Joep Verwoerd - Academia.edu (original) (raw)
Papers by Joep Verwoerd
The sampling unit was mounted at the stack of the hazardous waste incinerator DTO 9. The Control ... more The sampling unit was mounted at the stack of the hazardous waste incinerator DTO 9. The Control and evaluation unit was installed nearby the mounted sampling unit. Dioxin emission measurements at concentrations of the legal limit (0.1 ng/m) were done with 8-hour monitoring period to enable measurement periods conform to the European standard EN 1948-part 1. Dioxin emission measurements at very low concentrations (below 0.01 ng/m) were done with 1week monitoring period to have the advantage of very low detection limits. Using 1-week monitoring time detection limits of 0.001 ng/m could be achieved. max. 30 m recommended Sampling Unit
Hazardous waste has very complicated chemical compositions in a variety of physical forms and is ... more Hazardous waste has very complicated chemical compositions in a variety of physical forms and is difficult to characterize. Due to the complex transport phenomena within the incinerator the incineration process expects large uncertainties in the process chemistry and thermal/ emission control. For better understanding of the incineration process, process simulation was conducted using Computational Fluid-dynamics (CFD) to characterize temperature and species distribution in the incinerator. Hazardous waste in various forms is firstly converted to a hydrocarbonbased virtual fuel mixture. The combustion of the simplified waste was then simulated with a global 3-gas and an extended 7-gas combustion model. The distribution of temperature and chemical species is broadly investigated. The predicted temperature distribution has been validated with available measurement data from the operating rotary kiln waste incinerator AVR-Chemie in the Netherlands. New statistical post-processing of the standard CFD-output has been developed to give an overview of the average temperature profile and overall reactor behavior as valuable contribution to process control. Finally, an attempt has been made to simulate the multi-phase flow of the shredded solid waste within the incinerator in order to optimize the burner design.
Rotary kilns are widely used for incineration of hazardous waste with complex chemical compositio... more Rotary kilns are widely used for incineration of hazardous waste with complex chemical compositions and physical forms. The solid waste used to be burnt through containers in the rotary kiln, which leads to serious process instability. Recently AVR-Chemie, a hazardous waste incineration company in the Netherlands has implemented a solid waste homogenisation plant where the containerised solid waste is shredded into small particles. The shredded solid waste is incinerated subsequently in the kiln so as to get better combustion efficiency and smoother process operation. It is obvious that the particle trajectory and the mixing of the solid particles with combustion air depend very much on the design and operation parameters. But the solid particle behaviour under current furnace and operating conditions is so far not clear. Thus, process simulation and optimisation are conducted to study the flow and mixing behaviour of the shredded solid waste so as to assist an optimal design of the feeding system. The current paper addresses the recent results in modelling the solid particle flow and mixing behaviour, by using computational fluid dynamics (CFD) technique. The knowledge gained will be used for the design optimisation in an industrial scale rotary kiln incinerator at AVR-Chemie.
Incineration is an excellent disposal technology for all waste materials with heat release potent... more Incineration is an excellent disposal technology for all waste materials with heat release potentials, and provides high degree of toxic destruction and control for a broad range of hazardous materials. In the Netherlands, the hazardous wastes in various forms are processed at AVR-Chemie located at the Rotterdam harbour, through rotary kiln incinerators. The newly enforced regulations from the European Union with stricter emission levels require a better understanding of the incineration process and improved process control. However, the transport phenomena and combustion processes within the kiln system are very complex and not well understood. In order to get better understanding of the incineration process within the rotary kiln system, research was carried out to study the fluid flow and combustion behaviour of the incineration system. Computational Fluid-dynamics (CFD) was used to simulate the waste combustion process, and temperature measurements of the operating rotary kiln incinerator were conducted to validate the CFD model and to provide the information to kiln operators at AVR. This paper will present the latest results from the current research project for the simulation of gas flow and mixing, and combustion heat transfer for a wide range of hazardous waste streams.
The rotary kiln for the incineration of hazardous waste is a poorly defined reactor, and is contr... more The rotary kiln for the incineration of hazardous waste is a poorly defined reactor, and is controlled in a feedback manner. To explore the feed-forward control possibilities research has been conducted to use computational fluid dynamics (CFD) as an off-line tool for simulating the waste incineration process. The standard CFD output has been specially post-processed and used to construct a structured database. The generation of the CFD database and linking the CFD predictions to the actual process control situation, are illustrated in the paper. The database generated will help the operator in making kiln-operating decisions and to improve the current process control.
Journal of Environmental Science and Health Part A-toxic/hazardous Substances & Environmental Engineering, 2005
Hazardous wastes have complex physical forms and chemical compositions and are normally incinerat... more Hazardous wastes have complex physical forms and chemical compositions and are normally incinerated in rotary kilns for safe disposal and energy recovery. In the rotary kiln, the multifeed stream and wide variation of thermal, physical, and chemical properties of the wastes cause the incineration system to be highly heterogeneous, with severe temperature fluctuations and unsteady combustion chemistry. Incomplete combustion is often the consequence, and the process is difficult to control. In this article, modeling of the waste combustion is described by using computational fluid dynamics (CFD). Through CFD simulation, gas flow and mixing, turbulent combustion, and heat transfer inside the incinerator were predicted and visualized. As the first step, the waste in various forms was modeled to a hydrocarbon-based virtual fuel mixture. The combustion of the simplified waste was then simulated with a seven-gas combustion model within a CFD framework. Comparison was made with previous global three-gas combustion model with which no chemical behavior can be derived. The distribution of temperature and chemical species has been investigated. The waste combustion model was validated with temperature measurements. Various operating conditions and the influence on the incineration performance were then simulated. Through this research, a better process understanding and potential optimization of the design were attained.
Progress in Computational Fluid Dynamics, 2007
Processing of hazardous waste in a rotary kiln incinerator is a complex process. Since hazardous ... more Processing of hazardous waste in a rotary kiln incinerator is a complex process. Since hazardous waste has often very complicated chemical compositions and physical forms, the transport phenomena within the incinerator are not well understood, and the incineration process expects large uncertainties in process chemistry and is difficult for emission control. For better understanding of the incineration process, various transport phenomena taking place in the rotary kiln were discussed and analysed in this paper. To get more quantitative understanding, process simulation was conducted by using Computational Fluid-Dynamics (CFD) to characterise gas and solid flow and mixing, temperature and species distribution in the incinerator. To include all the waste streams in a single CFD model is a difficult task, and how to define the different waste streams with different calorific values and chemical compositions is a challenge to the CFD modelling. In this study, hazardous waste in various forms is firstly converted to a hydrocarbon-based virtual fuel mixture based on an overall mass and energy balance. The combustion of the simplified waste was then simulated with a combustion model. The distribution of temperature and chemical species is broadly investigated under various conditions. The predicted temperature distribution has been validated with available measurement data from an operating rotary kiln waste incinerator, and reasonable agreement between the predicted and measured data has been reached. has written a book 'Metrics of Material and Metal Ecology' Elsevier (Amsterdam).
Journal of Environmental Science and Health Part A-toxic/hazardous Substances & Environmental Engineering, 2002
Rotary kiln incinerators are widely used in the incineration of hazardous wastes of various types... more Rotary kiln incinerators are widely used in the incineration of hazardous wastes of various types. However, the complex transport and chemical processes within the kiln system are still not well understood. The complete destruction of hazardous compounds depends very much on gas mixing behavior of different air and waste streams, the distribution of gas temperature and residence time within the kiln and the secondary combustion chamber (SCC). Due to large variations of waste types and difficulties in feed characterization (physical, chemical and thermal properties), the incineration process meets great challenges in a smooth operation, with substantial fluctuations of gas temperatures within the system. The temperature fluctuations lead to uncertainties in the process chemistry and difficulties in emission control. The newly enforced regulations from the European Union with stricter emission levels require a better understanding of the incineration process and improved process control for lower emissions and a better environmental impact. In order to get better understanding of the incineration process within the rotary kiln system, research was carried out to study the kiln behavior in relation to better process control. One of the focuses was on the process simulation by using Computational Fluid-dynamics (CFD) to characterize gas flow, temperature distribution and waste combustion in the rotary kiln incinerator. Temperature measurement of the operating rotary kiln incinerator at AVR-Chemie, located at the Rotterdam harbor in the Netherlands, was conducted to validate the CFD model and to provide the information to kiln operators at AVR. This paper will address the environmental issues related to the hazardous waste incineration, and summarize the results from the current research project for the simulation of gas flow and mixing, combustion heat transfer, and new ideas to use CFD simulation results for process control of an incineration plant.
The sampling unit was mounted at the stack of the hazardous waste incinerator DTO 9. The Control ... more The sampling unit was mounted at the stack of the hazardous waste incinerator DTO 9. The Control and evaluation unit was installed nearby the mounted sampling unit. Dioxin emission measurements at concentrations of the legal limit (0.1 ng/m) were done with 8-hour monitoring period to enable measurement periods conform to the European standard EN 1948-part 1. Dioxin emission measurements at very low concentrations (below 0.01 ng/m) were done with 1week monitoring period to have the advantage of very low detection limits. Using 1-week monitoring time detection limits of 0.001 ng/m could be achieved. max. 30 m recommended Sampling Unit
Hazardous waste has very complicated chemical compositions in a variety of physical forms and is ... more Hazardous waste has very complicated chemical compositions in a variety of physical forms and is difficult to characterize. Due to the complex transport phenomena within the incinerator the incineration process expects large uncertainties in the process chemistry and thermal/ emission control. For better understanding of the incineration process, process simulation was conducted using Computational Fluid-dynamics (CFD) to characterize temperature and species distribution in the incinerator. Hazardous waste in various forms is firstly converted to a hydrocarbonbased virtual fuel mixture. The combustion of the simplified waste was then simulated with a global 3-gas and an extended 7-gas combustion model. The distribution of temperature and chemical species is broadly investigated. The predicted temperature distribution has been validated with available measurement data from the operating rotary kiln waste incinerator AVR-Chemie in the Netherlands. New statistical post-processing of the standard CFD-output has been developed to give an overview of the average temperature profile and overall reactor behavior as valuable contribution to process control. Finally, an attempt has been made to simulate the multi-phase flow of the shredded solid waste within the incinerator in order to optimize the burner design.
Rotary kilns are widely used for incineration of hazardous waste with complex chemical compositio... more Rotary kilns are widely used for incineration of hazardous waste with complex chemical compositions and physical forms. The solid waste used to be burnt through containers in the rotary kiln, which leads to serious process instability. Recently AVR-Chemie, a hazardous waste incineration company in the Netherlands has implemented a solid waste homogenisation plant where the containerised solid waste is shredded into small particles. The shredded solid waste is incinerated subsequently in the kiln so as to get better combustion efficiency and smoother process operation. It is obvious that the particle trajectory and the mixing of the solid particles with combustion air depend very much on the design and operation parameters. But the solid particle behaviour under current furnace and operating conditions is so far not clear. Thus, process simulation and optimisation are conducted to study the flow and mixing behaviour of the shredded solid waste so as to assist an optimal design of the feeding system. The current paper addresses the recent results in modelling the solid particle flow and mixing behaviour, by using computational fluid dynamics (CFD) technique. The knowledge gained will be used for the design optimisation in an industrial scale rotary kiln incinerator at AVR-Chemie.
Incineration is an excellent disposal technology for all waste materials with heat release potent... more Incineration is an excellent disposal technology for all waste materials with heat release potentials, and provides high degree of toxic destruction and control for a broad range of hazardous materials. In the Netherlands, the hazardous wastes in various forms are processed at AVR-Chemie located at the Rotterdam harbour, through rotary kiln incinerators. The newly enforced regulations from the European Union with stricter emission levels require a better understanding of the incineration process and improved process control. However, the transport phenomena and combustion processes within the kiln system are very complex and not well understood. In order to get better understanding of the incineration process within the rotary kiln system, research was carried out to study the fluid flow and combustion behaviour of the incineration system. Computational Fluid-dynamics (CFD) was used to simulate the waste combustion process, and temperature measurements of the operating rotary kiln incinerator were conducted to validate the CFD model and to provide the information to kiln operators at AVR. This paper will present the latest results from the current research project for the simulation of gas flow and mixing, and combustion heat transfer for a wide range of hazardous waste streams.
The rotary kiln for the incineration of hazardous waste is a poorly defined reactor, and is contr... more The rotary kiln for the incineration of hazardous waste is a poorly defined reactor, and is controlled in a feedback manner. To explore the feed-forward control possibilities research has been conducted to use computational fluid dynamics (CFD) as an off-line tool for simulating the waste incineration process. The standard CFD output has been specially post-processed and used to construct a structured database. The generation of the CFD database and linking the CFD predictions to the actual process control situation, are illustrated in the paper. The database generated will help the operator in making kiln-operating decisions and to improve the current process control.
Journal of Environmental Science and Health Part A-toxic/hazardous Substances & Environmental Engineering, 2005
Hazardous wastes have complex physical forms and chemical compositions and are normally incinerat... more Hazardous wastes have complex physical forms and chemical compositions and are normally incinerated in rotary kilns for safe disposal and energy recovery. In the rotary kiln, the multifeed stream and wide variation of thermal, physical, and chemical properties of the wastes cause the incineration system to be highly heterogeneous, with severe temperature fluctuations and unsteady combustion chemistry. Incomplete combustion is often the consequence, and the process is difficult to control. In this article, modeling of the waste combustion is described by using computational fluid dynamics (CFD). Through CFD simulation, gas flow and mixing, turbulent combustion, and heat transfer inside the incinerator were predicted and visualized. As the first step, the waste in various forms was modeled to a hydrocarbon-based virtual fuel mixture. The combustion of the simplified waste was then simulated with a seven-gas combustion model within a CFD framework. Comparison was made with previous global three-gas combustion model with which no chemical behavior can be derived. The distribution of temperature and chemical species has been investigated. The waste combustion model was validated with temperature measurements. Various operating conditions and the influence on the incineration performance were then simulated. Through this research, a better process understanding and potential optimization of the design were attained.
Progress in Computational Fluid Dynamics, 2007
Processing of hazardous waste in a rotary kiln incinerator is a complex process. Since hazardous ... more Processing of hazardous waste in a rotary kiln incinerator is a complex process. Since hazardous waste has often very complicated chemical compositions and physical forms, the transport phenomena within the incinerator are not well understood, and the incineration process expects large uncertainties in process chemistry and is difficult for emission control. For better understanding of the incineration process, various transport phenomena taking place in the rotary kiln were discussed and analysed in this paper. To get more quantitative understanding, process simulation was conducted by using Computational Fluid-Dynamics (CFD) to characterise gas and solid flow and mixing, temperature and species distribution in the incinerator. To include all the waste streams in a single CFD model is a difficult task, and how to define the different waste streams with different calorific values and chemical compositions is a challenge to the CFD modelling. In this study, hazardous waste in various forms is firstly converted to a hydrocarbon-based virtual fuel mixture based on an overall mass and energy balance. The combustion of the simplified waste was then simulated with a combustion model. The distribution of temperature and chemical species is broadly investigated under various conditions. The predicted temperature distribution has been validated with available measurement data from an operating rotary kiln waste incinerator, and reasonable agreement between the predicted and measured data has been reached. has written a book 'Metrics of Material and Metal Ecology' Elsevier (Amsterdam).
Journal of Environmental Science and Health Part A-toxic/hazardous Substances & Environmental Engineering, 2002
Rotary kiln incinerators are widely used in the incineration of hazardous wastes of various types... more Rotary kiln incinerators are widely used in the incineration of hazardous wastes of various types. However, the complex transport and chemical processes within the kiln system are still not well understood. The complete destruction of hazardous compounds depends very much on gas mixing behavior of different air and waste streams, the distribution of gas temperature and residence time within the kiln and the secondary combustion chamber (SCC). Due to large variations of waste types and difficulties in feed characterization (physical, chemical and thermal properties), the incineration process meets great challenges in a smooth operation, with substantial fluctuations of gas temperatures within the system. The temperature fluctuations lead to uncertainties in the process chemistry and difficulties in emission control. The newly enforced regulations from the European Union with stricter emission levels require a better understanding of the incineration process and improved process control for lower emissions and a better environmental impact. In order to get better understanding of the incineration process within the rotary kiln system, research was carried out to study the kiln behavior in relation to better process control. One of the focuses was on the process simulation by using Computational Fluid-dynamics (CFD) to characterize gas flow, temperature distribution and waste combustion in the rotary kiln incinerator. Temperature measurement of the operating rotary kiln incinerator at AVR-Chemie, located at the Rotterdam harbor in the Netherlands, was conducted to validate the CFD model and to provide the information to kiln operators at AVR. This paper will address the environmental issues related to the hazardous waste incineration, and summarize the results from the current research project for the simulation of gas flow and mixing, combustion heat transfer, and new ideas to use CFD simulation results for process control of an incineration plant.