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Applied Chemistry and Physics
Published in Robert A. Burke, Applied Chemistry and Physics, 2020
Prefixes may be added to hydrocarbon compounds. These prefixes indicate the number of what ever the prefix is shown in front of. Di is two, tri is three and tetra is four. Alkanes and alkenes are sometimes found with different structural formulas than the usual straight chains. These are referred to as isomers. An isomer is a compound that has the same molecular formula as the straight chained version, but a different structural formula. This concept is also referred to as branching (Figure 3.47). This has the effect of lowering the boiling point of the material. For example, butane has a boiling point of around 31°F. It can be used as a heating fuel like propane. Butane and propane are stored and used at ambient temperatures. However, with the boiling point of 31°F, the areas in the country where butane could be used in the winter would be limited by the winter time temperatures. If, however, butane is branched to form isobutane, this process lowers the boiling point of butane to around 10°F, making butane more useful as a heating fuel in many colder parts of the country.
Chemicals from Paraffin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
In the IUPAC system of nomenclature, however, the name butane refers only to the n-butane isomer (CH3CH2CH2CH3). Butane derivatives are highly flammable, colorless, easily liquefied gases that quickly vaporize at room temperature.
Overview of Oil Refining Process Units
Published in Soni O. Oyekan, Catalytic Naphtha Reforming Process, 2018
Butane is produced with other gases in an oil refinery from atmospheric distillation units and several downstream catalytic cracking, hydrotreating, hydrocracking, coking, paraffin isomerization, and catalytic reforming units. The listed refinery process units that produce butane are covered in subsequent sections. Butane can be disposed of by selling the gas either as butane gas or in combination with propane as in liquefied petroleum gas. Butane is useful as an excellent gasoline blend component in winter months in most of the Asian, North American, and European countries when the mandated vapor pressures of gasolines are higher than those for gasolines in the summer months. With the current drive to lower the concentrations of aromatic compounds in gasoline, alkylates produced via the reactions of butenes and pentenes with isobutane in alkylation units are premium high-octane gasoline blend components. Isobutane can be sold to petrochemical manufacturers and is more often used as feed in the production of isobutylene. Isobutylene can then be reacted with methanol to produce methyl tertiary butyl ether. MTBE is used as an oxygenate and octane blend component for gasoline and was a recommended oxygenate additive for gasoline before being replaced with ethanol in the United States due to some concerns with possible contamination of groundwater.
Catalytic properties of Al13TM4 complex intermetallics: influence of the transition metal and the surface orientation on butadiene hydrogenation
Published in Science and Technology of Advanced Materials, 2019
Laurent Piccolo, Corentin Chatelier, Marie-Cécile De Weerd, Franck Morfin, Julian Ledieu, Vincent Fournée, Peter Gille, Emilie Gaudry
During the reaction, the gases were continuously sampled through a leak valve and analyzed by a mass spectrometer (MS) evacuated by an oil diffusion pump capped with a liquid nitrogen trap (base pressure 2 × 10–10 Torr, analysis pressure 2 × 10–8 Torr). The MS intensities for m/z = 2, 40, 54, 56, and 58 were recorded for hydrogen, argon, butadiene (C4H6), butenes (C4H8), and butane (C4H10), respectively. In some cases, on-line gas chromatography (GC) was employed in addition to MS for determining the full distribution of 1,3-butadiene hydrogenation products, i.e. the three butene isomers (1-butene, trans-2-butene and cis-2-butene) and butane, using an automatic gas sampling device connected to an Agilent 6850 GC-FID [44]. With an Agilent HP-AL/KCl column (50 m × 0.53 × 15 µm) kept at 80°C, a chromatogram was recorded every 10 min.
Modelling and simulation of naphtha cracker
Published in Indian Chemical Engineer, 2019
K. K. Parmar, G. Padmavathi, S. K. Dash
The present investigation is to develop a model structure so that it can easily be extended to any reaction network with minimum effort and can be applied to all feeds cracked in the industry ranging from naphtha, heavy feed and gases for any given reactor geometry. Since naphtha is a complex mixture of naphthenes, paraffins and aromatics, the product distribution varies with the composition of naphthenes and paraffins. The ratio of n-paraffins to i-paraffins in the feed also affects the product distribution. The initial selectivity of the primary reaction products depends on the naphtha feed composition. In the present model for naphtha pyrolysis, naphtha has been considered as lumps of naphthenes, n-paraffins, i-paraffins and aromatics species with average carbon number properties. Since the light aromatics are not involved in cracking reactions [9] the rest of the species of the feed are assumed to initially undergo primary reactions which are then followed by a number of secondary reactions between the primary reaction products. The model requires the calculation of initial selectivity of the three primary reactions from the three feed components viz. naphthenes, n-paraffins, i-paraffins. The products of the primary reactions are hydrogen and methane, ethylene, ethane, propylene, propane, 1-butene, n-butane, i-butane and C4s. Important secondary reactions that will account for the major products obtained in naphtha pyrolysis were considered. The reaction kinetics model is based on published secondary reactions. Primary reaction coefficients are established from primary product distribution based on mechanism from individual species.
Hydrogenation of bio-oil in a needle-plate dielectric barrier discharge reactor
Published in Biofuels, 2023
Zhao Weidong, Jin Zhengxing, Qi Xiaolong, Kiatsiriroat Tanongkiat, Wang Junfeng
It can be seen from Table 4 that the gas phase products were mainly methane, ethylene and isobutane. According to the components of the reactants, it can be inferred that methane was mainly generated by methyl hydrogenation of guaiacol; ethane and ethylene were mainly formed by hydrocracking of ethyl acetate; propane and propylene were products of hydroxyl acetone dehydrogenation or butyric acid decarboxylation; isobutane was mainly formed by hydrodeoxygenation and methyl connection of hydroxyl acetone; n-butane and 1-butene were mainly obtained by hydrogenation of butyric acid and butanol; isopentane and n-pentane were mainly obtained by ring-opening after furfural hydrodeoxygenation [34].