Feasibility of quality process control of a naphtha fractioning unit based on near-infrared spectroscopic prediction of physical and chemical properties of medium naphtha streams

Near-infrared spectroscopy multivariate calibration models were used to predict physical and chemical properties of medium naphtha samples providing the means of appropriate process control of naphtha fractioning units. Relative density, distillation curve (initial boiling point, 5%, 10%, 30%, 50%, 70%, 90%, 95% evaporated and final boiling point) and chemical composition (PINA) were estimated from FT-NIR spectra in the 1660–1800 and 2200–2500 nm regions. Principal component analysis was used for exploratory data analysis and cross-validated one-block partial least-squares models were employed for calibration. Root mean square errors of prediction, based on 4–8 PLS factors, were close to the measured repeatability values and below the limits defined by ASTM methods. The present work has demonstrated the feasibility of performing several analyses required for quality control of a naphtha fractioning unit based on a single NIR spectrum, providing good means for fast process control.