Significance of and Challenges for Flue Gas Treatment Systems in Waste Incineration© Thomé-Kozmiensky Verlag GmbH (9/2016)
Flue gas cleaning downstream of waste incineration plants had its origins in the increased construction and deployment of such plants to counter rising air pollution in the nineteen-sixties. Back then, the ever-growing burden on the environment caused lawmakers to start enacting emission limits for air pollution control. An unceasing series of environmental scandals and increasingly better analytical methods and measuring instrumentation led to a constant reduction of the emission limits and, consequently, to ongoing adjustment and further development of the necessary process stages in flue gas cleaning. As a result, today minimum emissions can be reached even under the challenging condition of deployment of a very inhomogeneous fuel (waste) and, hence, waste incineration today is no longer a key contributor to air pollution. Today, the need for flue gas cleaning is not called into doubt anymore and has long become a matter of course in the industry and in society at large. Apart from ensuring efficient elimination of noxious gases, the focus of today’s further developments is on issues such as energy efficiency, minimization of input materials and recovery and recycling of by-products from flue gas cleaning as valuable raw materials. These issues are also deemed to be key challenges, especially when it comes to selecting sites for new plants in such a manner that potential synergies can be exploited. Such aspects will also have to be considered in the plans for the predicted mega-cities of the future.
Application of Modified NiCrMo Alloy Systems for Boiler Tube Surface Protection in Waste-to-Energy Environments© Thomé-Kozmiensky Verlag GmbH (9/2016)
Internationally, Waste to Energy and Incineration markets continue to grow in capacity as fossil fueled facilities decline and nuclear generation is curtailed. With this comes a greater need to burn more corrosive materials combust at higher temperatures and extract more energy. The reliability burden that this places on operators of plants is re-opening opportunities for thermal spray solutions as a cost effective solution for boiler tube protection. Where maintenance costs, opportunity costs and access restrictions may preclude alternative in-situ technologies, thermal spray technology may fill a gap in providing new reliable and flexible process and materials technologies for both mid- and long-term protection of water wall and superheater tubes. While historically thermal spray coating solutions have had a spotty record in waste to energy environments, advances in both process and materials technology specifically for WTE environments is such that coating performance now approaches the performance of high alloy wrought materials. This is verified through accurate laboratory modeling and scale tests and trials conducted by OEM’s and plants.
Integrated Development Concerning a Resource-Efficient Operation of MBT-Processes with RTO-Technology© Arbeitsgemeinschaft Stoffspezifische Abfallbehandlung ASA e.V. (9/2012)
Due to the installation of regenerative thermal oxidizers (RTO) for exhaust air purification in the field of mechanical-biological waste treatment plants three general issues emerged:
• corrosion, preferential in the crude gas feeding systems and in the discharge systems of clean gas,
• deposits at the ceramic heat storage units,
• unanticipated high consumption of additional fuel.
The paper refers to the objectives of a recently started research project dealing with these issues in an integrated approach, which particularly includes the interaction between the MBT-process itself and the exhaust air purification system.
Influence of hydraulic properties on the stability of landfills© IWWG International Waste Working Group (10/2007)
The paper shows results from laboratory testing of the influence of water saturation on the geomechanical properties. The water saturation influenced strength properties of the waste material and their impact on the overall landfill stability will be discussed.
A tank-in-series model to describe hydrodynamics and transfer of soluble substances in laboratory sanitary landfills© IWWG International Waste Working Group (10/2007)
A model of tanks-in-series with two types of reactors (rapid reactors and stagnant zones with exchanges between those zones) has been developped to describe the hydrodynamic and mass transfer in waste columns to study the effect of leachate recirculation. The model is compared with a classical tank in series model. Two similar columns (40 kg of dry waste) were equipped with probes inserted at different depths in the waste mass. In the first column, raw leachate was injected during more than 1260 days. On the second column three periods of nitrified leachate recirculation were performed.
State of the art of thermal treatment© IWWG International Waste Working Group (10/2007)
In the last decade several environmental legislations and landfill bans were put into effect. Due to these restrictions in landfilling, thermal waste treatment starts playing a more important role in European waste management systems. In this context the Waste Incineration Directive is fundamental, as all EU member states have to meet the same incineration standards from now on. Furthermore it is necessary to take into account the different level of the waste management infrastructure in several European countries. (Session A12: Incineration and gasification (I))