Open access peer-reviewed chapter

Thermodynamic Properties of Propanol and Butanol as Oxygenate Additives to Biofuels

By Eduardo A. Montero, Fernando Aguilar, Natalia Muñoz-Rujas and Fatima E. M. Alaoui

Submitted: May 19th 2016Reviewed: October 12th 2016Published: January 25th 2017

DOI: 10.5772/66297

Downloaded: 1450

Abstract

Alternative and renewable energy technologies are being sought throughout the world to reduce pollutant emissions and increase the efficiency of energy use. Oxygenate second-generation biofuels fuels lead to a reduction in pollutant emissions and their thermodynamic and transport properties allow that the facilities for transport, storage and distribution of fuels could be used without modification. Higher alcohols, like propanol and butanol, enhance the octane number, boosting the anti-knock effect in gasoline. Then the compression ratio of the engines can be increased without risk of knocking, leading to higher delivery of power. From the combustion point of view, the production of carbon monoxide and volatile hydrocarbons from the combustion of alcohols is less than the one of gasoline. This chapter covers mixtures of butanol and propanol with hydrocarbons. The properties reviewed are excess volume or density (VE), vapour-liquid equilibrium (VLE), and heat capacity (Cp).

Keywords

  • butanol
  • propanol
  • biofuel
  • density
  • enthalpy
  • phase equilibrium
  • heat capacity

1. Introduction

Biofuels, as environmental friendly fluids, have been paid much attention over the last decades. They contribute to diminish the greenhouse gas emissions due to its neutral carbon dioxide balance. Moreover, some oxygenated compounds are used as biofuel additives as they lead to a reduction in pollutant emissions and to an increase in the energy efficiency of vehicle engines [1, 2].

Some alcohols and ethers, as oxygenated compounds additives, are added to present gasoline with the aim of reducing the emission of gases that produce environmental impact. The advantages of these oxygenates can be classified into several categories. First, they can be obtained from renewable, agricultural and raw materials, reducing the dependence of fossil sources [3]. Second, they enhance the octane number, boosting the anti-knock effect in gasoline. Then, the compression ratio of the engines can be increased without risk of knocking, leading to higher delivery of power. From the combustion point of view, the production of carbon monoxide and volatile hydrocarbons from the combustion of alcohols is less than the one of gasoline. Amongst the thermodynamic properties, the heat of vaporization of alcohols is high and leads to a reduction in the peak temperature of combustion, which means lower emissions of nitrogen oxides.

Alternative and renewable energy technologies are being sought to reduce pollutant emissions and increase the efficiency of energy use. Propanol and butanol have been proposed as an alternative to conventional gasoline and diesel fuels [4, 5]. They are higher member of the series of alcohols with each molecule containing three or four carbon atoms rather than two as in ethanol. The EN standards of the European Union (EU) and the World-Wide Fuel Charter (WWFC) for gasoline include, for example, 2-propanol, 2-methyl-2 propanol (also known as tert-butyl alcohol, TBA), and 2-methyl-1 propanol [6, 7] as gasoline components.

The traditional production and consumption of bioethanol have found an alternative with the second-generation biofuels, such as biobutanol. For example, 85% ethanol, E85, needs some modification of the internal combustion engines specifications, unlike butanols, which can work directly in present engines. The energy content per volume unit of butanol is similar to the one of gasoline, and higher than the same for ethanol. Concerning the contribution to the anti-knocking effect, butanol behaves almost the same as other alcohols like methanol or ethanol. And in the presence of water, the mixture butanol/gasoline shows lesser tendency to separation of phases than the mixture ethanol/gasoline. Then, all the facilities for transport, storage and distribution of fuels can be used without modification. Butanol, which can be synthesized chemically or biologically, is an alternative transportation fuel since it has properties that would allow its use in existing engines with minor hardware modifications [5]. For practical purposes, ASTM D7862 [8] gives specifications for blends of butanol with gasoline at 1–12.5% in volume for automotive spark ignition engines. Three butanol isomers are covered by the specification, 1-butanol, 2-butanol, and 2-methyl-1-propanol, while specifically excludes 2-methyl-2-propanol (TBA).

Besides its use as fuel component, its industrial uses covers a broad range of applications as solvent or as reactive for the production of other chemicals. Applications, chemicals and products that use butanol include solvents, plasticizers, coatings, chemical intermediate or raw material, textiles, cleaners, cosmetics, drugs and antibiotics, hormones, and vitamins.

Since the 1950s, most butanol is obtained from fossil sources [6]. 1-butanol and/or 2-butanol could be obtained from reduction of butyraldehyde with hydrogen, which is previously obtained by hydroformulation reaction of propene (propyelene). Meanwhile, propylene oxide production leads to isobutene, from which TBA could be derived. Butanol from biomass is called biobutanol [9], and it can be used in unmodified gasoline engines. Biobutanol can be produced by fermentation of biomass by the ABE process [9, 10]. The process uses the bacterium Clostridium acetobutylicum, the bacterium for the production of acetone from starch. The butanol was a by-product of this fermentation. Other by-products as acetic, lactic and propionic acids, isopropanol and ethanol, as well as a certain amount of H2, are generated by the process. Ralstonia eutropha can also be used to produce biobutanol, by means of an electro-bioreactor and the input of carbon dioxide and electricity.

According to DuPont [11], existing bioethanol plants can be converted to biobutanol production with low economic cost. The main modification could affect to the fermentation process, with minor changes in distillation, as both alcohols use the same stocks: food energy crops (sugar beets, sugar cane, corn grain, wheat, etc.), non-food energy crops (switchgrass, cellulose, etc.) and agricultural by-products (straw, corn stalks, etc.).

Biopropanol is a rarely discussed biofuel. Tough propanol is included as regular component of gasolines [6], its frequent use as chemical solvent makes it rare to consider it as a fuel. Biopropanol could be produced from microbial fermentation of biomass (cellulose), but the process is extremely inefficient [12]. The issues with microbial production of biopropanol are analogous to the issues with microbial production of biobutanol, so if biobutanol becomes a more practical biofuel to produce, then biopropanol will also become more feasible.

This paper concerns thermodynamic properties of 1-propanol, 2-propanol, 1-butanol, 2-butanol and TBA. Accurate experimental data on thermodynamic properties should be available to check and develop predictive empirical equations, models and simulation programs. Industrial processes as storage, transport, separation and mixing processes also need reliable data for its design. As a result, the experimental literature reviews on properties of pure compounds and its mixtures with characteristic hydrocarbons can provide valuable information about the fluid behaviour under various temperature and pressure conditions.

The paper presents the literature review of available data on thermodynamic properties (density, vapour-liquid equilibrium, specific heat,) of the mixtures of 1-propanol, 1-butanol, TBA and its mixtures with hydrocarbons representatives of gasoline. Density has to do with the volumetric behaviour of the mixtures under pressure and temperature conditions and is the primary data to check equations of state. The vapour-liquid equilibria, which allows the calculation of the Gibbs function, deal with the equilibrium between the liquid and vapour phase under fixed pressure and temperature conditions. And the heat capacity gives information related to the sensible energy storage of the liquids. The review includes only the interval of temperature and pressure of every property reported. The wider is the range of pressure and temperature of the measured properties, so it would be the reliability of the applications of predictive and equations and models. Discussion of further data (uncertainties, experimental apparatus, etc.) would require more space than available. Interested readers should access the literature references to check these issues.

2. The literature review

Thermodynamic properties of liquid propanol and butanol and its liquid mixtures with some hydrocarbon have been obtained from the literature search using online library databases (Web of Science©, Scopus©, NIST© Standard Reference Database) and high impact electronic journals.

Special attention is given to alcohol + hydrocarbon mixtures. As stated, 1-propanol, 1-butanol and TBA have been selected as alcohols. As representative of hydrocarbons, n-heptane, 2,2,4 trimethylpentane (iso-octane), cyclohexane, methyl-cyclohexane, benzene, toluene and 1-hexene have been chosen. They represent linear, branched and cyclic alkanes, aromatics, as well as olefins, which are regular components of gasoline. Table 1 presents the list of selected compounds.

CompoundCAS numberChemical formula
Alcohols
1-Propanol71-23-8C3H8O
1-Butanol71-36-3C4H10O
Tert-butyl alcohol (TBA)75-65-0C4H10O
Hydrocarbons
Heptane142-82-5C7H16
2,2,4 trimethylpentane (TMP)540-84-1C8H18
Cyclohexane110-82-7C6H12
Methyl cyclohexane108-87-2C7H14
Benzene71-43-2C6H6
Toluene108-88-3C7H8
1-Hexene592-41-6C6H12

Table 1.

Selected alcohols and hydrocarbons.

Concerning properties, there is a huge amount of available thermodynamic data for pure compounds. With respect to the mixtures, density data are shown in Table 2 for binary mixtures alcohol (1) + hydrocarbon (2). Tables 3 and 4 present the vapour-liquid equilibria selected for mixtures alcohol (1) + hydrocarbon (2) and alcohol (1) + hydrocarbon (2) + hydrocarbon (3). Finally, heat capacity data for binary mixtures alcohol (1) + hydrocarbon (2) are provided in Table 5.

Substance 1Substance 2ReferencesYearTmin/KTmax/KPmin/kPaPmax/kPa
1-PropanolHeptane[13]1967298.15298.15101101
Heptane[14]1967348.15348.15101101
Heptane[15]1977298.15298.15101101
Heptane[16]1982423.11523.114225495
Heptane[17]1983298.15298.15101101
Heptane[18]1993313.15313.15101101
Heptane[19]1994278.15308.15101101
Heptane[20]1995298.15298.15101101
Heptane[21]1996298.15308.15101101
Heptane[22]1997298.15298.15101101
Heptane[23]1998278.15308.15101101
Heptane[24]2003308.15308.15101101
Heptane[25]2004293.15318.21101101
Heptane[26]2005298.15298.15101101
Heptane[27]2005298.15298.15101101
2,2,4 trimethylpentane[28]1981298.15298.15101101
2,2,4 trimethylpentane[29]2007298.15298.15101101
2,2,4 trimethylpentane[30]2007303.15303.15101101
2,2,4 trimethylpentane[31]2012298.15298.15101101
2,2,4 trimethylpentane[32]2015298.15323.15101101
Cyclohexane[33]1979298.15298.15101101
Cyclohexane[34]1980298.15298.15101101
Cyclohexane[35]1991298.15298.15101101
Cyclohexane[36]1996298.15308.15101101
Cyclohexane[37]1997298.15303.15101101
Cyclohexane[38]1998303.15303.15101101
Cyclohexane[24]2003308.15308.15101101
Cyclohexane[39]2004298.15298.15101101
Cyclohexane[26]2005298.15298.15101101
Cyclohexane[40]2007293.15303.15101101
Cyclohexane[41]2008303.15303.15101101
Cyclohexane[42]2016303.15313.15101101
Methylcyclohexane[43]1977303.15303.15101101
Methylcyclohexane[44]1996298.15298.15101101
Methylcyclohexane[45]2006298.15308.15101101
Benzene[46]1969298.15298.15101101
Benzene[33]1979298.15298.15101101
Benzene[34]1980298.15298.15101101
Benzene[47]1993308.15308.15101101
Benzene[58]1994298.15298.15101101
Benzene[59]2001303.15303.15101101
Benzene[24]2003308.15308.15101101
Benzene[39]2004298.15298.15101101
Benzene[50]2007288.15313.15101101
Benzene[51]2008298.15298.15101101
Benzene[52]2009298.15298.15101101
Benzene[53]2015303.15303.15101101
Toluene[54]1980298.15298.15101101
Toluene[47]1993308.15308.15101101
Toluene[48]1994298.15298.15101101
Toluene[55]2000303.15313.15101101
Toluene[24]2003308.15308.15101101
Toluene[56]2005303.15333.1510030000
Toluene[57]2006298.15298.15101101
Toluene[58]2006303.15333.15101101
Toluene[59]2008298.15298.15101101
Toluene[53]2015303.15303.15101101
1-Hexene[60]1993298.15298.15101101
1-Hexene[61]2010298.15298.15101101
1-Butanoln-Heptane[15]1977298.15298.15101101
n-Heptane[62]1979298.15298.15101101
n-Heptane[17]1983298.15298.15101101
n-Heptane[63]1984298.15298.15101101
n-Heptane[64]1994313.15313.15101101
n-Heptane[21]1996298.15308.15101101
n-Heptane[65]1997293.15293.15101101
n-Heptane[66]1997288.15298.15101101
n-Heptane[24]2003308.15308.15101101
n-Heptane[67]2003316.85458.1549304930
n-Heptane[26]2005298.15298.15101101
n-Heptane[68]2006288.15308.15101101
n-Heptane[69]2009288.15308.15101101
2,2,4 trimethylpentane[65]1997293.15293.15101101
2,2,4 trimethylpentane[66]1997288.15298.15101101
2,2,4 trimethylpentane[31]2012298.15298.15101101
2,2,4 trimethylpentane[70]2013298.15328.15101101
Cyclohexane[33]1979298.15298.15101101
Cyclohexane[34]1980298.15298.15101101
Cyclohexane[71]1983298.15318.15101101
Cyclohexane[72]1995293.15313.15101101
Cyclohexane[38]1998303.15303.15101101
Cyclohexane[73]2001298.15298.15101101
Cyclohexane[24]2003308.15308.15101101
Cyclohexane[74]2005298.15313.15101101
Cyclohexane[40]2007293.15303.15101101
Cyclohexane[75]2010293.15293.15101101
Cyclohexane[76]2014293.15333.15100100000
Cyclohexane[42]2016303.15313.15101101
Methylcyclohexane[43]1977303.15303.15101101
Methylcyclohexane[77]1989298.15298.15101101
Methylcyclohexane[78]2004303.15303.15101101
Methylcyclohexane[45]2006298.15308.15101101
Benzene[46]1969298.15298.15101101
Benzene[33]1979298.15298.15101101
Benzene[34]1980298.15298.15101101
Benzene[79]1993298.15298.15101101
Benzene[80]1994298.15308.15101101
Benzene[81]1996308.15308.15101101
Benzene[49]2001303.15303.15101101
Benzene[21]2003308.15308.15101101
Benzene[82]2004303.15303.15101101
Benzene[83]2008288.15313.15101101
Toluene[84]1940298.15298.15101101
Toluene[54]1980298.15298.15101101
Toluene[81]1996308.15308.15101101
Toluene[55]2000303.15313.15101101
Toluene[24]2003308.15308.15101101
Toluene[70]2013298.15328.15101101
Toluene[85]2015298.15328.15101101
1-Hexene[86]2013273.15333.15101101
TBAn-Heptane[62]1979299.15299.15101101
n-Heptane[64]1994313.15313.15101101
n-Heptane[87]2011303.15323.15101101
2,2,4 trimethylpentane[88]1999298.15298.15101101
2,2,4 trimethylpentane[89]2001298.15298.15101101
2,2,4 trimethylpentane[90]2005298.15318.15101101
Cyclohexane[71]1983298.15318.15101101
Cyclohexane[72]1995293.15313.15101101
Methylcyclohexane[88]1999298.15298.15101101
Benzene[79]1993298.15298.15101101
Benzene[91]1995313.15313.15101101
Benzene[81]1996308.15308.15101101
Benzene[82]2004303.15303.15101101
Toluene[81]1996308.15308.15101101
Toluene[88]1999298.15298.15101101
Toluene[55]2000303.15313.15101101

Table 2.

Reported density (g⋅cm−3) for binary mixtures alcohol (1) + hydrocarbon (2).

Substance 1 Substance 2 References Year Tmin/K Tmax/K Pmin/kPa Pmax/kPa 
1-propanol Heptane [92] 1966 357.72 371.52 101.32 101.32 
Heptane [14] 1967 347.97 347.97 39.72 73.63 
Heptane [13] 1967 303.13 333.12 3.92 39.81 
Heptane [93] 1980 278.16 303.14 1.67 10.17 
Heptane [16] 1982 423.15 573.15 200 5066 
Heptane [94] 1991 313.15 313.15 10.95 16.52 
Heptane [95] 1992 313.15 313.15 9.638 16.428 
Heptane [96] 1993 303.15 303.15 5.42 10.24 
Heptane [97] 1995 379.38 475.45 204.5 1032.8 
Heptane [98] 1995 316.78 357.58 19.60 101.33 
Heptane [99] 2000 298.15 298.15 – – 
Heptane [100] 2004 303.15 343.15 – – 
2,2,4, trimethylpentane [28] 1981 328.36 348.50 15.98 72.75 
2,2,4, trimethylpentane [101] 1994 357.88 365.46 101.3 101.3 
2,2,4, trimethylpentane [102] 1994 343.15 343.15 42.04 60.07 
2,2,4, trimethylpentane [29] 2007 303.15 303.15 4.88 10.45 
2,2,4, trimethylpentane [103] 2011 318.15 318.15 9.00 21.13 
Cyclohexane [104] 1977 298.15 298.15 2.79 14.29 
Cyclohexane [105] 1986 347.66 369.17 101.33 101.33 
Cyclohexane [98] 1995 347.58 347.58 101.33 101.33 
Cyclohexane [106] 1996 298.15 308.15 2.63 22.1 
Cyclohexane [107] 1997 323.15 333.15 27.92 61.17 
Cyclohexane [99] 2000 313.15 343.15 – – 
Cyclohexane [108] 2000 298.15 298.15 101.32 101.32 
Methylcyclohexane [109] 1969 360.13 366.83 101 101 
Methylcyclohexane [110] 1989 332.98 332.98 29.12 38.60 
Methylcyclohexane [111] 1997 358.75 373.60 101.3 101.3 
Benzene [112] 1947 298.94 363.52 13.33 99.99 
Benzene [113] 1963 349.12 365.92 101 101 
Benzene [114] 1964 493.16 558.18 2419.4 4904.2 
Benzene [104] 1977 298.15 298.15 2.79 13.04 
Benzene [105] 1986 350.03 361.85 101.33 101.33 
Benzene [115] 1987 313.15 313.15 7.01 25.98 
Benzene [107] 1997 323.15 333.15 22.02 56.70 
Benzene [116] 2001 313.15 313.15 7.047 26.069 
Benzene [117] 2006 313.15 313.15 7.00 25.91 
Benzene [52] 2008 323.15 323.15 17.98 39.89 
Benzene [51] 2008 329.45 368.35 50 94 
Toluene [115] 1987 313.15 313.15 7.01 11.35 
Toluene [118] 1996 298.15 298.15 2.63 5.39 
Toluene [119] 2003 293.15 370.15 – – 
Toluene [59] 2008 333.15 333.15 20.27 27.41 
Toluene [120] 2009 323.15 323.15 13.42 17.85 
1-butanol Heptane [121] 1966 361.92 376.92 91.2 91.2 
Heptane [122] 1967 387.93 434.34 192.65 496.63 
Heptane [63] 1984 333.15 363.15 8.01 89.49 
Heptane [123] 1990 353.15 373.15 101.32 101.32 
Heptane [124] 1994 313.15 313.15 4.39 13.22 
Heptane [98] 1995 312.34 357.58 12.93 74.47 
Heptane [125] 1996 328.45 366.55 25.63 101.38 
Heptane [126] 1997 303.15 303.15 1.35 8.26 
Heptane [99] 2000 298.15 298.15 – – 
Heptane [127] 2001 365.05 389.05 95 95 
Heptane [100] 2004 303.15 343.15 – – 
Heptane [138] 2010 349.00 387.75 53.3 91.3 
Heptane [129] 2012 313.15 313.15 2.51 13.22 
2,2,4-trimethylpentane [130] 2006 308.15 318.15 2 17 
2,2,4-trimethylpentane [103] 2011 318.15 318.15 7.2 16.4 
2,2,4-trimethylpentane [129] 2012 313.15 313.15 2.55 13.71 
2,2,4-trimethylpentane [131] 2013 313.15 313.15 11.55 13.50 
Cyclohexane [132] 1968 353.15 383.12 21.23 229.21 
Cyclohexane [133] 1982 293.15 293.15 – – 
Cyclohexane [71] 1983 318.15 318.15 3.41 30.59 
Cyclohexane [134] 1990 312.8 389.9 – – 
Cyclohexane [98] 1995 352.7 352.7 101.33 101.33 
Cyclohexane [108] 2000 298.15 298.15 101.32 101.32 
Cyclohexane [99] 2000 313.15 343.15 – – 
Cyclohexane [135] 2001 350.95 389.05 95 95 
Cyclohexane [136] 2002 325.6 386.12 40.0 101.3 
Cyclohexane [129] 2012 313.15 313.15 2.51 24.83 
Methylcyclohexane [109] 1969 369.75 385.65 101 101 
Methylcyclohexane [110] 1989 332.98 332.98 11.07 29.77 
Methylcyclohexane [111] 1997 368.45 390.50 101.3 101.3 
Benzene [137] 1939 298.15 298.15 0.85 12.59 
Benzene [128] 1963 353.21 390.83 101.32 101.32 
Benzene [114] 1964 513.17 558.18 2032.6 4751.2 
Benzene [115] 1987 313.15 313.15 2.52 24.37 
Benzene [79] 1993 298.15 298.15 0.82 12.83 
Benzene [139] 1995 354.03 425.26 105 303 
Benzene [140] 2004 308.15 308.15 4.03 20.28 
Benzene [141] 2006 313.15 313.15 2.49 24.37 
Toluene [84] 1940 376.12 390.83 101 101 
Toluene [142] 1963 378.63 390.83 101.33 101.33 
Toluene [115] 1987 313.15 313.15 2.52 8.48 
Toluene [134] 1990 349.5 389.9 – – 
Toluene [143] 1997 360.9 389.1 56.4 94.0 
Toluene [119] 2003 323.15 390.15 – – 
Toluene [140] 2004 308.15 308.15 2.49 6.39 
Toluene [129] 2012 313.15 313.15 2.49 8.39 
1-hexene [131] 2013 313.15 313.15 2.48 44.99 
TBA Heptane [145] 1982 313.15 313.15 12.33 19.23 
Heptane [146] 1983 352.47 371.42 101 101 
Heptane [124] 1994 313.15 313.15 14.81 19.20 
Heptane [147] 1995 351.40 368.23 101.3 101.3 
Heptane [127] 2001 352.25 369.45 95 95 
2,2,4-trimethylpentane [148] 1999 352.4 372.5 101.3 101.3 
2,2,4-trimethylpentane [89] 2001 318.13 339.28 15.85 59.49 
2,2,4-trimethylpentane [149] 2006 353.35 370.55 95.8 95.8 
Cyclohexane [150] 1976 344.43 354.33 101 101 
Cyclohexane [71] 1983 318.15 318.15 18.11 36.23 
Cyclohexane [151] 1985 328.19 343.28 30.43 95.1 
Cyclohexane [98] 1995 295.35 344.28 13.46 101.40 
Methylcyclohexane [110] 1989 332.98 332.98 30.44 46.33 
Methylcyclohexane [148] 1999 353.1 374.0 101.3 101.3 
Benzene [152] 1902 347.10 347.10 100.66 101.32 
Benzene [153] 1933 347.10 347.10 – – 
Benzene [137] 1939 298.15 298.15 5.60 13.96 
Benzene [154] 1969 318.15 318.15 18.12 34.32 
Benzene [155] 1977 346.58 353.98 101 101 
Benzene [79] 1993 298.15 298.15 5.59 14.83 
Benzene [98] 1995 296.66 347.19 13.59 101.51 
Benzene [156] 1998 308.15 308.15 10.18 23.48 
Toluene [156] 1998 308.15 308.15 6.40 12.97 
Toluene [148] 1999 355.4 383.8 101.3 101.3 

Table 3.

Reported vapour-liquid equilibria for binary mixtures alcohol (1) + hydrocarbon (2).

Substance 1Substance 2Substance 3ReferencesYearTmin/KTmax/KPmin/kPaPmax/kPa
1-butanol2,2,4-trimethylpentane1-hexene[131]2013313.15313.152.4844.99
1-butanoltoluene1-hexene[144]2015313.15313.152.5144.99
TBACyclohexaneBenzene[98]1995294.91344.2513.61101.36

Table 4.

Reported vapour-liquid equilibria for ternary mixtures alcohol (1) + hydrocarbon (2) + hydrocarbon (3).

Substance 1Substance 2ReferencesYearTmin/KTmax/KPmin/kPaPmax/kPa
1-propanolHeptane[157]1976298.15298.15101101
Heptane[158]1981184.97300.00101101
Heptane[159]1993298.15298.15101101
1-butanolHeptane[159]1993298.15298.15101101
2,2,4 Trimethylpentane[160]2012293.15313.1510125,000
Cyclohexane[76]2014293.15313.1510125,000
Toluene[161]1991298.15368.15101101
1-Hexene[86]2013293.15313.1510125,000

Table 5.

Reported heat capacity for binary mixtures alcohol (1) + hydrocarbon (2).

3. Discussion

3.1. Density of mixtures 1-propanol, or 1-butanol, + hydrocarbon

Table 2 presents density data for the selected mixtures alcohol (1) + hydrocarbon (2). Fifty-nine references correspond to mixtures 1-propanol (1) + hydrocarbon (2) and 51 to the one 1-butanol (1) + hydrocarbon (2), while only 16 references have been found for TBA (1) + hydrocarbon (2).

For 1-propanol (1) + hydrocarbon (2), only atmospheric pressure density data have been found for the binary mixtures, except Refs. [16, 56] that are above 5 MPa. The highest pressure, 30 MPa, is reported by Zeberg-Mikkelsen and Andersen [56]. Temperatures above 350 K are only measured by Zawisza and Vejrosta [16]. Concerning 1-butanol (1) + hydrocarbon (2), Refs. [67, 76] report pressure above the atmospheric pressure. Hundred Megapascal is the maximum pressure measured in Ref. [76]. Reference [67] also reports temperature above 350 K. Finally, mixtures TBA (1) + hydrocarbon are reported only at atmospheric pressure and moderate temperatures, being 323.15 K the highest measured temperature [87]. No data were found for the mixture TBA (1) + 1-hexene (2).

3.2. Vapour-liquid equilibrium of mixtures 1-propanol, or 1-butanol, + hydrocarbon

With respect to the binary mixtures, Table 3 shows 43 references for VLE data on 1-propanol (1) + hydrocarbon (2), 47 for 1-butanol (1) + hydrocarbon (2) and 24 for TBA (1) + hydrocarbon (2). No references for the mixtures 1-propanol (1) + 1-hexene (2) and TBA (1) + 1-hexene (2) were found, while [131] was the only one for 1-butanol (1) + 1-hexene (2). Most references were found for pressures lower or equal to atmospheric pressure. Studies done in Refs. [97, 122, 132] were measured at moderate pressures, below 1.0 MPa, and only Ref. [114] reports pressure close to 5 MPa for both mixtures 1-propanol (1), or 1-butanol (1), + benzene (2).

Concerning temperature, most measurements were performed at low and moderate temperatures. Within the interval 350–400 K, we found a limited number of 27 set of data [51, 63, 84, 98, 105, 109, 111113, 119, 121, 123, 125, 127, 128, 132, 134136, 142, 143, 146150, 155]. Only Refs. [16, 97, 114, 122, 139] report temperatures between 400 and 573 K.

Only three references were found reporting VLE data of ternary mixtures, as shown in Table 4, at atmospheric or lower pressures. Temperatures were moderate, with maximum at 344 K measured in Ref. [98]. No ternary mixture with 1-propanol was found.

3.3. Heat capacity of mixtures 1-propanol, or 1-butanol, + hydrocarbon

Only eight references reporting heat capacity of binary mixtures alcohol (1) + hydrocarbon (2) are cited. Three of them correspond to the binary mixture 1-propanol (1) + heptane (2) at atmospheric pressure and at moderate temperatures (up to 300 K). No other mixture of 1-propanol with the any of selected hydrocarbons was found.

While the heat capacity of 1-butanol with heptane, 2,2,4 trimethylpentane, cyclohexane, toluene and 1-hexane was measured by several authors. It must be pointed out that some measurements [86, 160, 161] have been performed at pressures up to 25 MPa and temperature of 313 K.

4. Conclusion

The literature review on thermodynamic properties of liquid mixtures of 1-propanol, 1-butanol and TBA with representative hydrocarbons has been reported. Seven hydrocarbons (linear, branched and cyclic alkanes, aromatics, and olefins) have been selected as representative of present and future unleaded gasoline. The review covers density, vapour-liquid equilibrium and heat capacity of mixtures.

The review of density data shows a big amount of data at low pressure and moderate temperatures. Only two references report data above 30 MPa at a maximum temperature of 333 K. And at temperatures above 450 K, the maximum pressure is 5.5 MPa. With respect to the vapour-liquid equilibrium, only one reference shows measurements over 555 K at 5 MPa. Heat capacity data of mixtures are very scarce, tough some high pressure and high temperature data can be found for some alcohol + hydrocarbon mixtures.

The performance of fuels and biofuels in engines and other devices shows a trend of increasing pressure and temperature, which leads to the need of more reliable predictive models for complex mixtures at such conditions. Availability of high pressure and high temperature thermodynamic properties is then a requisite for the implementation of these equation and models. The review shows a lack of reliable data at high pressure and high temperature thermodynamic data, which serve as a basis for the development of predictive equations and models.

© 2017 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

How to cite and reference

Link to this chapter Copy to clipboard

Cite this chapter Copy to clipboard

Eduardo A. Montero, Fernando Aguilar, Natalia Muñoz-Rujas and Fatima E. M. Alaoui (January 25th 2017). Thermodynamic Properties of Propanol and Butanol as Oxygenate Additives to Biofuels, Frontiers in Bioenergy and Biofuels, Eduardo Jacob-Lopes and Leila Queiroz Zepka, IntechOpen, DOI: 10.5772/66297. Available from:

chapter statistics

1450total chapter downloads

More statistics for editors and authors

Login to your personal dashboard for more detailed statistics on your publications.

Access personal reporting

Related Content

This Book

Next chapter

Photocatalytic Reforming of Lignocelluloses, Glycerol, and Chlorella to Hydrogen

By Masahide Yasuda

Related Book

First chapter

Contribution to the Assessment of Green Biomass of Atriplex halimus Plantation in Arid Western Algeria (Region of Naama)

By Aman Bouzid and Benabdeli Kheloufi

We are IntechOpen, the world's leading publisher of Open Access books. Built by scientists, for scientists. Our readership spans scientists, professors, researchers, librarians, and students, as well as business professionals. We share our knowledge and peer-reveiwed research papers with libraries, scientific and engineering societies, and also work with corporate R&D departments and government entities.

More About Us