Cyclohexane liquid temperature range

Nickel as well as platinum and palladium are the most important catalysts used in the liquid or gas phase usually in the temperature range of 170-230°C and pressure of 20-40 atm. Since the reaction is highly exothermic [Eq. (11.91)], efficient heat removal is required to ensure favorable equilibrium conditions and prevent isomerization of cyclohexane to methylcyclopentane ... 

The high-temperature solution process is state-of-the-art for the production of ethylene homopolymers as well as ethylene/1-olefin copolymers with a wide range of average molecular mass and copolymer composition [15]. This process is performed in a CSTR or in a cascade of two reactors, like the low-temperature process. Only the downstream equipment is different. The diluent is an aliphatic hydrocarbon such as cyclohexane, n-hexane, or a Cg-Cio alkane fraction. Homogeneous catalyst and co-catalyst are fed into the polymerization reactor mixed with solvent. Ethylene, hydrogen to regulate average molecular mass, and the comonomer are injected either as a gas or as a liquid. Temperature can be con-... 

In addition to the simulation of the catalyst, we also performed thermodynamic modeling studies on the reactants and products in order to investigate physical properties during the catalytic reaction. The solubility of hydrogen in benzene and benzene/cyclohexane mixtures was calculated with PC-SAFT at the temperature range 250-523 K. T-P Flash calculations were performed at constant pressure 10, 20 and 50 bar. The results are illustrated in Fig. 2. The composition of the liquid phase in these T-P Flash calculations is not kept constant, therefore the mole fraction of cyclohexane shown in Fig. 2 (0.36 (top) and 0.96 (bottom)) is approximate. 

Besides the pure component parameters, in particular the mixture parameters, for example of a g -model or an equation of state, should be checked carefully prior to process simulation. The procedure is shown in Figure 11.4 for the binary system acetone-cyclohexane, which may be one of the binary key systems of a multicomponent mixture. From the results shown in Figure 11.4, it can be concluded that the VLE behavior of the binary system can be reliably described in the temperature range 0-50 C with the Wilson parameters used. But from the poor -results, it seems that an extrapolation to higher or lower temperature may be dangerous, as already can be seen from the solid-liquid equilibrium (SLE) results of the eutectic system in the temperature range 0 to —lOO C and also from the incorrect temperature dependence of the calculated azeotropic data. 

Del Rio, A. Horstmann, S. Renuncio, J. A. R. GmehUng, J. Isothermal vapor-liquid equilibrium and excess enthalpy data for the binary systems methyl tert-butyl ether + cyclohexane and ethyl tert-butyl ether + cyclohexane, n-hexane, and n-heptane in a temperature range from 298.15 to 393.15 K. J. Chem. Eng. Data 2001, 46, 1181-1187. 

---