ABSTRACT
The challenges of continual depletion, economic crisis and environmental issues of the petroleum fuels have attracted the scientists' interest to seek for alternatives to fossil fuels. Biodiesel is the alternative to petrol diesel because; it has similar physicochemical properties to petrol diesel. However, biodiesel has not been competing favourably well economically with petrol diesel due to high cost of production. A process intensification technology was introduced in this work to produce safer, neater and cheaper biodiesel with fewer unit operations. A process intensify pilot plant was simulated, designed and constructed to produce biodiesel from Jatropha curcas seed oil and methanol in a molar ratio of 1:3 oil to methanol using five synthesized solid base catalysts. The pilot plant was made up of a stainless steel continuous stirred tank reactor, a stainless steel tank containing the oil and mixer for methanol/catalyst, a control panel, and solid-liquid separator. The process intensification excluded the following unit operations; neutralizer, washer, dryer, condenser and distillation column which are in the conventional process. Five solid base catalysts; bulk calcium oxide (CaO), super base calcium oxide (CaO/(NH4)2CO3)), bulk magnesium oxide (MgO), calcium oxide/magnesium oxide (CaO/MgO) and 10% potassium impregnated calcium oxide/magnesium oxide (10%K-CaO/MgO) were synthesized. These catalysts were first tested for their efficacy for production of biodiesel. Studies of the yields of biodiesel, glycerol and other impurities were carried out with transesterification reactions catalyzed by these catalysts, except bulk magnesium oxide at 600C with time. They all performed very well with CaO/MgO catalyzed reactions producing no glycerol for all the reaction conditions. Complete conversion of feedstocks to biodiesel without glycerol and other impurities were recorded in some of the reactions runs using CaO/MgO and 10%K-CaO/MgO catalysts.The methyl esters yields of 97.952%, 96.94%, 95.76%, 99.99% and 98.25% were obtained with bulk calcium oxide, super base calcium oxide, bulk magnesium oxide, calcium oxide/magnesium oxide and 10%K impregnated calcium oxide/magnesium oxide catalysts respectively. The biodiesel produced was characterized and its physicochemical properties were compared to the ASTM and EN standards. They had 53, 54, 48, 48 and 55 cetane numbers respectively. They all had energy value greater than the minimum required for biodiesel standard of 47 MJ/kg. Transesterification with 3:1 methanol/oil molar ratio had complete reaction.Commercial viability of the pilot plant was evaluated. The total investment cost and income generated per annum were N5 458 305.26 and N5 912 633.30. The return on investment was found to be 7.75% and the payback period was found to be 13 years. These analyses indicated that the pilot plant was commercially viable as compared with conventional technology.