Optimizing biodiesel cold flow performance and stability

Get an edge with Evonik's custom-tailored biodiesel additives

Cold flow improvers (CFIs) work by modifying the growth of crystallizing wax particles. As crystals form, cold flow improvers act as nucleators and co-crystallize with the saturated hydrocarbon chains, modifying the wax crystal size and shapes from plate-like to needle-like. The smaller wax crystals more easily pass through filters and are less able to form the three-dimensional gel structures that impair the flow of the fuel, optimizing product flow behavior. Dramatic improvements in cold filter plugging point and pour point can be obtained. A benefit of VISCOPLEX® CFIs is that, during re-warming, the smaller, more dispersed wax crystal structure helps the fuel return to a usable state more quickly.

Evonik's comprehensive portfolio of high-performance VISCOPLEX® CFIs is designed to control wax crystal formation in biodiesel from a variety of sources, resulting in excellent low-temperature flow performance. The CFIs can be used on their own at treat rates of 0.05 - 1.0% in order to significantly improve the cold filter plugging point (DIN EN 116), pour point (ASTM D 97) or cloud point.

VISCOPLEX® cold flow improvers offer many benefits for a wide range of biodiesel blends. In particular, they can:

• Improve the cloud point, pour point and cold soak filter test of biodiesel fuels from different sources (canola, soy, palm, etc.), thereby increasing the value for product sold against a CFPP target
• Improve biodiesel low-temperature handling properties while minimizing sedimentation and solidfication
• Allow blends of FAMEs with varying levels of low-temperature performance to meet regulatory specifications
• Improve the cold flow performance and filterability of blends of biodiesel (SME, RME, PME) with fossil diesel, thereby extending the range of blend ratios (B5, B10, etc.) that meet regulatory specifications

Application examples include biodiesel production and storage, biodiesel blending and passenger biodiesel.

Solutions for middle-distillate blends and the respective additive packages

VISCOPLEX® series 10

VISCOPLEX® series 10 products can be used to boost cold flow improver performance in combination with traditional additives, like ethylene-vinyl acetate copolymers. A low percentage of VISCOPLEX® in the additive package potentially allows it to reach lower target values at lower treat rates.

VISCOPLEX® 10-608

VISCOPLEX® 10-608 is effective as a cold flow improver in biodiesel and fossil fuels and potentially allows formulations to reach the lowest CFPP and PP in B2 through B20 fuels. The product is registered on BP's no-harm list for diesel cold flow improvers.