COLD FLOW IMPROVERS / WASA

Rapid economic growth calls for high energy demand, and diesel fuel plays a significant role in meeting the needs of the power generation and transport sectors. Maximizing diesel yield becomes a challenge to refineries in developing countries.

One of the challenges to increasing diesel yield is to meet the limits on cold flow specifications. Typical limits are cloud point, pour point, and cold filter plugging point (CFPP).

Among all the cold flow properties, CFPP has been shown to be the most useful because it provides an accurate prediction of the cold temperature operability of diesel during winter.
The correlation of CFPP and winter operability extends to the use of cold flow improvers (CFI). This fact allows the refineries to increase diesel yield by cutting the final boiling point (FBP) “heavier”. Thus, they can upgrade the light fraction of low-value residue into diesel with the help of CFI.

Many refineries have benefited from the experience of Cestoil Chemical in the area of CFI. Besides providing a wide variety of CFI, we also offer other services such as designing a diesel maximization program and conducting on-site optimization for diesel production.

To ensure a constant supply of CFI during the winter, Cestoil Chemical invested and commissioned a world-class plant to produce ethylene vinyl acetate copolymer (EVA), a major component for CFI.

Using Cold Flow Improver to reduce the CFPP of diesel is limited to an improvement of about 10 deg C. Beyond this limit, the correlation between CFPP and winter operability becomes poor. Eventually, excessive wax will settle down and plug the diesel fuel filter.

For diesel that receives more than 10 deg C of CFPP reduction with CFI, use of co-additives is essential. The co-additives, collectively known as Wax Anti-Settling Aids (WASA,) could modify the wax crystals and reduce their size drastically. The small wax crystals hardly settle and can pass through the filter more quickly, thus extending the operability to a lower temperature.

Use of WASA also prevents wax from settling when transporting diesel during the winter, thus enabling easier discharge of the fuel into storage tanks.

Find out how Cestoil can improve the quality and profitability of your process. Contact us now.