The sequential code ECLIPSE is used in the present work to perform a technical analysis of two industrial processes-a coke gas cleansing plant and a power plant-aiming their energetic and environmental optimization. The code is validated herein comparing its results against existing experimental data acquired at the above-referred plants, for the present operating conditions. Agreement is observed to be rather good. In order to optimize both processes as far as energy and environment aspects are concerned, alternative unit operations are suggested and are included in the production how sheet and entirely new processes are simulated. The improvements attained in both processes are noticeable. Therefore, ECLIPSE proved to be an adequate tool for global industrial processes simulation, analysis and optimization. However, the code exhibits some limitations in simulating detailed complex physical phenomena, such as combustion.