  This chapter compares different formulations for Economic nonlinear Model
Predictive Control (EMPC) which are all based on an established dissipativity
assumption on the underlying Optimal Control Problem (OCP). This includes
schemes with and without stabilizing terminal constraints, respectively, or
with stabilizing terminal costs. We recall that a recently proposed approach
based on gradient correcting terminal penalties implies a terminal constraint
on the adjoints of the OCP. We analyze the feasibility implications of these
dual/adjoint terminal constraints and we compare our findings to approaches
with and without primal terminal constraints. Moreover, we suggest a conceptual
framework for approximation of the minimal stabilizing horizon length. Finally,
we illustrate our findings considering a chemical reactor as an example.
