Page 94 - New Trends In Coal Conversion

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Minimization of Hg and trace 3

elements during coal combustion
and gasiﬁcation processes

Mercedes Díaz Somoano
Instituto Nacional del Carb on, INCAR-CSIC, Oviedo, Spain

Chapter Outline

3.1 Introduction 59
3.2 Mercury and trace elements in coal 60
3.3 Mercury and TE transformation during coal combustion and gasiﬁcation
processes 65
3.4 Current legislation and the European pollutant release and transfer
register 70
3.4.1 International legislation 71
3.4.2 Regional and national legislation: European Union 72
3.4.3 European pollutant release and transfer register 73
3.5 Technologies for mercury and TE control 75
3.5.1 Particle control devices 76
3.5.2 Flue gas desulfurization 78
3.5.3 Effect of NO x control 80
3.5.4 Speciﬁc technologies 81
3.6 Concluding remarks 83
3.7 Future work 83
References 84

3.1 Introduction

For many years, trace element (TE) emissions from coal conversion processes have not
been an issue of major concern in international or worldwide legislation. The main
exception is the United States, which has promulgated standards for mercury and other
TEs. However, during the last decade and due to the increasing concern about the
effects of trace pollutants in the environment, there are a number of international
and national agreements that aim to reduce TE emissions. In addition, existing pollu-
tion control equipment for other emissions is also effective in reducing most TE emis-
sions. However, the more volatile TEs, such as mercury, are captured to a much lower

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