Navid Qorbani stated that the overhaul began on October 12 and concluded on November 12. The operation focused on addressing reduced performance and activity of the unit’s catalysts, including the unloading and recharging of reactor catalysts. 

During the overhaul, 755 tons of domestically produced catalysts were loaded into five reactors. All equipment, including reactors, furnaces, towers, air fans, electrical devices, and precision instruments, were inspected, repaired, or replaced as needed. Following final inspections and preparations, the unit resumed operations at maximum capacity. 

Qorbani emphasized that the complex operations, conducted under nitrogen atmosphere conditions, were carried out entirely by domestic teams without foreign assistance. 

He noted that the refining units in Region 5, which fall under operational management, include the HPU, RCD, PSA, and gas fuel supply units for the refinery’s furnaces, as well as sour gas or amine treatment units. 

In the RCD unit, heavy residual oil from atmospheric and vacuum distillation, which is not marketable, undergoes hydrotreating.

This process removes sulfur and nitrogen, saturates olefins, and absorbs metal compounds, converting the oil into products such as diesel, kerosene, heavy oil, and refined residual TR. These products are further processed in the RFCC unit to produce gasoline, liquefied gas, and propylene. 

The RCD unit, designed in two separate phases with a capacity of 69,180 barrels per day, operates at 185 bar pressure and 380 degrees Celsius, utilizing catalysts and hydrogen gas. 

The HPU unit, designed to produce hydrogen from natural gas and steam at 800 degrees Celsius and 21 bar pressure, plays a critical role in catalytic processes. With a capacity of 135,000 cubic feet per day, the HPU uses PSA technology to extract 99.9% pure hydrogen. 

During the HPU overhaul in October, all catalysts were replaced, along with 14 tubes of H 1731, 100 top flanges in the furnace’s radiation section, and the High Shift reactor catalyst.