Soft sensor for continuous product quality estimation (in crude distillation unit)

Due to the strict norm requirements of keeping products in crude refining units within specifications, laboratory testing and quality control of the products are necessary. Given this reason, virtual soft sensor for continuous quality estimation of light naphtha as the crude distillation unit (CDU) product was developed. Experimental data included available continuous measurements of CDU process streams (temperatures, pressures and flowrate) and laboratory analyses undertaken twice a day. The results are soft sensor models for light naphtha vapor pressure (RVP) estimation.Soft sensor models have been developed conducting multiple linear regression analysis and using neural network-based models such as LNN, MLP and RBF. Considering statistical and sensitivity analysis, the best results for both oils were obtained with MLP and RBF neural networks. The results show possible application of the soft sensor models for estimating light naphtha RVP as an alternative for laboratory testing.

Research highlights▶ Linear and nonlinear soft sensor models for light naphtha quality estimation in refinery plant are developed. ▶ The best results were achieved by nonlinear soft sensor models using artificial neural networks. ▶ Developed nonlinear models can be used in light naphtha quality monitoring and estimation as an alternative to laboratory assays.