`Right first time’ acetylene bottle filling at Sabic

30 November 2008

Emerson Process Management’s PlantWeb digital plant architecture has enabled Sabic Europe, part of the Saudi Basic Industries Corporation (SABIC), to gain tighter control of acetylene production at its Geleen plant thereby reducing annual costs by €300,000, increasing throughput and plant availability, and improving efficiency by 30%.

Sabic Europe acetylene production site at Geleen

At the Sabic Acetylene production site at Geleen, empty gas cylinders are refilled with acetylene gas. This filling process, consisting of loading, automatic filling and administrating and managing the filling data, has been integrated into a newly installed plant automation system using Emerson’s DeltaV digital automation system and Foundation fieldbus networked instruments including Emerson’s Micro Motion Coriolis flowmeter for direct measurement of mass flow.

In comparison with the previous manual method of weighing and filling which often required cylinders to be reworked, throughput has increased by 25%. The man hours have been reduced by 20%, the physical work has been reduced considerably and as a consequence, the safety, health and welfare of the operators have been improved.

The new automated process that uses intelligent devices to ensure “right first time” filling of the acetylene bottles has removed the possibility of any under or over-filling. Under-filling leads to time consuming rework and over filling could potentially lead to an explosion.

Emerson's Micro Motion Coriolis flowmeter for direct measurement of mass flow

“The use of Micro Motion Coriolis mass flowmeters ensures bottles are filled to the set point every time without exception,” said Eric Heetkamp, Manager Operations and Marketing, Sabic Acetylene. “Previously, about 95% of the cylinders would have been filled correctly first time round and the operator would then have had to follow up with time consuming rework. The choice of mass flow technology combined with Foundation fieldbus communications has been proven to be an excellent investment.”

Foundation fieldbus devices are being used as an enabler of condition based maintenance strategies. Each valve has a built in alert, which, when networked using Foundation fieldbus can warn operators when recalibration is necessary.

Automated process uses intelligent devices to ensure 'right first time' filling of acetylene bottles

Emerson has been awarded the contract to maintain the automation/process instrumentation. The introduction of predictive maintenance has removed the downtime required for checking the accuracy of the flow meters and valves. Previously valves had to be checked as part of a planned shut down on average 24 times a year. This has been reduced to just two planned shut downs. The number of unplanned shutdowns has been reduced to zero.

By using a system of valve alerts, the availability of the filling process equipment has been increased and this has improved overall efficiency of the plant by some 30%. Annual savings of €300,000 have been made at the filling station because of the increase in operator efficiency, reduction in the number of planned shutdowns and increased plant availability. Another major contributing factor to these cost savings is lower maintenance costs.

“In the six years since the new set-up was installed we have seen the number of jams considerably decreased,” concluded Heetkamp. “The number of unplanned plant-wide shutdowns has been reduced to zero and we have total clarity concerning the costs of maintenance.”