The objective of this project is to study the robust output regulation problem of finite-dimensional nonlinear systems by means of infinite-dimensional internal model controllers. The output regulation problem arises in a large number of problems such as tracking, disturbance rejection and optimal steady-state control. Following the celebrated internal model principle, we aim at developing the theory of infinite-dimensional regulators by means of conservative and dissipative operators. During the project, we aim also at developing new tools for the stabilization of interconnections of PDE and (nonlinear) ODEs and at studying the finite dimensional realization of the proposed regulators. The control problem of heat exchanger networks will be used as a pilot test for experimental validations of the proposed methodology.