Software sensor design for COD estimation in an anaerobic fluidized bed reactor

In this paper, a method for unknown input estimation in stochastic system is presented. A key problem in bioprocess systems is the absence, in some cases, of reliable on-line measurements for real time monitoring applications. In this paper, a software sensor for an anaerobic digester is presented. Unmeasured components of the influent are estimated from available on-line measurements. Unknown input Kalman filter is discussed to estimate the state and unknown input of the process. First, the theory of unknown inputs optimal filtering in the stochastic case is exposed and a design procedure is proposed. The observer is applied to an anaerobic fluidized bed reactor to estimate the variations in Chemical Oxygen Demand (COD) concentration and experimental results are presented.

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On-line automatic control system for monitoring an anaerobic fluidized-bed reactor: response to organic overload

Water Science & Technology ◽

10.2166/wst.1994.0572 ◽

1994 ◽

Vol 30 (12) ◽

pp. 11-20 ◽

Cited By ~ 29

Author(s):

René Moletta ◽

Yves Escoffier ◽

Frédéric Ehlinger ◽

Jean-Pierre Coudert ◽

Jean-Pierre Leyris

Keyword(s):

Control System ◽

Automatic Control ◽

Fluidized Bed ◽

Automatic Control System ◽

Biological Process ◽

Biogas Production ◽

Fluidized Bed Reactor ◽

On Line ◽

Anaerobic Fluidized Bed Reactor ◽

And Control

The aim of this study was to develop an automatic system based on selected parameters collected from the biological process to control a fluidized-bed reactor. In the first part of this study, identification of parameters sensitive to overloads was carried out with vinasses as wastewater. From these results, three parameters, considered as the most realistic for the monitoring of the reactor, were selected: pH in the liquid phase, the biogas production and its concentration of dihydrogen. These were used to develop an algorithm based on expert system principle. This automatic control system calculated the flow rate of the feeding pump in order to adjust continuously the load applied to the reactor. The system was used to monitor and control several kinds of overload in an anaerobic fluidized bed reactor, of laboratory and pilot scales. The strategy used was able to operate automatically the digesters.

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Anaerobic fluidized bed reactor application to tropical fruit wine effluent

Water Science & Technology ◽

10.2166/wst.2007.469 ◽

2007 ◽

Vol 56 (2) ◽

pp. 33-38 ◽

Cited By ~ 10

Author(s):

N. Fernández ◽

S. Montalvo ◽

L. Guerrero ◽

E. Sánchez ◽

I. Cortés ◽

...

Keyword(s):

Fluidized Bed ◽

Particle Diameter ◽

Oxygen Demand ◽

Fluidized Bed Reactor ◽

Organic Loading Rate ◽

Tropical Fruit ◽

Fruit Wine ◽

Support Medium ◽

Anaerobic Fluidized Bed Reactor ◽

Reactor Application

The influence of the organic loading rate (OLR), the fluidization level (FL) and the particle diameter of natural zeolite used as support (DP), was evaluated at a laboratory scale anaerobic fluidized bed reactor (AFBR), treating tropical fruit wine effluent (vinasse). The experiment was carried out at an OLR from 2–5 kg COD/m3 d, FL of 20 and 40% and DP from 0.25 to 0.80 mm. It was demonstrated that OLR and FL had a slight influence on chemical oxygen demand removal and strong influence on the methane production rate. The COD removal was slightly higher for the higher particle diameter used. Additionally using the scanning electron microscope (SEM), it was observed that natural zeolites have excellent physical characteristics as a support medium in AFBR.

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