Reducing mercury emissions in bio-fuelled energy plants
In line with the Kyoto requirements for limitation of CO2 emission, the use of fossil fuels in the field of heat and power production needs to be reduced. Alternatively, renewable energy sources, such as biomass and bio-waste have already been exploited in dedicated plants or in addition to coal. Yet, their use affects the combustion conditions and leads to volatilisation of elements and particle formation some of which are considered toxic. Examples include metals such as lead, chromium, cadmium and particularly mercury that undergo changes while (co-) firing of biofuel-coalfuel blends. Motivated by this, the TOMERED project focused on developing and evaluating the potential of reducing the emission of these toxic metals with the aid of various technologies and techniques. For instance, fuel blending, development of low cost sorbents and novel multi-pollutant cleaning systems could become effective solutions. For this reason, a wide variety of tests were conducted at bench, pilot and large scale facilities. Thereby the impact of in-furnace NOx control technologies and combustion conditions was extensively investigated. The influence of air pollution control devices like Selective Catalytic Reduction (SCR)-DeNOx catalysts on mercury behaviour was studied in detail. More specifically, the efficiency of this emission control technology in terms of mercury removal from flue gases was assessed. The impact of SCR-DeNOx catalysts was investigated at different pilot- and full-scale facilities. Key findings involve specification of the effects of various aspects including fuel composition, SCR operation conditions, and, catalyst's age and type on mercury speciation. The results allowed for a better insight to be gained in this field and are expected to contribute to a greener and more toxic-free energy production. For further details click at: http://www.eu-projects.de/tomered
