Cooking oil filtration systems and methods

An in-situ method of removing at least a portion of one or more contaminants from a used cooking oil that includes one or more contaminants at a first contaminant level to provide a cooking oil that includes the one or more contaminants at a second contaminant level lower than the first contaminant level, the method comprising:

• intermittently increasing a gas pressure in an interior space of a housing disposed in an environment including a volume of the used cooking oil that includes the at least one contaminant at the first contaminant level, from a first pressure level to a second pressure level;
• closing a fluid flow valve proximate a fluid inlet to the interior space of the housing as the gas pressure increases from the first pressure level to the second pressure level, the closed fluid flow valve to obstruct a fluid flow path from the environment to the interior space of the housing;
• flowing the used cooking oil in the interior space of the housing through a filter element fluidly coupled to a fluid outlet as the gas pressure increases from the first pressure level to the second pressure level, to provide the cooking oil containing the one or more contaminants at the second contaminant level;
• expelling the cooking oil to the environment via the fluid outlet as the gas pressure increases from the first pressure level to the second pressure level;
• intermittently decreasing the gas pressure in the interior space of the housing from the second pressure level to the first pressure level;
• opening the fluid flow valve as the gas pressure decreases from the second pressure level to the first pressure level, the open fluid flow valve to clear the fluid flow path from the environment to the interior space of the housing;
• and
• flowing the used cooking oil from the ambient environment to the interior space of the housing via the flow path as the gas pressure decreases from the second pressure level to the first pressure level.