Algae-Based Renewable Fuel Promotion Act of 2011 - Amends the Internal Revenue Code to modify the definition of "cellulosic biofuel" for purposes of the cellulosic biofuel producer tax credit and the special depreciation allowance to mean any liquid fuel which is derived solely by, or from, qualified feedstocks. Defines "qualified feedstocks" as any lignocellulosic or hemicellulosic matter that is available on a renewable or recurring basis and any cultivated algae, cyanobacteria, or lemna.