Each sulfur recovery unit (SRU) has a capacity of 650 metric tons per day (MTPD) and operates based on the CLAUS processing system. The fourth unit will be constructed adjacent to the third unit within the battery limit of Khangiran Refinery.

The reasons and objectives for building a new SRU unit are as follows:

• Addressing environmental concerns
• Increasing sulfur production
• Extending the lifespan of catalysts