Topic
Carbochemistry
About: Carbochemistry is a research topic. Over the lifetime, 1010 publications have been published within this topic receiving 16626 citations.
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TL;DR: Nickel molybdate catalysts used in several different upgrading reactions of coal-derived materials from low-rank Australian coals have been regenerated and their activity assessed using a number of physical and chemical techniques as discussed by the authors.
5 citations
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01 Jan 1994
TL;DR: In this article, the use of image analysis in providing petrographic information has been investigated, along with several different techniques for the characterisation of char and coal particles, and it was shown that the analysis of coal petrography can provide a better characteristic assessment of any given coal type.
Abstract: The use of coal in the production of energy, will continue around the world into the next century, and onwards. From an environmental perspective, as well as a financial one, man has attempted to increase the efficiency of energy production from initial raw materials. Environmentally, the poor conversion of coal to energy means a waste of earth's resources, as well as the production of more waste. From a financial viewpoint, poor combustion means less energy per tonne of coal, hence less profit. Poor combustion will also mean higher levels of carbon in ash. Increased carbon levels will change the physical properties of the ash, and therefore reduce the possible number of outlets for its disposal.
It is essential, from a coal buyer’s point of view that he makes an 'informed' choice, as to the type of coal he is buying, especially if coals in question are imported. There is sufficient evidence to suggest that most techniques that currently exist are unable to characterise world coals successfully. The reason for this has been linked to the unusual petrographic nature of various world coals. It seems logical therefore, that an analytical technique based on the petrography of a coal, would be capable of providing a better characteristic assessment of any given coal type.
The use of image analysis in providing petrographic information has been investigated, along with several different techniques for the characterisation of char and coal particles. Char production itself has been studied, mainly concerned with the production of representative char samples. A range of different operating conditions were used, including temperature ranges of 1000°C to 1400°C, oxygen contents of 0 to 3 %, and residence times of 100 to 200 milliseconds.
From the experiments carried out, it was possible to correlate char structure to the initial coal using a reflectance/fluorescence program, specially designed for the measurement of a coals 'reactivity'. Other prediction systems, such Rank, Fuel Ratio and Reactive Macerals did not correlate as well to the combustion products from the Drop Tube Furnace.
5 citations
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TL;DR: In this paper, a Belgian coal was subjected to non-catalytic liquefaction with tetralin as a hydrogen donor solvent in a magnetically stirred 500 cm 3 autoclave (no. I) and a 70 cm 3 auto-closet which was shaken horizontally.
5 citations
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TL;DR: In this article, the pyrite-catalyzed liquefaction of Waterberg coal with the carbon monoxide/water system was investigated using a variety of methods, including gas chromatography/mass spectrometry and ion-trap detection.
5 citations
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TL;DR: In this paper, a comparison between normal and rapid heat-up modes of testing for a batch screening test to determine the initial activity of coal liquefaction catalysts was made, and the results indicated that only minor differences in conversions of coal to soluble products are obtained by using the two different tests.
Abstract: A comparison was made between normal and rapid heat-up modes of testing for a batch screening test to determine the initial activity of coal liquefaction catalysts. Some effects of choice of solvent, temperature, oil/coal ratio, catalyst/coal ratio, and coal batch on the test results are given. The results indicate that only minor differences in conversions of coal to soluble products are obtained by using the two different tests. No differences in hydrodesulphurisation were observed. Neither test is capable of causing nitrogen removal at the chosen test conditions.
5 citations