We are researching advanced operation support system which can help operators and provide them with novel knowledge. Advanced operation support system needs more essential information of plants such as temperature of reactor inside, real-time data of composition, prediction of the process behavior and so on. We use simulators as a way of getting such essential information of plants from the experience that we have developed process simulator. Our process simulator is strictly based on chemical engineering principle, namely, rigorous model which makes accurate simulation possible. However, it is hard to keep simulation highly-accurate against many reasons, e.g., change of process characteristics with degradation of plant equipments or catalysts. For this reason, we have proposed tracking simulator which runs in parallel with an actual process and adjust its parameters online. We developed an experimental steam reforming plant generating hydrogen from methane gas and the corresponding model for demonstration of tracking simulator. And then, we run tracking simulator with the process to visualize composition of reactor in real-time as an example of operation support