Increased thermodynamic efficiency coupled with reduced impact on the environment are fundamental aims in the generation and rational use of energy if a contribution is to be made towards sustainable development on both a local and worldwide scale. Technological developments over recent years in the field of thermal electricity generation, together with research and technologies emerging from environmentally friendly systems, are allowing increases in the efficiency of energy generating processes accompanied by a reduction in polluting gases released into the atmosphere. This work develops the methodology for defining and designing a cogeneration plant based on a combined cycle and using a computer program to provide time simulation. By way of example, the results obtained from the thermal power station of a chemical complex are given. As a novel feature, the work includes the application of a system to capture carbon dioxide, a gas that makes a significant contribution to the so-called 'greenhouse effect', the main cause of global warning. The work carried out allows highly accurate forecasting of future working of the cogeneration system in the proposed application, and analysis of the performance of the plant as a function of its capacity to capture carbon dioxide. The work also considers the feasibility of long-term confinement of the captured carbon dioxide in the deep ocean, and analyses its impact on plant efficiency. Finally, an economical analysis of the proposed plant is included in order to evaluate the impact of the potential carbon dioxide capture and storage system.