51314-4116-Developing Methodology to Study the Evolution of Chlorides in a Manual Oil Distillation Unit

Available for download

Product Number: 51314-4116-SG

ISBN: 4116 2014 CP

Author: Flora Machado

Publication Date: 2014

Member Price: $0.00

Non Member Price: $0.00

Price: $0.00

Qty:

During oil refining the presence of compounds such as chlorides naphthenic acids sulfides and carbonates can lead corrosion problems and consequently decrease equipment service life. The presence of salts in crude oil poses several challenges which need intervention by refining personnel in order to avoid problems such as reduced efficiency of catalysts and corrosion by chlorides. Among the salts present in crude oil sodium calcium and magnesium chlorides are the most common. Chlorides mainly calcium and magnesium suffer hydrolysis at temperatures around 150-350 ºC resulting in the formation of hydrochloric acid that tends to accumulate at the top of refining towers. The oil exploration in new fields the growing search for productivity and the efficiency of refining processes increasingly demand more strategies to monitor the processes and minimize operational costs.Therefore the presente work aims the development of a method suitable for investigations of the choride evolution during the crude oil refining in order to assess the hydrochloric acid generated during this process in an attempt to prevent the possible impacts to the refineries. A specific glassware system was adapted at the top of the distillation column of a manual distillation unit present at LabPetro Universidade Federal do Espírito Santo – Brazil. Six different types of oil were distilled according to standard method ASTM D 2892-11a totalizing eleven distillation procedures. The percentage of evoluted chloride was calculated by the salt mass balance based on its contents initially present in the crude oil and the chloride content left in the distillation residue. These percentages were correlated with the main counter-ions found (Na Ca and Mg) to check the contribution of each metal in the hydrolysis process. The salt mass balance is summarized in the quantification of salinity crude oils and all products generated after distillation analyzed according to standard method ASTM D 6470-99. Through the capture system at the top of column was possible to obtain aqueous extracts for quantification of chloride by potentiometric titration. Results show that the proposed method is effective for the evaluation of choride evolution on crude oil distillations because data obtained from the salt mass balance showed low losses and the replicates carried out had similar performance. It was observed that crude oils showing higher calcium concentrations compared to sodium concentrations had higher chloride evolution percentages.