A system for upgrading asphaltenes includes an asphaltene treatment line, a series of asphaltene upgrade units, a series of carbon fiber production units, an aqueous collection unit, and a gaseous collection unit. The series of carbon fiber production unit includes a demetallizing unit that includes a first supercritical water (SCW) treatment unit and a first centrifugation unit, a desulfurizing unit that includes a second SCW treatment unit and a second centrifugation unit, and a polycondensation unit that includes a third SCW treatment unit and a third centrifugation unit. A method for mesophase pitch production from an asphaltene feedstock and a method for manufacturing carbon fibers from asphaltene feedstock are also described.