Coker naphtha hydrotreating technology

Processing difficult feedstocks

Coker naphtha places extraordinary demands on hydrotreating processes. These difficult-to-process streams often contain high levels of silica, which decrease HDN catalyst activity. Complications can also arise because they have high concentrations of conjugated di-olefins that tend to polymerize, as well as olefins that immediately saturate and release heat that challenges temperature control. The sulfur content of coker naphtha can be 20 times higher than in straight-run naphtha.

The coker naphtha hydrotreater needs to run under severe operating conditions to meet product specifications. Yet refiners will still expect these units to operate at high levels of utilization and availability. To do this, carefully managed HDS and HDN feeds are required over the entire planned unit run length. The values of reactor temperature, hydrogen partial pressure, and treat gas-to-oil ratio must be set and controlled with extreme accuracy.

The typical coker naphtha hydrotreating reactor loop has three stages. The first stage selectively saturates diolefins to olefins, which react quickly at high temperatures. The second removes silica and saturates monoolefins. If not removed, silica quickly deactivates HDS/HDN catalysts. The third stage addresses the HDS/HDN reactions and drives bulk conversion.
Topsoe licenses and designs revamps and grassroot coker naphtha hydrotreating units at multiple capacities.

Catalysts can accelerate chemical reactions, control selectivity, and reduce energy requirements. Their ability to optimize process efficiency and product quality make them indispensable in industrial processes.