The Global Economic Crisis, the increasing energy demand of emerging countries such as China and India, and the recent nuclear emergency in Japan show the importance of energy in our society and its direct influence on economics. Sulfuric acid is the biggest chemical commodity- in terms of volume- produced in the world and has a wide range of uses and not only within the chemical industry. Consequently, sulfuric acid plants offer the oportunity of a potential focus of cost-energy optimization for any country''s economy. The key of solving this problem is exergoeconomics, also known as thermoeconomics, which is the branch of engineering that combines both energetic and economic principles in order to improve the performance of a cost-effective system. The goal of this work is twofold. First, to document the use of exergoeconomics in the study of thermochemical processes, since there is little information on this topic to date. Second, its application in the optimization of sulfuric acid plants by means of a four-step methodology: exergetic, economic, and thermoeconomic analyses, plus the optimization. The study was carried out in a wet sulfuric acid plant.