IPCO delivers sulfur granulation technology to Duqm refinery
Duqm Refinery and Petrochemical Industries Company (OQ8), a joint venture between OQ Group of Oman and Kuwait Petroleum International (KPI), is a US$9 billion refinery project located on the Arabian Ocean coast of Oman. Processing supplies from Kuwait and Oman as well as crude from other producers, the refinery has been fully operational for little more than a year and has already expanded capacity from 230 000 bpd to 255 000 bpd.
Output includes diesel, jet fuel, naphtha, LPG, and petroleum coke, and the scale of the operation means there is another significant export product in the form of sulfur.
To manage this sulfur output, OQ8 selected IPCO’s high-capacity SG20 drum granulation technology, a system capable of solidifying large volumes of sulfur into a form that meets Sulphur Development Institute Canada (SUDIC) standards.
IPCO SG granulators: meeting mega refinery needs
The SG range was developed in response to increasing capacity demand driven by environmental legislation (meaning more sulfur is extracted); the rise of large-scale ‘mega’ refineries, also producing more sulfur; and the need to convert this into a form safe and easy to store and transport.
Two models are available, the SG30 for solidification requirements of up to 2000 tpd, and the SG20, with a capacity of up to 800 tpd.
Three SG20 units have been installed at Duqm, with two operating around the clock and the third on standby, ready to take over when either of the others needs to be taken off-line for cleaning or maintenance.
While the design capacity of each IPCO SG20 granulator is 800 tpd, they have been tuned down to 450 tpd/unit to meet the client's current daily production need of 900 tpd.
Single-pass granulation process
Solid sulfur seeds are generated outside the drum by freezing sprays of liquid sulfur in a water bath at controlled pressures to form the desired size range. The particles are then conveyed into a rotating drum with appropriately placed flights attached to its inner surface. As the drum rotates, the flights create cascading curtains of sulfur particles, gradually pushing them towards the discharge end.
Spray nozzles on a header that runs the length of the drum coat the curtains of particles with liquid sulfur, progressively enlarging them to the required size.
The drum’s internal temperature is regulated by the evaporation of water from the nozzles positioned inside. A fan pulls air through the drum, expelling both water vapour and any airborne dust. This dust is captured by a wet scrubber before the process air is released into the atmosphere.
This method eliminates the need for recycling or multiple passes, simplifies operations, and allows flexibility in feed sulfur temperature. Recycled sulfur from the wet scrubber is reused as seed, reducing waste.
High-quality product
The resulting granules meet SUDIC’s stringent specifications for size, moisture content, friability and bulk density. The spherical shape of the granules – along with the repeated spraying and cooling of thin layers of molten sulfur as they pass through the rotary drum granulator – accommodates the natural shrinkage during the transition from melt to solid, without weakening the product.
The result is a solidified sulfur product in a form that is easy and safe to store, handle and transport.
Overcoming traditional challenges
Drum granulation has historically faced several limitations, which IPCO’s SG systems address:
1. Sulfur build-up: legacy systems required frequent shutdowns for cleaning. IPCO redesigned key components to reduce build-up, enabling up to a week of continuous operation.
2. Frozen nozzles: traditional spray nozzles are prone to freezing, disrupting flow and product quality. IPCO introduced a heated spray nozzle, eliminating this issue.
3. Roller wear: IPCO’s use of angled flights instead of tilted drums allows horizontal rotation, reducing roller stress and maintenance needs.
4. Dust emissions: IPCO uses a wet scrubber to trap sulfur dust. The captured material is reused in the seed generation system, reducing emissions and eliminating waste.
5. H2S control: hydrogen sulfide emissions are mitigated using an H2S scrubber, ensuring compliance with environmental standards.
6. Operational consistency: variations in climate and feedstock affect granulation performance. IPCO created process simulations from global SG system data, enabling optimised settings for varying conditions without operator guesswork.
Conclusion
IPCO’s SG20 drum granulators at Duqm represent a major step forward in sulfur solidification technology. They offer high output, improved environmental performance, and ease of operation, eliminating many drawbacks of traditional systems. With these innovations, IPCO ensures reliable, safe, and efficient sulfur processing, delivering a consistent premium product suitable for global transport and storage.
For more information visit https://www.ipco.com/en-us/industries/chemicals/sulphur