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The Effect of Furnace Temperature and Precursor Concentration Ratio to The Characteristics of Nanocomposite ZnO-Silica Iva Maula; Widiyastuti Widiyastuti; Tantular Nurtono; Fadlilatul Taufany; Siti Machmudah; Sugeng Winardi
IPTEK Journal of Proceedings Series Vol 1, No 1 (2014): International Seminar on Applied Technology, Science, and Arts (APTECS) 2013
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23546026.y2014i1.323

Abstract

Zinc Oxide is a semiconductor with relatively non-toxic, cheap and abundant properties which can be applied to LEDs. ZnO colloids are unstable due to further chemical reactions and coagulation so the addition of silica is needed to inhibit the growth of ZnO. ZnO was synthesized using sol-gel method by hydrolyze zinc acetate dihydrate in ethanol solution. Silica colloids was prepared by dissolving waterglass in distilled water at a temperature of 60 °C then passed into cation resin that has been activated using 2N HCl for ion exchange with Na+ to H+. In this study, the spray drying method was used to produce ZnO-silica nanocomposite. Morphological characterization of particles formed was analyzed using Scanning Electrostatic Microscope (SEM) (Zeiss Evo MA LS, Cambridge, England). X-Ray Diffraction (XRD) (Cu-Kα 1.54 A0, 40 kV, 30 mA, X’pert Pro, PAN alytical, Netherlands) and Fourier Transform Infrared (FTIR) (Therniscientific Nicolet iS10, US) were used to analyze the crystallinity and group functionalization, respectively. The results show that more particles are formed on 10% concentration volume of ZnO colloids rather than 5%.
The Effect of Water Contents to Diesel Fuel-Water Emulsion Fuel Stability Suryadi, Joko; Winardi, Sugeng; Nurtono, Tantular
IPTEK The Journal for Technology and Science Vol 30, No 2 (2019)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (725.949 KB) | DOI: 10.12962/j20882033.v30i2.4997

Abstract

The declining world oil and gas reserves along with increasing gas emissions from fossil fuel consumption has received serious attention as an urgent problem worldwide. The alternative solution to the problem uses emulsified fuel which is expected to provide better combustion efficiency and will contribute to emission reductions, such as NOx and particulate matter (PM). The one of most important factor in emulsion fuel is its stability. In this work, the effect of water contents to stability of diesel-water emulsion fuels has been investigated. The stability of emulsion fuel related to coalescence and sedimentation formation. The diesel fuel-water emulsification process was carried out in a standard stirred tank consisting of a cylinder tank (93 mm in diameter) and Rushton disk turbine (40 mm in diameter). Materials used consist of diesel oil (Pertamina DEX), demineralized water, surfactants (Lecithin, Triton X-100 and Tween 80). The surfactant used is a mixture of Lecithin - Triton X-100 (76.6%: 23.4%) and Lecithin - Tween 80 (45.5%: 54.5%) at 1% total volume of emulsion. The impeller set in constant speed at 1900 rpm. To reduce emulsification energy consumption, water is added gradually into the tank at 2 mL/min of flowrate. Water content varies at 5%, 10%, 20%, and 40% by total volume of emulsion. Physical properties of emulsion fuel such as viscosity and density at room temperature were investigated periodically. The characterization of emulsion fuel stability was measured by slope value of absorbance ratio at wavelength 450 nm and 850 nm. Sediment formation was periodically by visual observation as emulsion phase percentage. Emulsion droplet size was measured by Dynamic Light Scattering (DLS) method. Physical properties of emulsions such as density and viscosity tend to constant value in order of time. Emulsion fuel with 5% water content has the largest volume of emulsion phase in the rest of time, 83 % for L-T emulsion fuel and 95% for L-Tx. The lowest slope value shown by 5% emulsion fuel water content, -8.657×10-5 for 5% L-T emulsion fuel and -2,084 × 10-4 for 5% L-Tx emulsion fuel. Droplet size measurement of emulsion shown that different amount of added water caused the different droplet size of emulsion.
Studi Fluidisasi dan Pembakaran Batubara Polydisperse di Dalam Fluidized Bed Berbasis Simulasi CFD (Computational Fluid Dynamic) Mochammad Agung Indra Iswara; Tantular Nurtono; Sugeng Winardi
Jurnal Teknik Kimia dan Lingkungan Vol 2, No 1 (2018): April 2018
Publisher : Politeknik Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1244.137 KB) | DOI: 10.33795/jtkl.v2i1.62

Abstract

Penelitian ini bertujuan untuk mengetahui fenomena pembakaran batubara dimana dimensi alat, distribusi ukuran partikel, dan jenis kualitas batubara menggunakan validasi dari penelitian Wang. Penelitian ini mengarahkan pada simulasi berbasis CFD. Kondisi operasi pada saat simulasi pembakaran dilakukan pada kecepatan bubbling. Metode yang digunakan sebelum melakukan simulasi pembakaran merupakan kelanjutan dari simulasi fluidisasi dimana masih menggunakan geometri 2-D fluidized bed lalu dilakukan meshing, selanjutnya memasukkan persamaan energi. Geometri fluidized bed yang digunakan berbentuk tabung dengan panjang silinder fluidized bed 1370 mm, diameter silinder 152 mm. Bahan yang digunakan pada penelitian ini berupa pulverized coal dengan jenis batubara Bituminous dimana ukuran partikel dianggap polydisperse dengan ukuran partikel 1 mm dan 1,86mm yang masing-masing sebesar 50% fraksi massa dengan kecepatan 0,2 Kg/s dan suhu 1200 K, dan udara luar yang diinjeksikan dengan kecepatan 0,8 m/s dan suhu 300 K. Analisa pengambilan data adalah berupa kontur fase padatan, kontur temperatur pada fase-1 dan fase padatan, fraksi massa produk pembakaran, massa padatan awal dan akhir simulasi dengan time step sebesar 0,0001 detik dan number of time step sebesar 300000. Selanjutnya data tersebut diplot menjadi grafik temperatur terhadap time step dan disajikan dalam setiap 1 menit simulasi selama 5 menit simulasi.This research aims to determine coal combustion’s phenomenon, where the device’s dimension, particle size distribution, and the quality of rank coal  which validated Wang’s reseach. This reseach leads on CFD simulation. The operation condition has did in bubbling velocity. This method is a continuation from fluidization simulation which is use 2-D Geometry and then used the meshing method, and enter the energy equation. The geometry of fluidized bed used was tubular cylinder with 1370 mm length and 152 mm. Materials used in this study was pulverized coal with Bituminous coal type which the particle size was considered as monodispers with particle size was 1.43 mm and polydispersed with particle size was 1 mm with 50% mass fraction and 1.86 mm with 50% mass fraction with flow rate 0,2 Kg/s and the temperature is 1200 K, and the outside air are injected in 0,8 m/s and 300 K. The analysis of data retrieval is solid phase contour, temperature contours in phase-1 and solid phase, mass fraction of combustion product, initial solid mass and final solid mass simulation with time step 0,0001 s and the numberof time step 300000. Then the data is plotted into a graph temperature vs time step and presented in 1 minute simulation for 5 minute simulation.