36 research outputs found
InputOutput Linearizing Control Strategy for an Ethylene Dichloride Cracking Furnace Using a Coupled PDE-ODE Model
No full textNonlinear Optimization-Based Robust Control Approach for a Two-Stage Anaerobic Digestion Process
No full textA two-stage anaerobic digestion (AD) process has been applied to improve the efficiency of methane production from various organic materials. However, the performance of traditional process controllers may be limited by differences in the rate of biochemical reactions, process uncertainties, and the consequences of interconnection between the two bioreactors. In this work, a nonlinear optimization-based control strategy that applies an analytical model predictive control (AMPC) scheme with an adaptive optimal set-point is proposed for the control of the two-stage AD system. The objectives of the proposed control system are to stabilize the system under uncertain operating conditions and maximize biomethane production. The optimal set-points for the controller are adapted in real-time operation, and then the control system is performed to manipulate the controlled output to the optimal trajectories. Compensators and nonlinear state observers are applied to handle the process/model mismatch and estimate unmeasured variables. The proposed control system is applied to the process with disturbances, fluctuations of inlet stream concentrations, and changes in the bacterial growth rate, and the control performance is investigated. Simulation results show that the developed control scheme automatically adjusts the optimal set-points and provides adequate control actions to maintain the maximum rate of methane production. The results of this investigation demonstrate that the control strategy promotes different biochemical reactions, avoids the inhibition effect, and handles the mutual effects between acidogenic and methanogenic bioreactors for methane production effectively
Control of Ethylene Dichloride Cracking Furnace Using an Analytical Model Predictive Control Strategy for a Coupled Partial Differential Equation/Ordinary Differential Equation System
No full textInput–Output Linearizing Control Strategy for an Ethylene Dichloride Cracking Furnace Using a Coupled PDE-ODE Model
No full textAn
input–output (I/O) linearizing control scheme for a gas-fired
thermal cracking furnace is developed for a tubular reactor coil,
which is a type of tubular reactor surrounded by gas-fired burners
in the furnace. Due to the simultaneous interaction between the spatially
distributed dynamics of the reactor coil and the lumped radiating
wall, the typical proportional-integral-derivative control widely
used in industry may have insufficient performance to handle the complexity.
In this work, a feedback I/O linearizing controller is applied to
control a cracking furnace system that is described by a coupled PDE-ODE
model: ethylene dichloride cracking. The cracked gas temperature is
manipulated through the fuel gas flow to achieve the desired trajectories.
Control performances of the developed controller are illustrated through
simulation results for servo and regulatory problems. The proposed
method provides more robustness to handle control problems without
offset
Model-Based Control for Fed-Batch Enzymatic Hydrolysis Reactor of Lignocellulosic Biomass
No full textOptimization-Based Input/Output Linearizing Control Strategy for a pH Process with Multiple Titrant Streams
No full text
Model-based estimation and control of interface level in a two-phase vertical decanter: A case study of palm-oil/water system
No full textControl of Ethylene Dichloride Cracking Furnace Using an Analytical Model Predictive Control Strategy for a Coupled Partial Differential Equation/Ordinary Differential Equation System
No full textA nonlinear
optimization-based control system with analytical model
predictive control (AMPC) structure is formulated in cascade with
an off-line pseudo-steady-state calculator for an ethylene dichloride
(EDC) cracking furnace process described by a coupled partial differential
equation/ordinary differential equation model. The objective of the
proposed control system is to control the EDC cracking rate at the
desired set points by manipulating the fuel gas flow rate with constraints
to avoid extensive coke formation. To handle the complex behaviors
that are affected by radiating walls interacting with spatial dynamics
of the reactor coil, the set point calculator is employed to provide
an optimal target for the constrained optimization-based controller
in calculating the control actions. Simulation results show that the
proposed control system is successful to regulate the controlled output
at the desired set points. Control performance tests with servo and
regulatory problems demonstrate that the developed control system
is capable of providing excellent responses to achieve the desired
set point and reject process disturbance
