The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Riku Vahala - One of the best experts on this subject based on the ideXlab platform.

  • Shall we use hardware sensor measurements or soft-sensor estimates? Case study in a full-scale WWTP
    Environmental Modelling & Software, 2015
    Co-Authors: Henri Haimi, Francesco Corona, Michela Mulas, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    An array of data derived soft-sensors for estimating nitrate-nitrogen concentrations in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant have been designed in our earlier work. The array was designed to back up the existing hardware instrumentation in the process Unit. The importance of trustworthy information on nitrate-nitrogen concentrations is emphasized by their employment in control loops enhancing nitrogen removal. In this paper, we propose an automatic system for deciding whether the use of estimates or corresponding hardware measurements is preferable given the current condition in filters. The presented switching system is based on ranking the estimates and the measurements, and a preferability index that combines the assigned ranks. The ranking procedure employs a robust principal component analysis and statistics used as the measures of fit. The switching system was demonstrated to enable the employment of measurements and estimates in a complementary manner in operating the post-Filtration Unit. This study concerns data derived soft-sensors and corresponding hardware measurements.The soft-sensors estimate nitrate concentration in the tertiary filters of a WWTP.A system for deciding whether to use estimates or hardware measurements is proposed.The switching system is based on ranking the estimates and the measurements.The system allows the use of estimates and measurements in a complementary manner.

  • Monitoring nitrate concentrations in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant
    Journal of Process Control, 2013
    Co-Authors: Francesco Corona, Henri Haimi, Michela Mulas, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    Abstract Due to stringent environmental regulations, wastewater treatment plants are always challenged to meet new constraints in terms of water pollution prevention. In such an effort, the number of sensors and data available in the plants have increased considerably during the last decades. However, the quality of the collected data and the sensor reliability are often poor mainly due to the hostile environment in which the measurement equipment has to function. In this work, we present the design of an array of soft-sensors to estimate the nitrate concentration in the post-denitrification filter Unit of the Viikinmaki wastewater treatment plant in Helsinki (Finland). The developed sensors aim at supporting the existing hardware analyzers by providing a reliable back-up system in case of malfunction. The main stages of the soft-sensors’ design are discussed and the development illustrated in detail, starting from the preliminary preprocessing of the available process measurements where sample and variable selection has been performed, toward the calibration of the regression models and discussion on the performance results. The estimation accuracy together with the light computational cost of the developed soft-sensors demonstrate their potential for an on-line implementation in the plant's control system.

  • Nitrate estimation in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant: The Viikinmäki case
    Water science and technology : a journal of the International Association on Water Pollution Research, 2012
    Co-Authors: Michela Mulas, Henri Haimi, Francesco Corona, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    In this work we present and discuss the design of an array of soft-sensors to estimate the nitrate concentration in the denitrifying post-Filtration Unit at the Viikinmaki wastewater treatment plant in Helsinki (Finland). The developed sensors aim at supporting the existing hardware analyzers by providing a reliable back-up system in case of malfunction of the instruments. In the attempt to design easy to implement and interpretable sensors, computationally light linear models have been considered. However, due to the intrinsic nonlinearity of the process, also nonlinear but still computationally affordable models have been considered for comparison. The experimental results demonstrate the potential of the developed soft-sensors and the possibility for an on-line implementation in the plant's control system as alternative monitoring devices.

François Broust - One of the best experts on this subject based on the ideXlab platform.

  • Understanding the Secondary Reactions of Flash Pyrolysis Vapors inside a Hot Gas Filtration Unit
    Energy & Fuels, 2017
    Co-Authors: Miguel Ruiz, Eric Martin, Joël Blin, Laurent Van De Steene, François Broust
    Abstract:

    Ex situ hot gas Filtration (HGF) has been shown to be a simple and robust technique to upgrade the quality of flash pyrolysis oils. In this study, the secondary reactions inside the HGF Unit and their impact on product yields and the chemical composition of bio-oils were investigated in a total of 18 experiments conducted at both pilot and bench reactor scales (1 and 0.1 kg/h), with beech wood (BW) and sunflower stalks (SFS). The impact of HGF on yields was found to be dependent on the extent of secondary reactions which, in turn, were determined by three parameters: (a) HGF temperature, (b) HGF char cake thickness, and (c) AAEM content of the raw feedstock. Nevertheless, independently of the conditions used, the drop in the organic yield was less than 10 wt % with both BW and SFS feedstocks. Our results demonstrated that (1) cracking reactions mainly took place in the homogeneous gas phase and (2) dehydration, coking, and decarboxylation reactions took place in the HGF char cake, probably catalyzed by th...

Francesco Corona - One of the best experts on this subject based on the ideXlab platform.

  • Shall we use hardware sensor measurements or soft-sensor estimates? Case study in a full-scale WWTP
    Environmental Modelling & Software, 2015
    Co-Authors: Henri Haimi, Francesco Corona, Michela Mulas, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    An array of data derived soft-sensors for estimating nitrate-nitrogen concentrations in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant have been designed in our earlier work. The array was designed to back up the existing hardware instrumentation in the process Unit. The importance of trustworthy information on nitrate-nitrogen concentrations is emphasized by their employment in control loops enhancing nitrogen removal. In this paper, we propose an automatic system for deciding whether the use of estimates or corresponding hardware measurements is preferable given the current condition in filters. The presented switching system is based on ranking the estimates and the measurements, and a preferability index that combines the assigned ranks. The ranking procedure employs a robust principal component analysis and statistics used as the measures of fit. The switching system was demonstrated to enable the employment of measurements and estimates in a complementary manner in operating the post-Filtration Unit. This study concerns data derived soft-sensors and corresponding hardware measurements.The soft-sensors estimate nitrate concentration in the tertiary filters of a WWTP.A system for deciding whether to use estimates or hardware measurements is proposed.The switching system is based on ranking the estimates and the measurements.The system allows the use of estimates and measurements in a complementary manner.

  • Monitoring nitrate concentrations in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant
    Journal of Process Control, 2013
    Co-Authors: Francesco Corona, Henri Haimi, Michela Mulas, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    Abstract Due to stringent environmental regulations, wastewater treatment plants are always challenged to meet new constraints in terms of water pollution prevention. In such an effort, the number of sensors and data available in the plants have increased considerably during the last decades. However, the quality of the collected data and the sensor reliability are often poor mainly due to the hostile environment in which the measurement equipment has to function. In this work, we present the design of an array of soft-sensors to estimate the nitrate concentration in the post-denitrification filter Unit of the Viikinmaki wastewater treatment plant in Helsinki (Finland). The developed sensors aim at supporting the existing hardware analyzers by providing a reliable back-up system in case of malfunction. The main stages of the soft-sensors’ design are discussed and the development illustrated in detail, starting from the preliminary preprocessing of the available process measurements where sample and variable selection has been performed, toward the calibration of the regression models and discussion on the performance results. The estimation accuracy together with the light computational cost of the developed soft-sensors demonstrate their potential for an on-line implementation in the plant's control system.

  • Nitrate estimation in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant: The Viikinmäki case
    Water science and technology : a journal of the International Association on Water Pollution Research, 2012
    Co-Authors: Michela Mulas, Henri Haimi, Francesco Corona, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    In this work we present and discuss the design of an array of soft-sensors to estimate the nitrate concentration in the denitrifying post-Filtration Unit at the Viikinmaki wastewater treatment plant in Helsinki (Finland). The developed sensors aim at supporting the existing hardware analyzers by providing a reliable back-up system in case of malfunction of the instruments. In the attempt to design easy to implement and interpretable sensors, computationally light linear models have been considered. However, due to the intrinsic nonlinearity of the process, also nonlinear but still computationally affordable models have been considered for comparison. The experimental results demonstrate the potential of the developed soft-sensors and the possibility for an on-line implementation in the plant's control system as alternative monitoring devices.

Henri Haimi - One of the best experts on this subject based on the ideXlab platform.

  • Shall we use hardware sensor measurements or soft-sensor estimates? Case study in a full-scale WWTP
    Environmental Modelling & Software, 2015
    Co-Authors: Henri Haimi, Francesco Corona, Michela Mulas, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    An array of data derived soft-sensors for estimating nitrate-nitrogen concentrations in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant have been designed in our earlier work. The array was designed to back up the existing hardware instrumentation in the process Unit. The importance of trustworthy information on nitrate-nitrogen concentrations is emphasized by their employment in control loops enhancing nitrogen removal. In this paper, we propose an automatic system for deciding whether the use of estimates or corresponding hardware measurements is preferable given the current condition in filters. The presented switching system is based on ranking the estimates and the measurements, and a preferability index that combines the assigned ranks. The ranking procedure employs a robust principal component analysis and statistics used as the measures of fit. The switching system was demonstrated to enable the employment of measurements and estimates in a complementary manner in operating the post-Filtration Unit. This study concerns data derived soft-sensors and corresponding hardware measurements.The soft-sensors estimate nitrate concentration in the tertiary filters of a WWTP.A system for deciding whether to use estimates or hardware measurements is proposed.The switching system is based on ranking the estimates and the measurements.The system allows the use of estimates and measurements in a complementary manner.

  • Monitoring nitrate concentrations in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant
    Journal of Process Control, 2013
    Co-Authors: Francesco Corona, Henri Haimi, Michela Mulas, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    Abstract Due to stringent environmental regulations, wastewater treatment plants are always challenged to meet new constraints in terms of water pollution prevention. In such an effort, the number of sensors and data available in the plants have increased considerably during the last decades. However, the quality of the collected data and the sensor reliability are often poor mainly due to the hostile environment in which the measurement equipment has to function. In this work, we present the design of an array of soft-sensors to estimate the nitrate concentration in the post-denitrification filter Unit of the Viikinmaki wastewater treatment plant in Helsinki (Finland). The developed sensors aim at supporting the existing hardware analyzers by providing a reliable back-up system in case of malfunction. The main stages of the soft-sensors’ design are discussed and the development illustrated in detail, starting from the preliminary preprocessing of the available process measurements where sample and variable selection has been performed, toward the calibration of the regression models and discussion on the performance results. The estimation accuracy together with the light computational cost of the developed soft-sensors demonstrate their potential for an on-line implementation in the plant's control system.

  • Nitrate estimation in the denitrifying post-Filtration Unit of a municipal wastewater treatment plant: The Viikinmäki case
    Water science and technology : a journal of the International Association on Water Pollution Research, 2012
    Co-Authors: Michela Mulas, Henri Haimi, Francesco Corona, Laura Sundell, Mari Heinonen, Riku Vahala
    Abstract:

    In this work we present and discuss the design of an array of soft-sensors to estimate the nitrate concentration in the denitrifying post-Filtration Unit at the Viikinmaki wastewater treatment plant in Helsinki (Finland). The developed sensors aim at supporting the existing hardware analyzers by providing a reliable back-up system in case of malfunction of the instruments. In the attempt to design easy to implement and interpretable sensors, computationally light linear models have been considered. However, due to the intrinsic nonlinearity of the process, also nonlinear but still computationally affordable models have been considered for comparison. The experimental results demonstrate the potential of the developed soft-sensors and the possibility for an on-line implementation in the plant's control system as alternative monitoring devices.

Miguel Ruiz - One of the best experts on this subject based on the ideXlab platform.

  • Understanding the Secondary Reactions of Flash Pyrolysis Vapors inside a Hot Gas Filtration Unit
    Energy & Fuels, 2017
    Co-Authors: Miguel Ruiz, Eric Martin, Joël Blin, Laurent Van De Steene, François Broust
    Abstract:

    Ex situ hot gas Filtration (HGF) has been shown to be a simple and robust technique to upgrade the quality of flash pyrolysis oils. In this study, the secondary reactions inside the HGF Unit and their impact on product yields and the chemical composition of bio-oils were investigated in a total of 18 experiments conducted at both pilot and bench reactor scales (1 and 0.1 kg/h), with beech wood (BW) and sunflower stalks (SFS). The impact of HGF on yields was found to be dependent on the extent of secondary reactions which, in turn, were determined by three parameters: (a) HGF temperature, (b) HGF char cake thickness, and (c) AAEM content of the raw feedstock. Nevertheless, independently of the conditions used, the drop in the organic yield was less than 10 wt % with both BW and SFS feedstocks. Our results demonstrated that (1) cracking reactions mainly took place in the homogeneous gas phase and (2) dehydration, coking, and decarboxylation reactions took place in the HGF char cake, probably catalyzed by th...