Jurnal Rekayasa Kimia & Lingkungan
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Produksi Hidrogen Secara Fotokalitik dari Air Murni Pada Katalis NaTaO3
Get PDFStudy of hydrogen production as a green energy on NaTaO3 photocatalyst has been done. The aim of this work is to study the photocatalytic properties of NaTaO3 and NiO incorporated NaTaO3 used in water splitting reaction. The NaTaO3 powder with high crystallinity has been synthesized by a H2O2-asissted sol-gel route calcined at a temperature of 900 oC. NiO as a cocatalyst is deposited by impregnation of Ni(NO3)2.6H2O solution. The catalysts are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and diffuse reflectance UV-Vis (DR-UV-Vis). The photocatalysts have a band gap energy ca. 4.01 and 4.00 eV (corresponding to absorption edge of 310 and 311 nm). Photocatalytic activity towards hydrogen generation from water is investigated using a glass reactor under ultra violet (UV) light illumination. Photocatalytic of H2 and O2 production on the pristine NaTaO3 are 0.61 and 0.30 mmol g-1 cat.h-1, respectively. The activities are greatly enhanced 8.5 times higher by the incorporation of NiO as cocatalysts on the prepared oxides. NiO is found to give rise to more efficient photocatalytic activity for hydrogen evolution. The NaTaO3 nanoparticles produces using this facile have: better crystallinity, smaller size, and higher photocatalytic activity.Keywords: Sodium tantalum oxide; Nickel oxide; Sol-gel; impregnation; Hydrogen evolutio
The Phenomena of Spreading of Hydrotalcite Sol on A Porous Silica Surface Governed by Marangoni Effect
Get PDFWetting phenomena plays a crucial role in a wide range of technological applications. Spreading of liquids on solids involving phase change is encountered in many areas ranging from biological systems to industrial applications such as coatings, printing, painting and spraying. The fundamental study on wetting of membrane precursors namely hydrotalcite sols on a porous silica surface with different types of precursor material was successfully carried out. Relationship between the contact angle of a hydrotalcite droplet on silica surface and the Marangoni effect was also investigated. The presence of PVA in hydrotalcite sols was found to influence the rheological properties of the sols significantly, resulting in higher viscosity and ultimately leading to lower contact angle on solid surfaces. The degree of hydrotalcite's philicity on a substrate was improved by the addition of PVA solution. In this study, the spreading of a liquid droplet on a solid surface controlled by a surface tension gradient, due to Marangoni effect was found to drive better spreading of the liquid droplet. Marangoni Number, Ma was found to be proportionally related with the surface tension of the sols but inversely proportional to contact angles of the sols. Marangoni forces that decreased the contact angle, promoted spreading of hydrotalcite droplets on the selected glass substrates.Keywords: contact angle, hydrotalcite, marangoni effect, spreading, wetting evolutio
Sintesis Membran Poliuretan dari Asam Lemak Bebas Teroksidasi Tolulen Diisosianat
Get PDFPolyurethane (PU) membranes was prepared by reacting the free fatty acids and fatty acids that have been oxidazed from castor oil with a 2,4-toluen di-isocyanate (TDI). He effect of of monomer composition, temperature, and polymerization time was studied on the performances of flat sheet membrane. Experimental results showed that the optimum conditions of the membrane synthesis from free fatty acid by oxidation-methylation was obtained at ratio of 1.2: 0.56 (mol / mol), temperature of 100 C and polymerization time of 5 minutes. The resulting membranes are transparent, elastic, homogeneous, robust and has a glass transition point of 127.4 C and had stensile strength about 41.7 MPa. Infraredspectrum (IR) observation showed that the persistence of the peak CO from -NCO at wavenumber 2272.9 cm-1, whereas the -OH group was disaapear at wave numbers 3100-3300 cm-1. This indicated that the polymerization reaction of PU membrane synthesis from free fatty acids was done successfully.Keyword: Castor oil, free fatty acids, inframerah (IR), 2,4-tolulen di-isocyianat (TDI
Influence of Water-jet Nozzle Geometry on Cutting Ability of Soft Material
Get PDFHygiene is main reason for food processor to use waterjet cutting system. Traditionally food cutting process is low-quality, unsafe products, procedures and direct contact between product and labor. This paper introduced a low cost waterjet system for cutting soft material as identic food material. The low cost waterjet system has been developed by using a commercial pressure pump for cleaning purposes and modified nozzle. In order to enhance waterjet pressure for cutting products, a modified waterjet nozzle was designed. Paramater design of waterjet system was setup on nozzle orifice diameter 0.5 mm, standoff distance 15 mm, length of nozzle cylindrical tube 2.5 mm. Polycarbonate, polysterene, and polyethelene materials are used as sample product with thickness 2 mm, to represent similar properties with agriculture products. The experimental results indicate good possibilities of waterjet system to cut material in appropriate profile surface. The waterjet also can be used to improve cutting finished surface of food products. Therefore, utilizing a low cost commercial pump and modified nozzle for waterjet system reduces equipment price, operational cost and environmental hazards. It indicates viable technology applied to substitute traditional cutting technology in post harvest agriculture products.Keywords: cutting ability, modified nozzle, polymer material, water-jet syste
Hidrolisis Pati Sukun dengan Katalisator H2SO4 untuk Pembuatan Perekat
Get PDFBreadfruit starch is a unique resource which benefits for raw material of adhesive making. This study investigates hydrolysis method of breadfruit starch into dextrin with Sulphate Acid (H2SO4) catalysator. Dextrin hydrolysis is carry out in order to produce high dextrin percentage by subtracting the total glucose with free glucose. This study evaluates composition change because of breadfruit starch in various time and temperature. Optimum dextrin percentage is obtained at hydrolysis temperature of 100C, hydrolysis time 10 minutes, and 0.5 N H2SO4 concentration, with dextrin percentage of 77.12%. Furthermore, dextrin obtained is added by casein, cold water, triethanolamine, and water in order to form adhesive. The reserch result showed that the shear strength of the dextrin glue is 14 kg/cm2 which is larger than that of glue of Fox brands sold in the market that is only 12.48 kg/cm2. Because there is previous study regarding starch hydrolysis from breadfruit by using chloride acid catalysator, then data in this research show the influence of the sulphate acid usage as catalysator of adhesive. Based on the comparison, it seems that for breadfruit starch hydrolyzed at 100oC for 10 minutes, dextrin produced is less than that obtained by using chloride acid catalysator. The less dextrin percentage from breadfruit starch is caused by not all hydro sulphate ions are dissociated while mixing with starch. The mass balance is necessary to be completed including analysis of the breadfruit starch composition after hydrolysis to determine whether the starch has been degraded or not.Keywords: adhesive, dextrin, hydrolysis, shear strengt
Pengaruh Rasio Aditif Polietilen Glikol Terhadap Selulosa Asetat pada Pembuatan Membran Selulosa Asetat Secara Inversi Fasa
Get PDFPreparation of cellulose acetate (CA) membranes with ultrafiltration process had be done by phase inversion using dimethylformamide (DMF) as solvent. Poliethylene glycol (PEG) 1450 Da, as additive, was added with 10, 20, and 30% rasio of celluose acetate. The thin film of polymer solution was immersed on water bath coagulation at room temperature. The analysis of membrane morphology structure by Scanning Electron Microscope (SEM) JSM 5310 LV, Jeol-Japan showed the asymetric of membrane. The addition of PEG can improve the performance of the membrane. In resulting flux is higher than membranes without PEG. Increasing of PEG/CA ratio resulted in the higher flux with lower of rejection. The higher fluxes of water, dextran, and BSA are 146, 114, and 96 L/m2hr with 52,938 and 75,716% rejection for dextran and BSA.Keywords: cellulose acetate membranes, polyethylene glycol, ultrafiltratio
Pengaruh Kondisi Proses Terhadap Yield dan Kadar Lignin Pulp dari Pelepah Sawit dengan Proses Asam Formiat
Get PDFFormic acid pulping of oil palm frond was conducted to study the influence of process variables (formic acid concentration, hydrogen peroxide concentration, and pulping time) on the properties of pulp produced (yield pulp and lignin content). A second order polynomial model consisiting of three independent process variables was found to accurately describe the formic acid pulping of oil palm frond. The propose equations reproduce the experimental results for the dependent variables with erros less than 5% for both yield dan lignin content. The most influential factor on yield pulp was formic acid concentration. Whereas, the cooking time has greater influence on lignin content.Keywords: formic acid, lingocelulose, pulping, pulp organosolv, oil palm frond
Sintesis ZSM-5 dari Fly Ash Sawit Sebagai Sumber Silika dengan Variasi Nisbah Molar Si/Al dan Temperatur Sintesis
Get PDFPalm fly ash is biomass/waste in the palm oil industry. Palm fly ash has high content of amorphous silica. ZSM-5 is one of synthetic zeolite which is widely used as catalyst in industries. ZSM-5 has high activity and selectivity to several hydrocarbon conversion reaction. Hence, ZSM-5 is being investigated for the conversion of vegetable oil to hydrocarbon. It can be synthesized from silica and alumina. Sources of silica that can be added to the ZSM-5 synthesis, are sodium silicate, hydrated silica, water glass sol silica, gelled silica, clay, precipitated silicaand calcined silica. ZSM-5 was synthesized free-template by using palm fly ash as silica source. In this research synthesis of ZSM-5 was carried out in autoclave at 18 hours and Na2O/Al2O3 molar ratio by various molar ratio from 30 to 40 and temperature in the range of 150 to 190 oC. The product was then analized using FTIR method. The best ZSM-5 product was obtained at Si/Al molar ratio of 40 and process temperature of 150 oC. Keywords: FTIR, Palm fly ash, ZSM-
Konsep Dasar Proses Pembuatan Membran Berpori dengan Metode Non-Solvent Induced Phase Separation - Penentuan cloud point dan diagram tiga phasa
Get PDFApplication of membrane technology for separation processes has been an efficient optional to produce a high quality of separation product. This process has been widely using in many field of industry. Therefore, knowledge of this membrane preparation is important for controlling the pore size of resulted membrane. This paper explained the basic concept of membrane preparation via non-solvent induced phase separation (NIPS) process by immersion precipitation. The effect of concentration of polyethersufone on the formation of cloud point of dope solution in N-methylpirrolidone was investigated. Two kinds of non-solvent as water and ethanol were used in order to study phase separation mechanism of polymer solution. Base on the amount of non-solvent of water and ethanol needed for cloud point formation, the ternary phase diagram can be performed. The experimental result indicated constant concentration of polyethersulfone, amount of ethanol needed was higher than water to obtain cloud point formation of polymer solution.Keywords: cloud point of polymer solution, immersion precipitation, membrane preparatio
Perengkahan PFAD (Palm Fatty Acid Distillate) Dengan Katalis Zeolit Sintesis Untuk Menghasilkan Biofuel
Get PDFPalm Fatty Acid Distillate (PFAD) is a by-product of the manufacture of cooking oil. The PFAD has a high potential to be used as raw material for biofuel by catalytic cracking because it is a long-chain hydrocarbon. This research aims to study the influence of time and temperature conversion reaction to catalytic cracking reaction using zeolite catalyst synthesis. The PFAD cracking was taken place in a batch stirred tank reactor at the temperature of 240, 260, 280, 300oC for 60, 80, 100, 120 minutes. The changes in functional groups of cracking products were analyzed using FTIR (Fourier Transform Infra Red), while the analysis of components contained in the product was conducted using GCMS (Gas Chromatography Mass Spectra) analysis. The highest reaction conversion result (98.7%) was obtained at a temperature of 280oC and the reaction time of 100 minutes. The cracking process did not produce biofuels, but the compounds formed were in the form of tridecanoic acid (C13H26NO2), Cholest-8-en-3-ol (C28H48O) and methyl vinyl ketone (C4H6O).Keywords: FTIR, GCMS, PFAD, zeolite synthesy