Improved Catalytic Reagents Reduce Refinery Operating Costs
Solids-free ARI-100EXL, from Gas Technology Products LLC, has proven both efficient and cost effective in removing mercaptans from liquid hydrocarbon streams. In one specific case, a refinery had been using a once-through caustic solution process to remove hydrocarbons. This costly process required disposing of the caustic and replacing caustic with each operation. To reduce operating costs, the refinery installed a Merichem REGEN unit.
Reduced Refinery Operating Costs Achieved with ARI-100EXL Liquid Catalyst
When a Gulf Coast refinery decided to install a Merichem REGENSM unit, they took an important step in reducing the high operating costs associated with their existing once-through caustic solution process. The REGENSM process minimized costs associated with disposal of spent caustic and the purchase of replacement caustic providing a more cost effective method of removing sulfur from their hydrocarbon streams.
Extraction process operation
In any mercaptan extraction process, the hydrocarbon stream contacts the caustic solution which results in the following chemical reaction:
RSH + NaOH → RSNa + H2O
Once mercaptans are extracted, the caustic stream is separated from the hydrocarbon stream and sent to the caustic REGENSM unit. Air and ARI-100EXL are then injected into the caustic stream. The mercaptans are oxidized and converted to disulfides (RSSR) which regenerates the caustic as follows:
2 RSNa + 2 H2O + ½ O2 → RSSR + 2 NaOH + H2O
Next, the RSSR/Caustic is sent to a separator where RSSR is removed from the regenerated caustic by gravity separation, and the regenerated caustic is sent back to the mercaptan extractor.Enhanced operation
The Merichem REGENSM unit also includes a continuous catalyst injection system to:
- Improve catalyst addition efficiency by delivering a continuous flow of catalyst solution instead of periodically adding batches of catalyst
- Minimize operator attention and work
The success of the REGENSM application is the result of Gas Technology Products improved oxidation catalysts for use in Merichem's licensed process technologies.
SOURCE: Merichem Company -- Merichem Gas Technologies