Environmental Aspects of Coal Use

Until industrialization, the amounts of coal being used were minuscule and the environmental and health problems were local. However, during the past 200 years, increasingly large amounts of coal have been required to satisfy the ever-growing demand for global energy. 

As a result of environmental concerns, various technologies have been developed that capture potentially harmful elements and compounds before they can be emitted to the atmosphere. 

This chapter focuses on the enviromnental and human health issues related to coal production (mining) and coal utilization. Emphasis is placed on those issues that are related to the petrographic, chemical, and mineralogical composition of coal. 

The examination commences with the environmental issues associated with (1) coal mining (which, by inference includes coal in the seams), (2) coal preparation, (3) coal transportation and storage, and (4) followed by the emission-related environmental issues from commercial use of coal. 

Coal itself is harmless and presents no risk when it is in situ where it was coalified and deposited millions of years ago. When involved in coal-related activities, however, its environmental impacts are deleterious if the coal is utilized in the wrong place at the wrong time and in the wrong amounts. 

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The interesting aspect of one of these examples (Figure 3.20) is the inclusion of carbon dioxide within the cycle. Both postulates recognize the production of carbon dioxide from coal, thereby pointing out the relationship of carbon dioxide and coal but recognition of carbon dioxide as part of the natural cycle between plants, lignin, humus, and coal underscores the closeness of the relationship and the end product of the environmental aspects of coal use. 

The environmental aspects of coal use have been a major factor in the various processes, and the see-sawing movement of the fossil fuel base between petroleum, natural gas, and coal increased the need for pollutant control for large, coal-tired power plants. These power plants emit pollutants that, by atmospheric chemical transformations, may become even more harmful secondary pollutants (Moran et al., 1986). 

In addition to two new chapters. Environmental Aspects of Coal Use and Coal and Energy Security, much of the material in this edition has been rewritten to incorporate the latest developments in the coal industry. Citations from review articles, patents, other books, and technical articles with substantial introductory material are incorporated into the... 

Laboratory and bench-scale operations may not provide a trne picture of the generation of pollutants. But it is essential that the methods for treating efflnent streams to remove pollutants and the types of equipment used for environmental control be a very necessary part of the design and operation of any potential coal liqnefaction procedures. Therefore, it is essential that some consideration be given to this aspect of coal liquefaction (Nowacki, 1979,1980 Kimball and Munro, 1981 Speight, 2011). 

In a more general perspective, coal and its companion fossil fuels are not the only feedstocks that produce emissions that are of harm to the (Table 19.5). In fact, process operators must make very serious attempts to ensure that natural resources such as air, land, and water remain as unpolluted as possible and the environmental aspects of such an operation are carefully addressed. In addition, there must always be reason in the minds of the regulators. It may not always be physically and economically possible or necessary to clean up every last molecule of pollutant. But such rationale must not be used as a free license to pollute nor should the law be so restrictive that industry cannot survive. Rational thought must prevail. 

There is currently great concern about the environmental effects of airborne sulfur dioxide. Although SO2 is released into the atmosphere from natural sources such as volcanoes, the majority (ca. 200 million tonnes per year) is man-made either from industrial processes or domestic use such as coal and oil burning. The long-term consequences of large-scale release of SO2 into the atmosphere are undoubtedly severe, and have been the subject of much public debate. The most objectionable aspect of the problem is that often the acid rain , which results from SO2, occurs hundreds of miles from the source. 

While reliable data are not readily available on feedstock use by type, e.g., natural gas, oil, naphtha, and coal, a look at world r rves of natural gas, oil, and coal by region indicates that natural gas will be the dominant feedstock. Coal use will decline because of environmental aspects and high plant costs. Oil and naphtha viD continue to be used as feedstocks primarily in those regions or areas that do not have natural as reserves and are unable to receive natural gas by pipeline. Review of reserve data covering all feedstocks Indicates no shortage of feedstock material through the year 2000. 

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