Bioethanol under control
Digital automation delivers business advantages at Turkey’s first bioethanol fuel plant

When Tarkim in Mustafakemalpasa-Bursa, Turkey, was planning a greenfield project for a plant to produce fuel ethanol from grain, the company needed an automation partner that would be 100 percent reliable, as well as being able to complete the project in the shortest possible time and with the lowest costs.
The new facility being built by Tarkim is for the manufacture of bioethanol, the world’s largest source of renewable energy. Bioethanol has a number of advantages over conventional fuels. It is not a finite resource, and has the added advantage that the crops used for feedstock help to reduce greenhouse gas emissions by absorbing CO2 as the crop grows. Blending bioethanol with gasoline also helps to extend the life of diminishing oil supplies.

By encouraging the use of bioethanol, rural economies receive a boost from growing the crops necessary for its production. Bioethanol is biodegradable, and far less toxic than fossil fuels. In addition, using bioethanol in older engines can help reduce the amount of carbon monoxide produced by the vehicle, thus improving air quality. Another advantage of bioethanol is the ease with which it can be integrated into the existing road transport fuel system. In quantities up to ten percent, bioethanol can be blended with conventional fuel without the need for engine modifications. It also improves engine performance by adding two to three points to the octane rating, keeps engines cooler, acts as a fuel pipe antifreeze, and helps keep fuel injectors cleaner.

Operating in a highly competitive global market, accurate process control is very important for Tarkim. Control directly affects productivity, and hence the manufacturing cost per liter.

Built-in intelligence

The control system for the new bioethanol plant is based on Emerson’s PlantWeb digital plant architecture. This included a DeltaV digital automation system communicating with 381 field instruments, 108 control valves and 124 on/off valves using the Hart protocol. There are over 1200 I/O points, and Emerson also supplied redundant controllers and power supplies. The Emerson field devices include Rosemount intelligent pressure and temperature transmitters, Fisher control valves, and Fisher Fieldvue digital valve controllers. Micro Motion intelligent Coriolis mass flowmeters are used to measure slurry and syrup flow, and the project also included Intelligent Device Manager software from Emerson’s AMS Suite.

The bioethanol manufacturing process consists of several operations performed in series. Consequently, downtime on any unit affects the output from the others. With unscheduled downtime a critical factor, AMS Device Manager is used to help identify potential problems before they develop into events that could close the line.

The AMS Device Manager application is embedded within DeltaV and is used to access the predictive intelligence of the field devices to allow configuration, calibration, and diagnostic tests to be performed. This enables the operational team to collect, analyse and share operational and diagnostic information. Using the powerful diagnostics built into the AMS Suite, many potential problems can be resolved from the comfort and safety of the new central control room, reducing costs, minimizing downtime and increasing operational efficiency.

Rapid startup of the project was critical. The DeltaV system and AMS Suite helped to identify any configuration or wiring errors, and this contributed to solving many of the problems that emerged during the startup phase.

Tarkim worked with the Emerson team to ensure that startup was completed quickly and without any safety-related incidents. Training was arranged to familiarize the operators with the use of the DeltaV system and the AMS Suite, and this contributed to the fast startup of the project. Based on similar projects, startup of the Tarkim plant was scheduled to take up to three months; thanks to the contribution made by Emerson, the plant was in fact able to start up one month earlier. This provided cost savings of € 220,000 and helped book early revenues.

Proven performance

The plant has now been operating for over two years, and during that time it
has made no off-specification product or quality concessions. When changes have been required to improve the existing process, Emerson engineers have responded quickly with solutions to these requests. With the benefit of these experiences, the engineers at Tarkim have learned how to use the DeltaV system and are now able to make changes to the configurations themselves.

During this operational period, the reliability of the plant has been outstanding, with only two or three unexpected shutdowns. The alarm system built into the DeltaV system has ensured that these shutdowns have been resolved without any damage to instruments or equipment. Part of the process includes the addition of expensive enzymes. The process architecture is able to control these precisely, keeping raw material costs at a minimum. The PlantWeb architecture has also contributed to a 28 per cent increase in production over the original design capacity.

“PlantWeb has made a big contribution to minimizing production losses,” said Levent Kalin, Tarkim factory manager. “There are literally hundreds of limits for parameters which are set by the DeltaV digital system. These are checked regularly and alerts generated for any that are outside limits. When there is a problem, a fast solution gains us time for production. Consequently, our unit costs are approximately ten percent lower than we expected.”

“We were pioneers when we entered this sector,” said Ahmet Tüzün, Tarkim general manager. “Our global aim is to become an expert and a pioneer company, not only in bioethanol but more widely in the biofuels sector, to keep our existing position, and to expand the sectors we serve, not only in Turkey but also in other geographical territories. Based on the success of this project we would want Emerson to continue as our partners.”