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Trace Organics
Published in Robert H. Kadlec, Treatment Marshes for Runoff and Polishing, 2019
Contaminants in oil sands process-affected water include metals and naphthenic acids. Numerous treatment processes have been tested and employed (Allen, 2008; Brown and Ulrich, 2015). Naphthenic acid is a generic term used to refer to all of the carboxylic acids present in petroleum. In general, they contain one or more hydrocarbon rings and an aliphatic side chain (Figure 14.12). They are the most significant contaminants issuing from oil sands petroleum extraction, because they are relatively water-soluble (ca. 50 mg L). When separated from the oil sands solids, they become a significant pollutant in the tailings pond water (oil sands pond water, OSPW).
Chemicals from Paraffin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Naphthenic acid is removed from petroleum fractions not only to minimize corrosion, but also to recover commercially useful products. The greatest current and historical usage of naphthenic acid is in metal naphthenate derivatives. Naphthenic acids are recovered from petroleum distillates by alkaline extraction and then regenerated via an acidic neutralization process and then distilled to remove impurities. Naphthenic acids sold commercially are categorized by acid number, impurity level, and color, and used to produce metal naphthenate derivatives and other derivatives such as esters and amides.
Failure Modes
Published in David A. Hansen, Robert B. Puyear, Materials Selection for Hydrocarbon and Chemical Plants, 2017
David A. Hansen, Robert B. Puyear
Naphthenic acid is the collective name given to organic acids contained in some crude oils and crude oil fractions. It can cause corrosion at temperatures as low as 350°F (175°C). However, serious corrosion, observed as severe pitting and/or grooving, usually does not occur until the temperature exceeds 450°F (230°C).
Deacidification of diesel using tetramethylammonium hydroxid/ammonia under demulsifier
Published in Petroleum Science and Technology, 2019
Fen Yi, Xin Chen, Zhijun Dong, Hailian Yu
Diesel, used as the most important fuel of engine, contains a lot of acids, acids in diesel are composed of fatty acids, phenols and naphthenic acid (Tang, Yan, and Liu 2012). The content of naphthenic acid holds 95% of total acidic compounds, which brings serious harm to its processing facilities, storage devices, transportation pipelines, and engines (Li, Liang, and Xia 2013). Firstly, naphthenic acid is easy to cause emulsification during producing diesel, which results in separating diesel difficultly. Secondly, naphthenic acid is easy to be oxidized, and produce colloid sediments when diesel is in the process of storage and transportation, which reduces obviously stability and quality of diesel (Nie, Xue, and Li 2015). Finally, when diesel fuel is burned in internal combustion engines, naphthenic acid reacts with iron of cylinder block, forms naphthenate at higher temperature, which results in corrosion of cylinder block. Hence, naphthenic acid in diesel must be removed in order to produce qualified diesel. At present, there are a lot of deacidification methods, such as solvent extraction method, esterification method, alcohol/ammonia method, salt method, and alkali washing method (Yu and Hu 2017). Although these methods can effectively remove acids from diesel, serious emulsification appears in the deacidification system, moreover, separating diesel from emulsification system become very difficultly. Our researches show that adding demulsifier can eliminate effectively the emulsification problem, it can improve the deacidification effect of diesel (Hu and Yu 2016). In this paper, we developed a novel method to remove naphthenic acid from diesel. A kind of compound deacidification agent, consisted of tetramethylammonium hydroxid (TMAH) and ammonia, was used to remove naphthenic acid in diesel under nonylphenol ethoxylate as demulsifier, this method overcame the disadvantage of emulsion phenomenon.