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December 02-03, 2019 | Dubai, UAE
Oil & Gas
2
nd
International Conference and Expo on
Journal of Industrial and Environmental Chemistry | Volume 3
A probablisitic approach for optimal operation of gas processing plant under
uncertain inlet-outlet conditions
Mesfin Getu
Heriot-Watt University Dubai Campus, UAE
N
atural gas plant operations contribute hugely to the
economies of many developed nations that depend
on hydrocarbon resources. The plant operation is usually
subjected to continuous variations in upstream conditions,
such as flow rate, composition, temperature and pressure,
which propagate through the plant and affect its stable
operations. As a result, decision making for optimal operating
conditions of an in-operation plant is a complex problem and
it is exacerbated with the changing product specifications
and variations in energy supplies. This work presents a
new solution method to the problem, which is based on
chance constrained optimization. A deterministic model
is initially developed from process simulation using Aspen
HYSYS and later converted to a chance constrained model.
The probabilistic model is then relaxed to its equivalent
deterministic form and solved for optimum solution using
GAMS. The optimum solution is determined probabilistically
using chance constraints that are held at a user-defined
confidence level. Optimal solution is represented graphically
as a trade-off between reliability of holding the process
constraints and profitability of the plant. Two case studies
are presented to demonstrate the newmethod. Optimization
results show that uncertainty of plant parameters significantly
affect the economic performance of the plant operation. The
solution approach developed in this work is able to increase
the reliability of maintaining the profit by more than 95%
confidence level. As a result, the risk of constraints violation is
reduced from more than 50% using the typical deterministic
optimization to less than 5% with the developed chance
constrained optimization model. In addition, the results
from this study indicate that the variation of material flow
from the plant inlet has greater impact by more than 86% on
profit change compared to variation from the plant outlet,
which is less than 2%. Senstivity analysis result show on
how to reduce the effect of N2, CO2 and C5+ by holding the
corresponding constraint at a certain confidence level. The
developed solution method can aid as guidelines to flexible
plant operation decision making for the in-operating plant
by satisfying all the process constraints at certain confidence
level.
e
:
m.g.woldetensay@hw.ac.ukJ Ind Environ Chem, Volume:3
DOI: 10.35841/2591-7331-C3-015