A Generalized Method for Predicting Second Virial Coefficients

Abstract

Optimum temperature profiles during the pyrolysis of ethane exist because the yield goes up with increasing temperature, but consequently, the reactor must be shut down and cleaned out with increasing frequency because the carbon formed deposits along the reactor wall causing high pressure drop. The combined effect causes the yearly production of ethylene to go through an optimum. To find this optimum, a computer program was developed with the ability of handling 25 simultaneous reactions involving up to 25 components. It calculates the carbon deposition profile and the changing pressure profiles, as a function of a predetermined reaction gas temperature profile. The reactor will remain in production until the inlet pressure exceeds 8 atm. The average yearly production rate is calculated, assessing a reactor shut down penalty of 24 and 48 hr required for the cleaning of the clogged pyrolysis tubes. The optimum exit temperature for the 24-hr penalty was 1127°K with a corresponding 59% one pass ethane conversion. The 48-hr penalty lowers the optimum exit temperature to 1124°K and a 50.5% ethane conversion. The practice of increasing pressure to compensate for carbon buildup results in accelerated carbon deposition and is detrimental to the overall production scheme.

Vapor-liquid equilibrium measurements for the binary system methyl acetate+ethanol at 0.3 and 0.7 MPa

“…The second virial coefficients were calculated by the Hayden and O'Connell (1975) method. The liquid molar volumes of the pure compounds were estimated by the equation of Yen and Woods (1966).…”

Optimal design of extractive distillation for acetic acid dehydration with N-methyl acetamide

“…Hence, the association effect on vapour -liquid equilibrium cannot be neglected even at low pressure. The Hayden-O'Connell equation reliably predicts the solvation of polar compounds and dimerization in the vapor phase that occurs with mixtures containing carboxylic acids [17]. The association parameters shown in Table A in appendix B were adopted to calculate the fugacity coefficients.…”

Incorporating Pitzer equations in a new thermodynamic model for the prediction of acid gases solubility in aqueous alkanolamine solutions

“…In his publications (Pitzer and Mayorga, 1973;Pitzer, 1991) the origin of these equations and their application are discussed in some detail. To consider the deviation of real gas phase behavior from the ideal gas state, the Virial (George Hayden and O'Connell, 1975), PR (Peng and Robinson, 1976) or SRK (Soave, 1972) equations of state (EOS) can be used to calculate the fugacity-coefficients of the components in the gas phase.…”