**Integrated Method of Monitoring and Optimization of Steam Methane Reformer Process**

#### **Nenad Zeˇcevi´c \* and Nenad Bolf**

Department of Measurements and Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, 10000 Zagreb, Croatia; bolf@fkit.hr

**\*** Correspondence: nenad.zecevic@petrokemija.hr

Received: 14 March 2020; Accepted: 24 March 2020; Published: 31 March 2020

**Abstract:** Reforming of natural gas with steam represents the most energy-intensive part of ammonia production. An integrated numerical model for calculating composition of primary reforming products with cross-checking of outlet methane molar concentration, heat duty, maximum tube wall temperature, tube pressure drops, and approach to equilibrium was set up involving production parameters. In particular, the model was used for continuous monitoring and optimization of a steam methane reformer (SMR) catalyst in ammonia production. The calculations involve the solution of material and energy balance equations along with reaction kinetic expressions. Open source code based on Matlab file was used for modelling and calculation of various physical properties of the reacting gases. One of the main contributions is development of the rapid integrated method for data exchange between any distributed control system (DCS) and the model to accomplish continuous monitoring and optimization of SMR catalyst and reformer tubes. Integrated memory block was proposed for rapid synchronization between commercial DCS with the model solver. The developed model was verified with the industrial top-fired SMR unit in ammonia production located in Petrokemija, Croatia. Practical application of proposed solution can ensure overall energy savings of up to 3% in ammonia production.

**Keywords:** ammonia production; numerical modelling; steam methane reforming; simulation
