Measurement of Heat of Vaporization for Research Gasolines and

Subscriber access provided by Mount Allison University | Libraries and Archives

Biofuels and Biomass

Measurement of Heat of Vaporization for Research Gasolines and Ethanol Blends by DSC/TGA Gina M. Fioroni, Lisa Fouts, Earl D. Christensen, James E Anderson, and Robert L. McCormick Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.8b03369 • Publication Date (Web): 07 Nov 2018 Downloaded from http://pubs.acs.org on November 13, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Measurement of Heat of Vaporization for Research Gasolines and Ethanol Blends by DSC/TGA Gina M. Fioroni,*† Lisa Fouts, †Earl Christensen, †James E. Anderson, ‡Robert L. McCormick† †

National Renewable Energy Laboratory, Golden, Colorado 80401, United States

‡

Ford Motor Company, Dearborn, Michigan 48121, United States

KEYWORDS gasoline, engine knock, heat of vaporization, differential scanning calorimetry, thermogravimetric analysis

ABSTRACT

The heat of vaporization (HOV) is a relatively poorly studied fuel property that can be related to a fuel’s evaporation characteristics and knock resistance and therefore the emissions and efficiency of direct-injection spark-ignition engines. Methods for measuring the HOV of complex gasoline mixtures and blends of gasoline with ethanol and other oxygenates require additional development. Recently, we described a differential scanning calorimetry/thermogravimetric (DSC/TGA) method to perform HOV measurements. Herein we describe a detailed investigation of factors affecting the precision and accuracy of the DSC/TGA method and examine enthalpy evolution and

ACS Paragon Plus Environment

1

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 28

mass loss rate for research gasolines as a function of fraction evaporated. Examination of n-hexane evaporation using several DSC/TGA pan/lid configurations showed that initial sample loss can be reduced using a well-fitting pinhole lid on the sample pan, which reduces the evaporation rate during the balance of the experiment. However, additional experiments with research gasolines revealed that tight lid placement on the pans is not always achieved. Nevertheless, accurate total HOV measurements, with less than 10% initial sample loss, could be achieved for low volatility gasolines regardless of lid placement. A higher mass loss might be expected for higher vapor pressure (wintertime) gasolines. Because of variations in pan lids and their placement and their significant impact on results, quantitative comparisons between different samples of mass loss rate and heat flow curves versus time or fraction evaporated is not yet possible. However, features in the mass loss rate and heat flow curves are reproducible. Results show that ethanol–gasoline blend evaporation is highly influenced by the formation of near-azeotropic mixtures of ethanol and specific gasoline components, causing a flattening of the mass and heat curves, with a sharp evaporation rate reduction after the ethanol is evaporated.

INTRODUCTION Strategies for improving the efficiency of spark-ignition (SI) engines such as increasing compression ratio, engine downsizing and turbocharging, operating the engine at lower speeds, and cylinder deactivation all tend to increase in-cylinder pressures and temperatures and thus benefit from fuels with greater knock resistance. 1 Direct injection (DI) of the fuel results in fuel evaporation in the cylinder, beneficially cooling the fuel–air mixture to an extent determined by the fuels heat of vaporization (HOV). 2,3,4 This effect has been shown to increase knock resistance by the equivalent of approximately five octane numbers for conventional hydrocarbon gasoline


2

Page 3 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

(without oxygenates) 5 and can also contribute to increased efficiency through reduced pumping losses at low to medium loads. 6,7 The HOV of ethanol (924 kJ/kg at 25 ºC) is as much as three times that of typical gasoline hydrocarbons. 8 The increased evaporative cooling contributes to the high octane rating of ethanol (109 RON) and the increase in knock resistance when ethanol is blended with gasoline. 2,3,8,9,10 Other studies conducted in DI engines for fuels with matched research octane number (RON), but different ethanol content (up to 30% by volume) found no additional knock resistance for the higher HOV (higher ethanol content) fuels. 11,12,13 While it may seem that these studies conflict with the well-known effect of evaporative cooling in DI engines and the greater amount of cooling observed for ethanol blends, one explanation is that the HOV cooling effect is largely included in the RON rating for ethanol blends at these ethanol content levels. 1, 14 Other recent research 15 points out that for studies showing an HOV effect on knock resistance the HOV is covariant with octane sensitivity (OS = RON - motor octane number [MON]). 2,3,9,10 Studies that fix OS while varying HOV do not show a knock benefit. 11,12 Some have interpreted this to mean that HOV is captured as a thermal component of octane sensitivity. 14 Evaporative cooling can also significantly lower K as defined in the octane index equation (OI = RON – K*OS) increasing the positive effect of OS on knock resistance for downsized-boosted engines where K97%) of isoparaffinic and paraffinic compounds, perhaps leading to a continuous distribution of very similar azeotropes and the observed behavior. FACE H contains significant levels of isoparaffins, n-paraffins, cycloparaffins, aromatics, and olefins leading to a more complex evaporation profile. Analysis of Co-Optima Core Gasolines Table 7 contains the HOV results for the Co-Optima Core research gasolines measured by both TGA/DSC and DHA. All samples were measured using a pinhole lid except the high aromatic gasoline. This sample suffered from a very long run time (>3 h), signal drift, and significant residue remaining in the pan when a lid was used. Even without the use of a lid, there was still 0.3 mg of sample remaining that did not evaporate, representing 2% of the total sample mass. This may bias the measurement towards HOV higher values because the heat flow associated with the empty pans (which is subtracted from the total heat flow to give the actual sample heat flow) would not have reached its equilibrium and would be lower than the actual value. The percent differences from the DHA-based HOV estimate were well below 5% for three of the fuels and 6-7% for the high ethanol (E30) and high aromatic gasolines. Table 7. HOV at ~20°C of full boiling range gasoline samples measured by DSC/TGA and DHA Sample Name High Ethanol (E30) High Olefin High Cycloparaffin High Aromatic High Isoparaffin

HOV by DSC/TGAa (kJ/kg) 565 337 393 424, 412b 309

HOV by DHA (kJ/kg) 532 330 370 361 308

% Diff 6.1 1.1 2.9 6.6 0.3

a

Measured with pinhole lid, unless stated otherwise. bMeasured without pan lid.


18

Page 19 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

Plots of mass loss rate and heat flow for the Co-Optima Core gasolines are shown in Figure 5. Note that in most cases DHA reveals that the Core gasolines contain a single major compound. For example, the High Isoparaffin gasoline contains 76 wt% isooctane. As shown in Figure 5, mass loss rate and heat flow are relatively constant but then sharply drops above 90% evaporated presumably after this single component is fully evaporated. As observed for the FACE gasolines, there is also a sharp drop in mass loss rate and heat flow for E30 after the ethanol is fully evaporated. Note that the high mass loss rate and heat flow observed for the cycloparaffin gasoline are caused by a poorly fitting pan lid.


19

Energy & Fuels

0.06

a)

High Olefin

Mass Loss Rate, mg/s

0.05

High Isoparaffin High Aromatic

0.04

High Cycloparaffin E30

0.03 0.02 0.01 0 0

0.2

0.4

0.6

0.8

1

Mass Fraction Evaporated b)

0 ‐2

Corrected Heat Flow, mJ/s

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 28

‐4 ‐6 ‐8 ‐10 ‐12 ‐14 0

0.2

0.4

0.6

0.8

1

Mass Fraction Evaporated

Figure 5. Mass loss rate and heat flow data for the Co-Optima Core gasolines, all data acquired in Pt pans with pinhole lids. Instantaneous HOV and Cumulative HOV In our earlier DSC/TGA study of FACE A and H ethanol blends we proposed the use of a parameter called instantaneous HOV (iHOV). 22 This is obtained by dividing the heat flow curve (mJ/s) by the mass loss rate curve (mg/s) to obtain an instantaneous J/g signal. Conceptually, the iHOV describes the HOV of the compounds that are evaporating at any given point in time. However, examination of iHOV data shows an analytical artifact near the end of the evaporation


20

Page 21 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

period for samples containing ethanol. For example, Figure 6 shows iHOV versus fraction evaporated for FACE A and H E30 blends and the Co-Optima Core E30. The different time lags for the mass loss and heat flow in the iHOV quotient produce a sharp peak at the point where the ethanol is evaporated, and mass loss rate and heat flow are rapidly changing. For the more complex Co-Optima E30 – which is closer to a full boiling range gasoline – this peak dominates the latter half of the iHOV curve. While the concept of iHOV remains intriguing, currently we are aware of no approach to adequately calibrate or correct for these different time lags. Until this can be addressed the iHOV approach will not yield physically meaningful results in this region of the curve.


21

Energy & Fuels

a)

900

b)

600

800

500 600

cHOV, kJ/kg

iHOV, kJ/kg

700

500 400 300

FACE A

200

FACE A E10

400 300 200

FACE A FACE A E10

100

FACE A E15

100

FACE A E15

FACE A E30

FACE A E30

0

0 0

0.2

0.4

0.6

0.8

1

0

0.2


800

700

700

600

600

cHOV, kJ/kg

iHOV, kJ/kg

800

500 400 300 FACE H

0

1

300 FACE H E10 FACE H E15

0.4

0.6

0.8

FACE H E30

0

1

0

0.2


e)

0.8

400

100

FACE H E30

0.2

1

FACE H

FACE H E15

0

0.8

500

200

FACE H E10

100

0.6

900

d)

200

0.4


900

c)

0.4

0.6


1800

f)

1600

700 600

High Olefin

1400

High Isoparaffin

1200

500

High Aromatic

cHOV, kJ/kg

iHOV, kJ/kg

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 28

High Cycloparaffin

1000

E30

800 600

400 300 High Olefin

200

High Isoparaffin

400

High Aromatic

100

200

High Cycloparaffin E30

0

0 0

0.2

0.4

0.6

0.8

1

0


0.2

0.4

0.6

0.8


Figure 6. Calculated instantaneous HOV (iHOV) and cumulative HOV (cHOV) for the fuel samples. Note the analytical artifact in iHOV for the ethanol-containing samples (a nonphysical peak caused by differing time lags for heat flow and mass loss rate).


22

1

Page 23 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

As an alternative or complementary approach, the cumulative HOV (cHOV) can be used to represent the HOV of the mass fraction that has already evaporated.

22

This approach is

conceptually the same as calculating total HOV (at the end of the experiment) but doing so as evaporation process is proceeding. In fact, the cHOV value at the highest mass fraction evaporated is equal to the total HOV. As shown in Figure 6, where the sharp drop in iHOV (and associated analytical artifact) occurs with ethanol blends, the cHOV curve instead shows a clear change in slope from gradually increasing to gradually decreasing, with the analytical artifact no longer apparent. This cumulative approach also eliminates analytical artifacts and noise that occur at the very end of the evaporation period due to increasingly smaller mass loss and heat flow rates. While the iHOV approach (with limitations) gives the HOV of the compounds evaporating at any time, the cHOV approach shows the average HOV of the compounds that have evaporated up to that time. The former may be useful in understanding the evaporation dynamics (related to the remaining mixture composition) while the latter may provide insight into the aggregate amount of cooling provided by a fuel as it evaporates. The cHOV charts show that ethanol blending increases HOV over almost the entire evaporation process, and for all evaporation occurring above 0.2 mass fraction evaporated.

CONCLUSIONS DSC/TGA experiments with n-hexane show that sample loss early in the experiment and sample evaporation rate can be improved with a well-fitting pan pinhole lid, but that the observed evaporation rate is not reproducible and apparently dominated by how well the lid fits onto the pan. As such, at present it is not possible to discern absolute mass loss rate and heat flow trends between different samples. Despite difficulties in tightly controlling and replicating evaporation


23

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 28

rates, the measured HOV values for replicate runs of a given sample are reasonably close and agree well with literature (pure component) or DHA-derived (gasolines) values. The rates of heat flow and evaporative mass loss are closely related, thus differences in mass loss and heat flow rates tend to balance each other out in the HOV calculation. For total HOV of gasolines, if DHA is available it is likely the more accurate approach; however, DSC/TGA will typically give values within 5% of the DHA result. Examination of mass loss rate and heat flow curves versus time or fraction evaporated can reveal significant changes in these rates for some samples; however, comparison of curves between samples on a quantitative basis is difficult because these rates are dominated by pan/lid configuration and fitting. It is clearly desirable to develop pan lids that fit consistently onto the pans to allow better-controlled evaporation rates in DSC/TGA evaporation studies. Results show that ethanol-gasoline blend evaporation is highly influenced by the formation of near-azeotropic mixtures of ethanol and gasoline components, causing a flattening of the mass and heat curves, with a sharp drop when ethanol is fully evaporated. Similar behavior is to be expected for other alcohols that form non-ideal solutions with gasoline, such as methanol. Improved timeor mass-resolved HOV measurements might be obtained using hermetically sealed sample pans that are punctured by a robotic system at the start of the experiment, or alternatively by achieving more consistent lid placement and fit on the sample pans (e.g., by a robotic system or by improving the uniformity of the lid-pan mating surface). AUTHOR INFORMATION Corresponding Author *Gina M. Fioroni, [email protected]


24

Page 25 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

ACKNOWLEDGMENT This research was conducted as part of the Co-Optimization of Fuels & Engines (Co-Optima) project sponsored by the U.S. Department of Energy – Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies and Vehicle Technologies Offices. Co-Optima is a collaborative project of several national laboratories initiated to simultaneously accelerate the introduction of affordable, scalable, and sustainable biofuels and high-efficiency, low-emission vehicle engines. Work at the National Renewable Energy Laboratory was performed under Contract No. DE347AC36-99GO10337. The views expressed in the article do not necessarily represent the views of the U.S. Department of Energy or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes. Initial work on the FACE gasolines and blends was sponsored by the Coordinating Research Council as project AVFL-27. FACE A and H gasoline samples were kindly provided by the Coordinating Research Council. NOTES Disclosure: Whereas this article is believed to contain correct information, Ford Motor Co. (Ford) does not expressly or impliedly warrant, nor assume any responsibility, for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe the rights of third parties. Reference to any commercial product or process does not constitute its endorsement. This article does not provide financial, safety, medical, consumer product, or public policy advice or recommendation. Readers should


25

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 26 of 28

independently replicate all experiments, calculations, and results. The views and opinions expressed are of the authors and do not necessarily reflect those of their companies. This disclaimer may not be removed, altered, superseded or modified without prior Ford permission. ABBREVIATIONS ASTM, ASTM International, Co-Optima, Co-Optimization of Fuels & Engines, DI, direct injection, DSC, differential scanning calorimetry, FACE, Fuels for Advanced Combustion Engines, HOV, heat of vaporization, iHOV, instantaneous heat of vaporization, MON, motor octane number, RON, research octane number, S, sensitivity, SI, spark ignition, TGA, thermogravimetric analysis.

REFERENCES 1. Leone, T.; Anderson, J.; Davis, R.; Iqbal, A.; Reese, R.; Shelby, M.; Studzinski, W. The Effect of Compression Ratio, Fuel Octane Rating, and Ethanol Content on Spark-Ignition Engine Efficiency. Environmental Science and Technology 2015, 49, 10778-10789. 2. Kasseris, E.; Heywood, J. Charge Cooling Effects on Knock Limits in SI DI Engines Using Gasoline/Ethanol Knock Limits in SI DI Engines Using Gasoline/Ethanol. SAE Technical Paper 2012-01-1275 2012, No. doi:10.4271/2012-01-1275. 3. Kasseris, E.; Heywood, J. Charge Cooling Effects on Knock Limits in SI DI Engines Using Gasoline/Ethanol Blends: Part 2 - Effective Octane Numbers. SAE Technical Paper 2012-011284 2012, No. doi:10.4271/2012-01-1284. 4. Ratcliff, M.; Burton, J.; Sindler, P.; Christensen, E.; Fouts, L.; McCormick, R. Effects of Heat of Vaporization and Octane Sensitivity on Knock-Limited Spark Ignition Engine Performance. SAE Technical Paper 2018-01-0218 2018. 5. Chow, E.; Heywood, J.; and Speth, R. Benefits of a Higher Octane Standard Gasoline for the U.S. Light-Duty Vehicle Fleet. SAE Technical Paper 2014-01-1961 2014, No. doi:10.4271/2014-01-1961. 6. Wyszynski, L.; Stone, C.; and Kalghatgi, G. The Volumetric Efficiency of Direct and Port Injection Gasoline Engines with Different Fuels. SAE Technical Paper 2002-01-0839 2002, No. doi:10.4271/2002-01-0839.


26

Page 27 of 28 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Energy & Fuels

7. Jung, H.; Shelby, M.; Newman, C.; Stein, R. Effect of Ethanol on Part Load Thermal Efficiency and CO2 Emissions of SI Engines. SAE Int. J. Fuels Lubr. 2013, 6 (1), 456-469. 8. Chupka, G.; Christensen, E.; Fouts, L.; Alleman, T.; Ratcliff, M.; McCormick, R. Heat of Vaporization Measurements for Ethanol Blends up to 50 Volume Percent in Several Hydrocarbon Blendstocks and Implications for Knock in SI Engines. SAE Int. J. Fuels Lubr. 2015, 8 (2), 251-263. 9. Stein, R.; Polovina, D.; Roth, K.; Foster, M.; Lynskey, M.; Whiting, T.; Anderson, J.; Shelby, M.; Leone, T.; VanderGriend, S. Effect of Heat of Vaporization, Chemical Octane, and Sensitivity on Knock Limit for Ethanol - Gasoline Blends. SAE Int. J. Fuels Lubr. 2012, 5 (2), 823−843. 10. Wang, C.; Janssen, A.; Parakash, A.; Cracknell, R.; Xu, H. Splash Blended Ethanol in a Spark Ignition Engine - Effect of RON, Octane Sensitivity, and Charge Cooling. Fuel 2017, 196, 21-31. 11. Leone, T.; Olin, E.; Anderson, J.; Jung, H.; Shelby, M.; Stein, R. Effects of Fuel Octane Rating and Ethanol Content on Knock, Fuel Economy, and CO2 for a Turbocharged DI Engine. SAE Int. J. Fuels Lubr. 2014, 7 (1). 12. Thewes, M.; Küpper, C.; Rezaei, R.; Pischinger, S. Future Fuels for Modern DISI Engines. 19th Aachen Colloquium Automobile and Engine Technology, 2010; pp 539- 570. 13. Vuilleumier, D.; Sjoberg, M. Significance of RON, MON, and LTHR for Knock Limits of Compositionally Dissimilar Gasoline Fuels in a DISI Engine. SAE Int. J. Engines 2017, 10 (3). 14. Foong, T.; Morganti, K.; Brear, M.; da Silva, G.; Yang, Y.; Dryer, F. The Effect of Charge Cooling on the RON of Ethanol/Gasoline Blends. SAE Int. J. Fuels Lubr. 2013, 6 (1). 15. Sluder, C.; Szybist, J.; Ratcliff, M.; McCormick, R.; Zilger, B. Exploring the Relationship between Octane Sensitivity and Heat-of-Vaporization. SAE Int. J. Fuels Lubr. 2016, 9 (1), 80-90. 16. He, X.; Ratcliff, M.; Zigler, B. Effects of Gasoline Direct Injection Engine Operating Parameters on Particle Number Emissions. Energy & Fuels 2012, 26 (4), 2014-2027. 17. Butler, A.; Sobotowski, R.; Hoffman, G.; Machiele, P. Influence of Fuel PM Index and Ethanol Content on Particulate Emissions from Light-Duty Gasoline Vehicles. SAE Technical Paper 2015, 2017-01-1072. 18. Storch, M.; Koegl, M.; Altenhoff, M.; Will, S.; Zigan, L. Investigation of Soot Formation of Spark-Ignited Ethanol-Blended Gasoline Sprays with Singe- and Multi-Component Base Fuels. Applied Energy 2016, 181, 278-287.


27

Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 28 of 28

19. Kar, K.; Last, T.; Haywood, C.; Raine, R. Measurement of Vapor Pressures and Enthalpies of Vaporization of Gasoline and Ethanol Blends and Their Effects on Mixture Preparation in an SI Engine. SAE Int. J. Fuels Lubr. 2009, 1 (1), 132-144. 20. Balabin, R.; Syunyaiv, R.; Karpov, S. Molar Enthalpy of Vaporization of Ethanol-Gasoline Mixtures and their Colloidal State. Fuel 2007, 86, 323-327. 21. Sauerbrunn, S.; Zemo, M. Measuring the Heat of Evaporation by TGA-DSC. https://www.americanlaboratory.com/914-Application-Notes/644-Measuring-the-Heat-ofEvaporation-by-TGA-DSC (accessed January 20, 2018). 22. Fioroni, G.; Fouts, L.; McCormick, R. Measurement of Heat of Vaporization of GasolineEthanol Blends by Detailed Hydrocarbon Analysis and Differential Scanning Calorimetry Coupled to Thermogravimetric Analysis; Coordinating Research Council Project AVFL-27: Atlanta, 2016. 23. Cannella, W.; Foster, M.; Gunter, G.; Leppard, W. FACE Gasolines and Blends with Ethanol: Detailed Characterization of Physical and Chemical Properties; Coordinating Research Council Report AVFL-24: Atlanta, 2014. 24. Fouts, L.; Fioroni, G.; Christensen, E.; Ratcliff, M.; McCormick, R.; Zigler, B.; Sluder, C.; Szybist, J.; Dec, J.; Miles, P.; Ciatti, S.; Bays, J.; Pitz, W.; Mehl, M. Properties of Co-Optima Core Gasolines; Technical Report NREL/TP-5400-71341; National Renewable Energy Laboratory: Golden, CO, August 2018. 25. Reid, R.; Prausnitz, J.; Poling, B. The Properties of Gases and Liquids, 4th ed.; McGraw Hill: New York, 1987. 26. Demirel, Y. Energy: Production, Conversion, Storage, Conservation, and Coupling. In Green Energy, 2nd ed.; Springer, 2016. 27. Lemmon, E.; McLinden, M.; Friend, D. Thermophysical Properties of Fluid Systems. In NIST Chemistry WebBook, NIST Standard Reference Database Number 69; Linstrom, P., Mallard, W., Eds.; National Institute of Standards and Technology: Gaithersburg, MD. 28. Chickos, J.; Acree, W. Enthalpies of Vaporization of Organic and Organometallic Compounds, 1880-2002. J. Phys. Chem. Ref. Data 2003, 32, 519-878. 29. Andersen, V.; Anderson, J.; Wallington, T.; Mueller, S.; Nielson, O. Distillation Curves for Alcohol-Gasoline Blends. Energy and Fuels 2010, 24, 2683–2691.


28

Measurement of Heat of Vaporization for Research Gasolines and

Recommend Documents