The present invention is a self-powered method for conversion of disposable hydrocarbons into diesel and heating oil fuels and conversion of biomass into biodiesel fuel. The method is operated using a feedstock tank, a preparation tank for first stage warming of the feedstock, a first heat exchanger to separate out water as steam and light ends, a stack to vent steam to the atmosphere, a second heat extension to raise the temperature to the necessary for processing the feedstock in a cracking kettle, a fume incinerator burning the light ends to generate heat for the first and second heat exchangers, a distillation column to process the gases from the cracking kettle, a condenser to convert gas to liquid #2 diesel fuel, a filter and chiller unit and storage tanks to hold the fuels and residuals. The method uses retained heat in the residuals to preheat the feedstock to save energy.