Coal thermodynamics

Although biomass used directly for heating and cooking is the thermodynamically most efficient use, followed by use for electricity generation, the economics are much more favorable to convert to a liquid fuel. Economic considerations outweigh thermodynamics as an electricity generator, biomass must compete with relatively low-priced coal, but as a liquid fuel the competition is higher-priced oil. 

Fig. 7.41 A typical coal gasifier atmosphere at 871 °C plotted in the M-O-S thermodynamic stability diagram for elements commonly present in stainless steels and high temperature alloys...

Fig. 7.76 Superimposed simplified thermodynamic stability diagrams for three elements with oxygen and sulphur at 871°C. The shaded rectangle indicates possible activity ranges in coal gasification atmospheres (after Stringer )...

Based on thermodynamic property of each element, the behavior of trace metals in the coal combustion process was generally classified into 3 groups as follows ... 

C14-0087. Calculate the standard entropy change at 298 K of each of the following reactions, which are important in the chemistry of coal. Assume that coal has the same thermodynamic properties as graphite. 

The electrostatic precipitator in Example 2.2 is typical of industrial processes the operation of most process equipment is so complicated that application of fundamental physical laws may not produce a suitable model. For example, thermodynamic or chemical kinetics data may be required in such a model but may not be available. On the other hand, although the development of black box models may require less effort and the resulting models may be simpler in form, empirical models are usually only relevant for restricted ranges of operation and scale-up. Thus, a model such as ESP model 1 might need to be completely reformulated for a different size range of particulate matter or for a different type of coal. You might have to use a series of black box models to achieve suitable accuracy for different operating conditions. 

As an introduction to the technical aspects of the conference, the results of some studies conducted by the writer on two relevant subjects are presented below. The first commentary is concerned with the design of sour-water strippers and the effects of thermodynamic data on these designs the second commentary is concerned with the calculation of enthalpies of steam-containing mixtures, essential to the design of coal processing and related plants. 

Heat recovery efficiency is a consideration of major importance in the conversion of coal to secondary fuels. This parameter is defined as the percent of the heating value of the coal used which is recovered as heating value in the desired secondary fuel. Heat recovery efficiency which can be attained in a coal conversion process depends firstly on the theoretical chemical and thermodynamic requirements of the process, and secondly on the practical realization of the process. The first factor determines the theoretical maximum heat recovery efficiency that can be obtained under ideal circumstances. The second factor determines the extent to which the practical process approaches the theoretical ideal. 

The steam electric power generation industry is defined as those establishments primarily engaged in the steam generation of electrical energy for distribution and sale. Those establishments produce electricity primarily from a process utilizing fossil-type fuel (coal, oil, or gas) or nuclear fuel in conjunction with a thermal cycle employing the steam-water system as the thermodynamic medium. The industry does not include steam electric power plants in industrial, commercial, or other facilities. The industry in the United States falls under two Standard Industrial Classification (SIC) Codes SIC 4911 and SIC 4931. 

Advanced PEM Fuel Cells. APOLLON. Coals Development and construction of Advance polymeric fuel cells which will be able to operate under Hj and/or methanol fuels, aiming to thermodynamic efficiencies exceeding 50% with power densities of the order of 1 W/cm and significantly reduced manufacturing cost of the membrane electrodes assembly. 

Stracher, G. B., Taylor, T. P. Prakash, A. 2002. Coal fires a synopsis of their origin, remote sensing detection and thermodynamics of sublimation. In Shannon, S. (ed) Environmental Technology for Mining Case Histories of Mine Reclamation and Regulation. Robertson Geo-Consultants Inc., Reno. Nevada, 1-8. (Available on-line at www.infomine.com/technology/... 

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