lipase enzyme catalyst with a free variable of reaction temperature of 41,5 oC, 45 oC, 50 oC, 55 oC, 58,4 oC, the amount of biocatalyst is 6,63%, 8%, 10%, 12%, 13,36% mass based palmitic acid also reaction time of 7,6 hours; 24 hours; 48 hours; 72 hours; 88,3 hours and reacted with fixed variable in 500 rpm; 3:1 substrate ratio (fructose:palmitic acid) and solvent amount 10 ml. The mixture is then separated from the catalyst by filtration. The product was analyzed with determination of acid number to obtain conversion percent of fructose ester, determination of Hydrophilic Lipophilic Balance, Fourier Transform Infrared (FTIR) an surface tension determination. The optimum conversion rate obtained is 61,80% at 55 oC of reaction temperature, Novozyme®435 enzyme count is 12% and 72 hours of reaction time. From the result of fructose ester surfactant analysis obtained HLB 10,592 value which showed fructose ester surfactant can be used as emulsifier of oil in water.

METODE OPTIMASI PADA SISTEM PENGENDALIAN PROSES TANGKI PEMANAS BERPENGADUK Rudy Agustriyanto
Jurnal Teknik Kimia USU Vol 6, No 3 (2017)
Publisher : Universitas Sumatera Utara

In this research, PID (Proportional Integral Derivative) controller tuning was done using optimization method and the result was compared to the other well-known tuning methods (Direct synthesis, Ziegler– Nichols). The purpose of this research is to obtain the best output response when the set point and disturbance are changed. Tuning is a useful process to set the controller parameter that can affect the output response from the changing set point (servo problem) as well as from the disturbance (regulatory problem). The controller performance can be evaluated from the value of Sum Squares of Error when the system is controlled by PID controllers that is tuned with chosen method. The research result showed that optimization method was better than the other methods because it could give the best result.

MASERASI ALKALI DARI BATANG PISANG (Musa paradisiaca) MENGGUNAKAN PELARUT AQUADEST Lilis Sukeksi, Patima Valentina Haloho, Masniar Sirait
Jurnal Teknik Kimia USU Vol 6, No 4 (2017)
Publisher : Universitas Sumatera Utara

The purpose of this research is to determine the time of alkali absorption from banana stem in semibatch and batch. In this study maceration maseration is a leaching process used to obtain the time required for solvent to absorb alkali in banana stem ash. While the batch system maseration is a leaching process used to obtain the time required for the solvent to reach saturation point (stop absorbing). Data collection techniques in this research are: sample preparation and drying of banana stem, banana stalking process banana stem, brazing ash process of banana stem in semibatch and batch, and determination of alkaline content by titration method. From result of research can be concluded that banana stem potentially serve as source of alkali because potassium (K2O) and sodium (Na2O) content in banana ash sticks respectively 36,19% and 13,99%. Water content and yield of banana ash sticks were 78.6% and 17.7%, respectively. The time for the semibatch system is obtained in 72 hours, while for the batch system was obtained in 12 days. Normalities of alkali extracts in semibatch and batch maceration still increased. Where in the ratio of banana stem ash/solvent is 1 gram / 25 ml; 2 gram / 25 ml; 3 gram / 25 ml; and 4 gram / 25 ml respectively had a normality value that still increased from 0.219 N to 0.567 N; 0.407 N to 0.891 N; 0.578 N to 1,315 N; and 0.819 N to 1,345 N. The highest permeated alkali yield was obtained ratio (banana stem ash/ solvent) 1 gram / 25 ml of 52.37%.

PENGARUH KONSENTRASI KATALIS DAN WAKTU REAKSI PADA PEMBUATAN EPOKSI MINYAK GORENG BEKAS Yenni Listiana, Hilde Rosa Tampubolon, Mersi Suriani Sinaga
Jurnal Teknik Kimia USU Vol 6, No 3 (2017)
Publisher : Universitas Sumatera Utara

Epoxy is produced from an epoxidation of vegetable oil or natural oil with au nsaturated bond. Epoxy can be applied as a stabilizer, plasticizers in polyvinyl chloride (PVC) and can be used as an antioxidant in natural rubber processing, as a surfactant, anti-corrosive additive agent in lubricants and pesticide raw materials. The purpose of this research was to evaluate epoxy production from waste cooking oil. In this research, waste cooking oil was reacted with hexane as solvent, sulfuric acid as catalyst, glacial acetic acid and hydrogen peroxide. The catalyst concentration was varied from 1.5%, 2.1%, 2.5%, 3.1% and 3.5% and the epoxidation time was varied from 60, 120, 180, 240 and 300 min. The results showed that highest epoxy yield was achieved at reaction time of 300 min and 1.5% catalyst. At that condition, the iod number was 0,96 g I2/100 g WCO, oxirane oxygen content was 1.872 and oxirane oxygen conversion was 62.259%.

PEMBUATAN SABUN DENGAN MENGGUNAKAN KULIT BUAH KAPUK (Ceiba petandra) SEBAGAI SUMBER ALKALI Lilis Sukeksi, Andy Junianto Sidabutar, Chandra Sitorus
Jurnal Teknik Kimia USU Vol 6, No 3 (2017)
Publisher : Universitas Sumatera Utara

The purpose of this study is to examine the effect of reaction time and temperature toward the formed of soap product. This study begins by drying the skin of cotton and burning to gain the ash of cotton fruit skin. The combustion is done by using muffle furnace at 500 oC for 3 hours. Then, extraction is done on ash by using aquadest with a ration 1:3 to obtain alkali. This alkali will be used with cooking oil from palm in saponification process with fixed volume variable oil of 30 ml, velocity of stirring is 250 rpm, and oil volume : alkali volume 1:2 (ml). Whereas for the free variable are reaction temperature at 60 oC, 70 oC, 80 oC, stirring time at 60 minutes, 90 minutes, 120 minutes. The observed responses are density, acidity (pH), saponification number and free alkali. The best results were obtained at 80 °C and stirring time of 120 minutes with a density of 1.34 gr / ml, pH 9.1, saponification number of 200.349 and a 0.07% free alkali content.

PEMBUATAN BRIKET DARI KULIT KAKAO MENGGUNAKAN PEREKAT KULIT UBI KAYU Rosta Natalia Sinaga, Rosdanelli Hasibuan
Jurnal Teknik Kimia USU Vol 6, No 3 (2017)
Publisher : Universitas Sumatera Utara

This study aims to determine the effect of temperature variation carbonization, carbonization time and adhesive variation to charcoal characteristics of cocoa skin using cassava skin adhesive. Briquette is usually made using binder. Binder can embed charcoal each other to form strong and compact briquettes. Some other variables beside binder that influence the quality of briquettes include raw material, compacting presseure and carbonization process. This research used cocoa leather as raw material with cassava skin leaves as binder. All variables affect the content of fixed carbon of the briquettes that influence the caloricvalue of the briquettes. The caloricvalue is the most important factor for determining the quality of the briquettes. In this research, the highest caloricvalue of the briquettes was 4.375 cal/g. It was achieved when cocoa leather were carbonized by method 1 with compaction pressure of 85 kg/cm2 and binderconcentration of 15% where as raw material with particle size of 100 mesh. The caloricvalue of the briquettes was still very low and did not meet the qualification of Indonesian standard for briquettes. Based on the strength test, cassava skin leaves couldn’t be used as briquette’s binder. The produced briquettes that used cassava skin leaves as binder had soft structure and easily destroyed.

OPTIMASI SINTESIS ASAM AZELAT DARI ASAM OLEAT DAN HIDROGEN PEROKSIDA MENGGUNAKAN KATALIS ASAM TUNGSTAT Zuhrina Masyithah, Maria Paula Sihombing, Lawrena Valentine Br. Tohang
Jurnal Teknik Kimia USU Vol 6, No 3 (2017)
Publisher : Universitas Sumatera Utara

Azealic acid is an oleochemical product which is an output from oleic acid with oxidation cleavage process and commonly its aplication in polymer industry such as nylon production, plastic industry, glue industry and also as fiber in polyester industry. The purpose of this research is to obtain comparison design and analysis of variance in two method of synthesis azelaic acid namely one step and two steps oxidation. The result design reviewed by Response Surface Methodology using Minitab 17 trial version program with percent mass of the catalyst variable, molar ratio of the substrate variable and temperature variable. Based on the statistic analysis the percentage conversion (Y)in one step Y : 97,99 + 3,907X1 + 3,651X2 – 4,556X3 – 1,467X12 – 4,299X22 – 4,453X32 + 0,57X1X2 + 0,63X1X3 + 1,37X2X3 and for two steps Y : 98,505 + 6,164X2 + 2,164X3-7,83X22-5,18X32. The design has R2 = 92,80 % for one step and 89,95 % in two steps.

EKSTRAKSI TANIN DARI KULIT KAYU AKASIA DENGAN MENGGUNAKAN MICROWAVE: PENGARUH DAYA MICROWAVE, WAKTU EKSTRAKSI DAN JENIS PELARUT Iriany, Florentina Pandiangan, Christina Eka P
Jurnal Teknik Kimia USU Vol 6, No 3 (2017)
Publisher : Universitas Sumatera Utara

Tannin is one of complex polyphenol compound which soluble in polar solvent. Tannin could be extracted from acacia bark. This study aims to examine microwave-assisted extraction of tannins under influence of microwave power, extraction time, and solvent and its application to adsorb Cd and Cu. Tannin was extracted from acacia bark with feed-to-solvent ratio (1:20 g/ml). Power of microwave was adjusted 100 W, 180 W, 300 W, 450 W, and 600 W for 1 minute, 3 minutes and 5 minutes respectively using aquadest and ethanol as the solvent. The extracts were analyzed using UV-Vis spectrophotometer. Furthermore, the extract with the highest yield of tannins are used as the adsorbent. The concentration of Cd and cu were analyzed using Atomic Absorption Spectrophotometer. The result showed the highest yield of tannin 26.606 mg/g at 100 W and 3 minutes extraction time using ethanol as the solvent. The result showed that the adsorption capacity of adsorbent from tannin was 3.81 mg/g and 2.26 mg/g for Cd and Cu respectively.

EKSTRAKSI ABU VULKANIK GUNUNG SINABUNG UNTUK MENGHASILKAN SILIKA GEL Maulida, Melva Ginting, Herlinawati Wici
Jurnal Teknik Kimia USU Vol 6, No 3 (2017)
Publisher : Universitas Sumatera Utara

Silica gel is one of the silica based material. This research aimed to utilizetion volcanic ash of Sinabung mountains to make silica gel by extraction method. Volcanic ash was extracted using NaOH 4M for 30, 60, 190 and 120 minutes. Gel was formed by addip HCl 4, 6,and 8M. Sample were analyzed of using FTIR, SEM-EDX, gravimetri and AAS. Analysis silica sodium solution with concentration variation showed the biggest silica was 120 minutes. FTIR result indicated the presence of Si in volcanic ash and siloxane (Si-O-Si). SEM-EDX result silica content of silica gel was 51.96%. XRD result showed that diameter of silica was 33.412 nm and the crystallinity was 89%. Silica was applied on the largest Cu (II) absorption rate was130.725 mg/g with an adsorption efficiency of 98.66%.

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