SPYRO for Planning and Scheduling (SPSL) simulates the steady-state cracking process inside the radiant coil(s) of a steam cracking furnace in ethylene plants. It is based upon a fundamental kinetic scheme of more than 3000 reactions, representing a chain reaction mechanism of 128 molecular species and 20 radical species. SPSL is designed for use in Planning and Scheduling applications.
The fundamental basis of the SPYRO program allows accurate prediction of several parameters, such as:
- Effluent yield composition
- Tube Skin Temperature
- Coke Buildup
- Absorbed Duty
- Coil Pressure Drop
- Coil Outlet Temperature
SPSL has the capability of calculating numerical derivatives to any input parameter (including feedstock composition) in the form of the following calculation:
Feedstocks from ethane up to heavy gas oil can be modelled in the SPYROprogram.
Given the basic geometry of the radiant coil (pyrolysis reactor), SPYRO can simulate the performance of nearly any type of radiant coil in commercial use today. The furnace geometry is configured by TECHNIP for each optimization project in the pre-commissioning stage.
The input parameters of SPSL include hydrocarbon flow rate, dilution steam ratio, coil inlet pressure, coil inlet temperature, coke thickness, feed composition and specific adjustment parameters.
In third party LP programs the user has to specify boundary conditions such as:
- Prices of feedstock and products (olefins and by-products)
- Upper and lower limits of feedstock and product flow rates
- Objective functions such as minimum required production of a product.
- Plant operating constraints, such as flow, composition, pressure, etc.
- Furnace operating parameter windows, i.e. severity, DS-ratio, COP, etc.
Advantages of using SPSL:
- Run “What if” cases!
- Quick assessment of the operating conditions or profitability of a specific feedstock or blended feedstocks.
- Quick definition of optimal operating conditions
- Minimize the guessing; allow quick decisions by Planning and Scheduling engineers!