APC - Ammonia
The Ammonia Plant advanced control package uses three modules of Axens' latest generation multivariable controller MVAC. It is designed to maximize the benefits from the Ammonia Plant, in an environment with multiple constraints and complex multivariable interactions.
A ten step control strategy is implemented:
- Compensation for changes in feed quality.
- Primary reformer firing control: coil temperature balancing.
- Methane conversion optimization: reformer methane leakage control.
- Feed flow maximization and constraints protection.
- Steam/gas ratio minimization.
- Compressor inlet pressure maximization, for energy savings.
- H/N ratio control in synthesis loop, for stoechiometry
- NH3 conversion optimization: converter bed temperature profile control.
- Control of inerts concentration in the synthesis loop.
- Steam production management.
- Axens inferential technology is used for on-line estimation of:
- Primary reformer skin temperature.
- Methane leakage.
- Increase of Ammonia production (+ 4 % )
- Reduction of energy consumption ( - 5 % )
- Increase of steam export
- Improvement of operational stability
- Safe protection of plant constraints
- Increased catalyst run length
- Reduction of the complexity of operator workload