Naslov
Theoretical background for predicting the properties of petroleum fluids via group contribution methods

Autori
Bogdanić, Grozdana ; Pavliček, Jan ; Wichterle, Ivan

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
CD-ROM of Full Texts - [15] Symposium on thermodynamics and transport properties [1459] / I. Wichterle - Prag : Czech Society of Chemical Engineering (CSCHE), 2012

ISBN
978-80-905035-1-9

Skup
20th International Congress of Chemical and Process Engineering CHISA 2012

Mjesto i datum
Prag, Češka Republika, 25.08.2012. - 29.08.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
thermodynamic model; prediction properties of crude oil; group contribution method

Sažetak
As the continuation of our previous research [1–2], the simple model for prediction properties of crude oil is developed. The model is based on the concept of additive group contributions method [3], applying the pseudo-component approach [4]. The following input data are required: a complete TBP-analysis (boiling point temperature vs. liquid volume boil-off), a PNA (paraffin-naphthene-aromatic) analysis and density, preferably for each subfraction. Often, all of these data are not available for complex carbon mixtures such as crude oil. Therefore, various procedures for transforming incomplete information on C6+ fraction into satisfactory TBP analyses are used as described in references [4–5]. The procedure is as follows: the TBP curve is divided in several subfractions (the number of subfractions should be as low as possible: five to ten is recommended), as shown in Figure 1. Each subfration contains three model compounds: one paraffinic (P), one naphthenic (N), and one aromatic (A). Example of model compounds is shown in Figure 2, however, the final adjustment of the number of groups should be estimated in order to match the midvolume boiling point for each subfraction. The result of this procedure provides a set of well-defined model compounds which represent the complex petroleum mixture. The calculation is illustrated for subfraction III from Figure 1. The observed midvolume boiling point is 320.2 K at 0.101 MPa, and the following PNA analysis yields 36 % P, 55 % N and 9 % A. Standard procedures are used for estimation critical properties, acentric factor, and molecular masses of model compounds [6]. The input set of groups of model compounds is listed in Table 1. The number n is established with the bubble point of the mixture of model compounds adjusted to the observed midvolume boiling point. The good agreement was obtained after five iterations, and resulting group composition is shown in Table 2. n = 0.88 was obtained for T = 320.2 K, what corresponds to Mr = 132 (observed value 139), PP0 = 0.110, PN0 = 0.09 and PA0 = 0.107 MPa. Calculated thermodynamic properties are compared with the corresponding experimental values and a good agreement was obtained for light to medium crude oil fractions. For fractions with true boiling point about 600 K more experimental data and are needed to use the procedure with confidence. Literature: [1] A. Erceg Kuzmić, M. Radošević, G. Bogdanić, R. Vuković, Fuel, 86 (10-11), 1409-1416 (2007). [2] A. Erceg Kuzmić, M. Radošević, G. Bogdanić, V. Srića, R. Vuković, Fuel, 87 (13-14) 2943-2950 (2008). [3] G. Bogdanić: Additive Group Contribution Methods for Predicting the Properties of Polymer Systems, in Polymeric Materials, Ed. A. Nastasijević, Transworld Research Signpost, Trivandrum, India (2009). [4] K. S. Pedersen, Aa. Fredenslund, P. Thomassen, Properties of Oils and Natural Gases, Gulf Publishing Company, Book Division, Houston, 1985. [5] J. H. Erbar, Research Report 13, Gas Process Association, Tulsa, OK, 1977. [6] B. E. Poling, J. M. Prausnitz, J. P. O’Connell, The Properties of Gases and Liquids, McGraw-Hill, 5th Ed., New York (2000).

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Kemijsko inženjerstvo, Računarstvo

Napomena
Http://www.chisa.cz/2012/ CD ROM of Full Texts ; P1.78 ; contr. 1459

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