Jurnal Rekayasa Kimia & Lingkungan
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Modeling and Simulation on NOx and N2O Formation in Co-combustion of Low-rank Coal and Palm Kernel Shell
NOx and N2O emissions from coal combustion are claimed as the major contributors for the acid rain, photochemical smog, green house and ozone depletion problems. Based on the facts, study on those emissions formation is interest topic in the combustion area. In this paper, theoretical study by modeling and simulation on NOx and N2O formation in co-combustion of low-rank coal and palm kernel shell has been done. Combustion model was developed by using the principle of chemical-reaction equilibrium. Simulation on the model in order to evaluate the composition of the flue gas was performed by minimization the Gibbs free energy. The results showed that by introduced of biomass in coal combustion can reduce the NOx concentration in considerably level. Maximum NO level in co-combustion of low-rank coal and palm kernel shell with fuel composition 1:1 is 2,350 ppm, low enough compared to single low-rank coal combustion up to 3,150 ppm. Moreover, N2O is less than 0.25 ppm in all cases.Keywords: low-rank coal, N2O emission, NOx emission, palm kernel shel
Optimasi Proses Ekstraksi Oleoresin Jahe (Zingiber officinale Rosc) Menggunakan Ultrasonik
The study on extraction of oleoresin from ginger by using ultrasonic was carried out in order to obtain the optimum condition of extraction process. The effect of ratio of ginger to solvent (ethanol, X1), extraction temperature (X2), and extraction duration (X3) are studied on the yield of oleoresin. Response surface design method with Central Composite Design (CCD) was used to obtain a mathematical model which describes the relationship between the yield of ginger oleoresin and influencing variables. The experimental results indicate that the optimum condition of extraction which yield of oleoresin of 11.026% was found at ratio of ginger to ethanol (X1) of 1:4.68 gr.ml-1, extraction temperature (X2) of 420 OC, and extraction duration (X3) of 79 minutes.Keywords: extraction, response surface method, ginger oleoresin, ultrasoni
Adsorpsi Surfaktan Nonionik Alkil Poliglikosida pada Antar muka Fluida-Fluida
Nonionic surfactants have been used extensively in various industrial applications such as cleaning, personal care, crop protection, paint and coating, textile finishing, emulsion stabilization, food and leather processing. In this study, we have studied the adsorption of three nonionic surfactants of alkyl polyglycoside, namely commercial APG from Cognis and APG produced from glucose as well as APG synthesized from sago starch, at fluidfluid interfaces. The variation of surface and interfacial tension with the concentration of surfactant in the bulk was studied, and the data were fitted using a surface equation of state derived from the Langmuir isotherm. The agreement between ?(c) data and Langmuir isotherm model was very good.Keywords: adsorption, air/water interface, interfacial tension, surface tensio
Penentuan Kondisi Optimum Ukuran Partikel dan Bilangan Reynold Pada Sintesis Bioplastik Berbasis Sorgum
The article reported the laboratory experiment to obtain the optimal condition of particle size and Reynold Number of bioplastic film based on the plastic package standard of High Density Polyethylene (HDPE). Particle sizes of starch were varied at 63, 90, 106, 600, and 1000 micron, and the mixing rate were changes at 190, 252, 313, 375, and 437 rpm. The concentration of chitosan and gliserol added to solution were set as constant variable as 20 and 10 wt %, respectively. The temperature of gelatinitation was also fixed at 95OC. The fabricated of bioplastic film were characterized for mechanical property such as tensile strength, elongation at break and Modulus Young by using a Universal Testing Machine. The morphology of film sheets were observed by using a scanning electron microscopy (SEM). Moreover, the obtained film was also investigated for water uptake parameter. The result showed that the mechanical properties were improve by increasing mixing rate at smallest particle sizes of starch. The water uptakes shows decrease at hight mixing rate. SEM images showed that the morphology of bioplastic was almost simmilar to the morphology of HDPE. The optimum condition was found that the best film was obtained at particle size of starch 63 micron, Reynold Number of 959, with mixing rate of 375 rpm. The mechanical value at best condition was 19.27%, 757.046 Mpa, and 142.875 for elongation, Modulus Young, and tensile strength, respectively.Keywords: bioplastic, reynold Number, starch, sorgu
Kualitas Papan Komposit dari Sekam Padi dan Plastik HDPE Daur Ulang Menggunakan Maleic Anhydride (MAH) sebagai Compatibilizer
The utilization of rice husk as raw material on preparation of composite board could be used as alternative and cheap construction material. In this research, the composite board was prepared by mixing fined rice husk, recycledhigh density polyethylene (HDPE) plastic. Maleic Anhydride (MAH) was added ascompatibilizer. The objective of this research is to develop an alternative and a cheap technologyon fabrication of composite board by utilizing rice husk waste as filler and plastic from the type of recycled HDPE plastic as matrix. In order to improve the compactness of rice husk and recycled HDPE plastic thus the addition of MAH as compatibilizer is carried out. The research aspect learned is the MAH addition variation as much of 4% and 8% from HDPE plastic weight, and the mixing ratios of filler and matrix which are 30:70; 40:60; 50:50; 60:40; 70:30. Casting process of the homogonized solution was carried out at casting temperature of 145oC for 20 minutes. The research result obtained indicates that the value of composite board density has fulfilled standard of SNI 03-2105-1996. The maximum water adsorbtion is obtained on composition of filler and matrixof 60:40 where with the addition of MAH 4% and 8% they are 10,1% and 6.9%, respectively. The addition of MAH as much of4% and 8% has resulted composite board with tensile strength value that has fulfilled SNI standard. Whereas the addition of MAH as much of 8% could increase modulus of rapture value of composite board i. e. 82.5 85.2 kgf/cm2and they have fulfilled standard of SNI 03-2105-1996.Keywords: Composite board, Maleic Anhydride (MAH), Recycled HDPE plastic, Tensile Strength, modulus of rapture
Penggunaan Ultrasonik untuk Transesterifikasi Minyak Goreng Bekas
In this work, the ultrasound-assisted transesterification of used frying oil (UFO) was studied. A two-step pretreatment of degumming and esterification was conducted to prepare UFO as raw material for transesterification. The esterification and transesterification was performed by using ethanol as solvent in the presence of ultrasonic irradiations operating at frequency of 40 kHz. The esterification was carried out with oil to ethanol ratio of 1:10, temperature of 60oC and reaction time of 4 hours in the presence of 1 wt .% H2SO4 as an acid catalyst. Meanwhile, the transesterification reaction was carried out with oil to ethanol molar ratio of 1:8, 1:10, 1:12, 1:15; KOH catalyst concentration of 0.5, 0.75, 1, 1.25 and 1.5 wt.%; and reaction temperature of 40, 50 and 60oC. The highest biodiesel yield of 65% obtained at ultrasound-assisted transesterification condition of oil to ethanol molar ratio of 1:12, reaction temperature of 50oC and KOH concentration of 1 wt.%. The results of analysis of some parameters of the product showed biodiesel has fulfilled the specifications according to the Indonesian National Standard (SNI) 04-7182-2006 number.Keywords: Biodiesel, Esterification, Used frying oil, Transesterification, Ultrasoni
Penentuan Nilai Penyerapan Suara Pada Panel Dinding Beton Busa Sebagai Panel Alternatif Yang Ramah Lingkungan
Panel of foam concrete wall is a type of membrane panel which has maximum sound absorption and can create quite and environmentally friendly room. The purpose of this study was to determine the magnitudeof the sound absorption value using the Sabine formula in Reverberation Chamber at Syiah Kuala University acoustic laboratory. The result of this study show that peak value curve sound absorption of 0.67 accurs at the frequency of 250 Hz, and painting of the panel surface can increase the value of sound absorption to be 0.76 at the frequency of 250 Hz,but the slope of sound absorption value sharply decreased to be 0.07at the frequency of 1000 Hz. Treatment on the panel surface can increase or decrease the value of sound absorption especially at the low frequency regions.Keywords: Panel of foam concrete wall, Sabine formula, The value of sound absorptio
Sintesis dan Karakterisasi Membran untuk Proses Ultrafiltrasi
Asymmetric ultrafiltration (UF) membranes were prepared from three kinds of polymer namely polyacrilonitryle (PAN), polysufone (PS), and cellulose acetate (CA) by phase inversion method. Water was used as non-solvent. These membranes were charachterized for ultrafiltration membranes i.e measurement of solvent permeability (Lp), Molecular Weight Cut Off membranes (MWCO) with various molecular weight of solute dekstran, and morphology of the membrane by Scanning Electron Microscopy (SEM). SEM analysis includes surface area and cross section area. Membranes with polymer low concentration 10% as PAN-1, PS-1 and CA-1 have the larger Lp from PAN-2, PS-2, and CA-2 that have concentration 15% for the same type of polymer. These occur because of the larger pore membrane than high concentration of polymer. SEM analysis showed a homogeneous distribution in the surface membrane and pore of membran like sponge structure from cross section area. Membranes CA-1, CA-2, FS-1 and FS-2 have Molecular Weight Cut off (MWCO) for the solute dextran 40000 Da. For PS-2 and PS-2 membranes have MWCO of dextran above 20000 Da.Keywords: ultrafiltration membrane, solvent permeability coeficient, MWCO, membrane morpholog
Performance of Mixed Matrix Membrane Adsorbers for Lysozyme Separation
An application of EVAL based mixed matrix membrane adsorbers containing a strongcation exchange resins (Lewatit SP 112 WS) for capturing of Lysozyme (LZ) has been investigated.The preparation and performance of the mixed matrix membrane adsorbers is studied with 1-octanol as additive. The membranes in this study are prepared by immersion precipitation out of a DMSO solution containing 14% EVAL and with or without 14% 1-octanol. All membranes contain 65% resin based on dry solids. The morphology of the membranes are characterized using scanning electron microscopy.The membrane structure demonstrated open and interconnected porous structure with large resin particles are distributed in membrane structure. The MMM adsorber proved high adsorption capacity for capturing and concentrating LZ in feed solution. The Mixed matrix membranes (MMM) concept was anticipated as a moderate process with an increasedcapacity and a maximum adsorption capacity of 166 mg LZ/g membrane. The MMM act in protein separations both as protein purifier and concentrator and is an attractive alternative for packed bed systems because of its high capacity, high throughput, robustness, and ease of scaling up.Keywords: Mixed Matrix Membrane (MMM), Lysozyme (LZ), Adsorption, Membrane adsorbe
Pembuatan Papan Komposit dari Plastik Daur Ulang dan Serbuk Kayu serta Jerami Sebagai Filler
Production of composites was done by mixing the filler and matrix. The common matrix used to produce composite is plastic ore with types of poly propylene, poly ethylene and others. To know the characteristics of composite boards made from recycled plastic type poly ethylene so this research was conducted. This research aims to create a composite board made of solid waste sawdust and straw as a filler and recycled plastics as the matrix and to find out more details of the influence of variable solid waste types and ratio of solid waste weight and plastic toward the quality of the composite board product. Composite board manufacturing process was carried out by hot press method at a temperature of 145 oC for 20 minutes. The composite board products are tested on value of hardness, tensile strength, and thermal value. The results showed that the use of sawdust as a filler resulted the composite hardness value that is better (R79,5) compared with straw (R67) at a ratio of filler composition: matrix of 80:20 respectively. The use of sawdust also gives the value of tensile strength of 6.86 MPa that is better than the using a straw that valued of 3.62 MPa at composition ratio of filler: to matrix (60:40). Largest amount of heat needed to melt the composite boards are 31.19 J/g and 14.02 J/g at composition ratio sawdust: recycled plastics of 80:20 and at composition ratio straw: recycled plastics of 80:20, respectively. Visually composite board with a composition of sawdust:plastic HDPE 50:50 looks better with bright colors and shiny.Keywords: Composite, Solid waste, Plastic, Matrix, Filler, Poly ethylen