Knowledge Base /
Industry Applications, Petroleum Refining
Mimic Dynamic Simulation for Diesel Hydrotreater (DHT) Units
By Martin Berutti
Product: Mimic Simulation

The Mimic dynamic simulation application package for diesel hydrotreater (DHT) units provides a high performance solution for operator training and control system optimization.

In addition, the Mimic virtual plant with the DHT unit application package provides the complete environment for control system optimization and is an effective tool for teaching process and control engineers the control and operation of refinery Diesel Hydrotreater Units.

Diesel Hydrotreating Units are essential for the production of ultra clean diesel fuel (or EN 590).

Mimic Simulation Software allows refinery operation managers to:

  • Train operators on infrequent and dangerous process occurrences
  • Properly prepare an inexperienced operator workforce and create a smooth knowledge transfer process
  • Practice smooth operation of the process
  • Test control system enhancements
  • Increase overall plant safety

This application package uses Mimic Advanced Modeling Objects for dynamic, real-time, first principles modeling. The Mimic Advanced Modeling Objects are part of the Mimic Advanced Modeling Objects License that adds sophisticated modeling objects into the Mimic Simulation Studio modeling palette. These Objects can be used on Mimic systems for application software testing or operator training. The Mimic Advanced Modeling Objects License provides:

  • Medium to High Fidelity Simulation Performance
  • Rigorous First Principles process modeling using proven dynamic, real-time modeling methods
  • Modeling objects based on Unit Operations
  • Block to block communications of all parameters with one connection using Mimic Streams
  • Easy handling of individual stream component physical properties using Mimic Component Sets
  • Mimic OTM Process Snapshot support
  • Mimic OPC Server Access to all model parameters
  • Mimic OPC Bridge Communication with external Control Systems

Diesel Hydrotreater Unit Dynamic Simulation

Mimic Dynamic Simulation for a Diesel Hydrotreater Units provides accurate, real-time I/O updates to the off-line control system. The simulation consists of a collection of real-time, dynamic, first principles unit operation models configured to respond closely to the actual operations of the user’s facility. The MYNAH application package for DHT units includes dynamic models of the complete process unit including the following unit operations:

  • Feed mixing, surge drum, and preheating from FCCU (or Coker) and Crude Unit feed streams
  • Desulferization Reactors
  • Multi-bed Hydrotreater Reactor
  • Product Separation and Stripper Columns
  • H2S Absorption and Waste / Recycle Gas Compression
  • Utilities and lube oil systems

The model will be configured to match the design of the actual installed DHT unit. Stream data will be tuned to match the actual feed and product of the installed DHT unit. Prior to Model Acceptance Test the entire simulation will be tuned to meet the actual running plant performance data or projected plant design performance data.

Mimic Explorer showing complete process unit modeling of the DHT Unit

Hydrotreater and Desulferization Reactor Models

The hydrotreaters and desulferization reactors are rigorously modeled using Mimic's Advanced Modeling Reactor Object. Included in this model are the following capabilities:

  • Dynamic real time mass and energy balances
  • Dynamic Vapor Liquid Equilibrium Balance accounting for reaction mixture interaction with external streams, chemical transformations due to the reaction kinetics
  • Configurable equation of state activities and enthalpy correction factors to account for mixture non-idealities
  • Reaction modeling using the Power law dependencies with the Arrhenius type equation for reaction rate constants.
  • Tunable reaction rate constants (Activation energy, Pre-exponential factor, and reaction order for the species) for both, forward and reverse reactions
DHT Unit reactors in Mimic Simulation Studio showing the Multi-bed Hydrotreater and DHT Reactor

Instructor Station Environment

The Mimic Component Studio instructor station graphic allows full control of the dynamic Diesel Hydrotreater Unit simulation with a block flow diagram view of the major components of the process and easy-to-use process controls. The following instructor controls include:

  • Feed composition, flow rate, temperature and pressure along with other boundary conditions
  • Control of valve failures for ad-hoc driven scenarios
  • Process Snapshot controls for full-steady state and circulation of the catalyst
  • Operator training session scenarios used to train and score student operators
DHT Unit Instructor Station Graphic in Mimic Component Studio

Mimic Dynamic Simulation Application Packages

Mimic Dynamic Simulation Application Packages provide an excellent return on investment for plants training and operation budgets. Unlike other dynamic simulation technologies, they are:

  • Built for Operator Training and Control System Optimization. Because the dynamic simulation is built using Mimic Simulation Software, it fully supports operator training and configuration testing with any process control system environment. Mimic Simulated IO Drivers are non-intrusive and high performance, allowing IO simulation of any open process control system.
  • Easy to Customize and Modify. Mimic Operator Training Packages use Mimic Simulation Software Advanced Modeling Objects to deliver high-fidelity, dynamic process models. There is no hidden configuration in the solution. The user can easily modify the model to make it reflect the design of their plant design. The user can also add training scenarios and process snapshots as needed without limit.
  • Able to Work with Any Process Control System. Mimic models work directly with Mimic base level models and the Mimic Simulated IO System. This allows easy-to-maintain, accurate simulation of IO and control modules and provides real-time updates to the off-line control system.
  • Flexible, Powerful and Dynamic. The package is based upon Mimic Simulation Software; it is scalable from very small simulations to very large ones in the same software license. Mimic's multi-threaded simulation engine allows the fastest real-time performance of any simulation offering while still delivering accurate, dynamic simulations for a realistic operator experience at the control system operator station.
  • Scalable to Cloud Base Architecture. MYNAH Technologies is the industry leader in delivering cloud based dynamic simulation systems based upon VMWare Virtualization Technology. MYNAH's Virtual Dynamic Simulators offer breakthrough flexibility and performance unavailable in legacy simulation architectures.
MYNAH’s Virtual Dynamic Simulator brings the benefits of Cloud Based Computing to operator training systems

The Diesel Hydrotreater Application package is an excellent platform for refinery operations managers to optimize their automation platform and address their operator training needs. Mimic Simulation Software is an enabling technology that addresses the needs of the energy industry process operators (see the Business Case for the Virtual Plant).

Ordering Information:

For a quotation or more information on Mimic Dynamic Simulation for Diesel Hydrotreater Units, contact MYNAH Technologies at +1.636.728.2000 or