Solvent Deasphalting (SDA)

 
Solvent Deasphalting is one of the most interesting "Bottom-to-Barrel" technologies to process heavy residues in modern refineries.  
 

On the one hand due to the major price differences more and more heavy, high-sulfur crudes are used in refinery processes rather than light, low-sulfur crudes and on the other hand it requires more efficient residue processing technologies. 

A case in point is the long-known Solvent Deasphalting process used in lubricating oil refining. It is increasingly used by fuel refineries now because compared to other residue technologies (e.g. hydrocracker, coker, visbreaker, gasification) the SDA technology has the lowest investment cost. 

Compared to conventional SDA processes SDA PLUS offers crucial advantages:

• Optimal product qualities are achieved with high process efficiency based on most advanced column internals.
• With SDA PLUS existing SDA plants can be optimized and yields can be increased up to 10 %.
• With SDA PLUS the operating costs can be reduced by up to 25 % compared to conventional technologies.

At our own pilot plants and based on long-years‘ research and development various processes can be simulated for an optimum plant design. 

Main components of an SDA plant:  

• extractor
• DAO train
• pitch train
• solvent recovery

The PDA process using propane as the only solvent has been implemented by EDL on industrial scale in Hamburg.

Besides propane (C₃) Pörner / EDL can also use n-butane, i-butane (C₄) or portions of n-pentane and n-hexane for deasphalting. In this process C₃ and C₄ are normally mixed to reach higher yields of DAO which leads to a deteriorating quality of DAO, however. 

The higher DAO yields containing C₄ portions are in particular used for the technology variation to produce resin.