ISOBARIC VAPOR-LIQUID EQUILIBRIUM FOR THE BINARY SYSTEM 2,2,4-TRIMETHYLPENTANE + 1-BUTANOL

Increasing concern on greenhouse effect derived from vehicle exhaust gases have led to put in the spotlight the use of alternatives to commonly used fossil fuels. It is well known that the petroleum reserves are decreasing... [ view full abstract ]

Increasing concern on greenhouse effect derived from vehicle exhaust gases have led to put in the spotlight the use of alternatives to commonly used fossil fuels. It is well known that the petroleum reserves are decreasing while the air pollution is increasing [1]. The introduction of bioethanol as replacement for methyl tert-butyl ether (MTBE) opened the door to the production and utilization of a new kind of substances, mainly ethers and alcohols which come from the agriculture or from industrial wastes.

While bioethanol emerged as one of the components of 1^st generation biofuels, a second generation of, produced from almost any biomass source, are developed to reduce the greenhouse effect and due to the price of these feedstocks is lower. Biobutanol, which can be obtained from sugar cane and corn agriculture, can be added to commonly used gasolines due to its low vapor pressure. It has a heat capacity close to that of gasoline, being less susceptible to produce phase separation in the presence of water, and reducing air pollution [2]. Besides, concerning the hydrocarbons,2,2,4-trimethylpentane is an important component of gasoline since it is the standard 100 point on the octane number, because it increases the anti-knocking effect of the fuel.

This work reports the experimental isobaric vapor-liquid equilibrium for the binary system 2,2,4-trimethylpentane +1-butanol at 101.325 kPa. A glass i-Fischer VLE apparatus model 602 S was used in the equilibrium determinations. Pressure stability is better than 0.06 kPa and temperature uncertainty is ±0.04 K. Composition of vapor and liquid phase is estimated by means of density and speed of sound measurements with an Anton Paar DSA-5000 digital vibrating tube densimeter and sound velocity meter, with a precision of ±10−5 g·cm−3, ±0.1 m·s-1. Thermodynamic consistency of the experimental VLE data reported in this work has been checked out by means of different tests, the point-to-point Fredeslund’s and Wisniak’s consistency tests and the Wisniak’s L–W test.

References

[1] Directive 2009/28/EC of the EuropeanParliament and of the Council on the promotion of the use of energy from renewable sources.

[2] M Gautam, D. Martin. Proc. Inst. Mech. Eng. A: Power Eng. 214 (2000), 497-511.