Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical con...Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical conditions during the production, transportation, storage, and refining, heavier molecules can precipitate from crude oil. Thus, viscous sludge formed at the bottom of storage tanks can cause many problems including reduction of storage capacity of tank, oil contamination, corrosion, repair costs, environmental pollution, etc. The reduction of sludge viscosity can be achieved by reduction of its interfacial tension. In this study, different chemical and physical factors, influencing prepared emulsions（made of sludge, water and surfactant）, such as surfactants, solvents, temperature, pressure, and mixing conditions were investigated. Results showed that non-ionic surfactants（like bitumen emulsifier）, and solvents（such as mixed xylene, AW-400, and AW-402）, injection of additives, applying pressure, and mixing operations had a positive effect on reduction of emulsion viscosity. All experiments were carried out with sludge obtained from crude oil storage tanks at Kharg Island,Iran.展开更多
The features of acoustic bathymetry of sludge in crude oil tanks are considered. Different parameters of crude oil and sludge which are important for the selection of acoustic parameters such as sound speed, the acous...The features of acoustic bathymetry of sludge in crude oil tanks are considered. Different parameters of crude oil and sludge which are important for the selection of acoustic parameters such as sound speed, the acoustic impedances of “oil-sludge” boundaries and sound attenuation are analyzed and compared with experimental data. The main sources of errors of sludge volume estimation are discussed.展开更多
This study investigated the effects of gaseous emissions from crude storage tank and gas flaring on air and rainwater quality in Bonny Industrial Island. Ambient air quality parameters, rainwater and weather parameter...This study investigated the effects of gaseous emissions from crude storage tank and gas flaring on air and rainwater quality in Bonny Industrial Island. Ambient air quality parameters, rainwater and weather parameters were collected at 60 m, 80 m, 100 m, 200 m and control plot for 4 weeks at the Bonny. Rainwater parameters were investigated using standard laboratory tests. Data analyses were done using Analysis of variance, pairwise t-test and Pearson’s correlation statistical tools. Results show that emission rates, volatile organic compound (VOC) noise and flare temperature decreased with increasing distance from flare points and crude oil storage tanks. Findings further revealed the emission rates varied significantly with distance away from the gas flaring point (F = 6.196;p = 0.004). The mean concentration of pollutants between gas flare site and crude oil storage tank showed that CO (0.02 ± 0.001 - 0.002 ±0.001), SPM (0.011 ± 0.001 - 0.01 ± 0.001), VOC (0.005 ± 0.001 - 0.01 ± 0.001) and NO<sub>2</sub> (0.04 ± 0.001 - 0.005 ± 0.000) had significant variations (p > 0.05) with CO, O<sub>3</sub> and NO<sub>2</sub> having higher concentrations at the gas flare site while SPM, and VOC were higher around the crude oil storage tank site. Wind turbulence was higher around the gas flaring point (4.93 TKE) than the crude oil storage tank (4.55 TKE). Similarly, there was significant variation in the sun radiation, precipitation, and wind speed caused by gas flaring (1582.25 w/m<sup>2</sup>, 436.25 mm, 0.53 m/s) and crude oil storage tank (1536.25 w/m<sup>2</sup>, 3.91.41 mm, 0.51 m/s). There were also significant variations in flared temperature (F = 22.144;p = 0.001);NO<sub>2</sub> (F = 8.250;p = 0.001), CO (F = 6.000;p = 0.004) and VOC (F = 5.574;p = 0.006) with distance from the gas flaring point. The variation in the rainwater parameters with distance from the gas flaring indicated significant variations in pH (F = 5.594;p = 0.006). The study showed that the concentration of VOC and particulates were high in the supposedly control area which is perceived to be safe for human habitation. Significant variations exist in emission rate (p = 0.015), flare temperature (p = 0.001), NO<sub>2</sub> (p = 0.003), VOC (p = 0.001), noise (p = 0.041), hydrogen carbonate (p = 0.037) and chromium (p = 0.032) between the gas flaring and crude oil storage tank. Regular monitoring is advocated to mitigate the harmful effects of the pollutants.展开更多
This study investigated the use of microbial analysis as a bioremediation option for remediating petroleum sludge, which is part of the waste stream generated in the petroleum industry. The aim is to reduce environmen...This study investigated the use of microbial analysis as a bioremediation option for remediating petroleum sludge, which is part of the waste stream generated in the petroleum industry. The aim is to reduce environmental burden caused by the discharge of untreated sludge. Sludge sample was cultured in other to isolate microorganisms for the sludge treatment. The selected strain of the organisms after screening were Aspergillus flavus, Aspergillus niger, Verticillus sp, Penicillum sp, and Microsporium audouinii. Bioreactors (labeled A, B, C, D and O) were designed for the treatment of petroleum sludge. These reactors contain 2.0 × 10<sup>-2</sup> m<sup>3</sup> of the diluted sludge samples and the isolated organisms for the treatment process. On a weekly basis, the control reactors received 1.5 × 10<sup>-3</sup> m<sup>3</sup> of fresh and saline water respectively. After 12 weeks of treatment, sludge physicochemical characteristics showed distinct variations. From the result, reactor D was the best in terms of remediating the sludge as compared to other reactors. Friedman non-parametric test was performed to check if the weeks of treatment affected the reduction of the total hydrocarbon content (THC) in the five reactors and also checked for significant differences in the THC after treatments. The drop in the THC of the treated sludge ranged from 56.0% to 67.3%. These results showed the possibility of enhanced biodegradation of petroleum sludge by hydrocarbon utilizing microorganisms (fungi).展开更多
E32 grade corrosion resistant steel was welded with welding wires with three different S contents. The mi crostructure, mechanical properties, inclusions, and corrosion behavior of welded joint were investigated. The ...E32 grade corrosion resistant steel was welded with welding wires with three different S contents. The mi crostructure, mechanical properties, inclusions, and corrosion behavior of welded joint were investigated. The joint coupon corrosion test and potentiodynamic polarization test were carried out under the simulated corrosion environ- ment of the inner bottom plates of cargo oil tanks. The pitting initiation and propagation mechanism of the weld metal were studied by scanning electron microscopy and infinite focus. The results indicated that the microstructures of three kinds of weld metals are all composed of acicular ferrite, ferrite side-plate and proeutectoid ferrite. The micro- structure of heat affected zone is composed predominantly of bainite. Joint welded with low S filler wire has good me- chanical properties. S can decrease free corrosion potential and increase the corrosion tendency. The pitting initiation is oxide inclusion or sulfide oxide inclusion complex. S can induce the formation of occluded area and promote the corrosion propagation. The chemical compositions of weld metal is similar to base metal, which can limit the galvanic corrosion between weld metal and base metal, and avoid formation of corrosion step.展开更多
文摘Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical conditions during the production, transportation, storage, and refining, heavier molecules can precipitate from crude oil. Thus, viscous sludge formed at the bottom of storage tanks can cause many problems including reduction of storage capacity of tank, oil contamination, corrosion, repair costs, environmental pollution, etc. The reduction of sludge viscosity can be achieved by reduction of its interfacial tension. In this study, different chemical and physical factors, influencing prepared emulsions（made of sludge, water and surfactant）, such as surfactants, solvents, temperature, pressure, and mixing conditions were investigated. Results showed that non-ionic surfactants（like bitumen emulsifier）, and solvents（such as mixed xylene, AW-400, and AW-402）, injection of additives, applying pressure, and mixing operations had a positive effect on reduction of emulsion viscosity. All experiments were carried out with sludge obtained from crude oil storage tanks at Kharg Island,Iran.
文摘The features of acoustic bathymetry of sludge in crude oil tanks are considered. Different parameters of crude oil and sludge which are important for the selection of acoustic parameters such as sound speed, the acoustic impedances of “oil-sludge” boundaries and sound attenuation are analyzed and compared with experimental data. The main sources of errors of sludge volume estimation are discussed.
文摘This study investigated the effects of gaseous emissions from crude storage tank and gas flaring on air and rainwater quality in Bonny Industrial Island. Ambient air quality parameters, rainwater and weather parameters were collected at 60 m, 80 m, 100 m, 200 m and control plot for 4 weeks at the Bonny. Rainwater parameters were investigated using standard laboratory tests. Data analyses were done using Analysis of variance, pairwise t-test and Pearson’s correlation statistical tools. Results show that emission rates, volatile organic compound (VOC) noise and flare temperature decreased with increasing distance from flare points and crude oil storage tanks. Findings further revealed the emission rates varied significantly with distance away from the gas flaring point (F = 6.196;p = 0.004). The mean concentration of pollutants between gas flare site and crude oil storage tank showed that CO (0.02 ± 0.001 - 0.002 ±0.001), SPM (0.011 ± 0.001 - 0.01 ± 0.001), VOC (0.005 ± 0.001 - 0.01 ± 0.001) and NO<sub>2</sub> (0.04 ± 0.001 - 0.005 ± 0.000) had significant variations (p > 0.05) with CO, O<sub>3</sub> and NO<sub>2</sub> having higher concentrations at the gas flare site while SPM, and VOC were higher around the crude oil storage tank site. Wind turbulence was higher around the gas flaring point (4.93 TKE) than the crude oil storage tank (4.55 TKE). Similarly, there was significant variation in the sun radiation, precipitation, and wind speed caused by gas flaring (1582.25 w/m<sup>2</sup>, 436.25 mm, 0.53 m/s) and crude oil storage tank (1536.25 w/m<sup>2</sup>, 3.91.41 mm, 0.51 m/s). There were also significant variations in flared temperature (F = 22.144;p = 0.001);NO<sub>2</sub> (F = 8.250;p = 0.001), CO (F = 6.000;p = 0.004) and VOC (F = 5.574;p = 0.006) with distance from the gas flaring point. The variation in the rainwater parameters with distance from the gas flaring indicated significant variations in pH (F = 5.594;p = 0.006). The study showed that the concentration of VOC and particulates were high in the supposedly control area which is perceived to be safe for human habitation. Significant variations exist in emission rate (p = 0.015), flare temperature (p = 0.001), NO<sub>2</sub> (p = 0.003), VOC (p = 0.001), noise (p = 0.041), hydrogen carbonate (p = 0.037) and chromium (p = 0.032) between the gas flaring and crude oil storage tank. Regular monitoring is advocated to mitigate the harmful effects of the pollutants.
文摘This study investigated the use of microbial analysis as a bioremediation option for remediating petroleum sludge, which is part of the waste stream generated in the petroleum industry. The aim is to reduce environmental burden caused by the discharge of untreated sludge. Sludge sample was cultured in other to isolate microorganisms for the sludge treatment. The selected strain of the organisms after screening were Aspergillus flavus, Aspergillus niger, Verticillus sp, Penicillum sp, and Microsporium audouinii. Bioreactors (labeled A, B, C, D and O) were designed for the treatment of petroleum sludge. These reactors contain 2.0 × 10<sup>-2</sup> m<sup>3</sup> of the diluted sludge samples and the isolated organisms for the treatment process. On a weekly basis, the control reactors received 1.5 × 10<sup>-3</sup> m<sup>3</sup> of fresh and saline water respectively. After 12 weeks of treatment, sludge physicochemical characteristics showed distinct variations. From the result, reactor D was the best in terms of remediating the sludge as compared to other reactors. Friedman non-parametric test was performed to check if the weeks of treatment affected the reduction of the total hydrocarbon content (THC) in the five reactors and also checked for significant differences in the THC after treatments. The drop in the THC of the treated sludge ranged from 56.0% to 67.3%. These results showed the possibility of enhanced biodegradation of petroleum sludge by hydrocarbon utilizing microorganisms (fungi).
基金Sponsored by National Key Technology Research and Development Program of China(2011BAE25B01)
文摘E32 grade corrosion resistant steel was welded with welding wires with three different S contents. The mi crostructure, mechanical properties, inclusions, and corrosion behavior of welded joint were investigated. The joint coupon corrosion test and potentiodynamic polarization test were carried out under the simulated corrosion environ- ment of the inner bottom plates of cargo oil tanks. The pitting initiation and propagation mechanism of the weld metal were studied by scanning electron microscopy and infinite focus. The results indicated that the microstructures of three kinds of weld metals are all composed of acicular ferrite, ferrite side-plate and proeutectoid ferrite. The micro- structure of heat affected zone is composed predominantly of bainite. Joint welded with low S filler wire has good me- chanical properties. S can decrease free corrosion potential and increase the corrosion tendency. The pitting initiation is oxide inclusion or sulfide oxide inclusion complex. S can induce the formation of occluded area and promote the corrosion propagation. The chemical compositions of weld metal is similar to base metal, which can limit the galvanic corrosion between weld metal and base metal, and avoid formation of corrosion step.
