Resumen del autor, extraído del trabajo. In this paper some of the R&D directions that are being followed in the Mexican crude oil refining industry for the reduction of the gas emissions, generated by the high-energy consumption at the combustion equipment, are presented. These directions result from the relevance of the exergy concept (i.e. the second law of thermodynamics) in dealing with the three E’s model: Energy, Economy, Ecology. The exergy concept is able to deal with this three E’s model because of its implications not only in terms of energy but also in terms of economy and ecology.