In the process industry, a variety of basic thermal operations are used, in which gases or vapor mixtures must be cooled or condensed. If the water dew point falls below this unintentionally, it can lead to the formation of acids and therefore to corrosion depending on the gas composition. If surface condensers are used for the heat exchange, for example as in crude oil distillation, this corrosion known as "pitting", can destroy the apparatus in a short time. In order to counteract the corrosion, so-called corrosion inhibitors, can be used. However, these lead to significant additional costs and are difficult to use under changing process conditions. Therefore, the process is usually operated with a safety margin (pressure and temperature) to the water dew point, whereby the plant capacity is not fully exploited, and a significant optimization potential of the processes remains unused. To solve the problem, a model for calculating the phase equilibrium in multicomponent mixtures is created. The relevant process parameters are surveyed, and a simulation model of the reference plant is created, considering all affected parts of the plant that are necessary for a closed material and energy balance. The heat exchanger performance is determined based on CFD simulations and integrated into the model. Subsequently, an interface between the process prediction output data and the real process is implemented. The process state variables can be transmitted in real time to the process prediction model, and the determined data for optimization are fed back to the process control system, so that the process can be optimized in real time. As a result, a model should be in place to avoid "pitting" and increasing efficiency by at least 1 percentage point. The permanent monitoring of critical system parameters should substantially increase the availability of process systems. By reducing the currently required "safety margins" of process parameters, a reduction of the temperature in the condenser by 5 K should lead to a shift of the production yield towards diesel fuels, which creates a direct monetary added value for the plant operator.