Determination of naphtha composition by near infrared spectroscopy and multivariate regression to control steam cracker processes

Author(s)

da Silva, Vitor Hugo ^[1] ; Reboucas, Marcio V. ^[2] ; Salles, Alan Rocha ^[2] ; Pimentel, Maria Fernanda ^[1] ; Coelho Pontes, Marcio Jose ^[3] ; Pasquini, Celio ^[4]

Affiliation

^[1] Univ Fed Pernambuco, Dept Engn Quim, Recife, PE - Brazil

^[2] Braskem SA, Unidade Insumos Basicos, BR-42810000 Camacari, Bahia - Brazil

^[3] Univ Fed Paraiba, Dept Quim, BR-58059900 Joao Pessoa, Paraiba - Brazil

^[4] Univ Estadual Campinas, Inst Quim, Campinas, SP - Brazil

• Document type: Journal article
• Source: Fuel Processing Technology; v. 131, p. 230-237, MAR 2015.
• Web of Science Citations: 7

Abstract

Naphtha is an important feedstock for the petrochemical industry and accurate measurement of its detailed composition is essential for the optimization of pyrolysis processes. In the present work, the suitability of using near infrared (NIR) for the determination of 38 parameters used to characterize naphtha was evaluated: pooled composition (PIONA); specific composition groups (C3 paraffins; C4-C12 n-paraffins; C4-C12 iso-paraffins; C5-C7 + naphthenics; C8-C10 aromatics; C4-C6 olefins) and individual components (toluene, benzene, iso-pentane, cyclopentane, methyl cyclopentane; cyclohexane, xylenes, 1,3 butadiene and isoprene). Besides the usual comparison against reference methods, NIR predictions were also evaluated for their ultimate use in determining the coil outlet temperature (COT) for process control. 28 models for the naphtha parameters presented root mean square error (RMSEP) values lower or close to the reproducibility of the reference method and exhibited satisfactory correlation values (r(2)) when compared with r(max)(2). Among the ten remaining parameters, two (1,3 butadiene and isoprene) presented very low concentrations and it was not possible to obtain a suitable model. Eight parameters had RMSEP values higher than the intralaboratory reproducibility and/or r(2) values lower than expected. Despite this, the complete naphtha composition obtained from NIR prediction was demonstrated to be quite suitable for COT simulation, providing accurate COT values compared to the values estimated from the reference method. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 08/57808-1 - National Institute of Advanced Analytical Science and Technology
• Grantee: Celio Pasquini
• Support Opportunities: Research Projects - Thematic Grants