Abstract: The present invention improves biodiesel production in several ways. Unique combinations of unit operations and flow configurations are disclosed in mobile processing units that are feedstock-flexible and can be dynamically deployed in a distributed way. In some embodiments, a process includes introducing a waste oil and an alcohol into a reactor with an esterification-transesterification enzymatic catalyst. Free fatty acids are reacted with alcohol to produce fatty acid alkyl esters, and glycerides are reacted with alcohol to produce fatty acid alkyl esters and glycerin. A membrane separator removes glycerin, water, and alcohol. Unreacted free fatty acids are then separated and recycled, to generate a product stream with fatty acid alkyl esters. A genset may be provided for combusting glycerin to produce electrical power and thermal heat as co-products. This biodiesel process may be energy self-sufficient, require no external utilities, and avoid direct discharge of wastewater.

Abstract: This invention provides the market with low-cost retrieval of valuable used cooking oil to customer distribution centers, where a mobile production unit visits to create biodiesel fuel, which can be immediately used by customers to fuel their fleet. In some variations, a method comprises identifying a network of customer distribution centers, collecting used cooking oil transported from users to customer distribution centers, providing a mobile reactor to convert used cooking oil into biodiesel fuel under effective reaction conditions, producing biodiesel fuel on-site at the customer distribution centers, and introducing the biodiesel fuel, directly or via a fuel blend, into fleet vehicles. Related systems and apparatus are also disclosed. This invention provides a clean source of energy from waste, a lower-cost alternatives to petroleum-derived diesel fuel, and improved environmental footprints including lower fuel use and lower total carbon emissions.