Chapters authored
Conducting Polymers Films Deposited on Carbon Steel and Their Interaction with Crude Oil
The formation of scale/solids deposits inside the pipelines is a frequent problem in the petrochemical industry. These scales can be organic as the asphaltenes and inorganic as the accumulations of salts, which apart from blocking the inside of the pipes can also cause a change in the integrity of the steel. Therefore, it is necessary to avoid the conditions where deposition occurs, together with chemical and mechanical methods of remediation to mitigate the deposition. In this work we intend to use conductive polymers in order to inhibit the deposition of asphaltenes on carbon steel surfaces, by using polypyrrole (PPy) as material capable of conducting electrical current. The electrodeposition of PPy on carbon steel were performed by cyclic voltammetry (CV) and chronoamperometry (CA). The results showed that under certain experimental conditions it is possible to make a PPy film with adequate characteristics. Important factors were the grip and electrochemical stability of the formed film on steel, which depends on the electrosynthesis technique and in some cases favoured by a pre-treatment with a 10% HNO3 solution applied to the steel prior to electropolymerization. The PPy films deposited with pre-treatment completely covered the steel surface and showed better stability, adherence and generated a hydrophobic material.
Part of the book: Recent Insights in Petroleum Science and Engineering
Characterization of Crude Oils and the Precipitated Asphaltenes Fraction using UV Spectroscopy, Dynamic Light Scattering and Microscopy
Analysis of crude oil composition provides important information that impacts on the recovery, handling, and transportation of hydrocarbons. Crude characterization also provides data in the analysis of geochemistry of the source of origin. Crude oil characterization by optical methods is usually difficult because of its dark color; however, those characterizations are crucial because they give information that can affect some analysis procedures. Ultraviolet-visible (UV-vis) spectroscopy is a simple and practical technique that allows the characterization of crude oil through dilution in solvents. A comparative study of crude oil solutions contrasted with their asphaltene fractions was performed. Each solution was analyzed in triplicate, on a UV-vis spectrophotometer. Calibration curves for both raw solutions showed no significant variations, indicating stability. Additionally, the results of dispersion and migration phenomena indicated stability only for crude oil solutions. The aggregate size dispersion was different for each type of crude and varied with respect to time. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the type of morphology present for each type of asphaltene.
Part of the book: Recent Insights in Petroleum Science and Engineering