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ASPEN HYSYS SIMULATION-COURSE OUTLINE

Aspen HYSYS Simulation Module Simulation is the tool every process engineer should be conversant with. REALCHEM provides the necessary training for you to understand the simulation tool and help you to gain confidence to use it yourself. You can spend sufficient time learning and practicing the tool with guidance from REALCHEM.

Process Design and Simulation Process simulation is used for the design, development, analysis, and optimization of technical processes and is mainly applied to chemical plants and chemical processes, but also to power stations, and similar technical facilities. Process simulation is a model-based representation of chemical, physical, biological, and other technical processes and unit operations in software. Basic prerequisites are a thorough knowledge of chemical and physical properties of pure components and mixtures, of reactions, and of mathematical models which, in combination, allow the calculation of a process in computers. Aspen HYSYS is a comprehensive process modeling tool used by the world’s leading oil and gas producers, refineries, and engineering companies for process simulation and process optimization in design and operations. Why simulation software knowledge is important: For the design of various components in any plant/facility, Process Simulations are performed: •

To solve Mass and Energy Balance using in-built Mathematical Models.

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To obtain the Flow Rates, Compositions and Thermo Physical Properties of process streams at its various operating conditions.

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To Predict Phase behavior of Fluids. Simulations are also performed to detect abnormal conditions like:

• Formation of hydrates by hydrocarbons due to fall in Pressure & Temperature. •

Fall in temperature below Hydrocarbon or Water- Dew Point.

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Flashing of liquids across Control Valves or Drain Valves, etc.

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Condensation of Vapors due to cooling.

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Latent heat data required at relieving conditions (Temperature and Pressure) for Safety Valve Sizing calculations.

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Time behavior of inventory streams during Depressurization.

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Minimum temperatures during Venting from High Pressure Atmosphere, which may affect material selection upstream downstream of vent valve (inclusive).

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User can easily do steady state &dynamic process modeling in Aspen Hysys. Application of Steady state simulators: •

Process design (to determine the process conditions required to produce the desired product)

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Process equipment design (to size the equipment required to produce the desired product)

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Process design optimization (to determine the optimum configuration of equipment and maximize energy recovery)

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Process Optimization (to determine changes to the current operating conditions that can either reduce operating costs or Increase production).

Process simulation software describes processes in flow diagrams where unit operations are positioned and connected by product streams. The software has to solve the mass and energy balance to find a stable operating point. The goal of a process simulation is to find optimal conditions for an examined process. This is essentially an optimization problem which has to be solved in an iterative process. Process simulation always uses models which introduce approximations and assumptions but allow the description of a property over a wide range of temperatures and pressures which might not be covered by real data. Models also allow interpolation and extrapolation - within certain limits - and enable the search for conditions outside the range of known properties.

Modeling 2 | Page

The development of models for a better representation of real processes is the core of the further development of the simulation software. Model development is done on the chemical engineering side but also in control engineering and for the improvement of mathematical simulation techniques. Process simulation is therefore one of the few fields where scientists from chemistry, physics, computer science, mathematics, and several engineering fields work together. A lot of efforts are made to develop new and improved models for the calculation of properties. This includes for example the description of • Thermo physical properties like vapor pressures, viscosities, caloric data, etc. of pure components and mixtures • Properties of different apparatuses like reactors, distillation columns, pumps, etc. • Chemical reactions and kinetics • Environmental and safety-related data

Two main different types of models can be distinguished: 1. Rather simple equations and correlations where parameters are fitted to experimental data. 2. Predictive methods where properties are estimated. The equations and correlations are normally preferred because they describe the property (almost) exactly. To obtain reliable parameters it is necessary to have experimental data which are usually obtained from factual data banks or, if no data are publicly available, from measurements. Using predictive methods is much cheaper than experimental work and also than data from data banks. Despite this big advantage predicted properties are normally only used in early steps of the process development to find first approximate solutions and to exclude wrong pathways because these estimation methods normally introduce higher errors than correlations obtained from real data. Process simulation also encouraged the further development of mathematical models in the fields of numeric and the solving of complex problems.

History The history of process simulation is strongly related to the development of the computer science and of computer hardware and programming 3 | Page

languages. First working simple implementations of partial aspects of chemical processes have been made in the 1970 where, for the first time, suitable hardware and software (here mainly the programming languages FORTRAN and C) have been available. The modeling of chemical properties has been started already much earlier, notably the cubic equation of states and the Antoine equation are developments of the 19th century.

Steady state and dynamic process simulation Initially process simulation was used to simulate steady state processes. Steady-state models perform a mass and energy balance of a stationary process (a process in an equilibrium state) but any changes over time had to be ignored. Dynamic simulation is an extension of steady-state process simulation whereby time-dependence is built into the models via derivative terms i.e. accumulation of mass and energy. The advent of dynamic simulation means that that the time-dependent description, prediction and control of real processes in real time have become possible. This includes the description of starting up and shutting down a plant, changes of conditions during a reaction, holdups, thermal changes and more. Dynamic simulations require increased calculation time and are mathematically more complex than a steady state simulation. It can be seen as a multiply repeated steady state simulation (based on a fixed time step) with constantly changing parameters. Dynamic simulation can be used in both an online and offline fashion. The online case being model predictive control, where the real-time simulation results are used to predict the changes that would occur for a control input change, and the control parameters are optimized based on the results. Offline process simulation can be used in the design, troubleshooting and optimization of process plant as well as the conduction of case studies to assess the impacts of process modifications. The topics covered in this module are:

ASPEN HYSYS SIMULATION HRS (4 weeks) 1.1

Introduction to HYSYS Software

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DURATION: 48

1.2

HYSYS User Interface

1.3

Defining the Simulation Basis

1.4

Selecting a Unit Set

1.5

Adding a Stream

1.6

Flash Calculations

1.7

Adding Utilities

1.8

The Stream Property Value

1.10 Additional Exercises 1.11 Optimization in HYSYS 1.12 Set and Adjust Logic Operations 1.13 Flash Calculation 1.14 PFD Preparation 1.16 Oil Manager / Characterization 1.17 Pipe Sizing and Pressure Drop in HYSYS REALCHEM offers different courses for you to learn how to use Aspen HYSYS. If you want to work as a process engineer in any process engineering firm or any operation industry, then you should have good knowledge of “Aspen Hysys” software.

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