Rentech, Inc. (stands for Renewable Energy Technology) was a Los Angeles, California, based United States company that owned and operated wood fiber processing and nitrogen fertilizer manufacturing businesses. It provided wood chipping and wood pellet services through a subsidiary Fulghum Fibres, Inc. and sold nitrogen fertilizer through Rentech Nitrogen Partners, L.P. In addition, Rentech owned the intellectual property for a number of energy technologies, such as Rentech–SilvaGas Gasification Process and Fischer–Tropsch process based Rentech Process.