Roof Storage Tanks Research Articles

Flow coupling analysis and evaluation of different working conditions for crude oil storage tanks under dynamic heating

AbstractDuring periods of sharp demand increase, there is a need for significant expansion in the fundamental requirements for crude oil storage. As demand rapidly escalates, the prerequisites for crude oil storage necessitate substantial expansion. To scientifically and effectively reduce energy waste associated with heating oil, it is essential to study the heating methods and efficiency of crude oil storage tanks. Considering environmental temperature, solar radiation, and the physical properties of the oil, we have proposed a new heating model to elucidate the dynamic heating process of large floating roof storage tanks equipped with coils. Computational fluid dynamics (CFD) software was used to analyze the impact of the dynamic heating model on the temperature and velocity fields within the floating roof tank, taking into account different initial oil temperatures, oil levels, wind speeds, and types of crude oil during the winter heating process. Additionally, the research suggests the optimal maintenance heating temperature and duration for crude oil storage tanks during the winter season, introducing heating efficiency and inhomogeneity of temperature field as two evaluation metrics to compare the advantages of the dynamic heating method over traditional heating methods. This study provides fresh insights into the coil heating domain in crude oil storage tanks.

저장시설 배출량 산정기법 비교와 대기오염 방지시설 운용에 대한 LCA 분석

This study, to check the validity of storage tank emission regulation for the mandatory installation of air pollution prevention facilities for internal floating roof tanks and total hydrocarbon emission regulation, a reasonable emission calculation method is reviewed by comparing the engineering emission calculation methods in Korea and the United States. So when calculating storage tank emissions, it is recommended to calculate emissions by referring to the US AP-42, than life cycle assesment was conducted by composing four emission scenarios using the calculated emission information. From the side view, it was confirmed that it is more beneficial to improve the facility from a fixed roof storage tank to an internal floating roof storage tank than to operate an air pollution prevention facility for a storage tank filled with nitrogen.

Perancangan Internal Floating Roof Storage Tank P-7 di Proyek Pengembangan Kilang PT X – PT Y

Storage tanks are important equipment in the oil and gas industry, especially in receiving, stockpiling and distributing oil and gas. PT. X as the largest oil and gas processing company in East Kalimantan Province continues to improve the quality of oil and gas processing. In this case, the capacity and quality of storage tanks as one of the important components in oil and gas processing activities must also be increased. Since 2018, PT. X in collaboration with PT. Y carried out repairs and redesign of storage tanks. The storage tank design process must consider calculations that include the dimensions of the shell plate, circular base, and roof using the one-leg method. In addition, the calculation that includes wind strength and reference refers to the API 650 standard. The P-7 storage tank is a tank that stores light slop oil products with a capacity of 5654 m3 24 m and a height of 12.5 m with a shell course that is opened 7 and internal floating roof type which includes the scope of contractor redesign work with the help of AMETank software. From the calculation results, for the internal design of the floating roof storage tank, the thickness of the shell course 1 is 9 mm and the largest thickness is on the circular plate, which is 10 mm.

Steel Structure Prediction Model for Fixed Roof Oil Tanks

AbstractThis paper will focus on fixed roof storage tanks and its sub‐category cone roof tanks. Paper presents major factors and outputs of tank design process. Theoretical analysis is done for a cone roof tank model and correlation between tank surface, shell thickness and total steel weight used. Detailed algorithm for tank design was realized using MathCAD software using Eurocode standards. Using this algorithm, 432 hypothetical tanks were designed. Data analysis of the collected output data was analysed using R statistics programming language. Using regression models and testing them led to the optimum statistical model.For the purpose of this work, data for 21 real world tanks including fixed roof and floating roof tanks were collected. The data was collected with help of MOL, INA and few other EPC contractors. Paper compares real world data with outputs of the model.Model can be used for quick estimates and control of material consumptions. Taking few input parameters and applying minimal effort can lead to a very accurate steel consumption prediction. With additional real‐world data, acceptable ranges of deviation from the mean could be set‐up. Thus, allowing for better control on Client part or EPC companies.

Application Analysis of Oil and Gas Safety Active Protection System in the Sealing of Large External Floating Roof Tanks

In the use of large-scale external floating roof storage tanks, the application of sealing performance is very critical, which is related to the safety of storage tanks to a certain extent. In the practical application of storage tanks, it is found that the main cause of fire problems in large oil storage tanks with external floating roof is caused by sealing problems. Therefore, it is very important to deal with the sealing performance of large-scale external floating roof tanks when they are put into use. In this paper, the active safety protection system for large-scale external floating roof storage tanks is analyzed, and its application is analyzed, including its structural design, functional design and working principle design, and its specific application in XX project is put forward.

DISPERSION OF VOLATILE ORGANIC COMPOUNDS IN THE VICINITY OF PETROLEUM PRODUCTS STORAGE TANKS

Hydrocarbon storage tanks are important sources of emission of volatile organic compounds (VOCs) which have unfavorable effects on atmospheric chemistry and human health. The aim of this study is to calculate the emission of VOCs with emphasis on benzene, toluene, ethylbenzene, and xylene (BTEX) from storage tanks in the export port of Abadan petroleum refinery company in Mahshahr, Iran. The rate of VOCs emission from 32 external floating roof storage tanks containing 7 different types of organic liquids was calculated using TANKs 4.0.9d software in hot and cold seasons. Then, the dispersion of these pollutants was analyzed by implementing AERMOD model. Field measurement was performed in 6 points in the study area in hot and cold seasons to validate AERMOD modeling results. Results show that maximum quantities of benzene (0.0649 g/s) and ethylbenzene (0.0189 g/s) were emitted from light naphtha storage tanks, and maximum quantities of toluene (0.1635 g/s) and xylene (0.0593 g/s) were emitted from gasoline storage tanks in the hot season. Also, in the cold season, maximum emission of benzene (0.0335 g/s) observed from jet naphtha storage tanks, ethylbenzene (0.0093 g/s) from light naphtha storage tanks, and toluene (0.0826 g/s) and xylene (0.0314 g/s) from gasoline storage tanks. In 8-h and 24-h emissions of BTEX pollutants in the export port area, the most polluted points were identified as points 5 and 6 in the hot season and points 2 and 4 in the cold season. The highest BTEX emission rate was related to gasoline tank #14 with 0.2927 g/s in the hot season and 0.1497 g/s in the cold season. Comparison of predictions of the model with the measurements showed that mean value of absolute average relative deviation (AARD) was between 7-16% which indicates that an acceptable modeling was performed.

A comprehensive approach to analyze the risk of floating roof storage tanks

In this study, a comprehensive approach based on the Fuzzy Bayesian Network (FBN) was presented to reduce completeness, modeling, and parameter uncertainties and to analyze the risk of hazardous material release in floating roof storage tanks accurately. In this method, managerial, organizational, human and process factors, were investigated using human and process HAZOP technique before the occurrence of accident scenarios. These factors were examined after the intended scenario in a sequential modeling approach based on SHIPP methodology as a barrier model. Moreover, according to the initial probabilities and interference of barriers, the relevant conditional probability tables (CPTs) were modified by utilizing l-NOR gates, and the accident scenario model was developed using the Bow-tie (BT) model. Triangular fuzzy numbers and expert opinion incorporated into the Bayesian network to deal with the uncertainty in the occurrence probability of basic events and safety barriers. The methanol storage tank was selected to present the applicability potential of the proposed model. The results showed that the validation of the position and conditional probabilities (CPs) of barriers in the BT structure will reduce the uncertainties, and the combination of FBN and lNOR gate is an appropriate way to evaluate the risk of tanks accurately.

Failure Analysis of the Top Reticulated Shell Structure of a 20,000 Cubic Meter Floating Roof Storage Tank

The single-layer spherical reticulated shell structure is used as the fixed roof of a 20000 m3 internal floating roof tank. In the process of inspection and maintenance, the reticulated shell collapsed. In this paper, the strength, stiffness and stability of the design structure of the tank roof reticulated shell are calculated based on the finite element model, and the weak points of the shell structure are revealed, and the failure causes of the shell structure are comprehensively analyzed.

Fragility Assessment of Floating Roof Storage Tanks during Severe Rainfall Events

AbstractIn 2017, Hurricane Harvey, highlighted the vulnerability of floating roof storage tanks to severe rainfall events. Several floating roofs failed due to rainwater accumulating on them, causi...

Flashing Losses Emission Evaluation from Crude Oil Storage Tanks

Evaporation is a natural phenomenon describing when a liquid turns into gas. Evaporation from roof storage tanks is a major source of product loss in the crude oil industry. Evaporation is a natural phenomenon describing when a liquid turns into a gas. A liquid will tend to evaporate depending on its vapor pressure. A liquid’s vapor pressure is dependent on the surface temperature and composition of the liquid. Evaporation losses should be minimized to help maximize company revenue, meet regulatory requirements, and reduce greenhouse gas. This flashing loss is measured by carrying out the extensive experimental test. Therefore, this paper covers how to estimate oil flashing losses emissions factor (FLEF) percentage for crude oil storage tanks by using the new equation technique to minimize human errors. This statistical technique is a linear association between possible variables to assess flashing loss percentage as a function of operating temperature, sample point height (H1), oil tank height (H2), gas/oil ratio, gas gravity and oil gravity. A good result was obtained from the proposed equation as compared with popular equations by using graphical and statistical exactness. Lastly, modeling testing is ensuring excellent agreement with laboratory work by using new different samples.

Effect of containment structure on methane gas explosion in fixed roof storage tank

Effect of containment structure on methane gas explosion in fixed roof storage tank

Environmental Impact Monitoring of a Minero-chemical Complex in Catalão Urban Area of Pts, Pm10 and Pm2.5 by Edx Characterization

Depending on its nature, particulate matter has very different size, composition and morphology. By the combination of these criteria it is possible to distinguish the emitting sources (primary or secondary). The shape and the dimension of the particles have also a direct interaction with the risk assessment for human health. The minero-chemical complex consists of phosphate fertilizer manufacturing, rock phosphate and niobium mining open pits and it is located northeast of the urban area of the city. Environmental issues associated with it include the following: fugitive emissions which are primarily associated with operational leaks from tubing, valves, connections, flanges, packings, open ended lines, floating roof storage tank and pump seals, gas conveyance systems, compressor seals, pressure relief valves, tanks or open its/containments, and loading and unloading operations of products. Furthermore the area of study is characterized by a predominantly northeast winds direction. The monitoring was performed weekly particulates samples were collected in two seasonal episodes at one representative places in the urban area of Catalao (a Brazilian city located in Goias state) in the period from August to November of 2014. Suspended particles were sampled on pure fiberglass filters by using a High Volume air sampler and were analyzed via an energy dispersive X-ray microanalysis system (EDX). The airborne particulate matter was characterized from a physico-chemical point of view to supply information on the particle composition and the compounds carried on their surfaces. The microanalysis enables identification of several groups of particles such as: soot, Si-rich, metal-rich and biological particules. These results may help in controlling and preventing fugitive emissions in atmospheric air.

Dynamic Buckling of 50000m<sup>3</sup> Vertical Storage Tanks under Seismic Excitation

To study the dynamic buckling characteristics of storage tank subjected to three-dimensional seismic excitation, selecting 50000m3 large vertical floating roof storage tanks as research object, the base isolation system was introduced and allowing for the impact of floating roof. The finite element models of non-isolation and base isolation storage tank were established respectively by ADINA. The seismic responses of these two types of storage tank were calculated and the numerical solutions were compared. The results indicate that the dynamic buckling modes of these two types of storage tank system belong to plastic buckling; base isolation measure can effectively increase the critical load value of dynamic buckling and plasticity yielding, the improve rates up to 38% and 60% respectively. The effectiveness of the base isolation can be verified from the angle of buckling.

Estimation of evaporative losses during storage of crude oil and petroleum products

Storage of crude oil and petroleum products inevitably leads to evaporative losses. Those losses are important for the industrial plants mass balances, as well as for the environmental protection. In this paper, estimation of evaporative losses was performed using software program TANKS 409d which was developed by the Agency for Environmental Protection of the United States - US EPA. Emissions were estimated for the following types of storage tanks: fixed conical roof tank, fixed dome roof tank, external floating roof tank, internal floating roof tank and domed external floating roof tank. Obtained results show quantities of evaporated losses per tone of stored liquid. Crude oil fixed roof storage tank losses are cca 0.5 kg per tone of crude oil. For floating roof, crude oil losses are 0.001 kg/t. Fuel oil (diesel fuel and heating oil) have the smallest evaporation losses, which are in order of magnitude 10-3 kg/tone. Liquids with higher Reid Vapour Pressure have very high evaporative losses for tanks with fixed roof, up to 2.07 kg/tone. In case of external floating roof tank, losses are 0.32 kg/tone. The smallest losses are for internal floating roof tank and domed external floating roof tank: 0.072 and 0.044, respectively. Finally, it can be concluded that the liquid with low volatility of low BTEX amount can be stored in tanks with fixed roof. In this case, the prevailing economic aspect, because the total amount of evaporative loss does not significantly affect the environment. On the other hand, storage of volatile derivatives with high levels of BTEX is not justified from the economic point of view or from the standpoint of the environment protection.

Potential loading damage to industrial storage tanks due to volcanic ash fallout

The phenomenon of volcanic fallout ash from Mt. Etna in Sicily (Italy) is well known and frequent in recent years, as in the period 2001–2004. As a consequence, significant problems for the population, road, rail and air traffic and production activities have occurred. The industrial areas of Catania and Augusta-Priolo, located in south eastern Sicily, might be involved during particular weather conditions. This paper aims at determining the potential scenarios of damage to industrial facilities caused by volcanic ash fallout. The work has been focused on the study of both fixed and floating roof storage tanks, containing flammable liquids, and examines extreme failures damage causing the greatest loss of containment for these facilities. To include scenarios arising from natural phenomena (Na-Tech events) in the standard risk assessment procedure, the estimation of the vulnerability of these facilities is necessary. The study has been applied to the area surrounding Mt. Etna, and the procedure can also be extended to other case studies.

Solar radiation effects on evaporative losses of floating roof storage tanks

There are 40 storage tanks in the Khark Island for storing crude oil. Considering the hot summers of the island, light hydrocarbons vaporise and vented to the atmosphere. This process causes environmental pollution and also affects the quality of the crude oil besides the economic detriment. Therefore, crude oil evaporation loss associated with the storage tank is an important issue which should be carefully investigated to identify the potential means of its reduction. The aim of the present work is to determine the evaporative losses from external floating storage tanks and to study the absorptivity effects of their exterior surface paint on the losses due to the solar irradiation. The API standards along with the thermal analysis of the tank have been employed to evaluate the tank temperature variations and the evaporative losses of a typical tank based on the actual ambient conditions of the Khark Island. The results show that the paints with low absorptivity can reduce the evaporative losses significantly. Furthermore, experimental data has been provided to validate the calculated tank temperature variations, and reasonable agreements have been found.

Process safety management lessons learned from a petroleum refinery spent caustic tank explosion

AbstractA spent caustic tank exploded in a major Midwestern USA refinery on August 14, 2007. The explosion occurred while the operators were transferring spent caustic into the atmospheric‐relief, cone roof storage tank that had been in service since 1956. Fortunately, there were no injuries or fatalities. Property damage was, however, sufficient to interrupt the spent caustic disposal process. Unit operation was restored by commissioning an alternative, inherently safe spent caustic storage system.An investigation was launched to determine the explosion's cause. This article details the investigation's conclusions and corrective actions. It describes how a 2005 Hazard and Operability action item's intended purpose to reduce the risk for a PSM failure was defeated by equipment design errors, an unauthorized procedure deviation, and a series of management system failures. Lessons learned are communicated for organizations to avoid repeating similar mistakes. © 2010 American Institute of Chemical Engineers Process Saf Prog, 2010

Treatment of waste gas from the breather vent of a vertical fixed roof p-xylene storage tank by a trickle-bed air biofilter

This study applied a pilot-scale trickle-bed air biofilter (TBAB) system for treating waste gas emitted from the breather vent of a vertical fixed roof storage tank containing p-xylene (p-X) liquid. The volatile organic compound (VOC) concentration of the waste gas was related to ambient temperature as well as solar radiation, peaking at above 6300 ppmv of p-X and 25000 ppmv of total hydrocarbons during the hours of 8 AM to 3 PM. When the activated carbon adsorber was employed as a VOC buffer, the peak waste gas VOC concentration was significantly reduced resulting in a stably and efficiently performing TBAB system. The pressure drop appeared to be low, reflecting that the TBAB system could be employed in the prolonged operation with a low running penalty. These advantages suggest that the TBAB system is a cost-effective treatment technology for VOC emission from a fixed roof storage tank.

Pressurization of fixed roof storage tanks due to external fires

AbstractWhen a fixed roof storage tank is surrounded by a pool fire, and when the vents are not correctly dimensioned, the inside pressure can raise until the mechanical limits of the structure. The aim of this study is to develop a tool that will allow to follow the variations of the pressure and temperature in the gas phase, as a function of the size of the vent. This will help the sizing of new tank's vents or evaluating the risk of already build structures. The model also gives the temperature's distribution in the liquid phase, at each time step. In case of undersized vents, this information will be convenient to describe the phenomenological aspect of the accident after the rupture of the tank, i.e., to qualify and quantify the fire ball generated and its effect on persons and structures. Currently, if few analytical models exist to quantify the fire ball and its effects after the rupture, none are able to describe with accuracy the prerupture phenomena. The tool developed takes into account the two phases of the accident and allows to study complete and consistent scenarii. © 2010 American Institute of Chemical Engineers Process Saf Prog, 2011

Drinking water quality in roof storage tanks in the city of Amman, Jordan

This study investigates water quality in roof storage tanks in Amman and the effect of storage tanks' cleaning on water quality and consumer uses. Chlorine concentrations at a few storage tanks were low. All sampled tanks were free of fecal and total coliform. Cleaning roof storage tanks helps keep total heterotrophic plate count (THPC) at low levels. Total trihalomethane (TTHM) has fluctuated over time. Questionnaires revealed that while the majority of the people clean their roof storage tanks they do not drink the water; however, 85% of the people use the water for cooking.