Oil & Gas Science and Technology - Revue d'IFP Energies nouvelles

The effects of asphaltenes from two heavy oil residues on the sedimentation stability of residual marine fuels were assessed and compared. As base components of residual marine fuels, the vacuum residue (VacRes) and visbreaking residue (VisRes) were taken. The heptane-insoluble fractions (HI-fractions), including asphaltenes, isolated from vacuum residue and visbreaking residue, were analyzed to determine the elemental composition (XRF) and cluster parameters (XRD). The results of the analysis of the parameters of the asphaltene cluster (HI-fraction) for vacuum residue and visbreaking residue showed that d_γ – 6.1 and 5.9 Å, L_c – 26.72 and 20.78 Å, and L_a – 7.68 and 7.20 Å. The sedimentation stability of residual marine fuel was determined according to the ISO 10307-1-2009 (TSA) method and described using ternary phase diagrams. The ratio of stable compositions to the total number of possible compositions (with a step of 10 wt%) was 65/66 or 98.5% for residual marine fuel comprising a mixture VacRes/ULSD/LCGO (vacuum residue/ultra-low sulphur diesel/light catalytic gas oil). Meanwhile, the ratio of stable compositions to the total number of possible compositions was 38/66 or 57.6% for residual marine fuel comprising a mixture VisRes/ULSD/LCGO (visbreaking residue/ultra-low sulphur diesel/light catalytic gas oil).

Crude oil is the world’s leading fuel source and is the lifeblood of the industrialized nations as it is vital to produce many everyday essentials. This dependency on fossil fuels has resulted in serious environmental issues in recent times. Petroleum contaminated soils must be treated to ensure that human health and the environment remain protected. The restoration of petroleum-polluted soil is a complex project because once petroleum hydrocarbon enters the environment, the individual constituents will partition to various environmental compartments in accordance with their own physical–chemical properties; therefore, the composition and inherent biodegradability of the petroleum hydrocarbon pollutant determines the suitability of a remediation approach. The objective of this study was to assess the prospective of bioremediation as a feasible technique for practical application to the treatment of petroleum hydrocarbon-contaminated soils, by trending the changes in the properties of the petroleum due to biodegradation. Each polluted soil has particularities, thus, the bioremediation approach for each contaminated site is unique. Therefore, hydrocarbon-contaminated sites that have remained polluted for decades due to lack of proper decontamination treatments present in this part of the world would benefit from cost effective treatments. Most bioremediation case studies are usually based on hypothetical assumptions rather than technical or experimental data; providing data that show the capabilities of biodegradation of indigenous microbes on specific oil composition can lead to the creation of strategies to accelerate the biological breakdown of hydrocarbons in soil.