Systems and methods for purification of fats, oils, and grease from wastewater

A system for purifying fats, oils, and grease (FOG) from wastewater, the system comprising:

• a trash pump configured to pump the wastewater into the system;
• a grinder pump positioned downstream of the trash pump and configured to grind materials in the wastewater to a maximum dimension of 0.25 inch or less to form a process mixture;
• a first heat exchanger positioned downstream of the grinder pump and configured to heat the process mixture to a temperature of between 185° F. and 200° F.;
• a shaker tray positioned downstream of the first heat exchanger and configured to remove solids having a maximum dimension greater than 0.035 inch from the process mixture;
• a second heat exchanger positioned downstream of the shaker tray and configured to reheat the process mixture to a temperature of between 185° F. and 200° F.;
• a decanter positioned downstream of the second heat exchanger and configured to remove solids from the process mixture such that the remaining process mixture contains less than 1% solids;
• a third heat exchanger positioned downstream of the decanter and configured to reheat the process mixture to a temperature of between 185° F. and 200° F.;
• a centrifuge positioned downstream of the third heat exchanger and configured to remove liquids and solids from the process mixture to form purified FOG containing less than 2% water and less than 0.1% solids;
• a fourth heat exchanger positioned downstream of the centrifuge and configured to heat the purified FOG to a temperature of between 185° F. and 200° F.;
• and
• a storage vessel positioned downstream of the fourth heat exchanger and configured to collect the purified FOG therein.