Waste fatty acids, conversion biodiesel

Biodiesel is produced on the industrial scale by methanolysis of vegetable oUs (usually rape or soybean) or waste fat, particularly using frying oils. Methanolysis proceeds with modest amounts of base catalyst, provided the levels of free fatty acid and water in the oil are low (24, 25). The fatty acid content may be reduced by physical or chemical treatment before methanolysis but for waste fats, alternative processes that do not use base catalysis may be preferred. Lipase catalyzed methanolysis is less sensitive to fatty acid and water in the oil and has been tested in batch (26) and fixed-bed reactor (27) conversion of waste oil and grease to biodiesel. 

Transesterification of oil from waste oilseed fiuits with methanol was studied in both homogeneous and heterogeneous catalyzed systems. Potassium loaded on lTQ-6 (Delaminated zeolite lTQ-6) by ionic exchange was found to be an efficient base catalyst, which produced 87% biodiesel. The optimum conditions were found to be 1 20 ratio of oil to MeOH at 180° C with 5% catalyst with reaction time of 48 h. Though potassium leaching was observed, which led to deactivation of the catalyst, its regeneration and reusability were easy to perform [82], The catalyst was also reported to be active in the conversion of oil containing free fatty acids (5.58%) without any soap formation and functions as acid ase catalyst. 

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