Oil Tank Bottom Research Articles

Hydrothermal Carbonization of Crude Oil Tank Bottom Sludge for Energy Applications

Hydrothermal Carbonization of Crude Oil Tank Bottom Sludge for Energy Applications

Assessment of the Hydrocarbon Degrading Abilities of Three Bioaugmentation Agents for the Bioremediation of Crude Oil Tank Bottom Sludge Contaminated Libyan Soil

Bioremediation is a widely used environmental friendly treatment method for petrogenic hydrocarbon contaminated soils but its application to the treatment of crude oil tank bottom sludge (COTBS) contaminated soil is limited especially in Mediterranean countries such as Libya. Therefore in this study, the hydrocarbon degrading abilities of three bioaugmentation agents Pseudomonas sp (4M12), Pseudomonas xanthomarina (4M14) and Arthrobacter nitroguajacolicus (1B16A) (isolated from COTBS polluted soils) applied as part of a biostimulation-bioaugmentation (BS/BA) strategy were assessed in COTBS contaminated Libyan soils. Biostimulated (BS) and natural attenuation (NA) microcosms were also set up for comparative purposes. Gas chromatograph mass spectrometer (GC- MS) analysis revealed a total soil petroleum hydrocarbon (TPH) and polycyclic aromatic hydrocarbon (PAHs) content of 30,703 mg kg-1 and 13,816 mg kg-1 respectively. Two carcinogenic fractions (naphthalene and benzenamine, 4, 4`methylenbis [2-methyl-]) and 4 mutagenic fractions (pyrene, phenanthrene, fluorene and anthracene) were detected. Substantial PAH degradation occurred in 4M14 and 4M12 samples within 15 days in contrast to up to 23 days in 1B16A, NA. However, substantial reduction in TPH (> 97%) was only observed in 4M12 and 4M14 inoculated microcosms within 15 days compared to 25-30 days in 1B16A inoculated, BS and NA microcosms. 4M14 inoculated microcosms were most efficient at complete removal (D100) of all carcinogenic and mutagenic fractions; 4M14 (9-10 days), 4M12 (9-15 days), 1B16A (15-23 days), BS (18-21 days) and NA (18-22 days). Pseudomonas xanthomarina was therefore shown as the best candidate for use in a BS/BA approach for treating COTBS contaminated Libyan soils. This study shows the importance of pre-screening bioaugmentation agents for the removal of carcinogenic and mutagenic fractions prior to use; in order to carry out safe, efficient and sustainable COTBS bioremediation in Libya.

Recovery and Characterization of Oil from Waste Crude Oil Tank Bottom Sludge from Azzawiya Oil Refinery in Libya

In this work we present the results of quantitative and qualitative analyses of oil obtained from crude oil tank bottom sludge (COTBS) generated from Azzawiya oil refinery in Libya. The aim of the study was to recover and evaluate oil from waste oily sludge and to compare it with parent oil (Hamada crude oil) in order to assess the commercial potential of recycling the oil. The benefits would be two-fold, firstly to improve oil utilisation efficiency and secondly in reducing the environmental contamination associated with the petrogenic hydrocarbon industry. Oily COTBS and extracted oil were characterised and key properties were measured including water and oil content, light and heavy hydrocarbon content, solid content and organic matter content for COTBS and water content, density, specific gravity, API (American Petroleum Institute) gravity, viscosity, salt and ash content for the extracted oil. Solvent (hexane) extraction confirmed that the oily sludge contained 42.08% (± 1.1%) oil composed of light hydrocarbons (30.7 ± 0.07%) and heavy hydrocarbon (69.3 ± 0.4%) fractions. The water and solid contents were 2.9% (± 0.2%) and 55.02% (± 0.6%) respectively. The properties of the recovered oil were assessed; gas chromatograph spectrophotometer (GC-MS) results indicated that the oil contained 139 different hydrocarbon fractions with a total petroleum hydrocarbon (TPH) concentration of 29,367 mgkg-1 and a polycyclic aromatic hydrocarbons (PAH) concentration of 11,752 mgkg-1. Several parameters of the oil were measured and compared to the parent oil (Hamada crude oil) including density, specific gravity, viscosity, salt and ash content. The API of the extracted oil (33.03) was lower than the parent oil (38.8) due to a reduced light hydrocarbon (LHC) content. TGAFTIR hyphenation shows both mass loss of hydrocarbons— low, medium and high molecular mass over a range of temperatures between 60°C and 450°C. crude oil extract exhibited a non-Newtonian behaviour (shear thinning) for the shear rate sweep between 10 and 500/s. dynamic shear rheology data showed that the extracted oil exhibit more like a solid than liquid. Overall the findings of the study confirmed that COTBD has a significant amount of oil similar in properties to Hamada crude oil. This large amount can be reclaimed and recycles. Depending on this essay, a commercial process could be performed which in parallel will reduce the environmental contamination with hydrocarbons.

Influence of Inclusion on Corrosion Behavior of E36 Grade Low-alloy Steel in Cargo Oil Tank Bottom Plate Environment

Corrosion behavior of low-alloy steel was investigated in simulated cargo oil tank (COT) bottom plate service environment (10% NaCl solution, pH = 0.85). The corrosion behavior of inclusion was studied by in-situ scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that pitting corrosion was inclined to occur around the place where inclusions exist. After initial corrosion, an area of 10–20 μm in diameter was formed as a circinate cathode around the edge of inclusion. MnS inclusion dissolved in the simulated COT corrosion solution before low-alloy steel matrix, and pitting was formed at the place where MnS dissolved. TiO2 inclusion dissolved in the simulated COT corrosion solution after low-alloy steel matrix, and pitting was formed at the place where steel matrix dissolved. The corrosion tended to occur at the area where the curvature radius of inclusion is smaller. The size of round TiO2 inclusions had little influence on corrosion behavior in this certain environment.

Influence of inclusion and grain boundary on corrosion behaviour of low alloy steel in cargo oil tank bottom plate environment

Corrosion behaviours of low alloy steels with various alloying element contents were studied in simulated corrosion environment (pH = 0·85, 10% NaCl solution) of cargo oil tank (COT) bottom plate corrosion environment. Corrosion rate was measured, and the surface morphology of test steels was characterised using scanning electron microscope (SEM). The electrochemical results were investigated using polarisation curves and electrochemical impedance spectroscopy (EIS). The corrosion behaviour of inclusion was investigated using in situ SEM images and energy disperse spectroscopy (EDS) analysis. The effect of misorientation distribution on corrosion resistance of steel was evaluated using electron backscattered diffraction microscopy. The results showed that MnS dissolved into the simulated COT corrosion solution before steel matrix, whereas TiO2 would not be dissolved. A 10–20 μm area was formed as a circular cathode around inclusion centre. The corrosion was inclined to occur in the place where curvature radius of inclusion is small. An increase in the proportion of low energy grain boundaries was conducive to the improvement of corrosion resistance especially in the early stages of corrosion.

Numerical Simulation of Storage Tank Based on Control Theory of Fuzzy Rough Sets

In this paper we introduce the computer rough set theory and fuzzy control theory into the numerical simulation, and use the multimedia virtual simulation to do simulation on the heat transfer process of mechanical reserve tank, and establish 2D simulation model of tank, and add heat boundary condition in the oil tank bottom. Through the numerical simulation we obtain the curve of oil tank temperature and pressure with time. And through comparison of virtual computing results and experiment results, it verifies the reliability of the algorithm. At the end of this paper, we apply the multimedia virtual simulation technology to the basketball match, and analyze the technical parameters of the match. It provides the technical reference for the training of basketball players.

Removal of Oil Tank Bottom Sludge by Novel Biosurfactant, JE1058BS

Maintenance of crude oil storage tanks requires periodical washing of the tanks before ordinary repairs can be made to these systems. In this study, crude oil derived sludge in the oil storage tank was treated with various surfactants to disperse the sludge into a miscible fraction, including JE1058BS, a new biosurfactant produced by Gordonia sp. strain JE-1058. Phylogenetic analysis of the 16SrRNA sequence of the strain JE-1058 identified Gordonia polyisoprenivorans. The sludge was efficiently removed by dispersion with biosurfactant at concentrations of 1-10 g/L, with stable dispersion at 10 g/L for 3 weeks. Addition of the BS caused no significant changes except for water content in the physicochemical factors such as density, viscosity, and sulfur/nitrogen content, suggesting that the novel biosurfactant JE1058BS is useful for oil tank bottom sludge treatment.

Computational Simulation of Corrosion Perforation in the Oil-Tank Bottom with Cellular Automata

Corrosion perforation in the oil-tank bottom is one of the most damaging mechanisms in oil-tanks. This paper presents a two-dimentional cellular automata model which simulates the corrosion perforation in the oil-tank bottom. According to the mechanism of metal corrosion in the oil-tank bottom, the CA model which simulates the electrochemical reactions and diffusion steps of pitting corrosion is proposed. With a series of simulation, the results show that CA is a powerful approach to model corrosion perforation in the oil-tank bottom, which could be of practical importance in predicting the security of oil-tanks.

The Numerical Simulation of Settlement Characteristics of Storage Tank on the Soft Soil Base

According to analyze the settlement characteristics of storage tank foundation at water-filling preloading stage and stable loading stage based on numerical simulation, and researching the settlement characteristics of storage tank foundation. The research results show that the deformation of storage tank foundation is “tray” in shape, and the maximum settlement appears at the place 0.65D away from the center of storage tank bottom, D is the radius of storage tank. Uplift appears at the place 1.3D away from the center of oil tank bottom, and the final uplift value is 10mm.The main factor which influences the consolidation speed of storage tank foundation is permeability coefficient.

Analysis of the Influences of Soil Parameters on the Settlement of Storage Tank Foundation

The settlement characteristics of storage tank foundation at water-filling preloading stage and stable loading stage was analyzed based on numerical simulation. And the influences of foundation soil parameters on the settlement of storage tank foundation were studied. The research results show that Uplift appears at the place 1.3D away from the center of oil tank bottom, and the final uplift value is 10mm.The main factor which influences the consolidation speed of storage tank foundation is permeability coefficient. The consolidation settlement is determined by compression modulus and load.

Extraction of Hydrocarbons from Crude Oil Tank Bottom Sludges using Supercritical Ethane

A custom‐built, solvent recirculating, supercritical fluid extraction (SFE) apparatus was used to study the extraction of hydrocarbons from a crude oil tank bottom sludge (COTBS) with supercritical ethane. The SFE experiments were carried out varying the pressure (10 MPa and 17.20 MPa) and temperature (35°C and 65°C). The yield of the extracted hydrocarbon fraction increased with increase in extraction pressure at constant temperature, and decreased with increase in extraction temperature at constant pressure. The maximum extraction yield was obtained at the pressure and temperature conditions that lead to the highest solvent density. The extracted hydrocarbon fraction was a significantly upgraded liquid relative to the original untreated COTBS.

AE Source and Relation between AE Activity and Rate of Corrosion of Oil Tank Bottom Plate on Acidic Soils

In Service Inspection by Acoustic Emission technique offers the user significant advantages, such as the capability of monitoring corrosion damage of the bottom plates of an oil tank without opening it. In this study, the mechanism of AE generation due to the corrosion of tank bottoms on strong acidic sand was examined. During the corrosion process, the corrosion rate and the AE activity were estimated and the relation between these two factors was examined. The sources of AE due to the corrosion of tank bottoms on an acidic soil were specified. Here, the physical foundations of a global diagnosis technique based on the AE method for evaluating the corrosion damage to tank bottoms were presented.

Enhanced bioremediation of n-alkane in petroleum sludge using bacterial consortium amended with rhamnolipid and micronutrients

The purpose of the present study was to investigate possible methods to enhance the rate of biodegradation of oil sludge from crude oil tank bottom, thus reducing the time usually required for bioremediation. Enhancement of biodegradation was achieved through bioaugmentation and biostimulation. About 10% and 20% sludge contaminated sterile and non-sterile soil samples were treated with bacterial consortium (BC), rhamnolipid biosurfactant (RL) and nitrogen, phosphorus and potassium (NPK) solution. Maximum n-alkane degradation occurred in the 10% sludge contaminated soil samples. The effects of treatment carried out with the non-sterile soil samples were more pronounced than in the sterile soils. Maximum degradation was achieved after the 56th day of treatment. n-Alkanes in the range of nC8– nC11 were degraded completely followed by nC12– nC21, nC22– nC31 and nC32– nC40 with percentage degradations of 100%, 83–98%, 80–85% and 57–73% respectively. Statistical analysis using analysis of variance and Duncan’s multiple range test revealed that the level of amendments, incubation time and combination of amendments significantly influenced bacterial growth, protein concentration and surface tension at a 1% probability level. All tested additives BC, NPK and RL had significant positive effects on the bioremediation of n-alkane in petroleum sludge.

Use of Probiological Remediation Technology to Remediate Crude Oil Tank Bottom Materials: ABSTRACT

ABSTRACT Historically, the disposal of crude oil tank bottom materials has consisted of off-site transport to an incineration facility, a state approved landfill, or an off-site treatment facility. With increased treatment costs, regulatory limitations on landfill use, and increased environmental liability, producers have had to develop new strategies in order to dispose of their crude oil tank bottom wastes. One form of remediation which is proving highly effective in remediating production wastes is Probiological Remediation Technology' (PRT). PRT enables producers to treat their basic sediment wastes on-site using a highly specialized form of biological remediation. With treatment being accomplished on-site, high costs associated with storage, transportation, off-site treatment, and environmental liability are drastically reduced. Since 1987, PRT has been utilized in numerous remediation applications. In one instance, PRT methods were applied to remediate 3,200 cubic yards of tank bottom wastes which had accumulated on a south Texas oil and gas lease. Initially, total petroleum hydrocarbon (TPH) levels were in excess of 75,000 parts per million (PPM) or 7.5%. However, within six weeks, TPH levels were reduced to below acceptable state commission regulatory standards of 10,000 ppm ( PRT is highly effective in reducing contaminants commonly associated with oil and gas field operations. The science of PRT is complex, but application is simple and can be accomplished on-site, thereby reducing costs identified with off-site treatment, transportation, and/or disposal.. End_of_Record - Last_Page 637-------