The conventional process for producing biodiesel is base catalyst and requires anhydrous condition and feed stock with low levels of free fatty acid (FFA). Basic catalyst gives the higher reaction rate than acid catalyst. However, the basic catalysts involved soap formation of free fatty acid leading to the deactivation of catalyst and high production cost. Inexpensive feed stocks containing high levels of free fatty acid cannot be directly used with the base catalyst. This work deals with the synthesis of biodiesel from high free fatty acid containing crude degummed cotton seed oil (CDGCSO), using 5 wt % (weight of the oil) super phosphoric acid (SPA) as catalyst and evaluating the effect of the molar ratio (oil : alcohol) on percentage conversion. Molar ratio 1:10 showed greater yield. The acid catalysts do not form the soap and can simultaneously conduct esterification and transesterification of free fatty acid and oil to biodiesel. However, they are slower and necessitate higher reaction temperatures. Nonetheless, acid-catalyzed processes could produce biodiesel from low-cost feed stocks and lowering the cost of production.
