Petroleum Storage
Crude oil untreated and unrefined are stored in tanks for shipment to other locations or rocessing into finished products.
NoDoC prepare cost estimating and cost simulations models for storage of petroleum products.
In these NoDoC models all facilities required for the storage including environmental impacts and safety standards are considered.
Following is the brief description of the system that is for the purpose of understanding what NoDoC models are doing.
Ads by CinPlus-2.5c×Oil depots are usually situated close to oil refineries or in locations where marine tankers containing products can discharge their cargo. Some depots are attached to pipelines from which they draw their supplies and depots can also be fed by rail, by barge and by road tanker (sometimes known as "bridging").
Most oil depots have road tankers operating from their grounds and these vehicles transport products to petrol stations or other users.
An oil depot is a comparatively unsophisticated facility in that (in most cases) there is no processing or other transformation on site. The products which reach the depot (from a refinery) are in their final form suitable for delivery to customers. In some cases additives may be injected into products in tanks, but there is usually no manufacturing plant on site. Modern depots comprise the same types of tankage, pipelines and gantries as those in the past and although there is a greater degree of automation on site, there have been few significant changes in depot operational activities over time.
Fuel oil storage tanks can be used to store and dispense a variety of liquid products such as:
- HEATING OILS
- Diesel
- Kerosene (BS2869)
- Befoul
- AdBlue
- Waste oil
There are four basic types of tanks used to store petroleum products:
Floating roof tanks are advantageous, compared to fixed roof tanks, as it prevents vapor emissions (that are highly combustible) that help eliminate the chances of fire or an internal tank explosion. They are usually used for stable liquids (with no dynamic loads acting, as discussed later). However, adverse environmental conditions could affect floating roofs as accumulation of snow and rain water could result in roof submersing in the stored liquid. Nonetheless this static load can be incorporated in making assumptions on the response of the roof, which can be further used in the design of the tank with a significant factor of safety. An area of concern, although, is the dynamic loads that act upon the roof due to constant splashing of water or leaks that result in flooding of roof compartments. This could be partly corrected by having sufficient stiffness in the circumferential direction at the roof, but due to the irregular nature of such loads, it may not be possible to accurately predict its magnitude.
Also, while the liquid exits the tank, the floating roof steadily approaches the bottom leaving behind a wet shell (liquid droplets that are left behind as the level drops). This results in the evaporation of liquid droplets to the atmosphere and is termed as the withdrawal loss, a form of emissions similar to hydrocarbon leaving the fixed roof tanks. A flawless rim seal (closure between the roof and the shell) could impede the loss of liquid but most seals have a loss factor associated to them that is calculated based on tank diameter and wind blowing over the tank.
Another alternative to external floating roofs is an internal roof that combines the concept of conical fixed roof tanks that lie on top of pontoons. They too are affected by the withdrawal and storage losses that are mitigated using similar means. Most recently, engineers have been designing floating roof tanks with secondary seals to mitigate such emissions and prevent any seal friction caused by using tighter seals (a simpler solution to prevent any vapors to exist)
During the process of storing crude oil, light hydrocarbons such as natural gas liquids, volatile organic compounds, hazardous air pollutants and some inert gases, vaporize and collect between the liquid level and the fixed roof tanks. As the liquid level in the tank varies, these gases slowly release out to the atmosphere. A solution to prevent this from occurring is by installing vapor recovery units. These units capture the BTU-rich units for sale or use it onsite as fuel.
Another solution could be the use of foam chambers. These are designed to cover flammable hydrocarbon or water miscible liquids with low expansion foam or fire extinguishment or vapor suppression. The foam occupies the vacant space that was initially filled with air, one of the main sources of combustion, to prevent any potential hazards. They have the advantage over ground based monitors of directing all their foam directly onto the flammable liquid surface regardless of weather conditions.
The foam generator made foam by introducing air into a foam solution stream that was delivered to the top pourer system (TPS) in a variety of ways. The inlet of the TPS is fitted with a venturi jet designed to draw air into the stream through a series of holes located around the foam generator. The foam solution is obtained from mobile foam proportioning equipment located far away from the tank and routed back to it through pipelines.
These tanks must be periodically subject to cleaning operations because of sludge accumulation. Sludge accumulates as a consequence of SLOW sedimentation of high-gravity petroleum products such as paraffins, asphaltenes and other inorganic materials present in the oil. This leads to numerous problems in the management of the depots, loss of capacity and time, as well as accelerating the corrosive process in the storage tanks.
The traditional current and more widespread tank cleaning systems are based on the manual removal of the sludge, which entails many critical aspects during execution involving high safety risks, high amount of waste to be disposed of and prolonged tank shutdown time.
High attention to environmental safeguards, by following standard procedures, are important to avoid spills during the process and waste handling. The use of water is minimized or not needed in automatic on-line desludging. The water used for final tank cleaning can be reused.
NoDoC prepare cost estimating and cost simulations models for storage of petroleum products.
In these NoDoC models all facilities required for the storage including environmental impacts and safety standards are considered.
Following is the brief description of the system that is for the purpose of understanding what NoDoC models are doing.
Ads by CinPlus-2.5c×Oil depots are usually situated close to oil refineries or in locations where marine tankers containing products can discharge their cargo. Some depots are attached to pipelines from which they draw their supplies and depots can also be fed by rail, by barge and by road tanker (sometimes known as "bridging").
Most oil depots have road tankers operating from their grounds and these vehicles transport products to petrol stations or other users.
An oil depot is a comparatively unsophisticated facility in that (in most cases) there is no processing or other transformation on site. The products which reach the depot (from a refinery) are in their final form suitable for delivery to customers. In some cases additives may be injected into products in tanks, but there is usually no manufacturing plant on site. Modern depots comprise the same types of tankage, pipelines and gantries as those in the past and although there is a greater degree of automation on site, there have been few significant changes in depot operational activities over time.
Fuel oil storage tanks can be used to store and dispense a variety of liquid products such as:
- HEATING OILS
- Diesel
- Kerosene (BS2869)
- Befoul
- AdBlue
- Waste oil
There are four basic types of tanks used to store petroleum products:
- Floating Roof Tank used for crude oil, gasoline, and naphtha.
- FIXED ROOF Tank used for diesel, kerosene, catalytic cracker feedstock, and residual fuel oil
- Bullet Tank used for normal butane, propane, and propylene
- Spherical Tank used for isobutene and normal butane.
Floating roof tanks are advantageous, compared to fixed roof tanks, as it prevents vapor emissions (that are highly combustible) that help eliminate the chances of fire or an internal tank explosion. They are usually used for stable liquids (with no dynamic loads acting, as discussed later). However, adverse environmental conditions could affect floating roofs as accumulation of snow and rain water could result in roof submersing in the stored liquid. Nonetheless this static load can be incorporated in making assumptions on the response of the roof, which can be further used in the design of the tank with a significant factor of safety. An area of concern, although, is the dynamic loads that act upon the roof due to constant splashing of water or leaks that result in flooding of roof compartments. This could be partly corrected by having sufficient stiffness in the circumferential direction at the roof, but due to the irregular nature of such loads, it may not be possible to accurately predict its magnitude.
Also, while the liquid exits the tank, the floating roof steadily approaches the bottom leaving behind a wet shell (liquid droplets that are left behind as the level drops). This results in the evaporation of liquid droplets to the atmosphere and is termed as the withdrawal loss, a form of emissions similar to hydrocarbon leaving the fixed roof tanks. A flawless rim seal (closure between the roof and the shell) could impede the loss of liquid but most seals have a loss factor associated to them that is calculated based on tank diameter and wind blowing over the tank.
Another alternative to external floating roofs is an internal roof that combines the concept of conical fixed roof tanks that lie on top of pontoons. They too are affected by the withdrawal and storage losses that are mitigated using similar means. Most recently, engineers have been designing floating roof tanks with secondary seals to mitigate such emissions and prevent any seal friction caused by using tighter seals (a simpler solution to prevent any vapors to exist)
During the process of storing crude oil, light hydrocarbons such as natural gas liquids, volatile organic compounds, hazardous air pollutants and some inert gases, vaporize and collect between the liquid level and the fixed roof tanks. As the liquid level in the tank varies, these gases slowly release out to the atmosphere. A solution to prevent this from occurring is by installing vapor recovery units. These units capture the BTU-rich units for sale or use it onsite as fuel.
Another solution could be the use of foam chambers. These are designed to cover flammable hydrocarbon or water miscible liquids with low expansion foam or fire extinguishment or vapor suppression. The foam occupies the vacant space that was initially filled with air, one of the main sources of combustion, to prevent any potential hazards. They have the advantage over ground based monitors of directing all their foam directly onto the flammable liquid surface regardless of weather conditions.
The foam generator made foam by introducing air into a foam solution stream that was delivered to the top pourer system (TPS) in a variety of ways. The inlet of the TPS is fitted with a venturi jet designed to draw air into the stream through a series of holes located around the foam generator. The foam solution is obtained from mobile foam proportioning equipment located far away from the tank and routed back to it through pipelines.
These tanks must be periodically subject to cleaning operations because of sludge accumulation. Sludge accumulates as a consequence of SLOW sedimentation of high-gravity petroleum products such as paraffins, asphaltenes and other inorganic materials present in the oil. This leads to numerous problems in the management of the depots, loss of capacity and time, as well as accelerating the corrosive process in the storage tanks.
The traditional current and more widespread tank cleaning systems are based on the manual removal of the sludge, which entails many critical aspects during execution involving high safety risks, high amount of waste to be disposed of and prolonged tank shutdown time.
High attention to environmental safeguards, by following standard procedures, are important to avoid spills during the process and waste handling. The use of water is minimized or not needed in automatic on-line desludging. The water used for final tank cleaning can be reused.
