@book{scholars7270, note = {cited By 0}, year = {2016}, publisher = {Nova Science Publishers, Inc.}, journal = {Asphaltenes: Fundamentals, Applications and Future Developments}, title = {Asphaltenes and crude oil fouling}, pages = {35--60}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85152978823&partnerID=40&md5=40e1ac0326d8ebdd57ad778ab33b57e7}, abstract = {Asphaltenes are complex, ring structured molecules of crude oil, surrounded by resins. Understanding of composition, properties and behavior of asphaltenes has been driven by the problems caused by it during crude oil production, processing and transportation. Asphaltenes are composed of the heaviest components in crude oil and are defined by their solubility behavior rather than by their chemical behavior, as the fraction of crude oil that is insoluble in n-alkanes like n-pentane and nheptane and soluble in aromatics like toluene. Crude oil fouling is widely attributed to asphaltenes precipitation and deposition which causes many problems, like efficiency loss at heat transfer equipment, operating problems, adverse environmental effects, reduced profit margins and higher revenue losses. The stability of the colloidal suspension of asphaltenes dispersed by resin molecules may be affected by various parameters, like, temperature, pressure and fluid composition. Bulk temperature plays an important role in dissolving the dispersed asphaltenes in crude oil. However, there are conflicting views on effect of bulk temperature on solubility of asphaltenes in crude oil. Experiments in an automated flocculation titrimeter were conducted on six different crude oils at five different temperatures. The test results were interpreted in terms of Heithaus onset titration parameters and using Hildebrand's regular solution theory. The results show that the value of peptizability parameter, Pa, for all the oils decreased from 0.9 to 0.10 with the temperature, showing a decrease in asphaltenes colloidal stability with the increase in temperature. The solvating power of oil, P0, increased from 0.5 to 4.5 with the increase in temperature and the measure of overall stability of crude oil, P, increased from 1 to 5.5 with the increase in temperature. Hildebrand solubility parameter of asphaltenes increased from 18.5 to 22.5 MPa0.5 and the parameter of the oils increased from 15 to 33 MPa0.5 with the increase in temperature showing an increase in solubilizing characteristics of oil and solubility of asphaltenes, as a function of temperature. From the results, it is concluded that solubility of asphaltenes in oil increased with the increase in bulk temperature from 20{\^A}oC to 95{\^A}oC. {\^A}{\copyright} 2016 Nova Science Publishers, Inc.}, author = {Ramasamy, M. G. and Chandio, Z. A.}, isbn = {9781634856201; 9781634856058} }