The Acid-IER Method - a Method for Selective Isolation of Carboxylic Acids from Crude Oils and Other Organic Solvents (2003)

The Acid-IER Method - a Method for Selective Isolation of Carboxylic Acids from Crude Oils and Other Organic Solvents Heidi Mediaas; Heidi Mediaas Statoil ASA Search for other works by this author on: This Site Google Scholar Knut V. Grande; Knut V. Grande Statoil ASA Search for other works by this author on: This Site Google Scholar Britt M. Hustad; Britt M. Hustad Statoil ASA Search for other works by this author on: This Site Google Scholar Anita Rasch; Anita Rasch Statoil ASA Search for other works by this author on: This Site Google Scholar Håkon G. Rueslåtten; Håkon G. Rueslåtten Statoil ASA Search for other works by this author on: This Site Google Scholar Jens Emil Vindstad Jens Emil Vindstad Statoil ASA Search for other works by this author on: This Site Google Scholar Paper presented at the International Symposium on Oilfield Scale, Aberdeen, United Kingdom, January 2003. Paper Number: SPE-80404-MS https://doi.org/10.2118/80404-MS Published: January 29 2003 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Mediaas, Heidi, Grande, Knut V., Hustad, Britt M., Rasch, Anita, Rueslåtten, Håkon G., and Jens Emil Vindstad. "The Acid-IER Method - a Method for Selective Isolation of Carboxylic Acids from Crude Oils and Other Organic Solvents." Paper presented at the International Symposium on Oilfield Scale, Aberdeen, United Kingdom, January 2003. doi: https://doi.org/10.2118/80404-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE International Oilfield Scale Conference and Exhibition Search Advanced Search AbstractThe amount of acidic crude oils produced worldwide is increasing. These oils introduce problems throughout the hydrocarbon value chain due to their high content of carboxylic acids, examples of which are naphthenate deposition in production facilities and refinery corrosion. In order to deal with these problems, it is often necessary to isolate the carboxylic acids in different fluid streams or solids to allow further analysis without interference from other compounds.This paper presents and verifies an ion-exchange method that can be used for selective isolation of carboxylic acids from crude oils, distillate fractions and other organic solvent. The efficiency and selectivity of the method have been demonstrated as >98 mol-% using two synthetic carboxylic acids. Its usefulness for isolation of carboxylic acids from solids and non-organic solvents has also been demonstrated, exemplified by calcium naphthenate deposits and water.IntroductionAmong the oilfields found and developed around the world, an increasing fraction contains naphthenic acids and has a high TAN-value (Total Acid Number). Producing and refining high-TAN crude oils introduces a number of problems, e.g. calcium naphthenate deposition in process facilities offshore,1–4 and corrosion in refinery equipment.5In order to understand the mechanisms behind these and other naphthenic acid-related problems, it is of utmost importance that the acids can be isolated selectively, thereby allowing for thorough characterization of the acids. Through the years, a number of works dealing with isolation and characterization of acids in crude oils, base oils, oil shale, etc. have been published. The different methods are most easily grouped into the categories solid/liquid extraction,6–12 liquid/liquid extraction,13 and chromatography.14,15 Methods for direct extraction of acids from water are also described.16–18The idea of using a sugar-based QAE Sephadex A-25 ion exchange resin (Acid-IER) was presented to Statoil by private consultant Bjørn A. Ardø, who also worked with Statoil to develop the idea into a working procedure for isolating carboxylic acids from crude oils. The fact that it is sugar-based makes the IER hydrophilic, and, therefore, more selective towards carboxylic acids than hydrophobic IERs.The present paper describes the Acid-IER method in detail, and gives examples of its use for isolating acids from a crude oil and its distillates as well as from water and calcium naphthenate deposits. The high efficiency and selectivity of the Acid-IER method has been demonstrated using two synthetic acids dissolved in an acid-free crude oil.Laboratory equipmentThe experimental set-up and equipment used during carboxylic acid isolation are ordinary laboratory equipment, e.g. filter funnels, filtering flasks, and round flasks. During the filtering process two filter paper qualities were used - 5891 Black Ribbon and 5893 Blue Ribbon from Schleicher & Schuell - hereafter referred to as coarse and fine filter paper, respectively.Solvent evaporation was done using a rotavapor (Labrota 4003 equipped with rotacool and rotavac, Heidolph). The rotation and temperature set points were 120 rpm and 60°C, respectively. The pressure was reduced gradually to 35 mbar. The acids were dried further in a heating chamber (60°C) until the weight was stable. Keywords: acid-ier method, isolation efficiency, mole weight, selectivity, extraction, tan, average mole weight, efficiency, selective isolation, acid Subjects: Improved and Enhanced Recovery This content is only available via PDF. 2003. Society of Petroleum Engineers You can access this article if you purchase or spend a download.