INA Fires Up Transformative Delayed Coker at Rijeka Refinery

Croatia’s INA Industrija Nafte DD has started production at a new delayed coking unit at its 90,000 b/d Rijeka refinery along the northern Adriatic Sea. The startup marks a major milestone in the company’s refinery upgrading project.

INA introduced feedstock into the delayed coking unit on Sept. 1 after completing mechanical work and commissioning activities, majority owner MOL Group said in a Sept. 21 release. That step formally began production from the new unit.

The delayed coking unit has operated continuously since startup and has reached about 70% of its design capacity, according to the company. INA plans to increase throughput gradually as it continues optimizing process performance.

The unit converts heavy refinery residues into products with higher value. Since startup, it has produced all key products at the required quality, demonstrating progress as INA moves toward stable operation.

The delayed coker is anticipated to increase diesel production by as much as 30% while processing the same volume of crude. MOL Group also expects the unit, once fully operational, to eliminate Croatia’s need to import vacuum gas oil.

The wider Rijeka refinery upgrade represents an investment of nearly €700 million. That expenditure forms part of a combined €1.3 billion invested by INA and MOL Group in refining and logistics modernization over the past 12 years.

“The start-up of the new unit went really well,” said Zsuzsanna Ortutay, president of INA’s management board. Ortutay added that the delayed coking unit would improve the sustainability and profitability of INA’s refining business while supporting energy supply in Croatia and the surrounding region.

INA expects the unit to achieve stable operation by yearend following the planned increases in throughput and continuing process optimization. Final plant performance testing and project closeout activities are scheduled to follow stable operation.

INA awarded the project’s lump sum, turnkey engineering, procurement, and construction contract in December 2019. The contract went to KT-Kinetics Technology SPA, a subsidiary of Maire Tecnimont SPA.

The contracted work covered construction of a new delayed coking complex, including coke handling and ship loading facilities. It also included a sour water stripper and amine recovery units needed as part of the expanded refinery configuration.

Additional work involved modifications to the refinery’s existing hydrocracker, sulfur recovery unit, utilities, and offsite systems. The project scope also called for coke storage and construction of a marine jetty.

More than 60% of the existing refinery was expected to undergo work under the project, according to Maire Tecnimont. The company valued the contract at about €450 million and initially scheduled completion for 2023.

The delayed coking project forms part of INA’s broader Downstream 2023 New Course program. Under that strategy, INA called for concentrating crude processing at the Rijeka refinery while assigning a different role to its 44,000 b/d Sisak refinery.

Plans for the Sisak site included its conversion into a location for bitumen, renewable, and potentially lubricant production. The strategy also identified the site as a future logistics hub.

Ownership of INA is divided among MOL Group subsidiary MOL PLC, the Republic of Croatia, and private and institutional investors. MOL PLC holds a 49.1% stake, the Republic of Croatia owns 44.8%, and private and institutional investors control the remaining 6.1%.

The startup advances a refinery modernization effort centered on deeper conversion of heavy residues and greater production of higher value fuels. INA’s immediate focus remains the gradual increase of throughput, stable operation by yearend, and the testing and closeout work that will complete the project.