Economic NMPC for heat-integrated chemical reactors

This paper presents the application of economic NMPC for a heat-integrated chemical reactor. The chosen case study is given by the ammonia synthesis reactor. Through the application of economic NMPC, it is possible to move the operating point close to the unstable region, corresponding to a 12% increase in the extent of reaction with nominal operations conditions. As a further advantage, the increased conversion of ammonia corresponds to a higher outlet temperature of the system which can be utilized to produce high and medium pressure steam. The proposed economic NMPC is able to adjust in the case of disturbances fast to the new optimal conditions and maintains the productivity of the reactor without engaging into limit-cycle behaviour or extinction of the reactor.