Group contribution model for determination of molecular diffusivity of non-electrolyte organic compounds in air at ambient conditions Farhad Gharagheizi a , Ali Eslamimanesh b , Amir H. Mohammadi b,c,n , Dominique Richon b a Saman Energy Giti Co., Postal Code 3331619636, Tehran, Iran b MINES ParisTech, CEP/TEP—Centre E ´ nerge´tiqueetProce´de ´s, 35 Rue Saint Honore ´, 77305 Fontainebleau, France c Thermodynamics Research Unit, School of Chemical Engineering, University of KwaZulu-Natal, Howard College Campus, King George V Avenue, Durban 4041, South Africa article info Article history: Received 28 January 2011 Received in revised form 12 September 2011 Accepted 19 September 2011 Keywords: Diffusion coefficient Air Artificial Neural Network Group contribution Accurate model Outliers abstract Determination of diffusion coefficients of pure compounds in air is of great interest for modeling of air pollution control processes. In this communication, a Group Contribution (GC) method is applied to represent/predict the molecular diffusivity of chemical compounds in air at 298.15 K and atmospheric pressure. 4661 compounds from various chemical families have been investigated to propose a comprehensive and predictive model. The final model is resulted from coupling the Artificial Neural Network (ANN) with group contributions. Using this dedicated model, we obtain satisfactory results quantified by the following statistical results: Squared Correlation Coefficient ¼0.995, Standard Deviation Error ¼0.02, and Average Absolute Deviation ¼1.4% for the calculated/predicted properties from existing experimental values. & 2011 Elsevier Ltd. All rights reserved. 1. Introduction Controlling environmental pollution, especially air and water pollution, has become one of the major topics for researchers who care about environmental health (Sattari and Gharagheizi, 2008). Some of the pollutants are toxic and/or corrosive. Toxic air pollutants are those considered as hazardous to human health or the environ- ment (Cheremisinoff, 2002). Atmospheric contaminations arise from exhausts generated by industrial processes, power plants, transporta- tion, etc. For instance, we may cite release of volatile organic compounds (VOCs) or accidental discharges as a result of abnormal operation from polyethylene and ethylene-oxide-glycol plants (pet- rochemical complexes) into the atmosphere (Cheremisinoff, 2002). The environmental regulations such as ‘‘The Clean Air Act Amend- ments of 1990’’ were adopted to reduce the aforementioned air pollutions resources. In this context, accurate knowledge of diffusion coefficients of the chemical species in air is of particular interest (Sattari and Gharagheizi, 2008; Cheremisinoff, 2002). Emitted pollutants are either dispersed by wind or diffused from emission sources. Dispersion of pollutants is mainly accomplished by diffusion (Sattari and Gharagheizi, 2008; Cheremisinoff, 2002; Strauss, 1971). Quantifying workplace exposures, mainly focused by industrial hygiene, is a key environmental issue. The starting point for exposure assessment is to determine the amounts (concentra- tion) of pollutant in given area. Concentration is related to exposure (exposure is expressed in unit of concentration e.g. (mol/l) multi- plied by time (s)), and is consequently a fundamental parameter in developing an air pollution model (Sattari and Gharagheizi, 2008; Frumkin, 2005). Fick’s diffusivity law is generally used for determination of the concentration profiles of a chemical substance inside a media (e.g. air pollutants into the air) as follows (Sattari and Gharagheizi, 2008; Cheremisinoff, 2002; Strauss, 1971): @C @t ¼ rUðDrCÞ ð1Þ Here, C is the concentration of pollutant, t denotes the time, and D stands for the molecular diffusivity of pollutant into the air. Experimental values of diffusion coefficients may not unfortu- nately be always available especially for new chemical species applied in nowadays industries. Their experimental determina- tions may be normally considered as expensive and time-con- suming (Lugg, 1968). Hence, general and reliable models are required to be developed with the aim of reducing significantly the required experimental work. Up to now, many correlations have been presented for evaluation of the diffusion coefficients in gaseous binary mixtures. Regarding Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/ces Chemical Engineering Science 0009-2509/$ - see front matter & 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.ces.2011.09.035 n Corresponding author at: MINES ParisTech, CEP/TEP—Centre E ´ nerge ´ tique et Proce ´de ´ s, 35 Rue Saint Honore ´ , 77305 Fontainebleau, France. Tel.: þ33 1 64 69 49 70; fax: þ33 1 64 69 49 68. E-mail address: amir-hossein.mohammadi@mines-paristech.fr (A.H. Mohammadi). Please cite this article as: Gharagheizi, F., et al., Group contribution model for determination of molecular diffusivity of non-electrolyte organic compounds in air at ambient conditions. Chemical Engineering Science (2011), doi:10.1016/j.ces.2011.09.035 Chemical Engineering Science ] (]]]]) ]]]–]]]