Coal under

Lurgi coal gasifleadon process A process involving the gasification of coal under pressure with mixtures of steam and oxygen. The reactions produce CO and H,. 

Gasification technologies for the production of high heat-value gas do not all depend entirely on catalytic methanation, that is, the direct addition of hydrogen to coal under pressure to form methane. 

We compared and discussed about the release behavior of trace metals from coal under the condition of coal combustion, pyrolysis and steam gasification. Under the condition of combustion, the residual fraction of Zn and Sb was grater than in case of pyrolysis and the residual fraction of Se was smaller. Because a part of trace metals in coal was oxidized during combustion. Moreover the release of Se and Sb was promoted when steam existed in atmosphere, and the release of Hg was suppressed. 

Sokol skaya, El piner IE (1957) The halogen treatments of coals under the action of ultrasonic waves. Dokl Akad Nauk SSSR 114(2) 372-374... 

Figure 10. Sequence of reactions leading to solubilization of coal under mild...

Shinn, J. H. Vermeulen, T. "Scanning Electron Microscopy Study of the Solubilization of Coal Under Mild Conditions". Paper submitted for presentation at Scanning Electron Microscopy Symposium, Washington, D.C., April 1979. 

The liquefaction mechanism was discussed by distinguishing the fusible coal from non-fusible one. The importance of solvolytic hydrogen transfer is pointed for the liquefaction of non-fusible coal under atmospheric pressure. 

Furthermore, artificial weathering of coal under carefully controlled conditions in the laboratory reveals a rapid loss of thermally extractable mobile... 

A requirement for application of Equation 1, however, is that the polymer be uncrosslinked. Most vapor sorption studies on coal have been conducted on the covalently crosslinked portion of coals. Under this condition, simultaneous evaluation of x and M. must be made. Two groups of researchers have adopted this approach.(S 2) We have adopted an alternative approach by conducting vapor sorption studies on the uncrosslinked portion of the coal, x parameters can thus be directly calculated from the pressure-sorption data using Equation 1. 

The conversion of a non-coking coal to a coking coal under hydrogenation conditions has been reported previously in the literature with little reference made to the mechanism of the process From the results reported here, it appears... 

Watt, J. D., The Physical, and Chemical Behaviour of the Mineral Matter in Coal Under Conditions Met in Combustion Plant. Part I, The Occurrence, Origin, Identity, Distribution, and Estimation of the Mineral Species in British Coals, British Coal Utilization Research Association, Literature Survey, 121 p., Leatherhead, Surrey, England, 1968. 

Dr. Friedel. No. Products of the pyrolysis of coal under high temperature carbonization conditions surely must arise from degradation. The quantitative prediction of C7 alkane isomers from coal may possibly indicate a relationship in compositions of coal and petroleum. The hydrocarbons from each perhaps should be similar since both are supposedly derived from organic plants ... 

Successfully applying the method used by Fenton to prepare his concentrates depends upon two factors. First, there must be adequate density differences between the macerals in the sample, and second, there must be an initially high concentration of the required maceral. In attempting to separate either resinite or cutinite from sporinite of the same coal, neither of these conditions can be fulfilled, at least when the coal is of bituminous rank or higher. If, however, samples on a semi microscale are acceptable, it is possible to prepare concentrates of resinites of satisfactory purity from bituminous coals by simple mechanical means. The method has been described by Murchison and Jones (17) and mainly involves picking with fine probes on differently prepared surfaces of coal under a stereoscopic microscope. Resinites from lignites pose less of a problem because their occurrence in fairly substantial lumps is quite common these and fossil resins such as kauri gum and amber usually can be prepared to a purity of almost 100% with ease. 

The resinites of different rank were subjected to treatment with molecular oxygen to determine if the low rank material again showed little response. It was also hoped that the experiment might help to explain certain features displayed by the resinites from bituminous coals under the microscope. 

Generally we will be interested in comparing the relation between reaction rate and rank under different reaction conditions. If we define the reactivity of a coal under certain reaction conditions as the ratio of its reaction rate to the reaction rate of a standard coal, from Equations 1 and 2 we can write that... 

The conclusions that can be drawn from this study of the irradiation of hvab coal under extreme temperatures are ... 

Reaction of Coals under Conditions of High Energy Input and High Temperature... 

The combustion of pulverized coal at both atmospheric and higher pressure has been studied by Hazard and Buckley (4G), using three sizes of burners. The coal is pulverized to 93% through a 200-mesh screen. Experiments on burning pulverized coal under pressure have also been described (7G). 

Gas phase studies were performed at 0.1 MPa total pressure with a flow rate of loo cc/min H2 and loo cc/min He (Linde). The helium stream was diverted through a saturator containing the liquid reactant UAL (Aldrich) such that its volume fraction in the inlet to the reactor was 0.5%. The gas hourly space velocity was 120 lh g1 catalyst. Prior to reaction, the catalyst was pretreated at 673 K for at least 2 hours following a 1 K/min rise to the reduction temperature. The reactor was coaled under... 

Tests on the activity of LP-produced Fe-based nanopowders for liquefaction of a sub-bituminous coal under high (688 K, 1 h of reaction) and low (658 K, 0.25 h of reaction) severity conditions have been reported.38 The catalysts tested were Fe7C3 (92 m2 g 1 (BET), particle size = 17 nm (XRD))and Fe XS (42 m2 g 1 (BET), particle size = 14 nm (XRD).38 For comparison, a commercial superfine iron oxide catalyst (SFIO, supplied by Mach I, Inc.) whose major phase has been identified in one study as y-Fe20339 (surface area = 195 m2 g 1 (BET), particle diameter = 3 nm (XRD)) and in other study as the ferrihydrite40 was also evaluated under similar conditions. The coal liquefaction experiments were carried out in 50 cm3 horizontal microautoclave reactors loaded with 3 g of sub bituminous Black Thunder coal and 5 g of tetralin used as hydrogen donor. Catalyst loadings of 0.7% and 1.4% of as-received coal... 

The data obtained from coal analyses (Table 1.1) establish the price of the coal by allocation of production costs as well as to control mining and cleaning operations and to determine plant efficiency. However, the limitations of the analytical methods must be recognized (Rees, 1966). In commercial operations, the price of coal not only reflects the quantity of coal but also invariably reflects the relationship of a desirable property or even a combination of properties to performance of coal under service conditions (Vorres, 1993). 

As a result, the formation of various national standards associations has led to the development of methods for coal evaluation. For example, the American Society for Testing and Materials (ASTM) has carried out uninterrupted work in this field for many decades, and investigations on the development of the standardization of methods for coal evaluation has occurred in all the major coal-producing countries (Montgomery, 1978 Patrick and Wilkinson, 1978). There are in addition to the ASTM, organizations for methods development and standardization that operate on a national level examples are the International Organization for Standardization (ISO) and the British Standards Institution (BS), which covers the analysis of coal under one standard number (BS 1016) (Table 1.2). 

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