Mechanism of High Temperature Corrosion by Model Naphthenic Acids
Naphthenic acid (NAP) corrosion is one of the major concerns for corrosion engineers in refineries, particularly with the increasing acidity in “opportunity crudes”. However, complex compositions of NAP in crude oil make it difficult to evaluate accurately their corrosive behavior. In the present study, several model acids, including 4-phenylbutyric acid, 1-naphthoic acid, and 4-cyclohexyl pentanoic acid, have been tested in lab scale experiments previous applied to real crude fractions. Pretreatment/challenge protocol tests the corrosive behavior of the model acids under temperature and velocity ranges close to those encountered in refineries. This work demonstrates that the pretreatment of carbon steel and 9Cralloy with model acids yields iron oxide scales with different morphology and chemical composition as determined by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). It is postulated that the formation of the iron oxide scale resulted from the decomposition of iron naphthenate on the surface at high temperatures.
Review of naphthenic acid corrosion in oilrefining
AbstractNaphthenic acid corrosion is a major concern for the oil refinery business. While much is now known about the phenomenon, it is still not completely understood because of the complex influences on corrosion of the type of acid and other constituents in the crude oil and the effects of both temperature and fluid flow. A review of this form of corrosion has been undertaken with respect to the role of crude oil composition, temperature, fluid velocity, physical state (vapour or liquid), pressure, and materials of construction. Simple measures of corrosivity based on the total acid or neutralisation number are insufficient. The sulphur content of the crude is important but the extent to which the various sulphur containing compounds act as inhibitors or corrodents is not understood. There is little knowledge also of the nature of films formed on the steel surfaces under operating conditions and the role of natural inhibitors that may be present in crudes requires more attention.
Factors Likely to Influence Tort Litigation in the European Union
As the European Union moves towards harmonization in a variety of business, political, and regulatory settings, an opportunity exists to influence the form of tort liability found in these nations. The opportunity should not be missed, with rising concern that U.S. influences will set into motion costly litigiousness, particularly as EU member nations pull back on the level of social programmes available to cover costs typically included in tort claims. To assist policymakers in their deliberations about European Union tort directives, this paper provides discussion of the frequently cited key differences between the U.S. tort systems and what is found in most EU member nations. The discussion is focused on available evidence regarding the influences of these differences as well as important areas of future research. The most important areas seem to be (1) the need to enforce European Law when no defined regulatory body exists for this purpose; (2) the connection between government social programmes and the need for tort liability compensation; (3) and the influence of rules governing payment of legal costs and lawyer fees.