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Papers by Elisabetta Brunazzi

Research paper thumbnail of The GX Fiber Bed – A Novel Mist Eliminator with Improved Aerosol Removal Performances

Undesired aerosol formation in gas–liquid contact devices like for instance absorbers, quench coo... more Undesired aerosol formation in gas–liquid contact devices like for instance absorbers, quench coolers, or condensers, causes severe complications in industrial processes. Gas-liquid coalescing filter media, normally called fiber beds or candles filters, have received great attention in a wide variety of industrial applications, being a removal technology with one of the highest achievable droplet removal efficiency for submicron particles. This work deals with a novel multi-layer fiber bed, the GX mist eliminator, developed by AWS Corporation srl with improved performances compared to the conventional single-layer fiber bed commercialized by the Company. The novel fiber bed was conceived by means of a developed design model that takes into account constructional and operating parameters. The model was validated by experiments carried out on a lab scale unit. The performances of the novel fiber bed were then validated by experiments carried out in a pilot plant installed on a product...

Research paper thumbnail of Biomethane production: Mass and Energy Balances of Alternative Supply Chains

Industrial & Engineering Chemistry Research

Two supply chains for biomethane are here analyzed and modeled: gasification of short rotation fo... more Two supply chains for biomethane are here analyzed and modeled: gasification of short rotation forestry (SRF) poplar wood chips and anaerobic digestion of two species of microalgae, Chlorella vulgaris, and Nannochloropsis gaditana. Mass and energy balances are carried out along the whole systems, from the cultivation step to the stages of upgrading and injection into gas grid. A simulation model is employed to obtain gasification and upgrading parameters, energy requirements, and CO2 emission. Harvesting of microalgae requires high inputs of energy and fertilizers, while syngas upgrading is more demanding than biogas treatment, as high volumes of water and CO2 must be separated. Yields of the supply chains are very different: 7:1 biomethane:syngas ratio and 2:1 biomethane:biogas ratio have been estimated. Both of the supply chains could be optimized by using heat recovery methods. The highest removal of CO2 and steam can be attained through absorption by triethylene and monoethanolamine solution, respecti...

Research paper thumbnail of Macro-instabilities in Eccentrically Agitated Vessels

Laser Doppler anemometry and flow visualisation are used to shed light into the main turbulent fl... more Laser Doppler anemometry and flow visualisation are used to shed light into the main turbulent flow features of an unbaffled vessel stirred by an eccentrically positioned Rushton turbine. Two main vortices, one above and one below the impeller, are present and the former vortex dominates the flow field, driving a strong circumferential flow around it. The vortices are not steady but oscillate slowly and periodically inducing a kind of flow instabilities, which may have a significant impact on macro-mixing. The characteristic frequencies of such flow instabilities were found to increase with reducing the impeller blade thickness, thus it is argued that their origin is related to the interaction between the impeller discharged stream and the vessel wall/bottom. 1.

Research paper thumbnail of Special Issue Distillation and Absorption

Research paper thumbnail of Rottura della simmetria in un micro-mescolatore a T

Research paper thumbnail of Experimental investigation of reactive distillation packing Katapak®-SP11: hydrodynamic aspects and size effects

This paper presents the results of an experimental study carried out to examine the hydraulic beh... more This paper presents the results of an experimental study carried out to examine the hydraulic behaviour of Katapak-SP11, a new structured catalytic packing of Sulzer Chemtech. Liquid holdup, dry and wet pressure drop, gas capacity and loading of two sizes of packing have been measured using the air-water system at ambient conditions. The experimental results collected are useful for supporting theoretical developments in hydrodynamic modelling and analysis of scale up issues. Data have been used to derive a set of correlation equations to describe the above quantities in terms of gas and liquid loads.

Research paper thumbnail of Experimental and numerical analyses of unsteady flow regimes and mixing in a micro T-mixer

Research paper thumbnail of Unsteady flow features in a T-shaped micro-mixer

Research paper thumbnail of Flow transitions and instabilities stemming from clearance variations in stirred vessels. Paper to be presented to the ICheaP-6

Research paper thumbnail of Modeling the hydrodynamics of last-generation catalytic structured packings

Modern catalytic structured packings offer a uniform catalyst support where catalyst particles ca... more Modern catalytic structured packings offer a uniform catalyst support where catalyst particles can be embedded thus combining its features with the well-known advantages of a structured packing (high capacity and high mass-transfer efficiency). In this work, the hydrodynamic properties of a novel family of catalytic structured packings (KATAPAK-SP) have been modeled using a modified version of a hydraulic model originally proposed by Hoffmann et al. for MULTIPAK. Modifications to the model included: (1) the adaptation of a more suitable liquid holdup correlation for the open channels, and (2) the use of a different split factor for the liquid flowing through the catalyst bags and the open channels. 1. Hoffmann et al., Chem. Eng. Proc., 43, 383 (2004).

Research paper thumbnail of Implementation of an Industry 4.0 system to optimally manage chemical plant operation

Research paper thumbnail of Steady and unsteady regimes in a T-shaped micro-mixer: Synergic experimental and numerical investigation

Chemical Engineering Journal

Research paper thumbnail of Measurement of liquid hold-up in catalytic structured packings: comparison of different experimental techniques

Research paper thumbnail of On the problems of solvent recovery from printing processes

Research paper thumbnail of Optimized design of obstacle sequences for microfluidic mixing in an inertial regime

Lab on a Chip

A fast method for designing optimal sequences of passive mixing units is provided for inertial fl... more A fast method for designing optimal sequences of passive mixing units is provided for inertial flows. Intense mixing is achieved through highly-controlled stretching of the fluid contact surfaces.

Research paper thumbnail of A Study on the Effect of Flow Unsteadiness on the Yield of a Chemical Reaction in a T Micro-Reactor

Micromachines

Despite the very simple geometry and the laminar flow, T-shaped microreactors have been found to ... more Despite the very simple geometry and the laminar flow, T-shaped microreactors have been found to be characterized by different and complex steady and unsteady flow regimes, depending on the Reynolds number. In particular, flow unsteadiness modifies strongly the mixing process; however, little is known on how this change may affect the yield of a chemical reaction. In the present work, experiments and 3-dimensional numerical simulations are carried out jointly to analyze mixing and reaction in a T-shaped microreactor with the ultimate goal to investigate how flow unsteadiness affects the reaction yield. The onset of the unsteady asymmetric regime enhances the reaction yield by more than 30%; however, a strong decrease of the yield back to values typical of the vortex regime is observed when the flow undergoes a transition to the unsteady symmetric regime.

Research paper thumbnail of The role of flow features and chemical kinetics on the reaction yield in a T-shaped micro-reactor

Chemical Engineering Journal

Research paper thumbnail of A multi-layered view of chemical and biochemical engineering

Chemical Engineering Research and Design

Research paper thumbnail of Optimally Managing Chemical Plant Operations: An Example Oriented by Industry 4.0 Paradigms

Industrial & Engineering Chemistry Research

Research paper thumbnail of Unsteady flow regimes in a T-shaped micro-mixer: mixing and characteristic frequencies

Industrial & Engineering Chemistry Research

Research paper thumbnail of The GX Fiber Bed – A Novel Mist Eliminator with Improved Aerosol Removal Performances

Undesired aerosol formation in gas–liquid contact devices like for instance absorbers, quench coo... more Undesired aerosol formation in gas–liquid contact devices like for instance absorbers, quench coolers, or condensers, causes severe complications in industrial processes. Gas-liquid coalescing filter media, normally called fiber beds or candles filters, have received great attention in a wide variety of industrial applications, being a removal technology with one of the highest achievable droplet removal efficiency for submicron particles. This work deals with a novel multi-layer fiber bed, the GX mist eliminator, developed by AWS Corporation srl with improved performances compared to the conventional single-layer fiber bed commercialized by the Company. The novel fiber bed was conceived by means of a developed design model that takes into account constructional and operating parameters. The model was validated by experiments carried out on a lab scale unit. The performances of the novel fiber bed were then validated by experiments carried out in a pilot plant installed on a product...

Research paper thumbnail of Biomethane production: Mass and Energy Balances of Alternative Supply Chains

Industrial & Engineering Chemistry Research

Two supply chains for biomethane are here analyzed and modeled: gasification of short rotation fo... more Two supply chains for biomethane are here analyzed and modeled: gasification of short rotation forestry (SRF) poplar wood chips and anaerobic digestion of two species of microalgae, Chlorella vulgaris, and Nannochloropsis gaditana. Mass and energy balances are carried out along the whole systems, from the cultivation step to the stages of upgrading and injection into gas grid. A simulation model is employed to obtain gasification and upgrading parameters, energy requirements, and CO2 emission. Harvesting of microalgae requires high inputs of energy and fertilizers, while syngas upgrading is more demanding than biogas treatment, as high volumes of water and CO2 must be separated. Yields of the supply chains are very different: 7:1 biomethane:syngas ratio and 2:1 biomethane:biogas ratio have been estimated. Both of the supply chains could be optimized by using heat recovery methods. The highest removal of CO2 and steam can be attained through absorption by triethylene and monoethanolamine solution, respecti...

Research paper thumbnail of Macro-instabilities in Eccentrically Agitated Vessels

Laser Doppler anemometry and flow visualisation are used to shed light into the main turbulent fl... more Laser Doppler anemometry and flow visualisation are used to shed light into the main turbulent flow features of an unbaffled vessel stirred by an eccentrically positioned Rushton turbine. Two main vortices, one above and one below the impeller, are present and the former vortex dominates the flow field, driving a strong circumferential flow around it. The vortices are not steady but oscillate slowly and periodically inducing a kind of flow instabilities, which may have a significant impact on macro-mixing. The characteristic frequencies of such flow instabilities were found to increase with reducing the impeller blade thickness, thus it is argued that their origin is related to the interaction between the impeller discharged stream and the vessel wall/bottom. 1.

Research paper thumbnail of Special Issue Distillation and Absorption

Research paper thumbnail of Rottura della simmetria in un micro-mescolatore a T

Research paper thumbnail of Experimental investigation of reactive distillation packing Katapak®-SP11: hydrodynamic aspects and size effects

This paper presents the results of an experimental study carried out to examine the hydraulic beh... more This paper presents the results of an experimental study carried out to examine the hydraulic behaviour of Katapak-SP11, a new structured catalytic packing of Sulzer Chemtech. Liquid holdup, dry and wet pressure drop, gas capacity and loading of two sizes of packing have been measured using the air-water system at ambient conditions. The experimental results collected are useful for supporting theoretical developments in hydrodynamic modelling and analysis of scale up issues. Data have been used to derive a set of correlation equations to describe the above quantities in terms of gas and liquid loads.

Research paper thumbnail of Experimental and numerical analyses of unsteady flow regimes and mixing in a micro T-mixer

Research paper thumbnail of Unsteady flow features in a T-shaped micro-mixer

Research paper thumbnail of Flow transitions and instabilities stemming from clearance variations in stirred vessels. Paper to be presented to the ICheaP-6

Research paper thumbnail of Modeling the hydrodynamics of last-generation catalytic structured packings

Modern catalytic structured packings offer a uniform catalyst support where catalyst particles ca... more Modern catalytic structured packings offer a uniform catalyst support where catalyst particles can be embedded thus combining its features with the well-known advantages of a structured packing (high capacity and high mass-transfer efficiency). In this work, the hydrodynamic properties of a novel family of catalytic structured packings (KATAPAK-SP) have been modeled using a modified version of a hydraulic model originally proposed by Hoffmann et al. for MULTIPAK. Modifications to the model included: (1) the adaptation of a more suitable liquid holdup correlation for the open channels, and (2) the use of a different split factor for the liquid flowing through the catalyst bags and the open channels. 1. Hoffmann et al., Chem. Eng. Proc., 43, 383 (2004).

Research paper thumbnail of Implementation of an Industry 4.0 system to optimally manage chemical plant operation

Research paper thumbnail of Steady and unsteady regimes in a T-shaped micro-mixer: Synergic experimental and numerical investigation

Chemical Engineering Journal

Research paper thumbnail of Measurement of liquid hold-up in catalytic structured packings: comparison of different experimental techniques

Research paper thumbnail of On the problems of solvent recovery from printing processes

Research paper thumbnail of Optimized design of obstacle sequences for microfluidic mixing in an inertial regime

Lab on a Chip

A fast method for designing optimal sequences of passive mixing units is provided for inertial fl... more A fast method for designing optimal sequences of passive mixing units is provided for inertial flows. Intense mixing is achieved through highly-controlled stretching of the fluid contact surfaces.

Research paper thumbnail of A Study on the Effect of Flow Unsteadiness on the Yield of a Chemical Reaction in a T Micro-Reactor

Micromachines

Despite the very simple geometry and the laminar flow, T-shaped microreactors have been found to ... more Despite the very simple geometry and the laminar flow, T-shaped microreactors have been found to be characterized by different and complex steady and unsteady flow regimes, depending on the Reynolds number. In particular, flow unsteadiness modifies strongly the mixing process; however, little is known on how this change may affect the yield of a chemical reaction. In the present work, experiments and 3-dimensional numerical simulations are carried out jointly to analyze mixing and reaction in a T-shaped microreactor with the ultimate goal to investigate how flow unsteadiness affects the reaction yield. The onset of the unsteady asymmetric regime enhances the reaction yield by more than 30%; however, a strong decrease of the yield back to values typical of the vortex regime is observed when the flow undergoes a transition to the unsteady symmetric regime.

Research paper thumbnail of The role of flow features and chemical kinetics on the reaction yield in a T-shaped micro-reactor

Chemical Engineering Journal

Research paper thumbnail of A multi-layered view of chemical and biochemical engineering

Chemical Engineering Research and Design

Research paper thumbnail of Optimally Managing Chemical Plant Operations: An Example Oriented by Industry 4.0 Paradigms

Industrial & Engineering Chemistry Research

Research paper thumbnail of Unsteady flow regimes in a T-shaped micro-mixer: mixing and characteristic frequencies

Industrial & Engineering Chemistry Research