Pervaporation-assisted esterification of oleic acid and ethanol was investigated by means of heterogeneous acid catalysis with the aim of increasing the ethyl oleate yield. The experimental strategy comprised kinetic tests with Amberlyst 15 Wet (Rohm & Haas), the characterization of hydrophilic Pervap 1000 membrane (Sulzer) and the evaluation of the membrane-assisted reactor. Kinetic tests were carried out to study the effect of temperature, catalyst loading and ethanol/organic acid molar ratio for the esterification of oleic acid and ethanol. The ester yield and initial reaction rate were used as response. The hydrophilic poly(vinyl alcohol) membrane was able to remove water from the reaction medium and, hence, the ester yield was increased. The potential of coupling esterification and pervaporation was demonstrated, with a two-fold increase in the reaction yield of ethyl oleate.

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.