Alexander P. Popov

Vapour-liquid critical temperatures and pressures of normal alkanes with from 19 to 36 carbon atoms, naphthalene and m-terphenyl determined by the pulse-heating technique

Abstract The paper presents the results of measuring the critical temperatures and the critical pressures of normal alkanes: nonadecane, eicosane, docosane, tetracosane, hexacosane, octacosane, triacontane, hexatriacontane, and also naphthalene and m-terphenyl. The pulse-heating method of a wire probe immersed in the liquid under investigation applicable to thermally unstable substances has been used. Equations of state of a polymeric fluid of the van der Waals and Redlich-Kwong type have been written in a ‘self-consistent-field’ approximation. Dependences of the critical constants of chain molecules on the number of links have been obtained. Equations for calculating the critical temperatures and pressures of normal alkanes have been derived. The results of calculations are compared with experimental data.

Critical temperatures and pressures of 1-alkanols with 13 to 22 carbon atoms

Abstract The paper gives the results of measuring the critical temperatures and pressures of thermally unstable 1-alkanols CnH2n+1OH with a number of carbon atoms n=13–18,20,22. The method of pulse heating of a wire probe located in the liquid under investigation has been used. Equations that correlate the critical temperatures and pressures of 1-alkanols with the number of carbon atoms in a molecule have been obtained. The results of measurements are compared with the values predicted by various methods. The acentric factors of 1-alkanols have been calculated.

Critical temperatures and pressures of linear alk-1-enes with 13 to 20 carbon atoms using the pulse-heating technique

Abstract The paper presents experimental critical temperatures and critical pressures of thermally unstable alk-1-enes CnH2n with a number of carbon atoms n=13–20. The method of pulse heating of a wire probe placed in the liquid under investigation has been used. Equations for correlation of the critical temperatures and pressures of alk-1-enes with a number of carbon atoms in a molecule have been obtained. The acentric factors of alk-1-enes have been calculated.

Critical temperatures and pressures of some alkanoic acids (C2 to C22) using the pulse-heating method

Abstract This paper presents experimental critical temperatures and pressures of 12 alkanoic acids C n H 2 n O 2 with carbon numbers from 2 to 22. The method of pulse heating of a wire probe placed in the liquid under study has been used. Equations for the correlation of the critical temperatures and pressures of alkanoic acids with the number of carbon atoms and molar mass have been obtained.

Temperatures of the attainable superheat of some thermally unstable liquids

The paper gives the results of measuring the temperatures of the attainable superheat of some liquids that are thermally unstable at these temperatures. The technique of heating a thin wire probe placed into a liquid under study with electric-current pulses has been used. The length of pulses is from 10−5 to 10−3 s, which corresponds to a heating rate of 105 to 108 K·s−1. The influence of a chemical reaction in the liquid phase on the temperature of the attainable superheat has been considered. In particular, it has been shown that boiling initiated by an elementary act of an exothermic chemical reaction is of a low probability. A method of calculating the temperature of the attainable superheat of thermally unstable liquids under conditions of quick heating has been developed. A method for the determination of the kinetic parameters of thermal decomposition from the measurements of the temperature of the attainable superheat is discussed.

Temperature of Attainable Superheating of Some Commercial Petroleum Products

Measurements of the temperature of attainable superheating of A-76L and AI-93 motor gasolines; L-0.5–40, L-0.2–40, and Z-0.5–35 diesel oils; TS-1 and RT jet propellants; and T-1500 transformer oil are performed by the method of pulsed heating of a wire probe placed into the liquid under study. The rate of increase of the probe temperature is 105–107 K/s. The pressure varies from atmospheric to near-critical. The temperature of attainable superheating of rocket propellants is also calculated by the theory of homogeneous nucleation. A conclusion is made that, if the thermal properties of a concrete batch of petroleum products are known, the theory of homogeneous nucleation provides a fairly accurate estimate of the temperature of attainable superheating of substances with so complex a composition.