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Abstrak :
Carbon Nanotube (CNT) merupakan material multifungsi yang akan dibutuhkan dalam jumlah besar di masa depan. Terdapat metode yang sangat menjanjikan untuk memproduksi CNT dalam jumlah besar yaitu dengan Chemical Vapor Deposition (CVD) dalam reaktor unggun terfluidisasi. Oleh karena itu, penelitian ini difokuskan untuk dapat menghasilkan model reaktor unggun terfluidsasi sehingga dapat dikembangkan menjadi reaktor skala pabrik yang mampu memproduksi CNT dalam skala besar secara efisien. Persamaan peristiwa perpindahan untuk fenomena fisik yang berlangsung dalam reaktor akan dikombinasikan dengan persamaan kinetika reaksi dengan menggunakan Computational Fluid Dynamics (CFD) dalam COMSOL Multiphysics sehingga dihasilkan sebuah model reaktor. Selanjutnya model akan disimulasikan dengan variasi parameter proses. Hasil simulasi menunjukkan bahwa profil konsentrasi metana dipengaruhi oleh suhu dinding reaktor, rasio umpan, laju alir gas, tekanan umpan, dan ukuran katalis. Konversi metana dan yield karbon meningkat seiring dengan peningkatan suhu dinding reaktor, kandungan hidrogen dalam umpan, dan kecepatan fluida di dalam reaktor. Sedangkan konversi metana menurun seiring meningkatnya tekanan umpan dan ukuran katalis. Konversi metana pada model reaktor unggun terfluidisasi yang disimulasikan adalah sebesar 77% dengan Yield CNT yang dihasilkan sebesar 0.66 gCNT/gCat dalam waktu reaksi selama 5 jam. ......Carbon Nanotube (CNT) is well known material having an unique properties and will become future materials. Promising way to synthesize a large scale of CNT is through the Chemical Vapor Deposition in fluidized bed reactor. Focus of this research is to get fluidized bed reactor model which representate the condition and performance in the real reactor. Method of this research is develop model of mathematic equation based on mass, momentum, and energy balance. COMSOL Multiphysics is used to develop the model and for running simulation for several process parameter such as temperature, pressure, etc. The simulation results show that the methane concentration profile is influenced by the temperature of the walls of the reactor, the feed ratio, gas flow rate, feed presure, and radius of catalyst particles. Conversion of methane and carbon yield increases with increasing temperature of the reactor wall, the addition hydrogen in reactant and the velocity of the fluid in the reactor. Conversion of methane decreases with increasing of feed pressure and radius of catalyst particles. In this model, conversion of methane was about 77% and Yield of CNT was about 0.66 gCNT/gCat for 5 hours of reaction.

Abstrak :
Fabrikasi Carbon Nanotube CNT secara komersial terhalang oleh biaya produks meliputi: sumber karbon, katalis, dan energi. Stainless steel merupakan substrat potensial untuk fabrikasi CNT, kandungan Fe dan Ni menjadikan stainless steel berfungsi ganda sebagai substrat sekaligus katalis. Pada penelitian ini stainless steel di preparasi dengan HCl 37,8 dan oxidative heat treatment 850 oC selama 30 menit. Penelitian ini bertujuan mengidentifikasi pengaruh oxidative heat treatment pada stainless steel dalam pembentukan CNT. Identifikasi dilakukan menggunakan sumber karbon asetilena dan kamper. Substrat stainless steel 304 divariasikan atas foil, pelat, dan wiremesh. Hasil penelitian dengan asetilena selama 20 menit pada ketiga variasi menghasilkan carbon loss diatas 90. Hal ini disebabkan peningkatan persentase Cr menghambat pembentukan nano partikel katalis. Dengan bantuan ferrocene substrat foil, pelat, dan wiremesh menghasilkan CNT dengan massa 0,0573 gram; 0,0701 gram; dan 0,1246 gram disertai penurunan carbon loss mencapai 30. Penggunaan substrat stainless steel 316 dengan kandungan Cr lebih rendah dan tambahan waktu sintesis menjadi 60 menit menghasilkan massa 0,6325 gram dan carbon loss 2,76. Identifikasi dengan menggunakan kamper selama 60 menit menghasilkan peningkatan massa CNT pada stainless steel 304 foil 0,831 gram; pelat 1,856 gram; wiremesh 2,6305 gram dan 316 pelat 2,1075 gram .

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Commercial CNT fabrication is hindered by its production costs including carbon sources, catalysts, and energy. Stainless steel is potential for CNT fabrication as Fe and Ni contents function as substrate and catalyst. Stainless steel is prepared with HCl 37,8 and 850 oC oxidative heat treatment for 30 minutes. This study aims at identifying oxidative heat treatment effect on stainless steel in CNT formation performed using the carbon sources of acetylene and camphor. 304 stainless steel substrates are varied including foil, plate, and wiremesh. By using acetylene for 20 minutes results in carbon loss above 90 increasing the Cr inhibiting the formation of nano particles catalyst. The addition of ferrocene decrease the carbon loss up to 30 and CNT of 0,0573 gram 0,0701 gram and 0,1246 gram are formed in foil, plate, and wiremesh. The use of 316 stainless steel substrate with lower Cr content and additional time of synthesis to 60 minutes yield a mass of 0,6325 gram and carbon loss 2,76 . The 60 minutes identification using camphor results in CNT mass increase in the 304 stainless steel foil 0,831 gram plate 1,856 wiremesh 2,6305 gram and 316 plate 2,1075 gram.

Abstrak :
Carbon nanotubes (CNT) were synthesized from liquefied petroleum gas by a chemical vapor deposition method using a Fe-Co-Mo/MgO supported catalyst. Metal loading was varied from 2.5 to 20 wt%. The catalyst with metal loading of 10 wt% produced the highest CNT yield, at 4.55 g CNT/g catalyst. This high CNT yield was attributed to the high pore volume of the catalyst. The diameter of the CNT was quite variable: the outer diameter ranged from about 4 to 12 nm, while the inner diameter ranged from about 2 to 5 nm. The catalyst with 10 wt% metal loading produced CNT with the highest surface area and the largest total pore volume. XRD analysis detected the existence of highly oriented pyrolytic graphite, C(002), at 2 theta ? 26o, which was attributed to the CNT.

Abstrak :
The production of Carbon Nanotubes (CNT) has a problem with the limited results of Aligned CNT (ACNT) products, due the fact that an effective and economical method has not yet been discovered. This research used catalytic decomposition of methane with the Water-Assisted Chemical Vapor Deposition (WA-CVD) method by using a bench-scale plate structured catalyst reactor and a fixed bed reactor. The Fe-Ni/Al2O3 Catalyst prepared by sol-gel/dip-coating and Ni-Cu-Al Catalyst prepared by co-precipitation were used to make the CNT. Transmission Electron Microscope (TEM) results show there are various types of nanocarbons produced, such as CNT, bamboo-shaped CNT and also quasi-spherical carbon onion shapes. Based on comparative results without adding the water vapor method, ACNT, which were obtained with WA-CVD, tend to grow vertically, even though they have not yet formed neat and uniform shapes. In addition, an increased number of CNT have high purity results. It shows that the role of water vapor significantly improves the quality of CNT.