Our initial research and development on pour point depressants (PPD) began in the 1980’s with work initiated at the Amoco Research Center. Successful developments led to our pour point depressants being utilized by foreign government ministries including Oil and Natural Gas Corporation Limited (ONGC). ONGC is the second largest publicly traded company within its country.
Crude oil and fuel transportation and use are often problematic due to the pour points of these fuels. At the pour point, part of a fuel (mainly wax and paraffin) starts to agglomerate and produce crystals of increasing size as the temperature is further reduced. The occurrence of these semi solid areas results to liquid fuel being entrapped within semi solid regions, effectively increasing the viscosity of the fuel and reducing its flow properties. This physical change is faced with the use of pour point depressants (PPDs).
PPDs are long alkyl chain polymers that bind to wax or paraffin molecules and create longer chains. These longer chains have less binding sites available for agglomeration. PPDs cannot stop the crystal forming process completely. Their action is to slow down the formation, thus keeping the formed crystals at low sizes that are unable to entrap fluid phase and increase viscosity of the fuel. By slowing down the nucleation process, pour point is shifted to lower temperatures.
Different compounds have been used for PPDs, including long chain fatty acid esters, polyacrylates, polymethacrylate, α- olefin maleate copolymers, condensation products of chlorinated paraffins and naphthalene polyacrylates, and others.
The precipitation occurrence of wax and paraffin crystals can be simulated and optimized with the help of computational chemistry methods. Density Functional Theory and Ab Initio calculations are ideal for the investigation of this physical chemical procedure that starts with dispersion forces as the temperature is lowered and proceeds with high energetic bindings at nucleation sites.