02113 Coal dewatering system and method

02113 Coal dewatering system and method

0 1 Solid fuels (preparation) Several coal samples were treated with methanol for 2-120 h, dried and characterized on their compressive strength, grin...

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0 1 Solid fuels (preparation) Several coal samples were treated with methanol for 2-120 h, dried and characterized on their compressive strength, grindability, and by SEM analysis. The strength of the treated coal was reduced to about half of that of the parent coal. and the grindability of the treated coal increased with the treatment time. By SEM analysis it was demonstrated that the treatment with methanol formed fractures, which was one reason for the higher grindability.

03/02112 Chemical desulfuriration of Turkish Cayirhan lignite with HI using microwave and thermal energy Elsamak, G. G. et cl/. Fuel, 2003, 82, (5), 531-537. The purpose of the present work was to investigate the effect of the concentration of HI and reaction time in the chemical desulfurization of Cayirhan lignite in a microwave energy set up and to compare the results with those obtained in a thermal heating system. As the concentration of the HI was increased, the extent of desulfurization was also increased in all the experiments done for all of the samples of lignite. The main difference between the thermal and microwave heating was the extremely short times for desulfurization in the case of microwave experiments. After desulfurization experiments S,,,,t/C ratio of all of the samples decreased to a lower value than that of the raw lignite which was 0.034. The loss of the sulfur containing bands in the FTIR spectra of the desulfurized lignite showed that the HI treatment was effective in the cleavage of dithioethers and thioetheric groups. Sulfur containing functionalities like thioethers and thiols although usually requiring strong reducing agents could be removed in significant amounts with concentrated hydroiodic acid from the coal matrix. The rapidity of the desulfurization reactions with microwave heating in concentrated HI was probably due to localized superheating which made HI more effective in the reactions such as with thioethers and thiols that normally resisted to cleavage by HI under thermal heating conditions.

03lO2113

Coal dewatering

system and method

McIntosh, M. J. and Huynh, D. Q. PCT Int. Appl. WO 03 18.716 (Cl. ClOFSiOO) 6 Mar 2003, AU Appl. 200211,741 The dewaiering system? which is especially suitable for dewatering a high moisture, carbomferous solid such as brown coal or lignite, includes a preheater vessel comprising a chamber for heating coal, an inlet means to permit the passage of coal into the chamber, and an outlet means for permitting the passage of coal from the chamber. The dewatering vessel also includes a heating means associated with the preheater vessel to heat coal contained in the chamber and a nonreturn valve means to substantially prevent heated coal removed from the preheater chamber via the outlet means from reentering the preheater vessel via the outlet means. The dewatering system further including a dewatering unit adapted to receive the heated coal from the outlet means via the non-return valve means and to thereby dewater the coal.

03/02114 Cost-efficient and BATAC jigs

beneficiatlon

of coal by ROMJlGs

Sanders, G. J. et al. Coal Preparation, 2002, 22, (4), 181-197. Jigs represent one of the earliest types of machinery employed in mineral separation Their adaptation to process coal established jigs as the most popular and efficient method of coal cleaning for over a century until the arrival of dense medium process. Increased demand for more and more cost-efficient methods of beneficiation lead to a review of the jigging process. Application of new concepts and the use of new technology of manufacture and controls resulted in new forms of jigs. The under-bed pulsated Batac jig is shown to have improved performance over the Baum types. A comparative cost study showed substantial capital and operating cost advantages against dense medium bath or cyclone alternatives. The principle of moving bed jigging is revived in the ROMJIG for the treatment of very large sizes. De-shaling at sizes up to 350-400 mm opens up the way to cheap primary separation of discard, allowing economical mining of lower grade deposits and providing cheap alternatives to upgrading capacity of existing plants.

03/02115 Desulfuriration atmosphere Hu, H.

PI al. ofFurl

Preprints Chemistry.

of coal with pyrolysis

qf’ Symposia 2003, 48,

-

American

in different

Chemical

Socirt.v,

Division (1) 409-410. In non-isothermal experiments a lignite with a S content of 0.72 wt% was pyrolysed up to temperatures of 400, 450, 500, 550, 600, 650 and 700” in a Nz or an ethylene/N2 stream. It was shown that a better S removal during lignite pyrolysis could be achieved at low temperatures by addition of ethylene to Nz. The ethylene could avoid the retention of S in the coal at such temperatures, and at higher pyrolysis temperatures the lower weight loss of the coal by use of ethylene was attributed to the reaction of ethylene with the coal.

358

Fuel and Energy Abstracts

November 2903

03/02119 Effect of iron and calcium compounds emission during coal combustion Guan. R. (‘I NI Divi.vion

q/ Fwl

Preprints Chrwi,~tr~~.

of Sw~posru 2003. 48, (I),

Amerium 310-311.

on NO

Clwmictr/

Swiat

I’,

Bituminous coal was demineralized, and this demineralized coal was doped with Ca and Fe salts to evaluate the role of these elements on NO formation during combustion. The combustion experiments were performed in a laboratory scale reactor, and the flue gases were analysed by a gas analyser. During the oxidation of the volatiles from the coal, little NO was formed but form 500-650’ the emission of NO increased, and it was shown that the peak temperature of NO formation was 50” higher than that of 02 consumption. The formation and oxidation of CO was accelerated by Fe and Ca, and the conversion of NO was more affected by Fe than by C’a.

03/02117 Investigation of partial oxidation of hydrogen sulfide for dry desulfurization of fuel gases Kliemczak, U. Freiher,qer FOr.Y(.hllNR.Fhqft(, .4, 2002. A868. l-226. (In German) The dry direct desulfurization of fuel gases from coal gasification by partial oxidation of HzS was investigated by heterogeneous catalytic partial oxidation followed by separation of the S from the dust, or by a non-catalytic partial oxidation of HzS in the homogeneous gas phase and spray separation of the S. Additionally a heterogeneous catalytic partial oxidation on a fixed bed of coke was investigated. By the catalytic partial oxidation of the HZS and the S separation from the dust, insufficient desulfurization was achieved. The partial oxidation of HzS in the homogeneous gas phase followed by spray separation of the S also achieved insufficient results. The use of a coke fixed bed showed that the partial oxidation of HzS under non-catalytic condition could not be optimized significantly by this method, but under catalytic conditions and activated carbon with defined pore sizes it was possible to achieve 94% desulfurization of the gases.

03/02118 Molecular d namics simulations of the effect of NaCI-dopin on the ca clnatlon characteristics in desulfurlxat 1 on processes y Murakami, T. et (11.Journal of Chmicol Ennginrering qf Japan, 2003, 36. (3), 225-230. Desulfurization performance of wasted seashells was twice as high as that of limestone, which was currently used as a desulfurizer in fluidized bed coal combustors. NaCl-doping into limestone was also effective in improving the desulfurization efficiency. From X-ray diffraction (XRD) analyses of calcined seashell, limestone and NaCIdoped limestone, on the other hand, not only the calcined seashell but also the NaCl-doped limestone had strong peaks of CaO crystal, and these two materials had high desulfurization activity. This improvement was hypothesized to be due to NaCl causing a change in the crystal structure of CaO. In order to elucidate the effect of NaCl addition on the CaO crystal structure in the incineration of CaCOa, the change of structures was simulated by means of molecular dynamics simulations of CaO. In the simulation, one molecule of NaCl was exchanged into one molecule of CaO. A pair of correlation functions and the distances between Ca and 0 atoms, which were obtained by the simulations, were compared with those from the crystal CaO. NaCI-doping affected the crystallization temperature of CaO. The crystallization temperature increased due to adding a little bit of NaCI. From the result of the pair correlation functions obtained in NaCl-doped CaO, the difference of the potential energy of NaCl from that of CaO seemed to contribute to the crystallization of the bulk of CaO. The simulation and experimental results obtained suggested that NaCl-doping contributed to crystallizing the CaO molecules.

03/02119

Neutralization

of acid quarry water

Ladnorg, U. and Brendl, H.-G. Industrie Ceramique & Verriere, 2003, 983, 21-22. (In French) To neutralize acid quarry water linked brown coal seam, WBB Fuchs developed a system based on highly reactive chalk lime with the Schaefer Kalk company. This system is described in the article.

03/02120 Nonchemical fuel from coals

methods for preparation

of liquid

Didenko, A. N. I:vrstiw Akudetnil Nauk, Energetika. 2002, 5. 103- 118. (In Russian) Treating coal and its minerals with ultrahigh frequency resulted not only in the dispersal of coal, but also its cleaning from impurities. This can be used in preparation of water-coal mixtures to replace heavy fuel oil and diesel fuel. The economics of the process was also considered.

03/02121 Optimtzatlon of o rational parameters in sulfideremoving process from coa p”gas in SCS technology Jiang, D. and Chen. X. Chinese)

Huugong

Jinzhnn.

2002,

21.

(6).

425-427.

(In