Liquefied petroleum gas

molten crude oil botch upDirect Flame Production of hundred Nanotubes (CNTs) From Liquefied Petroleum Gas (LPG)AbstractLiquefied petroleum gas (LPG) is a common rest home fuel use for cooking purpose in India. LPG is very rich in its carbon content because of its special(prenominal) mixing components of predominantly C3 alkane (Propane C3H8) or C4 alkane (Butane C4H10) which provides a better chance of producing strong and soundly quality nano products like nanotubes, nanotubes nanowires, nanoparticles etc. In our laboratory a lab scale flame reactor is intentional and developed for producing carbon nanotubes exploitation LPG as the carbon source in the presence of breed as an oxidant under atmospheric conditions. The design aspects and the best operational conditions of the flame reactor for producing carbon nanotubes atomic number 18 discussed. The nanotubes obtained were purified and were further characterized using SEM, TEM XRD and Raman.KEYWORDSCarbon Nanotubes (ca rbon) TEM (Transmission electron microscopy) LPG (alkanes) Raman (Raman spectroscopy) XRD Flame Synthesis1. IntroductionLiquified petroleum gas (also called as LPG or Autogas) is a mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles and it is increasingly replacing chlorofluorocarbons as an aerosol propellant and a refrigerant to reduce the damage and degeneration of the ozone layer. LPG is a clean, convenient vigour source, which can be stored as a liquid under moderately high pressure and used as a gas in commercial and residential heating applications. It is a common household fuel used for cooking purpose in India, LPG is rich in its carbon content because of its specific mixing components of predominantly C3 alkane (Propane C3H8) or C4 alkane (Butane C4H10) which provides a better chance of producing strong and good quality nano products like nanotubes, nanotubes nanowires, nanoparticles etc.Carbon nanotubes (CNTs) are among the amazing objects tha t science sometimes creates by accident, with let out nitty-gritty to, but that will likely revolutionize the technological landscape of the century ahead. Our society stands to be importantly influenced and shaped by carbon nanotube applications in every aspect, Carbon nanotubes read been compoundd for a immense time as products from the action of a catalyst over the gaseous species originating from the thermal decline of hydrocarbons 1. Since their discovery by Sumio Ijima 2 several ways of preparing them have been explored. The CNTs have been synthesized by confused methods e.g. electric arc discharge, laser evaporation and chemical vapor deposition (CVD) 3-5.Though researchers have been successful to synthesize multi-wall nano tubes they can beget only in milligram to gram quantities in a a few(prenominal) hours. However as many an(prenominal) potential applications 6-7 of CNTs require kilogram to ton quantities.Apisit Songsasen et al 8 have synthesized CNTs by means of catalytic decomposition of LPG on a Zeolite-supporting Nickel catalyst. Qian et al 9 have describe the formation of CNTs by the decomposition of liquefied petroleum gas (LPG) containing sulfur in the presence of Fe/Mo/Al2O3 catalyst, Since this contains sulfur of a few to several hundred ppm, which can lead to poisoning the catalyst heavily, few reports currently exist on using LPG or natural gas directly for production of carbon nanomaterials, only Prokudina et al 10 has reported CNT synthesis from LPG by CVD method, but till date no information and literature is reported on direct flame synthesis of CNTs by LPG. The main challenge in this field is to develop methods to start nanotubes on a bountiful scale and at low cost. As Flame synthesis of nano carbons creation a continuous flow method, in which flowing gaseous feedstock mixture could produce CNTs in large quantities it has several advantages like easy scale up, particle size control, dual role of feed gas which serves bo th as carbon source and fuel, and in-situ generation of catalyst. Hence it is one of the preferred methods for start production of not only CNTs but also other nano particles and nano metal oxides. This method is very multipurpose and is of widespread importance.Many groups have investigated gas-phase continuous-flow production of carbon nanomaterials using other hydrocarbons. These studies typically involve transition a mixture of carbon source gas and organo metallic catalyst precursor molecules through a heated furnace. In this paper we report the direct flame synthesis of carbon nanotubes using LPG and air as our gaseous feedstock in a diffusion image burner without any external use of a catalyst and synthesis at optimum process parameters.2. ExperimentalThe flame reactor (Fig.1) has been indigenously designed to produce carbon nanotubes at our university. The detailed setup and process instrument and diagram (PID) of the reactor (Fig. 2) has been discussed in detail in our previous work 11. In general our reactor operates under atmospheric pressure. The metric quantity of the LPG and the oxidant reaches the ignition chamber where the partial combustion process occurs where the CNTs are produced. During the process we have observed the dark orange flame color which is perfectly in a spindle form. on the entire length of the flame, its temperature was recorded using a K-type thermocouple where this temperature can provide some selective information regarding the growth of nanotubes. The soot thus produced is captured on a glass fiber filter (Axiva GF/A) with the aid of a vacuum pump and the collected soot is scrapped carefully and weighed and later heat treated and oxidized at 550 OC in the presence of air for 60 minutes to remove any traces of amorphous carbon impurities and and soce the sample is reweighed in order to estimate the loss of amorphous carbon as an impurity then the samples are later characterized by SEM, TEM, XRD and Raman for their q uality. The total amount of thermally oxidized and purified sample from the experiment (for 30 minute run) weighed only 0.8g.3. Results and Discussion3.1 Scanning Electron Microscope AnalysisThe samples were analyzed using Phillips XL 30 serial Scanning Electron Microscope (SEM) from National Center for Compositional Characterization of Materials (NCCCM), Hyderabad. From the Figs (3a 3d) we can see a laboured growth of carbon nanotubes at various flow rates with respect to the oxidant to fuel (O/F) ratios between 0.7 1.0 slpm/slpm (standard litre per minute). The total diameter range of the CNTs from the SEM image was found to be around 200 nm -1000 nm and lengths greater than 40 m.3.2 Transmission Electron Microscope AnalysisThe TEM (Technai -12, FEI) images (Fig 4a) shows the presence of thickly packed multiwalled CNT with an average diameter of 150 250 nm which is still surrounded by traces of carbonaceous nanoparticle aggregates possibly caused due to the sprinkling of the sample in the solvent. This can be assumed that the agglomerated carbon nanoparticles were actually protected by the CNTs during the thermal treatment, as the CNTs might have formed a net like layer coating the nanoparticles and protecting it from the heat and oxidation. Fig 4b shows a thick multi walled CNT around 250 nm in its diameter with tons of traces of agglomerated carbon nanoparticles which can be accounted for the presence of C60 particles which is also in agreement with the XRD analysis in Fig 5. The broken caps of the CNTs also reveal the disorientation and a defective growth of the grapheme layers as seen in the Raman analysis in Fig 6.3.2 X-ray Diffraction AnalysisThe XRD (PW1830 Phillips) analysis was carried out using CuKa1 type of radiation with a wavelength (l) of 1.54060 . XRD (Fig. 5) of nanotubess produced using LPG-air at an O/F ratio of 0.7 slpm/slpm shows a heterogeneous crystallinity in the sample. The raw scan detected three strong peaks. The first peak at 2 go of 25.77O was found with (110) orientation of atoms along its plane with peak same to graphite with an orthorhombic type of system and an end-centered lattice. The molybdenum peak at 2 angle of 43.159O was found with (245) orientation of atoms along its plane with peak corresponding to C60 molecule with a cubic type of system and a primitive lattice. The third peak at 2 angle of 83.475O was found with (112) orientation of atoms along its plane with peak corresponding to graphite with a hexagonal type of system and a primitive type lattice respectively.3.2 Raman AnalysisRaman analysis (Horiba Jobin Yvon T64000, Raman Spectrophotometer) was carried out only on the best sample (Fig.6) which clearly shows the D band G band respectively. The D band (the disorder band is wholesome-known in broken in graphitic materials and located between 1330-1360 cm-1 when it is excited with a visible laser) it is expected to be observed in Multi Walled Nanotubes (MWNT). However when the D band is observed in SWNTs 12, it is assumed to contain defects in the tubes. The G band or (TM- Tangential Mode) 12, corresponds to the stretching mode of the -C-C- stay in the graphite plane 12. This mode is located near 1580 cm-1. From the figure we can say that the nanotubes are in the slightly disordered graphite phase based on the D band wavelength record at 1349 cm-1. This D band also confirms the presence of amorphous state of carbon in the mass sample. Based on the G band from the figures, there appears two peaks at 1560 and 1600 cm-1 respectively which proves the presence of multi layers of disordered graphene sheets. On analyzing the level of graphitization using the D and G band intensities ratio, we find that the sample is normally well graphitized with small degree of crystallinity and its ID/IG ratio was found to be around 0.939.4. ConclusionsCarbon nanotube (CNT) is a versatile group of applied chemicals with high degree of applications on larger scale in various disciplines. The synthesis, purification and the cost still remains an un-doubted debate around the world hence an economical blast is to be developed in order to produce large amounts of good quality CNTs from an economical and a resourceful fuel. LPG as a general commodity plays a major role since its availability in India is high and it is a very economical source of fuel as well. Here, we were able to successfully synthesize semicrystalline, CNTs from LPG with an average diameter of 100 500 nm using the direct flame synthesis approach.References1. Bharat Bhushan, springer spaniel Handbook of Nanotechnology, Springer-Verlag Berlin Heidelberg, New York, 2004, Chap 3, pp 39 40.2. S. Iijima, Nature 354, (1991), 56.3. T.W. Ebbesen and P.M. Ajayan, Nature 358, (1992), 220.4. T. Guo, P. Nikolaev, A.G. Rinzler, D. Tomanek, D.T. Colbert and R.E. Smalley, J. Phys. Chem. 99, (1995), 10694.5. J. Kong, A. M. Cassell and H.J. Dai, Chem.Phys. 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