Croatian oil company INA has initiated a critical phase in its extensive €700 million investment aimed at modernizing the Rijeka oil refinery. The launch of live-process testing at the new heavy residue processing unit marks a significant milestone, as it involves operational trials with process fluids to ensure all systems function correctly before full-scale commissioning is scheduled for March 2026.
This live testing follows preliminary cold tests and will gradually incorporate steam, water, and fuel gas, culminating in the introduction of petroleum products. Throughout this phase, the refinery’s systems are being monitored under strict safety protocols to assess process stability, automation performance, and equipment reliability under actual operational conditions.
INA has identified this stage as one of the most technically challenging aspects of the project. Upon completion of testing, the refinery is expected to reach its nominal capacity by 2026. This development represents not only INA’s largest investment to date but also stands out as one of Croatia’s most consequential industrial undertakings.
The modernization program encompasses comprehensive upgrades to the Rijeka facility, including enhancements to existing infrastructures, the construction of new port facilities, storage silos, an enclosed coke transport system, and a new electricity substation, which will be the largest in Croatia. These improvements aim to elevate the refinery’s operational efficiency, optimize crude utilization, and increase the production of high-value products.
Upon becoming fully operational, the upgraded unit is projected to boost diesel production by up to 30%, thereby reducing Croatia’s reliance on fuel imports—particularly crucial during peak tourist seasons. Furthermore, the project is anticipated to eliminate the necessity for vacuum gas oil imports from European markets, predominantly sourced from Russia in the past, thus enhancing national energy security.
