Papers by Keyword: Toluene

Abstract: Used cooking oil is potential as raw material to produce biodiesel. We discovered fatty acid ethyl esters (FAEEs) and methyl esters (FAMEs) as biodiesel content indicator from esterification and trans-esterification reactions of used cooking oil with sulphuric acid and toluene sulphuric acid as catalysts. The purpose of this study was to examine some characteristics of FAEE and FAME synthesis from used cooking oil. The FAEEs and FAMEs were detected by separation in thin layer chromatography (TLC) and Fourier Transform Infrared (FT-IR) and compared to laurate standar. The used cooking oil was produced after frying of meat chicken for seven hours in a household. The Retardation Factor (R_f) of TLC of FAME of methyl laurate was 0.36 and FAEE of ethyl laurate was 0.23. The wavenumber indicating specific functional group of =CH was 3392 cm^-1, while of alcohol as ester compound was 1739.79 cm^-1. The wavenumber of C-C and CO groups were 1635.64 cm^-1 and 1165 cm^-1, respectively. These indicate the ester group in used cooking oil, which reflects the formation of bio-diesel.

Abstract: The present work deals with the investigation of the transformations of the solid and liquid phases at high energy planetary ball milling of toluene together with titanium powder. The sequence of structural toluene transformations using FT-IR spectroscopy was investigated. Phase constitutions and morphology of ball milled titanium powders were studied by X-ray diffraction and scanning electron microscopy. It is shown that mechanically induced destruction of toluene occurs by the mechanism of catalytic cracking. During ball milling, concentration of aromatic hydrocarbons in the liquid phase decreases, at the same time the content of alkenes, cycloalkanes, and isoalkanes increases. The main solid products of the mechanosynthesis were cubic and hexagonal titanium carbo-hydrides.Evolution of lattice parameters, crystallites sizes, and micro-stresses of the solid phases during ball milling as a function of the mechanical energy dose have been discussed.

Abstract: Two series of Ag-loaded β-zeolites with silica/alumina ratio of 25 and 36 were prepared by ion exchange technique. The silver loading was varied in a range of 2-10 wt%. The samples were characterized by low-temperature nitrogen adsorption, Infrared and UV-vis spectroscopy, and transmission electron microscopy. Adsorption/desorption properties of zeolites were examined using a specially designed setup. Toluene was used as a model hydrocarbon. It was found that adsorption capacity of zeolites grows up along with silver content increase till 8%, and reduces then. According to data of physicochemical methods, at low loading the silver exists in cluster and ionic forms, while at high loading agglomerated particles predominate, which worsens the adsorption properties.

Abstract: Vehicles are the dominant source of many air pollutant emissions in urban areas. The effects caused by vehicle emissions have been receiving increasing attention, and recent epidemiological studies show elevated risks of cardiovascular morbidity, cancer, allergic diseases for drivers, commuters and individuals living near roadways. During the experimental research conducted in this paper, emission characteristics of Otto 1.1 EFI engine were investigated in varying operating modes in order to adequately simulate the movement of the Fiat Punto Classic (FPC) passenger car in city driving conditions in line with the New European Driving Cycle (NEDC). The NEDC is a stylized cycle, with periods of constant acceleration, deceleration and constant speed, and it is supposed to represent the typical usage of a passenger car in Europe. The analysis of exhaust gas samples was conducted by using the gas chromatography technique in combination with the photoionization detector (GC/PID). The results of emission tests indicate high concentration levels of toluene in the exhaust gas mixtures, ranging from 7.07 to 116.87 ppm. The total mass of the emitted toluene after 100 km of driving in accordance with the NEDC was 7.7647 g.

Abstract: Crosslink concentration is an important property affecting the major characteristic of cured rubber. One of the important parameter to determine the crosslink concentration of a vulcanized rubber by swelling measurement is the rubber-solvent interaction parameter known as ‘kai’ value denoted as χ. For single rubber, the χ value is known however, the χ_1,2 for rubber blends are unknown. This research concerned with the investigation to determine the χ_1,2 for rubber blends solution (uncured rubber). Natural rubber (NR) and styrene butadiene rubber (SBR) rubber blends solution were blend at 7 different ratios of 100/0, 80/20, 70/30, 60/40, 50/50, 40/60 and 0/100 and were dissolved in toluene. The χ_1,2 value of each rubber blends were determined based on the intrinsic viscosity measurement. Crosslink concentrations of vulcanized rubber blends obtained from the swelling measurement were then compared against the value determined from simple extension measurement (stress-relaxation method). This cross-checking was to ensure the accuracy and reliability of χ_1,2 value for rubber blends solution.

Abstract: Concern about environmental protection has increased over the years and the presence of volatile organic compounds (VOCs) in water poses a threat to the environment. In this study, coconut shell activated carbon (PHAC) was produced by potassium hydroxide activation via microwave for benzene and toluene removal. Equilibrium data were fitted to Langmuir, Freundlich and Tempkin isotherms with all the models having R² > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238mg/g for benzene and toluene, respectively. The equilibrium parameter (R_L) falls between 0 and 1 confirming the favourability of the Langmuir model. Pseudo-second-order kinetic model best fitted the kinetic data. The PHAC produced can be used to remediate water polluted by VOCs.

Abstract: Work is devoted to the study of new catalysts on the basis of polymermetalyc complexes of transition metals in the oxidation of toluene. Catalytic agents on the basis of iron (III) complexes with the copolymer polietilenimin-polyacrylic acid put on a silicate substrate have been investigated. Special attention is paid to study influence of physical and chemical parameters on oxidation process, to fixing of kinetic and thermodynamic indexes of process.

Abstract: Polycarbosilane (PCS) fibers have been made using a solvent which is a mixture of N,N-dimethylformamide (DMF) in toluene. Polycarbosilanes (PCS) obtained from NaBond with concentration 1.2 g/ml dissolved in solution toluene and N,N-dimethylformamide (DMF) was stirred gently for 24 h at ambient temperature. DMF was mixed with toluene at ratios 22%, 24%, 26%, 28% and 30%. Electrospinning apparatus (nanoE-Spinning) from NaBond was used. In a vertical electrospinning set up, the solution in a glass syringe delivered to the tip of a 6-gauge (0.5 mm inner diameter) stainless steel needle. The tip to collector distance was adjusted to 100 mm with applied high voltage at 10kV. A stainless steel plate with dimension 100 mm x 100 mm wrapped by aluminum foil was used as collector. The electrospinning non-woven fiber was cured at temperature 200°C (2°C/min), for 1h, 1.5h, and 2h, and fibers with DMF concentration 30% was also pyrolysis at 1000 °C for 3 h in inert atmosphere. The samples were tested and observed with FTIR spectroscopy, and SEM-EDS apparatus. The results showed that PCS fibers can be made from dissolving PCS with toluene with the addition of DMF to increase the polarity of the solvent and the formation of fibers is done by using electrospinning which is supported by the presence of voltage from the outside. Fiber curing is done at 200 °C to evaporate the toluene, the DMF, and resulting stronger fibers than before. The addition concentration of DMF in toluene and curing time will affect the composition of the resulting PCS fiber. Curing time on PCS fibers will affect the composition of solvents such as DMF and Si-H bond on which to assert their PCS fiber cross linking conditions. PCS fiber morphology is known of changes in fiber diameter and fiber uniformity. Smallest PCS fiber average diameter 4.81 μm resulted from 28% DMF with curing time 2 hours and the largest achieved from 22% DMF with curing time 1 hour around 14.22 μm. Composition of pyrolyzed fiber was SiO_0.587C_0.413, with average density 3.1033 g/cc and average diameter the fiber was 3.06 μm.

Abstract: Experimental study the degradation efficiency of toluene by bipolar corona discharge coupled with TiO₂ photocatalysis. Bipolar corona discharge can degrade the toluene efficiently and rapidly, the final products are mainly carbon dioxide and water. Toluene removal efficiency reduces when the initial concentration of toluene increasing, while toluene removal quantity is increased. Removal of toluene decreases with the gas flow rate increasing, the removal quantity first increases and then decreases. Bipolar corona discharge and a photocatalytic coupling can inprove the degradation efficiency further. Increase of the applied voltage help to improve the removal of toluene, and also to improve the coupling effect of the photocatalyst. In optimized conditions, the removal efficiency of toluene can be more than 90%. The chemical reaction process of the toluene oxidation and the TiO₂ catalysis mechanism are discussed. It is pointed out that the OH* produced by corona discharge has important significance for rapid oxidation of toluene.

Abstract: The goal of this research was to synthesize two different catalysts, namely K-OMS-2 and MnO_x. The K-OMS-2 was an octahedral manganese complex prepared by hydrothermal method, while manganese oxide (MnO_x) was directly synthesized by precipitation method. Both catalysts were employed to decompose toluene, an organic solvent that is widely used in industries. The catalysts were characterized by means of X-ray diffraction (XRD) and N₂-physorption. The surface areas of K-OMS-2 and MnO_x were 83.50 and 20.04 m²/g, respectively. The precipitation route gave XRD patterns of γ-Mn₂O₃ structure_, and a successful structure of an octahedral molecular sieve manganese oxide was obtained by the hydrothermal method. The toluene degradation was carried out in gas hourly space velocity (GHSV) range of 20,000-60,000 h^-1 with toluene concentration of 7,700 ppmv. The higher GHSV over K-OMS-2 gave the lower contact time consequently resulting in the lower %toluene degradation, whereas the best GHSV over γ-Mn₂O₃ was suitable at 40,000 h^-1. The complete oxidation temperature of toluene over K-OMS-2 occurred at 260 °C and was lower than the temperature by γ-Mn₂O₃ at 300 °C. The higher surface area of K-OMS-2 may not facilitate internal toluene diffusion to active K-OMS-2 sites because molecular toluene (5.6 Å) cannot migrate through its smaller pore diameter (4.6 Å); however, the fully oxidized K-OMS-2 can provide higher average oxidation state (AOS) and higher amount of lattice oxygen assisting toluene degradation compared to γ-Mn₂O₃. The full factorial design of experiment (DOE) exhibited a strong effect of temperature and catalyst types on toluene removal; in contrast gas hour space velocity (GHSV) exhibited no significant effect on %toluene removal even with increasing GHSV.