Based on the condition of equipment and technical level of medium and small scale nitrogen fertilizer plants

increasing the net value of ammonia was considered as the goal of optimization study. The whole optimal problem was decomposed. Then the generalized predictive control (GPC) of the temperature of ammonia reactor hot spot for the stability of online-optimization adjustment

and boundary control for the single-direction factors were realized. Adaptive on-line optimization of operation conditions was successfully accomplished. The operation performance of ammonia reactor was improved

the net value of ammonia was increased by 0. 4%

and system pressure dropped by 1. 2 MPa.