Modelling of Solid Recovered Fuel (SRF) Properties Based on Material Composition – Chloride Quality© Thomé-Kozmiensky Verlag GmbH (9/2016)
Producing solid recovered fuels (SRF) is a well-established route for recovering energy resources from municipal solid waste (household and/or commercial). Chloride content critically impacts the quality of SRF. It directly influences operation of thermal processes, having deleterious effects through the high temperature corrosion of the boilers and through demands placed on the flue gas treatment (FGT) system, which could impact emissions control. Whereas design and specification of process plant can mitigate the technical issues associated with the presence of chloride experienced during thermal treatment, processing such fuels is associated with increased capital, operating and maintenance costs. This, at best, restricts the uptake/use of SRF or increases the cost of its treatment towards achieving a reduced chloride content.
CO2 Capture and Re-Use at a Waste Incinerator© Thomé-Kozmiensky Verlag GmbH (9/2016)
Recently a new innovative process developed by Procede Gas Treating B.V. has been commissioned at line 3 of the Twence plant, a Waste-To-Energy (WTE) plant located in the eastern part of the Netherlands. In this process the CO
2, that usually is emitted to atmosphere, is in this new application, scrubbed from the flue gas and the obtained pure CO
2 stream is used to produce a sodium bicarbonate slurry (SBC). Instead of the conventional SBC flue gas scrubbing process, where dry SBC particles are used, this SBC slurry will be injected to remove the acid components from the flue gas, before the gas is emitted to atmosphere. Due to the implementation of this process the carbon footprint of the Twence installation is reduced. The new SBC plant produces 8,000 tons of sodium bicarbonate annually and to produce this amount of SBC 2,000 ton per year CO
2 is captured from the flue gas. The CO2 originates for about 50 percent from biomass.
New Developments for an Efficient SNCR Monitoring and Regulation System by Evaluating the NOx Mass Flow Profile© Thomé-Kozmiensky Verlag GmbH (9/2016)
When the SNCR process was introduced first in the eighties of the last century the focus was directed towards applying this low cost technology mainly in combustion plants where only relatively low NO
x reduction rates were required. In these types of boilers, like waste-to-energy plants (WtE), the required NOx limits < 200 mg/Nm
3 could be maintained easily. Today, NO
x limits of 100 mg/Nm
3 and lower can be achieved and guaranteed at all operating conditions for these applications. Therefore, the SNCR process represents the Best Available Technology (BAT) today. As a result, more and more owners of waste-to-energy plants take advantage of the low costs at comparable performance and replace their existing SCR system with SNCR.
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.
Use of a Fabric Filter for the Sorption – What Has to be Considered? – Experiences and Solutions –© Thomé-Kozmiensky Verlag GmbH (9/2016)
In almost all flue gas cleaning systems installed at WtE-plants, the fabric filters are central components. A good example for this is the conditioned dry sorption process which is currently preferentially used in Europe. Within the filter not only the particles and the particulate heavy metals are separated from the gas flow, but also all reaction products resulting from the separation of gaseous pollutants such as HF, HCl, SOx, heavy metals and in this respect particularly Hg as well as PCDD/PCDF. In addition to this the fabric filter constitutes an excellent reaction chamber with high additive powder density in the filter cake.
New Developments of an Effective SNCR Control System
Incorporating the NOx Mass Flow Profile© Thomé-Kozmiensky Verlag GmbH (12/2015)
The NO
x reduction rates which have been achieved in recent years using non-catalytic technologies (SNCR) have proved to be reliable even in applications which were believed to work only with the more costly SCR process in the past. In the meantime, SNCR has advanced to be the Best Available Technology (BAT) in grate-fired combustion plants.
Flue Gas Treatment – State of the Art© Thomé-Kozmiensky Verlag GmbH (12/2015)
For the removal of air pollutants from the flue gas, a flue gas treatment system is required downstream the boiler. Such treatment systems consist of a system of cleaning processes for the reduction of particulate, vapour and gaseous substances in the flue gas.