In-line Estimation of Sulfur and Nitrogen Contents during Hydrotreating of Middle Distillates

The main objective of this work is analyzing whether it is possible to develop an empirical correlation for in-line estimation of the sulfur and nitrogen contents of the middle distillates Hydrotreating (HDT) products for control purposes. Correlations are based only on readily available in-line information of specific gravity variation between feedstock and products, without considering any piece of information about the kinetic behavior of the catalyst. Experimental data were obtained in pilot plants under operating conditions that are representative of refinery operations. Results indicate that the removal of nitrogen and sulfur compounds during middle distillates HDT can be monitored in-line in real time, based on the available measurements of specific gravity. This allows for development and implementation of advanced in-line procedures for monitoring and control of the HDT process in real time.