New method dynamically models hydrocarbon fractionation

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Hydrocarbon Processing

OSTI ID:122682

Kesler, M G; Weissbrod, J M; Sheth, B V ^[1]

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1. Kesler Engineering, East Brunswick, NJ (United States)

A new method for calculating distillation column dynamics can be used to model time-dependent effects of independent disturbances for a range of hydrocarbon fractionation. It can model crude atmospheric and vacuum columns, with relatively few equilibrium stages and a large number of components, to C{sub 3} splitters, with few components and up to 300 equilibrium stages. Simulation results are useful for operations analysis, process-control applications and closed-loop control in petroleum, petrochemical and gas processing plants. The method is based on an implicit approach, where the time-dependent variations of inventory, temperatures, liquid and vapor flows and compositions are superimposed at each time step on the steady-state solution. Newton-Raphson (N-R) techniques are then used to simultaneously solve the resulting finite-difference equations of material, equilibrium and enthalpy balances that characterize distillation dynamics. The important innovation is component-aggregation and tray-aggregation to contract the equations without compromising accuracy. This contraction increases the N-R calculations` stability. It also significantly increases calculational speed, which is particularly important in dynamic simulations. This method provides a sound basis for closed-loop, supervisory control of distillation--directly or via multivariable controllers--based on a rigorous, phenomenological column model.

• OSTI ID: 122682
• Journal Information: Hydrocarbon Processing, Journal Name: Hydrocarbon Processing Journal Issue: 10 Vol. 74; ISSN HYPRAX; ISSN 0018-8190
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
ALGORITHMS
CALCULATION METHODS
DISTILLATION EQUIPMENT
ENERGY BALANCE
EXPERIMENTAL DATA
FLUID MECHANICS
FRACTIONATION
HYDROCARBONS
MATERIAL BALANCE
MATHEMATICAL LOGIC
MATHEMATICAL MODELS
NATURAL GAS PROCESSING PLANTS
PETROLEUM REFINERIES
PROCESS CONTROL