Refining Vegetable Oils: Chemical and Physical Refining

This review presents recent technologies involved in vegetable oil refining as well as quality attributes of crude oils obtained by mechanical and solvent extraction. Usually, apart from virgin oils, crude oils cannot be consumed directly or incorporated into various food applications without technological treatments (refining). Indeed, crude oils like soybean, rapeseed, palm, corn, and sunflower oils must be purified or refined before consumption. The objective of such treatments (chemical and physical refining) is to get a better quality, a more acceptable aspect (limpidity), a lighter odor and color, longer stability, and good safety through the elimination of pollutants while minimizing oil loss during processing. However, the problem is that refining removes some essential nutrients and often generates other undesirable compounds such as 3-MCPD-esters and trans-fatty acids. These compounds directly influence the safety level of refined oil. Advantages and drawbacks of both chemical and physical refining were discussed in the light of recent literature. Physical refining has several advantages over chemical one.

Supercritical Fluid Application in the Oil and Gas Industry: A Comprehensive Review

The unique properties of supercritical fluid technology have found wide application in various industry sectors. Supercritical fluids allow for the obtainment of new types of products with special characteristics, or development and design of technological processes that are cost-effective and friendly to the environment. One of the promising areas where supercritical fluids, especially carbon dioxide, can be used is the oil industry. In this regard, the present review article summarizes the results of theoretical and experimental studies of the use of supercritical fluids in the oil and gas industry for supercritical extraction in the course of oil refining, increasing oil recovery in the production of heavy oil, hydraulic fracturing, as well as processing and disposal of oil sludge and asphaltenes. At the end of the present review, the issue of the impact of supercritical fluid on the corrosion of oil and gas equipment is considered. It is found that supercritical fluid technologies are very promising for the oil industry, but supercritical fluids also have disadvantages, such as expansion or incompatibility with materials (for example, rubber).

Criticality Analysis Techniques Applied to Optimize Maintenance Management Processes

The techniques of criticality analysis are tools that allow identifying and hierarchy for their importance the assets of an installation on which it is worth directing resources (human, economic, and technological). In other words, the process of criticality analysis helps determine the importance and consequences of potential failure events of production systems within the operational context in which they perform. Taking as reference the maintenance management model (MMM) of the eight phases, this chapter related to techniques of prioritization and criticality is part of Phase 2 of the MMM. In the following chapter, the most important theoretical aspects of equipment hierarchical analysis techniques are explained, based on the qualitative and quantitative risk model (failures frequencies and consequences). Finally, two case studies in the oil refining industry are developed; the first case uses the tool qualitative risk matrix (QRM), and the second case uses the tool risk analytic hierarchy process (RAHP).

OBTAINING DIESEL FUEL WITH IMPROVED PROPERTIES

It is known that one of the ways to increase the level of operational properties of diesel fuels is the injection of special components – additives – into their composition. Today this way is a quite rational and economically feasible for Ukraine, especially in the absence of high-quality oil raw materials for the production of fuels, which in turn leads to a significant dependence on imports. The range of additives used in diesel fuels is very diverse, which makes it difficult to select a balanced package, especially considering their effectiveness and compatibility with each other. This procedure can be a bit simplified by adding poly-functional additives to diesel fuel, the use of which is devoted to a lot of periodical literature. Based on the relevance of the direction of scientific research related to improving the properties of diesel fuel, which is produced at the enterprises of the oil refining industry in Ukraine, we proposed to use a substance belonging to the class of aromatic diazocompounds and having polyfunctional properties in the composition of diesel fuels. Thus, this additive was added to a straight-run diesel fraction (240–350 °C) in an amount of up to 1.0%, followed by a study of the properties of the resulting mixture. Studies have shown that the additive significantly improves low-temperature properties (by -10 °C), contributes to an increase in fuel density and viscosity, and additionally gives diesel fuel a stable color (from yellow to orange). Consequently, it can be used in the composition of commercial diesel fuels with improved performance properties.

Artisanal refining of crude oil in the Niger Delta: A challenge to clean-up and remediation in Ogoniland

While the activities of multinational oil corporations contribute significantly to oil pollution and environmental degradation in most oil-producing countries, the extent to which illegal artisanal refineries contribute to the environmental problems in Niger Delta remains unclear. Extant literature attributes this to the expanding activities of the artisans as well as the use of crude technology in illegal oil refining. Given the widespread nature of the artisanal oil-refining economy in the Niger Delta region, we assess its contribution to the growing environmental pollution in the region. By artisanal oil refining, we mean small-scale crude oil processing or subsistent distillation of petroleum that is often outside the boundaries of the state law. This study links the continual failure of the clean-up programme in the Niger Delta to the booming artisanal crude oil-refining economy in the region. Using predominantly qualitative methods of data collection and content analysis, we adopted the enterprise value chain analysis to underscore the underlying local economic interests and external economic opportunities that sustain oil bunkering, oil theft and petro-piracy. We conclude that these illegal refining processes significantly undermine the Ogoniland clean-up project and make the remediation programme unsustainable in Nigeria.