Features of analysis of associative hydrocarbon media. Applicability of refractometric methods

Abstract

The refractive index and optical absorption of solutions of crude oil in toluene were investigated. It was found that the optical properties of systems with an extremely low content of macromolecular substances deviate significantly from Bouguer -Lambert -Beer and other laws. The sensitivity of the refractive index to association of the macromolecular components of hydrocarbon systems was revealed. To increase the accuracy of the analysis, the necessity of a detailed study of the optical properties of associative hydrocarbon systems before plotting calibration curves was demonstrated.Refractometric methods of assessing product quality and composition are widely used in petrochemistry, and the refractive index of petroleum refining products is a quantity regulated by state standards. For this reason, great importance is attributed to the reliability of determining the broad spectrum of properties based on the refractive index.In recent years, instrument-building companies have proposed flow analyzers for monitoring product quality in oil refineries (OR). Many domestic OR -Yaroslavl', Kirishsk, Omsk, etc. -have already introduced systems for monitoring product quality and production processes that include automated instruments -flow analyzers.The analyzers (photometers and prismatic refractometers) are equipped with a built-in microprocessor or external computer which allows obtaining information on the manufacturing process in real time. The principle of action of most of these instruments -the flow refractometer -is based on measuring the refractive index of the medium at a certain wavelength or taking the refractometric spectrum. The instruments are tuned for operation in the visible or UV regions of the spectrum. Linear calibration curves are used to interpret the data.

Laser-induced Fluorescence with Multivariate Analysis in Characterizing Crude Oils from Some Selected Oil Fields in Ghana

“…With changes in heat and pressure over a long period, these layers are converted to kerogens which are estimated to be about 10 16 tons of carbon. It is the most abundant content of living matter by 10,000-fold (Evdokimov & Losev, 2007). Due to heat and pressure, the kerogens are cracked to form crude oil which may migrate from one layer to another till it is trapped by a cap rock that is neither porous nor permeable, hence called the source rock (Ante, 2013).…”

“…Crude oil is made up of mainly organic carbon (85 -87 %) and hydrogen compounds (12 -14 %) with different complex mixes such as naphthenes, methane, butane, paraffin and other aromatic hydrocarbons (Evdokimov & Losev, 2007). Petroleum is categorized as a naphthenic base, intermediate base or paraffin base depending on its hydrogen predominance.…”

“…These natural oils are found in different parts of the world and can be obtained from an extensive range of geological sources. The Sedimentary rocks of the oil fields are of unique geological composition and, therefore, the need to identify their physical characteristics [2,1]. Crude oil analysis is essential for characterization and standardization in the petroleum industry.…”