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Butane and Naphtha Hydroisomerization
Published in Mark J. Kaiser, Arno de Klerk, James H. Gary, Glenn E. Hwerk, Petroleum Refining, 2019
Mark J. Kaiser, Arno de Klerk, James H. Gary, Glenn E. Hwerk
There are three pentane isomers: n-pentane, isopentane (2-methylbutane), and neopentane (2,2-dimethylpropane). Neopentane is practically never formed during pentane hydroisomerization, because there is no catalytic pathway that enables its formation. The only equilibrium that is of practical significance is that between n-pentane to isopentane.
Feedstock Composition and Properties
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
The fraction known as pentanes plus is a mixture of pentane isomers and higher molecular weight constituents (C5+) that is a liquid at ambient temperature and pressure, and consists mostly of pentanes and higher molecular weight (higher carbon number) hydrocarbon derivatives. Pentanes plus includes, but is not limited to, normal pentane, isopentane, hexanes-plus (natural gasoline), and condensate.
List of Chemical Substances
Published in T.S.S. Dikshith, and Safety, 2016
n-Pentane is a flammable liquid. It has applications in industry as an aerosol propellant and as an important component of engine fuel. N-propane is a CNS depressant. Studies with dogs have indicated that it induces cardiac sensitization. In high concentrations it causes incoordination and inhibition of the righting reflexes.
Parametric optimization of organic Rankine cycle using TOPSIS integrated with entropy weight method
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Deepak Tiwari, Ahmad Faizan Sherwani, Mohd Muqeem, Ashwni Goyal
The selection of appropriate working fluid for ORC system is an important facet. The working fluids are selected based on their critical pressure, critical temperature, maximum operating temperature of the cycle, global warming potential (GWP), ozone layer depletion potential (ODP), flammability, toxicity, availability, and cost. Furthermore, working fluids are further chosen based on their slope of T-s diagram, namely, wet, dry, and isentropic. Dry and isentropic working fluids are preferred over wet working fluid considering expander blade erosion and improvement in cycle performance (Quolin et al. (2013); Wu, Zhu, and Yu (2016)). The performance of the ORC system employing zeotropic mixture is better than pure fluid (Sadeghi et al. (2016)). In this study, zeotropic mixture Butane/Pentane, Hexane/Pentane, and Isohexane/Pentane are considered as working fluids. It is clear from Table 2 that the working fluids, Butane, Pentane, Hexane, and Iso-hexane are dry in nature, exhibit zero ODP and negligible GWP.
Optimization and thermo-economic performance analysis of organic Rankine cycles using mixture working fluids driven by solar energy
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2019
Deepak Tiwari, Ahmad Faizan Sherwani, Nishant Kumar
Figure 7 shows the exergy destruction in the components of the ORC system at the mass fraction of 0.6/0.4. It indicates that mixture of isohexane/pentane exhibits largest exergy destruction followed by mixture of hexane/pentane and butane/pentane in condenser, whereas mixture of hexane/pentane and butane/pentane exhibits highest exergy loss in evaporator followed by condenser and expander. Moreover, mixture of butane/pentane exhibits the largest exergy destruction in pump, whereas mixture of isohexane/pentane and hexane/pentane contributes a nearly equal amount of exergy destruction in the pump. The exergy destruction is found in evaporator and condenser because of significant difference of temperature between heat-supplying and heat-absorbing fluid.
Thermodynamic and multi-objective optimisation of solar-driven Organic Rankine Cycle using zeotropic mixtures
Published in International Journal of Ambient Energy, 2019
Deepak Tiwari, Ahmad Faizan Sherwani, Akhilesh Arora
Pure working fluids have isothermal phase change during evaporation and condensation. Mixtures of pure fluids are mostly zeotropic in nature. The zeotropic mixtures are prepared by mixing of different pure fluids having similar chemical properties with a significant difference in boiling temperatures of pure components (Geng, Du, and Yang 2016). The zeotropic mixtures represent nonhomogeneous composition in vapour and liquid phases and isobaric temperature glide during evaporation and condensation (Lu et al. 2016). The temperature glide is the difference between the temperature of saturated vapour (dew point) and saturated liquid (bubble point). The isobaric temperature glide of zeotropic mixtures during the phase change process brings better thermal match between heat source and working fluid in the evaporator as well as between the cooling medium in the condenser thereby reducing the exergy destruction in heat exchangers due to reduction in finite temperature difference up to a significant level (Wang, Zhao, and Wang 2010; Wang et al. 2010; Aghahosseini and Dincer 2013; Zhao and Bao 2014b). The application of the zeotropic mixture has explored the new range of the working fluid (Feng et al. 2015). In this study five zeotropic mixtures of hydrocarbon butane/isopentane, butane/pentane, isobutane/pentane, isopentane/isobutane and cyclohexane/R123 are used. The considered working fluids are not only thermodynamically efficient in comparison with pure fluids, but also have a very less harmful impact on the environment. The flammability issue limits the application of hydrocarbons. The flammability of hydrocarbon is suppressed by mixing of hydrofluoro carbon and hydrofluoric-olefin (Abadi and Kim 2017).