Significance of and Challenges for Flue Gas Treatment Systems in Waste Incineration

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.