Coal parameters affecting

Apart from the temperature, the ratio of water to coal is an essential parameter affecting the composition of the gas. These... 

Dhooge, P. M. and Park, S. M. (1983) Electrochemistry of coal slurries - 2. Studies on various experimental parameters affecting oxidation of coal slurries. J. Electrochem. Soc. 130, 1029-1036. 

These, and other, behaviour differences have prompted initiation of several exploratory studies in order to assess the response of selected Western coals to liquefaction procedures and identify the parameters that affect this response. This paper summarizes some of the more important observations recorded in the course of that work. 

Three of the most important parameters that affect the hydrogenation of coal and the products obtained are the catalyst, the temperature and the residence time. The effects of these parameters on the chemical nature of the products are still not fully understood. 

Modeling of the Trapping of H2S in the Organic Matrix. Lack of data on the dependence of various properties of coal on the coal composition, porosity, etc., impedes the feasibility of calculation of the fraction of H2S that is released from the tth group but that is transformed to a more stable group before it is emitted from the particle and detected. However, a simple model can be used to determine which parameters may affect the trapping of sulfur in the coal. 

Co A1PO-18 and CoAl PO-34,1 -hexanol is the maj or product during the initial stages of the reaction, but this is converted into 1-hexanal and hexanoic acid 1,6-hexandiol, 1,6-hexanedial and AA appear later. However, the formation of the 1,6-oxidized products was not kinetically related to that of the compounds oxidized at one C atom only. Therefore, attack at the two terminal C atoms occurred concurrently, because the amount and dispersion of Co atoms accommodated on the iimer walls of the AlPO framework were such that two Co(III) ions were separated by about 7-8A Clearly, this is affected by the Co/P ratio, which is the main parameter influencing the Co dispersion and hence the distribution of products. With CoAPO-18, a selectivity of 33.6% to AA was obtained at a 9.5% w-hexane conversion, at 100 °C after 24 h, with oxygen as the oxidant, the major by-products being hexanoic acid and 2-hexanone. The overall terminal selectivity achieved was 65%. 

The ANL capacitive flowmeter was installed at the vertical line of the SLTF (see Fig. 6.19), thus, particle settling problems would not occur. The only parameter that affected the velocity measurement was the velocity profile. Figure 6.24 shows that particle velocities were measured over a range of solids concentrations. For coal concentrations of 3.5-33 wt.%, the measured velocities were independent of coal concentration and 7% accurate when compared with timed-diversion measurements. For higher coal concentrations, the measured velocities deviate from the diversion measurements velocity measurements were = 30-80% higher for 43 and 49 wt.% slurries, but 40%... 

Pneumatic transportation of solids is important to many industrial processes, for example transporting coal and powder particles. To an operator of such a pneumatic conveyor, the mass flow rate of the solids is the primary process parameter to be measured accurately. A solid/gas flow is very difficult to control because it behaves quite differently from solid/liquid flows. A recent review (Yan, 1996) discussed several variables that may affect the performance of a flow instrument. The distribution of solids in a pneumatic pipeline can be highly inhomogeneous consequently, the particle velocity distribution over the pipe cross section can be widespread. Figure 6.28 shows examples in which the roping type flow is particularly difficult to understand and monitor. 

Another study, carried out in the Iberian Peninsula, reported on the response of epiphytic lichens affected by air pollution in the vicinity of a coal-fired power station in northern Spain (Terron Alfonso and Barreno Rodriguez, 1994). Certain parameters were developed to allow the differentiation of three isocontaminated areas. The dominant elements in the ash emitted by the power station were Si, Al, Fe, Ca and K. The ash contained additional elements in smaller amounts. However, no report was made of the elemental content of the lichens. 

The CBM exploration and production potential in China is huge. However, because of the three-low character of Chinese coal seams, which is low reservoir pressure, low permeability and low gas saturation, the production recovery is quite low in the past few decades. Since permeability is one of the critical parameters for the success of CBM recovery process while cleat compressibility can significantly affect the permeability, it is necessary to study the characters and change laws of cleat compressibility with different effective stresses and temperatures. These laboratory-tested data can be converted to in-situ data, so it will provide important guidance to the field production (Gu 2009, Pattison et al. 1996, Reiss 1980). 

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