Energy Audit of Fluid Catalytic Cracking Unit of and Oil Refinery

Abstract

Mechanical 2008 Project Report 2008 Mechanical Project Report Project Report 08MME

Energy conservation is a viable tool to promote economic efficiency especially in energy intensive industries such as oil refining. It has proven to be effective tool for overcoming the problem of scarcity of energy resources, and the ever-growing demand on them during the various stages of economic development. Energy conservation pro- motes production efficiency and enhances the international competitiveness in a world that is now oriented towards a new international economic order, with more liberal and free trade. At least 25 % of the operating cost of an oil refinery is attributed to energy consumption. Therefore, over the last two decades, refineries have taken a hard look at the efficiency of energy utilization of their technologies and equipment. The energy audit of FCCU of an oil refinery is carried out. Objective of this au- dit was to assess performance of pump, compressors, fans, compressed air system, steam distribution system, insulation system and waste heat recovery system accord- ingly, appropriate recommendations is to be suggested for increasing energy efficiency of the plant. It is evident that 52% of the total consumed energy can be saved by installing VFD and there is a possibility to save total Rs.374.57 Lacks by incorporating the modiffica- tions suggested, with maximum payback period of only 17 months. It is noticed that around 7-10 % of the total energy consumed can be saved in compressed air system by reducing discharge pressure, hence 1151539 kWh/annum of energy and Rs.60.45 Lacks can be saved immediately. In case of steam system, total savings in HP steam, MP steam and LP steam will be Rs.12.96 Lacks, Rs.25.8 Lacks and Rs.10.93 Lacks respectively, by replacing all damaged steam traps, with maximum payback period of only 3 months. It is also evident that total Rs.181.36 Lacks can be saved by ap- plying detachable insulation covers on valves, valve anges and steam tracing lines. It is also noticed that total Rs.31.69 Lacks can be saved by reducing 15 oC exhaust vii gas temperature of flue gas cooler. It is strongly recommended to install gas turbine immediately in exhaust CO gas line of Regenerator-I and hence Rs.1323 Lacks can be saved with payback period of 12.69 months. In case of FD fans, it is suggested to operate only one fan in fully rated capacity and hence Rs.62.6 Lacks can be saved.