Location: Pancevo, Serbia
End-user: NIS a.d. Novi Sad, Serbia
Fluids: Diesel lubricator and jet fuel antioxidant
Start-up date: 2012
The construction project for the new plant at the Pancevo oil refinery, MHC/DHT, which was intended to produce jet fuel and Euro diesel, did not initially include systems for dosing antioxidants in jet fuel or additives in Euro diesel.
The dosage of antioxidants is regulated by the “Official Gazette of RS,” no. 64/2011, Annex II, and the dosing of additives for required lubricity and electrical conductivity in Euro diesel is regulated according to Standard EN-590.
Therefore, it was necessary to initiate a project to install systems for dosing antioxidants in jet fuel and additives in Euro diesel.
As a result, NIS a.d. Novi Sad, the Serbian oil company, released a tender, which was awarded to WIG after the bidding phase.
The additives dosing system is supplied from a single cylindrical horizontal tank divided into two parts, with volumes of 60 m³ and 40 m³ respectively.
The tank contains two different types of additives. The first part, with a volume of 60 m³, holds the additive for diesel fuel. The second part, with a volume of 40 m³, holds the additive for jet fuel. Below the lowest level of the tank, four self-priming gear pumps are installed, each with a capacity of 19 l/min. A bypass valve is installed before the injection block to set the inlet pressure, which should be about 5 bars higher than the main line pressure. For optimal performance, the additive is injected downstream, with a static mixer installed in the main pipeline.
According to technical requirements, the system doses additives into two lines—diesel and jet fuel—as two independent entities. Each dosing unit consists of two completely separate metering lines, ensuring continuous dosing under all operating conditions and high system redundancy. The solution is based on a specially designed module connected to a control unit, which can control the additives for each line. The modular system includes an injection unit with PD flow meters, solenoid valves, filters, and an injection controller connected to the main line standards. Depending on the fluid flow in the main line and prediction formulas, a pulse signal opens and closes the valves in the injection block.
The additives dosing system can be controlled via a local display or remotely from the control room. This type of system control is considered redundant. In case of a communication breakdown between the control room and the dosing system, a locally configured HMI takes over control.
The system operates with redundancy. Two SMAR controllers, type DF73, are installed, working in full redundancy. This ensures a high degree of system security in the event of a controller failure. If one controller fails, the redundant controller takes over as the primary.
