RPME speaks to experts to check whether it is time for the tank farm owners and operators to go wireless
Tank farms whether for oil or chemicals require daily checks and accurate measurements. It was not long ago when highly skilled technicians periodically would climb to the top of a tank and with a dip-stick measure the level of fluids.
This task was not only time consuming, but also potentially very dangerous.
However, the measurement and technology specialist companies have risen to the challenge over the years and come up with various products to make measurements easier and in real-time.
Refining and Petrochemicals Middle East caught up with experts in the field of instrumentation and automation to find out how the face of measurements is changing.
Efficient, safe and environmental friendly operation of storage tanks and terminals are among the most important daily challenges every terminal manager has to deal with.
At the same time, productivity and increasing yields are fundamental demands.
Every single storage tank farm or terminal needs to provide maximum storage space at the
lowest costs with the highest safety standards, says Costas Arvanitis, Tank Gauging expert of Endress +Hauser.
Switzerland headquartered, Endress+Hauser is a major supplier of measurement instrumentation and inventory control systems for monitoring and controlling liquids during processing, transportation and storage – at terminals or tank farms.
One of the major trends the company identifies in measurement of liquids in a storage tank is wireless instrumentation. “Wireless solutions are becoming more and more popular in the process industry for monitoring applications where the field measurement is not part of a control or a safety loop.
In storage tanks and especially in existing ones where cables are not available or is difficult to install then wireless solutions is the ideal alternative,” said Arvanitis.
Wireless communications like Wireless Hart and Wireless Modbus provide users with more information for less cost.
A Modbus based wireless network is the considered as one of the most reliable infrastructure to satisfy the requirements of transmitting multiple tank parameters. Where in the past only slow proprietary communication busses for distances over kilometers were possible, wireless Modbus combines the benefits of a standard protocol and off-the-shelf components.
Although the distances from one station to the next are limited, these can be combined to cover distances of several kilometers, as they are typical in big refineries.
Through the architecture of Modbus transmission of multiple parameters, e.g. temperature profile data or multiple densities is basically as fast as transmitting a single level parameter. In many fields of application, having more information available is synonymous with being more productive.
Wireless has filled a gap where instrumentation became suddenly a viable option, while before, the costs of cabling was simply excessive and hence unfeasible, says Frank van Bekkum, Business Manager Legislation, Standards & Compliance, Honeywell Enraf.
“Now we can have instrumentation on difficult and remote locations and even have mobile employ for example carried by people, aiding in all types of tasks and functions, from safety with gas detectors to mobile asset tracking.”
Off course miniaturised electronics, reduced power requirements and improved battery technology were also necessary technology enablers to wireless, he adds.
“We should also realize that not all wireless applications are battery based. Wireless can also be a very attractive option when for example an existing cabling infrastructure is limited, outdated or unreliable,” says van Bekkum.
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No wireless for me
But also is not rosy in wireless implementation in remote locations. There are some users who have great reservations in monitoring their farms through a wireless device, so why is there this reservation?
Wireless has enabled many users to make use of modern and more reliable measurement equipment. But the interesting part is that the real benefits of wireless are mostly indirect, says Van Bekkum. He does agree the use of wireless for critical applications such as overfill prevention is still not readily accepted.
International Standards and sound engineering practices still do not fully endorse use of wireless for this type of applications.
Part of this might be caused by emotions, and lack of experience, but truth is that availability, for example due to radio frequency interference of a neighbouring site using also wireless or even adverse weather conditions is still not 100% understood, Van Bekkum says.
However, the Honeywell expert reckons wireless has demonstrated to be a viable alternative, for example on sites where the existing wired infrastructure has limitations, but are sufficient for just the critical instrumentation.
Wireless can then be added and will then even augment many of the modern instrumentation benefits by offering fast data transfer and diagnostics data for non critical applications.
For example the existing wires can then be used for overfill alarming, while the tank inventory data, such as level, temperature profiles etc. is then using the wireless system.
“Crucial when deploying wireless remains the proper planning of the available ‘ether’ (frequency and bandwidth).
“There are limitations, and unfortunately wireless is sometimes applied without the needed due-diligence, and as result of the poor planning the wireless then performs below standard and is finally thrown out as unreliable. This off course doesn’t help improve the profile and reputation of wireless,” Van Bekkum says.
But one of the major risks that Wireless has eliminated, according to Kittu Rajagopal, Rosemount Tank Gauging Middle East Specialist of Emerson Process management is loss of communication due to ageing of wires.
This is a common application in MEA where Radar Tank Gauging Systems are upgraded using existing wiring that are over 25+ years old.
Rajagopal also sees a huge demand in instruments for various applications in storage tanks as
there is very high rate of storage tank construction right now.
“There are over 1,000 new tanks being built in the Middle East and Africa region, many of them in the sites of our major customers in Saudi Arabia and Kuwait. We are experiencing an increasing demand for tank storage solutions and services in the region as capacity expansions are getting implemented, as well as new major grassroots developments,” he says.
Fast commissioning, efficient maintenance and improvement of production quality is some benefits that wireless solutions can provide, agree all the instrumentation and automation experts and they believe, like Arvanitis, “in the end, all of these advantages add up to greater overall plant availability.”
While the Middle East is not a leader in technology for tank farms, the specialists don’t think the day is far off.
“When we started actively positioning Radar as the ultimate Non Contact measurement solution for Tank gauging during the mid-90’s, the adoption rate in the Middle East was amongst the fastest compared with other world areas.
“Today, safety has taken the driver’s seat for growth in our business and we see the Middle East closely catching up with the US, EU, and Asia Pacific. We are driving a number of safety campaigns to elevate the significance of reliable gauging needs not only for Inventory Control but also more importantly for Safety and Overfill Protection, concludes Rajagopal.
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So what do you do when the tanks start to corrode?
Five Minutes with Chris Todd, Denso Regional Manager, Middle East to find a solution
How serious a problem is corrosion in storage terminals?
Site Managers do a great job of preventing the harmful effects of corrosion by using coatings in the atmospheric zone and using Cathodic Protection (CP) below ground. Unfortunately that’s not the full story.
The bases of Aboveground Storage Tanks (AST) present highly corrosive conditions. ASTs can accumulate significant quantities of atmospherically deposited salt particles. Rainwater or moisture run-off from the walls will transport these accumulated deposits to the base of the AST forming a strong electrolyte and causing electrochemical corrosion.
This can corrode the periphery of the tank base, the weld area and the lower wall. It can also cause crevice corrosion in the underside of the tank base. These will lead to metal loss, perforation and potentially even structural problems. The concrete annulus can also spall and degrade.
Any seal installed to the base of the tank, at time of construction, can degrade over time or become damaged by the cyclic movement caused by emptying and filling the AST.
To make matters worse, any CP installed will not protect the portion of the tank base that rests on the concrete annular foundation. Corrosion of the steel, degradation of the concrete, and loss of an effective seal can create a route for the ingress of water to the underside of the tank causing corrosion damage to the external base of the AST.
Crucially this corrosion is unseen and hard to detect. A hidden problem which is all too often ignored until it is too late.
How does it affect the oil or chemicals stored?
External corrosion typically has no direct effect on the oil or chemical stored but nobody wants to take valuable ASTs offline to repair the affects of costly corrosion damage. Prevention is better than cure.
Plenty of Codes of Practise relate to Design, Construction, Commissioning and Operation of ASTs. In contrast, guidance on how to eliminate accumulation of moisture under the tank is almost non-existent. So, you can start to see why this important area is sometimes neglected.
What solutions do you offer?
Because tank base corrosion is such a hidden problem, we want to create awareness and share our knowledge and expertise in this area. We offer a surface tolerant, Denso Tank Base Protection system that gives long lasting protection, and is easily installed with no need for excavation, lifting, blast cleaning or other disruption.
Are there any specific problems relating to corrosion in the Middle East and do you have any products to tackle that?
All our products are designed for use in specific climates and we are proud to have supplied a range of products into the Middle East and for use in Sabkha soil conditions for several decades for example our Densopol range of pipewrapping tapes for protection of buried pipe.
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Fujairah – the new storage hub
The sleepy fishing village is today a sought after port for oil and petroleum product storage
As you drive by the coast of Fujairah, which is located on the south of the Strait of Hormuz, it is difficult not to notice the tanks farms defining the city’s skyline.
The once sleepy village of the United Arab Emirates today is transforming itself to be one of the largest ports for refuelling of ships with bunker fuels and its location has made it an ideal place for storage of crude, petroleum products and chemicals.
As early as last month, Gulf Petrochem inaugurated a 412,000 cubic meters storage capacity at $136 million capital expenditure which the company plans to expand to 1.2 million cubic meters. Gulf Petrochem already trades 18% of the Gulf market and has ambitions to reach 25% with additional 408,000 cubic meters in 2014.
Vopak Horizon already has a total storage of 2.1 million cubic metres in Fujairah. The company is a joint venture between Royal Vopak, Horizon Terminals – wholly owned by Emirates National Oil Company (ENOC), the Government of Fujairah and Kuwait’s Independent Petroleum Group.
According to Bloomberg, Royal Dutch Shell is in talks to secure as much as one million cubic meters of crude oil storage at the United Arab Emirates port, in what would be the region’s first such deal with foreign companies.
Fujairah is actively encouraging companies to build storage tanks for gasoline and other products that can then be traded.
Storage operators typically lease space to oil companies or traders. The trading unit of Saudi Arabian Oil Company will lease space for refined fuel at Vopak Horizon’s tank farm. Saudi Aramco Products Trading will use the storage to facilitate purchases of gasoline, diesel and other products for Saudi domestic needs.
So with all of this activity, oil storage capacity in Fujairah is expected to rise by 2 million cubic metres (mcm) just this year to just over 6 mcm, port data show. Fujairah had 4.07 mcm of oil storage capacity at the end of 2012, port figures show, with Vopak Horizon Fujairah accounting for about half.
Another 2 mcm is expected to come online in 2013, including capacity additions from companies such as the Emirates National Oil Company, GPS Chemoil and Socar Aurora, along with smaller players such as Gulf Petrochem.
According to data supplied by port authorities, another 2.3 mcm of storage will be added when the seventh phase of Vopak Horizon’s expansion project comes online and Singapore-based Concord Energy and China’s Sinopec finish their 880,000 cubic metre project.
By 2015, Fujairah’s oil storage capacity is expected to rise to almost 9 mcm, according to the port.
