Application of Predictive Feedforward Compensator to Microalgae Production in a Raceway Reactor: A Simulation Study

Abstract

Abstract:In this work, the evaluation of a predictive feedforward compensator is provided in order to highlight its most important advantages and drawbacks. The analyzed technique has been applied to microalgae production process in a raceway photobioreactor. The evaluation of the analyzed disturbance rejection schemes were performed through simulation, considering a nonlinear process model, whereas all controllers were designed using linear model approximations resulting in a realistic evaluation scenario. The predictive feedforward disturbance compensator was coupled with two feedback control techniques, PID (Proportional-Integral-Derivative) and MPC (Model Predictive Control) that are widely used in industrial practice. Moreover, the classical feedforward approach has been used for the purpose of comparison. The performance of the tested technique is evaluated with different indexes that include control performance measurements as well as biomass production performance. The application of the analyzed compensator to microalgae production process allows us to improve the average photosynthesis rate about 6% simultaneously reducing the energy usage about 4%.

Propagation of Inoculum for Haematococcus pluvialis Microalgae Scale-Up Photobioreactor Cultivation System

“…The main environmental factors ensuring that the process of photosynthesis in microalgae proceeds satisfactorily is light (sunlight or artificial light), temperature, and pH [16].…”

Evaluation of an Interpolated Controller in an Industrial Photobioreactor

“…The influence of solar irradiance on the culture pH will be considered as an input disturbance as has been motivated in previous works [14]; in general, except for occasionally fast changes due to cloud cover variability, the response of pH to this disturbance is very slow, in comparison with its response to controlled CO 2 injections [16], [17]. In this work, it is assumed that the integral action of the controller will compensate the effect of this disturbance due to the solar irradiance.…”

“…In the literature, different strategies have been used to manipulate the CO 2 in order to regulate pH in photobioreactors. From single on-off controllers [10] to predictive control algorithms, [11]- [14], event-based control approaches, [15]- [17], model-free solutions [18], PID with feedforward controllers [19], PID with filter for robustness using dynamic compensation based on Wiener Models controllers [20], and Active Disturbance Rejection Controllers (ADRC) [21]. The non-linear dynamic and the presence of actuator saturation (due to the use of a valve for CO 2 injection) for this process suggest the use of advanced control strategies.…”

Biomass estimation of an industrial raceway photobioreactor using an extended Kalman filter and a dynamic model for microalgae production

“…The photobioreactor, as showed in Fig. 1a, consists of two channels of 50 m length each and connected by U-shaped bends (180°), with a sump of 0.59 m 3 (0.65 m long × 0.90 m wide × 1 m deep) where air or CO 2 are automatically injected to control the dissolved oxygen and pH of the culture [19][20][21]. The culture is circulated by a paddle-wheel of 1.2 m diameter.…”