This article introduces ontologies, Knowledge Graphs, agents and their role in the context of Industry 4.0. The importance of interoperability of agents in cross-domain scenarios using the J-Park Simulator (JPS), which is part of the Knowledge Graph () is shown. The dispersion of air pollutants from a power plant situated in Berlin is investigated with the help of JPS. The article describes how interoperability between agents in cross-domain scenarios can be achieved and discusses related open problems.