Aboveground Storage Tanks Research Articles

An autonomous self contained wall climbing robot for non‐destructive inspection of above‐ground storage tanks

PurposeThe aim of this research is to design a wall climbing robot (WCR) for the non‐destructive inspection (NDT) of the above‐ground storage tanks (ASTs) autonomously making the industrial inspection and maintenance tasks safer.Design/methodology/approachA WCR is designed that can be equipped with any NDT sensor. It uses permanent magnets as an adhesion mechanism to crawl over the steel tank walls. A surface coverage algorithm is proposed for the WCR to scan the AST wall surfaces autonomously with the NDT sensors to perform the necessary inspection tasks.FindingsThe proposed surface coverage algorithm performs the complete coverage of the AST walls under different obstacle configurations. It has been tested and demonstrated in simulations.Originality/valueA surface coverage algorithm is proposed for the WCR to perform the non‐destructive inspection of the ASTs autonomously. It can also be used in applications like cleaning glass building and painting ship hulls, etc.

A Wireless Hydrocarbon Pollution Measuring and Monitoring System

The goal of the proposed system is to protect sensitive areas of the country from hydrocarbon pollution with the use of a global system for mobile communications/general packet radio service (GSM/GPRS) accessed from mobile observation points (MOPs). The primary applications of this system are detection of leaks from an underground or aboveground storage tank (UST/AST), monitoring waste water discharge/ monitoring bilge water, monitoring water quality, monitoring groundwater, monitoring oil-water separators, monitoring storm drain effluents, and static soil gas headspace analysis. The basic version of the system is equipped with: a GPS position locator, a contamination probe sensitive to hydrocarbons, and a GSM/GPRS connection with the central www server

222 石油タンク浮屋根のスロッシング応答

222 石油タンク浮屋根のスロッシング応答

AE Global Diagnosis System for Corrosion of Bottom Floors in Aboveground Oil Storage Tanks(Inspection Systems for Maintaining Social Safety)

AE Global Diagnosis System for Corrosion of Bottom Floors in Aboveground Oil Storage Tanks(Inspection Systems for Maintaining Social Safety)

Health monitoring of aboveground storage tanks’ floors: A new methodology based on practical experience

An acoustic-emission technique is developed as a nonintrusive method and suitable maintenance-planning tool for inspecting the floors of storage tanks in order to find an optimum service-period duration. This paper deals with the methodologies and experiences gathered from field testing of above-ground storage tanks via the acoustic-emission technique conducted in refineries until now. The results of field testing conducted to date has led us to create a grading system for the purpose of maintenance of tank floors. The location of leak and corrosion sources that is based on the arrival-time difference in the acoustic-emission measurement is discussed, and findings gathered through source-location-placement algorithm and results are presented as a 2D map of tank-floor sources.

Characterization of microbial contamination in United States Air Force aviation fuel tanks

Bacteria and fungi, isolated from United States Air Force (USAF) aviation fuel samples, were identified by gas chromatograph fatty acid methyl ester (GC-FAME) profiling and 16S or 18S rRNA gene sequencing. Thirty-six samples from 11 geographically separated USAF bases were collected. At each base, an above-ground storage tank, a refueling truck, and an aircraft wing tank were sampled at the lowest sample point, or sump, to investigate microbial diversity and dispersion within the fuel distribution chain. Twelve genera, including four Bacillus species and two Staphylococcus species, were isolated and identified. Bacillus licheniformis, the most prevalent organism isolated, was found at seven of the 11 bases. Of the organisms identified, Bacillus sp., Micrococcus luteus, Sphinogmonas sp., Staphylococcus sp., and the fungus Aureobasidium pullulans have previously been isolated from aviation fuel samples. The bacteria Pantoea ananatis, Arthrobacter sp., Alcaligenes sp., Kocuria rhizophilia, Leucobacter komagatae, Dietza sp., and the fungus Discophaerina fagi have not been previously reported in USAF aviation fuel. Only at two bases were the same organisms isolated from all three sample points in the fuel supply distribution chain. Isolation of previously undocumented organisms suggests either, changes in aviation fuel microbial community in response to changes in aviation fuel composition, additives and biocide use, or simply, improvements in isolation and identification techniques.

Above-ground storage tank inspection using the ‘Robot Inspector’

Above-ground storage tanks are used to store bulk fluids, such as oil, foodstuffs, pesticides and fertilisers. If one of these tanks were to leak, the potential damage to the environment would be catastrophic. To prevent such a disaster, the tanks are regularly inspected to ensure that the steel plates have not corroded, which could cause a failure of the tank. Robot Inspector is a semi-autonomous robotic inspection system, for the inspection of above-ground storage tank floors. It is the product of the Robot Inspector Consortium, a group of European companies and research organisations, part funded under the CRAFT co-operative research program.

Guest Editorial: Nuclear Power and Public Health

Guest Editorial: Nuclear Power and Public Health

Underside Corrosion of above Ground Storage Tanks (ASTs)

Underside corrosion of a failed above ground storage tank (AST) was investigated by the physio-chemical analysis of water sample that was ingress between the tank bottom plate and the concrete foundation. The results of the water sample analysis showed pH (5.8), temperature (30°C), Conductivity (4800 μs/cm), dissolved oxygen (3.5mg/l), chloride (674mg/l), carbonate (16.90mg/l) and nitrate (23.10mg/l). The levels of the parameters studied were generally high and above statutory safe limits. The results showed that the physico-chemical characteristics of the water sample have diagnostic and predictive values to implicate and promote underside corrosion of the studied above ground storage tank. Journal of Applied Sciences and Environmental Management Vol. 9(1) 2005: 161-163

A mathematical model for the cathodic protection of tank bottoms

A mathematical model previously developed for predicting the cathodic protection of pipeline networks is extended to treat cathodic protection of the bottoms of cylindrical above-ground storage tanks. A single tank was modeled for which protection was provided by an anode located infinitely far from the tank bottom, by a series of anodes distributed around the circumference of the tank, and by an anode grid laid directly underneath the tank bottom. The influence of an insulating barrier associated with secondary spill containment was also modeled for the arrangements in which anodes are placed adjacent to the tank bottom. The performance predictions are strongly dependent on anode placement, the oxygen content of the soil, and the presence of insulating barriers associated with secondary spill containment.

石油タンク底板の沈下挙動解析(J02-1 タンク構造,J02 シェル構造の計算力学と先端アプリケーション)

When constructing the bottom of aboveground oil storage tanks, the bottom plates are first laid out on the flat foundation, and they then are joined by welding the joints in sequence. As the foundation is difficult to be made completely homogeneous over the bottom area, the settlement of the bottom plates is not uniform under liquid pressure. The depressions of the bottom plates are sometimes found at the first internal inspection which is usually made about 10 years after the oil storage. This paper presents plane strain finite element analysis for the localized bottom depression in aboveground oil storage tanks. Load-incremental, elastic-plastic large deformation analysis is carried out considering contact with the foundation. The relationship of the stress at the depressed bottom plate to the liquid pressure is discussed together with the deformation of the depression.Copyright © 2004 by ASME

Report on aboveground storage tank fi re in Tomakomai City, Hokkaido (2003)

Report on aboveground storage tank fi re in Tomakomai City, Hokkaido (2003)

Geophysical Investigation of Vadose Zone Conductivity Anomalies at a Hydrocarbon Contaminated Site: Implications for the Assessment of Intrinsic Bioremediation

Electromagnetic (EM-31), dc resistivity, and ground penetrating radar (GPR) methods were used to investigate part of a former refinery site in Kalamazoo, Michigan, USA. The study area is underlain by about [Formula: see text] of heterogeneous glacial drift deposits overlying a sandy outwash unit. Three large above ground storage tanks (ASTs) formerly occupied the study area and were removed by the U.S. Environmental Protection Agency (USEPA) in 1997. EM-31 surveys revealed eight remnants of buried pipe ranging from [Formula: see text] to more than [Formula: see text] in length. Emanating from some of these abandoned pipe segments are extensive near surface conductivity anomalies, with values ranging from [Formula: see text] to greater than [Formula: see text] vs. background values of less than [Formula: see text]. GPR and dipole-dipole resistivity surveys performed along selected profiles with anomalous conductive zones revealed a channel form within the shallow subsurface. Shallow hand augured soil borings into these conductive zones encountered hydrocarbons perched on thin clay lenses, or trapped in low permeability sandy-silt layers, while borings in background conductivity areas showed only clean sand and silt. We also observed that areas underlain by clays in association with perched hydrocarbons exhibited a higher conductivity (greater than [Formula: see text] and up to [Formula: see text]) when compared to areas underlain by uncontaminated clays. Based on these observations and results of our prior work in similar settings, we infer that the conductivity anomalies may be due to the occurrence of intrinsic biodegradation of the hydrocarbons. Thus, the previous conductive model originally proposed by our research group for ‘aged’ hydrocarbon spills at the water table can be extended upward to include vadose zone occurrences of biodegradation of these contaminants. The findings from this study have significant implications for the use of geophysical techniques in the assessment of vadose zone biodegradation.

Effect of alcohol addition on the movement of petroleum hydrocarbon fuels in soil.

Groundwater contamination by fuel spills from aboveground and underground storage tanks has been of growing concern in recent years. This problem has been magnified by the addition of oxygenates, such as ethanol and methyl-tertiary-butyl ether (MTBE) to fuels to reduce vehicular emissions to the atmosphere. These additives, although beneficial in reducing atmospheric pollution, may, however, increase groundwater contamination due to the co-solvency of petroleum hydrocarbons and by the provision of a preferential substrate for microbial utilisation. With the introduction of ethanol to diesel fuel imminent and the move away from MTBE use in many states of the USA, the environmental implications associated with ethanol additive fuels must be thoroughly investigated. Diesel fuel movement was followed in a 1-m soil column and the effect of ethanol addition to diesel fuel on this movement determined. The addition of 5% ethanol to diesel fuel was found to enhance the downward migration of the diesel fuel components, thus increasing the risk of groundwater contamination. A novel method using soil packed HPLC columns allowed the influence of ethanol on individual aromatic hydrocarbon movement to be studied. The levels of ethanol addition investigated were at the current additive level (approx. 25%) for ethanol additive fuels in Brazil and values above (50%) and below (10%) this level. An aqueous ethanol concentration above 10% was required for any movement to occur. At 25% aqueous ethanol, the majority of hydrocarbons were mobilised and the retention behaviour of the soil column lessened. At 50% aqueous ethanol, all the hydrocarbons were found to move unimpeded through the columns. The retention behaviour of the soil was found to change significantly when both organic matter content and silt/clay content was reduced. Unexpectedly, sandy soil with low organic matter and low silt/clay was found to have a retentive behaviour similar to sandy subsoil with moderate silt/clay, but little organic matter. It was concluded that sand grains might have a more important role in the adsorption of petroleum hydrocarbons than first realised. This method has shown that soil packed HPLC columns can be used to provide a quick estimate of petroleum hydrocarbon, and possibly other organic contaminant, movement in a variety of different soil types.

Development and verification of a screening model for surface spreading of petroleum

Overflows and leakage from aboveground storage tanks and pipelines carrying crude oil and petroleum products occur frequently. The spilled hydrocarbons pose environmental threats by contaminating the surrounding soil and the underlying ground water. Predicting the fate and transport of these chemicals is required for environmental risk assessment and for remedial measure design. The present paper discusses the formulation and application of the Oil Surface Flow Screening Model (OILSFSM) for predicting the surface flow of oil by taking into account infiltration and evaporation. Surface flow is simulated using a semi-analytical model based on the lubrication theory approximation of viscous flow. Infiltration is simulated using a version of the Green and Ampt infiltration model, which is modified to account for oil properties. Evaporation of volatile compounds is simulated using a compositional model that accounts for the changes in the fraction of each compound in the spilled oil. The coupling between surface flow, infiltration and evaporation is achieved by incorporating the infiltration and evaporation fluxes into the global continuity equation of the spilled oil. The model was verified against numerical models for infiltration and analytical models for surface flow. The verification study demonstrates the applicability of the model.

Behavior of Localized Bottom Bulge in Aboveground Oil Storage Tanks Under Liquid Pressure

The bottom plate of aboveground oil storage tanks can bulge, separating from the foundation due to welding deformation. When such a bulge is subjected to liquid pressure, it deforms continuously to make contact with the foundation from the edge, and the remaining area of the bulge decreases with increasing liquid pressure. As a result, the deformation is extremely localized and plastic strain occurs at the bulge. This paper presents a plane strain finite element analysis for the evaluation of localized bottom bulges in aboveground oil storage tanks. Load-incremental, elastic-plastic large deformation analysis is carried out considering the bottom plate contact with the foundation. The relationship of the plastic strain at the bulged bottom plate to the liquid pressure is discussed together with the deformation of the bulge. As a result, the bottom plate thickness has a significant effect on the deformation, but the bulged height does not. After the bulged center makes contact with the foundation, the stress and strain do not increase with increasing liquid pressure. In addition, the permissible bulged profile specified by API Standard 653 elastically deforms to make contact with the foundation under low liquid pressure.

Plant Uptake of Methyl tert -Butyl Ether (MTBE) from Ground Water

Methyl tert-butyl ether (MTBE) is an important ground-water contaminant. Gasoline spills and leaks from pipelines, underground and aboveground storage tanks, and other transport modes are major sources of MTBE contamination. A six-channel system was set up and used to examine the effect of alfalfa plants on the fate and transport of MTBE. Contamination by MTBE was established by continuously feeding a solution of 0.84 mM MTBE into each channel at 1 L/day. The concentrations of MTBE in the channel ground-water effluent, at the channel soil surface, and within alfalfa plant stems were monitored. By incorporating plant water use with the concentrations of MTBE in plant water, the authors obtained the mass fluxes of MTBE transported by alfalfa plants grown in soil channels. Even with the same contaminant concentration in the growth channel, alfalfa plants took up MTBE nonuniformly. The more vigorous the growth of plants, the higher the MTBE concentration in the plant water, and the more MTBE removed by the pl...

Buckling of aboveground oil storage tanks under internal pressure

Overpressurization can occur due to the ignition of flammable vapors existing inside aboveground oil storage tanks. Such accidents could happen more frequently than other types of accident. In the tank design, when the internal pressure increases, the sidewall-to-roof joint is expected to fail before failure occurs in the sidewall-to-bottom joint. This design concept is the socalled "frangible roof joint" introduced in API Standard 650. The major failure mode is bifurcation buckling in this case. This paper presents the bifurcation buckling pressures in both joints under internal pressure. Elastic and elastic-plastic axisymmetric shell finite element analysis was performed involving large deformation in the prebuckling state. Results show that API Standard 650 does not evaluate the frangible roof joint design conservatively in small diameter tanks.

THE THREAT OF OIL SPILLS FROM STORAGE TANKS AT END USER FACILITIES

ABSTRACT The oil pollution prevention program of the U.S. Environmental Protection Agency (EPA) addresses a large regulated community—the owners and operators of several hundred thousand nontransportation-related facilities. Regulated oil facilities generally are thought of as refineries, terminals, production field tanks, fuel oil dealers, or gasoline service stations. Some studies of the nationwide petroleum storage capacity do not even consider tanks owned by petroleum consumers, while others recognize that end users constitute a significant part of the nation's oil storage. The storage capacity of fixed petroleum tankage in the tertiary segment (agricultural, commercial, electric utility, industrial, military/government, residential, and transportation sectors) is estimated to comprise more than 20 % of the total U.S. storage capacity. EPA estimates that more than one-half of the facilities required to prepare Spill Prevention Control and Countermeasure (SPCC) plans are such end users. The focus of oil pollution prevention, of course, is preventing spills. Several years ago, an American Petroleum Institute report on aboveground storage tank incidents stated that more than 25% of large petroleum releases in the United States were from tanks controlled by companies outside the petroleum industry. Recent data on large spills (10,000 gallons or more) show similar patterns. Of course, most nontransportation-related spills are from storage tanks or facilities in the petroleum industry (production wells, refineries, terminals, tank farms, and fuel oil dealers). More than 40%, however, are from electric utilities, manufacturing plants, military bases, airports, railroad yards, and other end user facilities. Smaller spills come from a variety of facility types. It is important for EPA and other groups to recognize the end user community and the threat of spills from end user facilities, and to begin to work with the owners and operators of end user facilities to educate them about EPA's oil pollution prevention regulation.

Buckling of aboveground oil storage tanks under internal pressure

Overpressurization can occur due to the ignition of flammable vapors existing inside aboveground oil storage tanks. Such accidents could happen more frequently than other types of accident. In the tank design, when the internal pressure increases, the sidewall-to-roof joint is expected to fail before failure occurs in the sidewall-to-bottom joint. This design concept is the socalled "frangible roof joint" introduced in API Standard 650. The major failure mode is bifurcation buckling in this case. This paper presents the bifurcation buckling pressures in both joints under internal pressure. Elastic and elastic-plastic axisymmetric shell finite element analysis was performed involving large deformation in the prebuckling state. Results show that API Standard 650 does not evaluate the frangible roof joint design conservatively in small diameter tanks.