Filta service technician Richard Erin, 42, wipes off the vacuum-based filtration system after cleaning a fryer at Cerveceria La Tropical in the Wynwood section of Miami, on Wednesday, May 24, 2023.

Since May, Eric Whitman and his family have been helping restaurants in Bristol County and Rhode Island filter their old cooking oil or recycle it into eco-friendly biodiesel fuel. Whitman manages a ...