Seminar Nasional Teknik Kimia Kejuangan
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Pengaruh 5% MgO pada CuO-ZnO-Al2O3 sebagai Katalis Bifungsi untuk Sintesis Langsung DME dari Syngas pada Tekanan 15 Bar
Get PDFThe application of fossil fuels for transportation and household is one of the main reasons for environmental issues. Imports of liquefied petroleum gas (LPG) are continuously rising up to 70%, while domestic production is constant or even decreases. Therefore, the Indonesian government encourages to use dimethyl ether (DME) as an alternative energy for LPG to reduce import. The objective of this study was developing a catalyst based in CuO-ZnO-MgO-Al2O3 as a bifunctional catalyst for direct synthesis of DME from synthetic gas. The mineral composition in the proposed catalyst was about 31:16:53 by mass. The preparation methods of the catalyst include co-precipitation and 5 hours calcination at 350℃. The performances of CuO-ZnO-Al2O3 (CZA) and CuO-ZnO-Al2O3 with 5% MgO (CZMA5) were observed. The catalysts were activated using a mixture of 5% H2 and N2 as reducing gas. Furthermore, the activity of the catalyst was tested by conducting a direct synthesis of DME from a synthetic gas consisting of 65% H2, 28% CO, 7% N2. The DME synthesis was carried out in a fixed bed reactor at 15 bar, with two different temperatures of 260 and 280℃. The maximum DME yield achieved by 0,12% using the CZA bifunctional catalyst at 260℃ and 15 bar
Efek Kombinasi Natrium Hipokhlorit dan Pemutih Optis dalam Proses Bleaching dan Pengaruhnya Terhadap Kualitas Bahan Tekstil
Get PDFBleaching is a process that aims to eliminate the lignin content (natural pigment) in the pulp or fiber to obtain a high and stable color brightness. The fiber bleaching process must use reactive chemicals to dissolve the lignin content in the fiber to obtain a high degree of brightness. The bleaching process is affected by the amount of Natrium hipoklorit and Optical Bleaching Agent (OBA). The higher the use of Natrium hipoklorit as a whitening agent, the higher the percentage reduction in weight on the fabric and the white level on the fabric, the greater the weight. In this study the concentration we used was 20 ml, 40 ml, and 60 ml. The higher the experimental concentration, the higher the degree of white, the stiffness and the resulting flexibility. In the bleaching process using Natrium hipoklorit is also affected by the chemical Sky Stabilyzer which serves to slow down the decomposition of Natrium hipoklorit so that it can produce a maximum white degree
Pengaruh Konsentrasi KOH dan Suhu terhadap Adsorpsi Cu pada Limbah Cair Batik dengan Adsorben Bonggol Jagung
Get PDFIn Indonesia, corn is one of the staple foods with a high demand. However, corncobs are still considered as waste with very limited exploitation. This study aims to utilize corncobs as an adsorbent of copper (Cu) in batik dye wastewater which should not more be 2 mg/L when discharged into the enviroment. The analytical method to determine copper concentration was the Atomic Absorption Spectrophotometer (AAS). This research began with the production of corncobs as adsorbent in a furnace at the 350°C for 2 hours. The adsorbent was activated by KOH at various concentrations and was wet destructed by 65% HNO3. The result showed that the highest copper concentration in batik waterwaste was 23.306 ppm at 50°C while the lowest was 4.105 ppm at 75°C. According to KOH concentration, result showed that the highest copper concentration was 10.417 ppm at KOH 0.5 N and the lowest was 0,529 at KOH 2 N. Based on the mathematical analysis this adsorption follows the isotherm model suitable for Cu adsorption is the Freundlich model
Pengaruh Perbedaan Rasio Mol Gliserol dengan Asam Asetat dan Jumlah Katalis terhadap Konversi Reaksi Asetilasi Gliserol Menggunakan Katalis Karbon Teraktifasi-Asam Sulfat
Get PDFEsterification of glycerol with acetic acid produces highly important oxygenated biofuel additives, which are generally called as acetins namely, mono acetyl glycerol, di acetyl glycerol, and tri acetyl glycerol. Individually, each acetylated product has its own potential applications in various fields. Generally, esterification of glycerol is performed over homogeneous mineral acids. However, the use of these mineral acids is usually limited by several technical and environmental drawbacks. The challenge is to replace them with highly efficient heterogeneous solid acid catalysts which are easier to separate from the products, stable at high temperatures and less toxic. This study is to perform activated carbon catalyst on esterification of glycerol by varying molar ratio glycerol to acetic acid (1:3, 1:4, 1:5, and 1:6) and amount of catalyst (3%, 5%, 7% and 9%). The highest conversion was about 81.19% which was performed at 1:6 molar ratio and 5% catalyst amount
Pirolisis Limbah Pangkal Bambu Betung (Dendrocalamus asper)
Get PDFBamboo is one type of grass which is part of non-timber forest products. The chemical properties of bamboo contain of cellulose, lignin, pentosan, ash, and silica. This study using waste of betung bamboo base. To make tar from betung bamboo it is necessary to go through a pyrolysis process. Pyrolysis is a process of thermal decomposition carried out in an inert condition. In this study using the fast pyrolysis method where the main product is tar while charcoal and non-condensable gas are by product. Tar start producing at low temperature and ended at temperature above 600°C because of secondary reaction mechanism that cause tar start to decompose to gas and charcoal. This study using 500°C to 900°C with, 1 hour and 3 hours temperature process condition. The optimum mass result of tar reached at 1 hour 600°C is 19.2420 gram while at 3 hours 600°C is 13.1972 gram. Based on this research, it can be concluded that lower temperature process produced more tar and higher temperature process decrease mass of tar produced, in this case the optimum temperature for betung bamboo pyrolysis reached at 600°C
Efisiensi Penurunan Kadar Logam Cu pada Limbah Cair Industri Elektroplating dengan Proses Elektrokoagulasi
Get PDFLiquid waste in the electroplating industry contains heavy metals such as nickel, copper and zinc. If the waste is discharged directly to the environment without any prior treatment it will cause damage to humans and the environment. One method that can be used to treat this wastewater is electrocoagulation. Where electrocoagulation is an electrolysis process that requires electric power, electrical conductors and electrodes. The purpose of this research is to determine the efficiency of reducing the concentration of Cu in the variation voltage and stirring speed on the electrocoagulation processes. First and second order reaction rate constant have been evaluated. Eighty mL of electroplating waste is added to reactor, stirred using magnetic stirer in the variation of voltage (12,14,16 V) and in the variation speed (200, 300, 400) rpm. Every 40 minutes samples were analyzed using AAS. Electrocoagulation processes were stopped in 160 minutes. The results showed the highest efficiency in the variation of voltage and string speed are 95.92% and 96.81 % in that order. First order reaction rate constant in the variation stirring speed and voltage are 0,0163 s-1 and 1,8937 s-1 respectively. On the other hand second order reaction rate constant in the variation stirring speed and voltage are 0,0269 s-1 dan 3,9322 s-1 respectively
Pengaruh Konsentrasi H2SO4 (Asam Sulfat) pada Proses Hidrolisis dan Waktu Fermentasi Terhadap Pemanfaatan Limbah Sagu Menjadi Bioetanol
Get PDFBioethanol is a renewable alternative energy source that can be used as an alternative fuel. Bioethanol is a fermented product that can be made from substrates that contain carbohydrates (sugar, starch, cellulose). Sago pulp is a very abundant biomass that has not been utilized properly, so far sago pulp has only been used as fertilizer and animal feed. Biomass containing cellulose such as sago pulp can be converted into bioethanol through hydrolysis and fermentation processes. The purpose of this study is to examine the use of sago pulp as a raw material in the manufacture of bioethanol, determine the effect of sulfuric acid concentration on the hydrolysis process and determine the optimum time of bioethanol production by the method of separate hydrolysis and fermentation (SHF). The steps taken in this research were pretreatment of sago pulp using NaOH 1M. Acid hydrolysis using H2SO4 with variations in concentrations of 1 M, 2 M and 3 M at 100oC with a reaction time of 3 hours. The fermentation process uses Saccharomyces cerevisiae with a variation of fermentation time of 1 day, 2 days, 3 days, 4 days and 5 days. The results showed the highest sugar content was found in the hydrolysis process of sago pulp with the addition of 2M sulfuric acid concentration which was 134.08 g / L. The highest levels of bioethanol in the SHF process were also obtained at 4 days fermentation for 8% or 63.14 g / L
Kinetics Study on Lithium Leaching of Spent Lithium Iron Phosphate Batteries in Low Concentration of Sulfuric Acid
Get PDFRecovery of valuable metals from spent lithium iron phosphate (LiFePO4) batteries are quite challenging because it needs a lot of process. The recycling of these spent batteries can avoid environment contamination from the waste, meanwhile the valuable metallic components in the batteries including lithium can be treated as a resource for potential recovery of lithium. Low concentration of sulfuric acid (H2SO4) as a leachant and hydrogen peroxide (H2O2) as an oxidant, was used to leach elements from cathode materials of spent LiFePO4 batteries that mainly contained Li, Fe and P. Li could be selectively leached into the solution and while Fe and P was assumed to remain in the residue. The significant effects of acid concentration, solid-liquid ratio, reaction temperature and reaction time on the leaching rate are determined. Under the optimum conditions of 0.1 M H2SO4, 2 vol% H2O2, S/L ratio of 75g/L, 60 °C and 60 min, the leaching efficiency determined were 74.74% for Li and 0.99% for Fe. A leaching mechanism of shrinking-core model with diffusion through product layer control was proposed. It was found that the apparent activation energy was 12.69 kJ mol-1 as calculated by the Arrhenius equation together with an enthalpy (∆H) of 10 kJ mol-1 and an entropy (∆S) of -264.54 Jmol-1K-1
Pengolahan Pasir Silika Lokal Skala Pilot Plant sebagai Pengganti Pasir Standar Ottawa untuk Pengujian Kuat Tekan Mortar Semen
Get PDFThis research is the development of laboratory scale research on the use of local silica sand in Indonesia as a substitute for Ottawa standard sand for cement mortar testing. From several local silica sands in Indonesia, Sidrap sand originating from South Sulawesi was selected for further development on a pilot scale. Silica sand processing included the process of washing, drying, sieving or gradation in accordance with ASTM C778. The characterization of the processed silica sand included SiO2 content, sludge content, petrological analysis, roundness, and cement mortar compressive strength test at 3, 7 and 28 days and the results were compared to those of standard Ottawa sand