05-08-2013

Emerson support services help MOL increase throughput and reduce energy usage

Emerson Process Management’s support services have helped the MOL Group increase throughput, improve product quality and reduce energy usage at the Algyõ gas plant in Hungary. Control loop audits, advanced process control project management, and model predictive control project support have together helped MOL achieve savings of over €9 million since 2006.

MOL Group is one of Central Europe's leading international oil and gas companies. Its Algyõ plant, located near Szeged can process up to 12 million cubic meters of gas per day. The gas processing plant includes three columns on each of the two distillation column trains. 

“Exploration and production projects are playing an important role in MOL Group’s portfolio, and for these we need good partners. The cooperation between MOL and Emerson has resulted in great achievements, since distillation columns involve highly interactive, multivariable processes that are difficult to control,” said Károly Oláh, production manager at MOL. “Emerson has completed a number of major projects at our plant that have enabled significant reductions in process variability, provided large energy savings and reduced emissions.”

The relationship between the two companies started in 2006, when MOL Group employed consultants from Emerson’s Control Performance Service to carry out a detailed audit of control loops, valves and instruments to identify areas requiring maintenance, replacement, tuning or redesign. The improved control loop performance reduced the variability of key process parameters by 84 per cent. Loop optimization also reduced re-boiler duty and heating requirements, saving €670,000 per year in natural gas equivalent and cutting CO2 emissions by 4.3 percent.

In 2007, as part of an on-going energy-saving initiative, MOL upgraded the plant’s distributed control system to Emerson’s DeltaV™ digital automation system, and the following year Emerson performed further Control Performance Service work on the related Oil Absorption Plant. These enhancements stabilized the hot oil cycle system and improved the operation of the de-ethanizer column.

In 2009 MOL took advantage of the DeltaV system’s embedded advanced process control (APC) capabilities by adding Emerson’s SmartProcess® Distillation Optimizer. This technology enables model predictive control for distillation columns and has yielded further benefits including better control of the product quality – which in turn enabled MOL to further decrease costs by reducing the quantity of product blending required.

Emerson provided support for this project covering the operation of the unit when using model predictive control. The project was managed by Emerson’s European strategic services group, with support from the local Emerson team in Hungary. Emerson’s distillation solution has now been applied to five of the plant’s six gas distillation columns, reducing energy costs by €1,200,000 per year.

The most recent project at the plant was a performance audit of the model predictive control based on MOL’s current operation and plant operating objectives. Following Emerson’s recommendations, changes have been made to the control system for two of the columns. The changes included modifying the structure of the regulatory control scheme; introducing a new component to the model predictive control scheme to better predict and account for impurities; and updating the procedure for using laboratory data within the calculations.

The changes made at the plant have also reduced the site heat load, which prompted MOL to look at how best the heat supply can be managed for the whole site. Emerson is supporting this project with a study to evaluate the heat balance across the site, as well as the heat loads on the furnace. Emerson’s support will include designing and implementing the recommended modifications.

“Our relationship with Emerson has been very successful in improving the performance of our Algyõ gas plant,” continued Oláh. “Emerson’s outstanding support and extensive industry experience has established them as trusted partners, and we will continue to use their local and global resources whenever the need arises.”