DIPPR Project 851

Project 851: Critical Properties of Pure Compounds

Table of Contents


Project Definition

Steering Committee Chair

Purpose

Results Expected

Technical Description

Compounds Studied (1985-2004)

Project Investigator

 


 

Project Definition: Experimentally determine the critical point (temperature, pressure, density/volume) of pure compounds; concentrate on key compounds for which reliable data are lacking. Many such compounds are unstable at their critical temperature; thus, new rapid methods of measurement are required.

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Purpose: Provide basic data required for the correlation and prediction of essential physical and thermodynamic properties used for process design and operation. Critical properties are exceedingly important; they are used to estimate such properties as departure functions, liquid density, viscosity, heat capacity, heat of vaporization, thermal conductivity, diffusion coefficients, and surface tension. Critical properties are also essential for correlation of vapor pressure and liquid density over the entire saturated liquid range. The estimation methods commonly used for critical properties (e.g., Lydersen's method) do not give reliable results for compounds which are unstable or contain multiple function groups. For example, previously accepted critical data for the aldehydes were confirmed and corrected. In addition, a study made by one of the DIPPR® member companies indicated that published data for diols were almost totally inaccurate. This project is directed toward the use of new experimental methods which can give better results for such compounds as well as the more stable compounds.

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Technical Description: The approach to the critical state is time-dependent and is affected by gravity. However, a close approach can be reached within a few seconds, if an ultra-rapid heating source is provided. Gravity is less important with a shallow sample. Thus, to measure critical properties of an unstable compound, a small sample in a rapid heating device, with fast temperature and pressure sensors, is needed. Work to date has involved use of a rapidly heated sealed-ampoule apparatus and also a low residence time flow apparatus.

Wiltec Research Company has developed a new flow measurement method for critical properties and vapor pressures which requires ultra low residence times. This technique would be of considerable use to a number of DIPPR® projects in the following areas: (1). To supply data for development of a critical point estimation method.; (2) . for measurement of critical temperatures and pressures of unstable and multi functional compounds; and (3) for measurement of boiling points and vapor pressures of compounds that decompose when treated using existing methods.

The method is capable of residence times as low as 0.1 sec for total heat-up time from ambient temperature, and extends Wiltec’s present range of critical temperature measurement capability by about 100º C. This is quite significant and will extend the capability on paraffin hydrocarbons from C18 to about C30.

This method opens a completely new region for study which until now has been inaccessible due to decomposition. Critical properties are measured as a function of time for unstable reacting compounds. The data are then analyzed to extrapolate the measured values to zero reaction. Several alternative techniques have also been developed for this procedure.

The compounds included in this project are selected by the Project Steering Committee, consisting of one representative from each of the project sponsors. See Table I for a list of compounds studied previously.

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Project Investigator

David VonNiederhausern

Wiltec Research Company, Inc.
488 South 500 West
Provo, UT 84601
Phone: 801-374-6648; Fax: 801-374-6674
Web site: http://www.wiltecresearch.com

Dr. Eugene D. Nikitin Institute of Thermal Physics of RAS
Amundsena Str., 106, 620016 Ekaterinburg, Russia
Phone: +7-343-267-8810
Fax: +7-343-267-8800
Web: http://itp.uran.ru/nikitin-eng

 

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Steering Committee Chair:

 Mark Liepa, LyondellBasell Industries, 3801 West Chester Pike, Newtown Square, PA 19073-2387; Phone: 610-359-2102; Fax:  610-359-2434.

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Results Expected: Measurements on about 7 compounds each year (this is an average; some compound measurements are attempted, but the measurements can’t be made for a variety of reasons).

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Compounds Studied (1985-2004)

(Publication References cited below noted as follows:1985 [1]; [P]indicates publication is pending; [NR] indicates data has not been approved for release/publication )

1985 [1] (Critical temperature and volume unless otherwise noted)


1. n-Octane (Tc)

6. Ethyl-3-ethoxy propionate

2. Toluene (Tc)

7. Valeric acid

3. Acetaldehyde

8. 2-Propoxyethanol

4. Acetophenone

9. 2-Butoxyethanol

5. Dimethylformamide

10. Ethylene glycol

1986 [1] (Critical temperature and volume)


1. N-Methylpyrrolidone

7. Undecan-1-ol

2. Cyclopentene

8. 2-Ethoxyethyl acetate

3. n-Propyl mercaptan

9. 2-Butoxyethyl acetate

4. n-Butyl mercaptan

10. 1-Methoxy-2-propyl acetate

5. Cyclohexane

11. Titanium tetrachloride

6. Tetralin

12. 2-Ethylhexanoic acid

1987 [1] (Critical temperature and volume unless otherwise noted)


1. Propanal

8. Monoethanolamine (Tc)

2. n-Butanal

9. Benzaldehyde (Tc)

3. n-Pentanal

10. Formic acid (Tc)

4. n-Octyl mercaptan

11. Diethylene glycol (Tc)

5. Cyclohexyl mercaptan

12. Dimethyl disulfide (Tc)

6. 2-(2-Propoxyethoxy)ethanol

13. Maleic acid (Tc)

7. 2-Cyclohexylcyclohexanone (Tc)

 

1988 [1] (Critical temperature and pressure)


1. Toluene

7. n-Hexanal

2. Cyclohexane

8. n-Octanal

3. Cyclopentene

9. n-Decanal

4. Propanal

10. 2-Ethoxyethyl acetate

5. n-Butanal

11. 2-Butoxyethyl acetate

6. n-Pentanal

12. 2-Ethylhexanoic acid

1989 [2] (Critical temperature and pressure)


1. Acetophenone

6. Valeric acid

2. 2-Butoxyethanol

7. 1-Methoxy-2-propyl acetate

3. 2-Propoxyethanol

8. 2-(2-Propoxyethoxy)ethanol

4. Ethylene glycol

9. 2-(2-Butoxyethoxy)ethanol

5. Ethyl-3-ethoxy propionate

10. Monoethanolamine

1990 [3] (Critical temperature, pressure, density)


1. n-Hexanal (Tc, dc)

5. n-Decanal (Tc, dc)

2. n-Heptanal (Tc, Pc, dc)

6. Tetralin (Tc, Pc)

3. n-Octanal (Tc, dc)

7. N-Methylpyrrolidone (Tc, Pc)

4. n-Nonanal (Tc, Pc, dc)
(also remeasured Propanal Pc)

 

1991 [3] (Critical temperature, density)


1. 2-Hexanone

7. 3-Octanone

2. 3-Hexanone

8. 4-Octanone

3. 2-Heptanone

9. 2-Nonanone

4. 3-Heptanone

10. 3-Nonanone

5. 4-Heptanone

11. 4-Nonanone

6. 2-Octanone

12. 5-Nonanone

1992 [4] (Critical temperature, pressure and volume)


1. 2-Hexanone

7. tert-Amylmethyl Ether

2. 2-Heptanone

8. Ethyl tert-Butyl Ether

3. Cumene

9. Isopropyl Acetate (Tc, dc)

4. Ethylbenzene

10. 2-Pentanone

5. Toluene

11. Hexafluoroethane

6. Propene

 

1993 [5] (Critical temperature, pressure and volume)


1. Acrylonitrile

6. 2-Methoxyethanol

2. Cyclohexanol

7. 2-(2-Methoxyethoxy)ethanol

3. Ethyl Thioacetate

8. y -Butyrolactone

4. 2-(2-Ethoxyethoxy)ethanol

9. 2-Nonanone

5. Methoxy benzene (Anisole)

10. Isopropyl Acetate (Pc)

1994 [5]  (Critical temperature, pressure and volume)


1. 1,4-Butanediol

4. 1,2-Ethanediamine

2. 2-(2-Butoxyethoxy)ethyl Acetate

5. 1-Methoxy-2-propanol

3. 2-(2-Ethoxyethoxy)ethyl Acetate

 

1995 [6]  (Critical temperature and pressure)


1. 1-Butoxy-2-propanol

5. 2-Methyl-1,3-propanediol

2. Di-(2-aminoethyl)amine

6. 1,2-Propanediol

3. Diethyl Sulfide

7. Propylene Carbonate

4. 1,2-Ethanediol

 

1996 [6] (Critical temperature and pressure)


1. Acetonitrile

5. s-Phenylethyl Alcohol

2. 1-n-Propoxy-2-propanol

6. N-(2-Aminoethyl)
ethanolamine

3. 1-t-Butoxy-2-propanol

7. 1,3-Propanediol

4. 1-Dodecanethiol

 

1997 [7] (Critical temperature and pressure)


1. Toluene*

8. Propylene carbonate

2. 2-(2-amino ethylamino)ethanol

9. 1,4-butanediol

3. 1,3-propanediol

10. DEG ethyl ether acetate

4. 2-methyl-1,3-propanediol

11. Ethylbenzene*

5. 2-(2-butoxy ethoxy)ethyl acetate

12. Phenyl acetate

6. Styrene*

13. Squalane*

7. Diethylene triamine

 

* These compounds were for a special study undertaken by the investigator.

1998 [8] (Critical temperature and pressure)


1. Triacontane ( Extrapolated)

5. 2-Phenylethanol

2. Dodecanethiol

6. Acrylamide (not done, may be for another investigator)

3. Thioanisole

7. 1-t-butoxy-2-propanol

4. Allyl Alcohol

 

1999 [9] (Critical temperature and pressure)


1. Dibutyl Disulfide (Extrapolated)

6. Dipropylene glycol

2.  1,2-epoxy-2-methylpropane

7. Diethyl oxalate*

3.  N-methyldiethanolamine

8. n butyl acrylate*

4.  1,3-butanediol

9. 4-formylmorpholine*

5. gamma-butyrolactone

10. Napthalene*

* compounds selected by the project investigator

2000 [9] (Critical temperature and pressure)


1. Alkanoic acids with 2,6,8,11,12,14,15,16,17,20,22 carbons (Dr. Nikitin's work)

6. Dimethyl disulfide

2.  2-(2-aminoethoxy)ethanol

7. Oxazole

3.  t-butyl acetate

8. Phenyl iscoyanate

4.  1,1-ethanediol diacetate

9. Sulfolane (Extraplated)

5. p-diisopropylbenzene

2001 [10] (Critical temperature and pressure)


1. 1,6-hexanediol

3. 1,3-benzenediol

2.  1,2-benzenediol

4. Piperazine

2002 [P] (Critical temperature and pressure)


1. 2,4,4-trimethyl-1-pentene

4. Dimethyl terphthalate (approximate)

2.  p-tolualdehyde

5. N-methylacetamide

3.  Bisphenol A (not done)

6. Diphenylmethane


2003 [P] (Critical temperature and pressure)


1. Dimethyl carbonate

4. 3-methylthiophene

2. Methoxyacetone

5. 2-phenoxyethanol

3. 2-methylthiophene


2004 [P] (Critical temperature and pressure)


1. 2-methylpropanal

8. Benzaldehyde

2. 2-methoxy-1-propanol

9. p-tolualdehyde

3. 2-ethoxyethanol

10. Benzyl alcohol

4. Tetrahydrothiopene

11. p-tolualcohol

5. Methyl acetoacetate

12 Benzoic acid

6. Ethylene glycol diacetate

13. p-toluic acid

7. Phenyl mercaptan

Published Results:

[1] 1985-1988 project results have been published in the AIChE Symposium Series,vol. 86, no. 275 (1990).

[2] 1989 project results have been published in the AIChE DIPPR Data Series, No. 1 (1991).

[3] 1990-91 project results were published in the AIChE DIPPR Data Series, No. 2 (1994).

[4] 1992 project results were published in J.Chem.Eng. Data 40 (4), 765-768 (1995).

[5] 1993 and 1994 project results will be published in J Chem Eng Data 41 (6), 1252-1254 (Nov./Dec., 1996).

Note: Three compounds were too reactive to permit accurate measurements: 1,4-dichloro-butane; 2-(2-aminoethylamino)ethanol; phenyl acetate.

[6] 1995 and 1996 projects were published in J.Chem.Eng. Data 45 (2), 154-156 (2000).

[7] 1997 projects were published in J.Chem.Eng. Data 47 (4), 761-764 (2002).

[8] 1998 results were published in J.Chem.Eng. Data 51 (6), 1982-1985 (2006).

[9] 1999 and 2000 results were published in J.Chem.Eng. Data 51 (6), 1990-1995 (2006).

[10] 2001 results were published in J.Chem.Eng. Data 51 (6), 1986-1989 (2006).

Pending Publication:

2002, 2003 and 2004 results have been approved for publication.