Cambridge, UK — Fluenta, the global leader in the use of ultrasonic sensing technology for the measurement of flare gas, has recently completed work on the Dangote Refinery, Africa’s biggest oil refinery with the installation of 18 ultrasonic flare gas meters on large pipelines around the plant.
The Nigerian authorities are leading the charge in the control and regulation of flaring gas, looking towards eliminating the need for routine flaring over the next few years. A key component in that challenge is accurate measurement.
Fluenta spent more than four months working with its exclusive Nigerian representative, Daptem Engineering, and the Dangote project team to deliver a workable, accurate and reliable flare measurement solution.
Whilst it’s not unusual to have high levels of customisation associated with such installations, the wide variety and sizes of pipelines, which ranged from 18” to 90” diameters presented a unique engineering challenge that required a novel and ingenious approach.
Larger pipelines make it difficult to measure accurately as the acoustic pulse has to travel over greater distances, thereby weakening the signal strength and possibly leading to less accurate readings. In addition, flared gas expelled through these pipelines is high in CO2, a particularly difficult gas to measure using ultrasonic technology because of the high signal-attenuation associated with this fluid.
In order to reduce the distance between the transducer faces and thereby maintain strong reliable signals, the team implemented a “0.5 offset” compared to a “zero offset”, where the transducers normally go in the pipes between 18 and 36”,
On pipes between 40 to 60”, additional insertion tubes were used to reduce the tip-to-tip distance between the transducers and to maintain their non-intrusive design. A 0.5 offset was used again, with transducers angled to 70 degrees (instead of the normal 45 degrees) to further reduce the distance between transducer faces and reduce the effects of signal beam drift and attenuation.
The 90” pipe solution involved using the same solution, but with longer insertion tubes.
Radek Kurkowski, director at Fluenta, says: “Flare gas measurement and control is vital to ensure compliance with environmental regulations and to help identify potential safety hazards. This is especially true at a plant on this never-seen-before scale and with the world’s largest flare pipe.
“Delivering this solution meant some really close work with our local partner and the client project team, and we are delighted with the end result – which will support bringing energy security to Nigeria and the wider Africa region. Our team used a wide range of tools in our engineering arsenal to deliver a superior pipe flare gas measurement solution.”
Fluenta has deep experience of working in Africa. In 2017, the company was approached by an International Oil Company (IOC) working in Nigeria, who were looking for a reliable flare measurement solution.
Fluenta developed bespoke solutions in response to the IOC’s requirements, which were installed in 2019. Since then, the IOC has ordered an additional 32 Fluenta flare measurement meters. Fluenta has now been awarded preferred supplier status and all flare gas flowmeters on the IOC’s assets have been replaced (or are in the replacement process) with the Fluenta solution.
Fluenta will be speaking further on the challenges of combustion efficiency and industry challenges to track methane emissions from flaring at NiHMEC (Nigeria Hydrocarbon Measurement Conference) taking place 4-5 Oct in Lagos, Nigeria.
