Climate change, environmental legislation and binding targets for renewable energy, alongside an increased focus on the economic benefits of energy and fuel conservation, are driving the adoption of new technologies as sources of energy. With these dynamics, it is evident that waste heat recovery technologies can play a key role in reducing in reducing indirectly the CO2 footprint of existing fossil power generation and achievement of renewable energy targets. Since the recovered heat is effectively ‘free of charge’, there is a direct positive impact on the energy costs to the end user. This project aims to implement a Organic Rankine Cycle system in a Petrochemical plant, in this case a Low density Polyethylene Plant because is generated hug quantities of heat waste in the polymerization reaction during 8000 hours/year. Also is evaluated the Technical and economical advantages in order to check the feasibility of the implementation of Organic Rankine Cycle System in a Petrochemical Plant. The impact of this Project could give a good guide of the feasibility of the implement ORC system in Industrial process, because the most projects launched with this Technology have been usually used in Geothermal Applications.