0 1 Solid fuels (derived so/id fuels)
To provide the basis for the design of two coal authority mine water management schemes, IMC Consulting Engineers (IMC) carried out step-drawdown pumping tests at the Deerplay (Lancashire) and Frances (Fife) abandoned collieries in the summer of 2000. Sup- plementary hydrochemical studies were funded by NERC and under- taken by the University of Newcastle and Queens University Belfast (QUB). The results of the step-drawdown tests can only be interpreted by invoking a substantial component of turbulent flow in large open voids. Overall, the Deerplay system behaves in a manner analogous to natural aquifers, lending itself to modelling (using VSS-NET) to obtain effective hydraulic parameters that may be applicable in similar systems of flooded bord-and-pillar workings elsewhere. The hydrochemical results for both sites showed some similarities, for example there was evidence of depth stratification of water quality in both cases, but also contrasts. For instance, although the total Fe in the mine water pumped from the Deerplay Colliery rose gradually to a plateau at ~30 mg/L, the water remained net-alkaline throughout the testimate. In contrast, not only did the total iron in the Frances waters rise in abrupt steps to as much as 600 mg/L, but the water also switched from being net-alkaline at the beginning of the test to become strongly net-acidic by the end.
03/02135 Progress toward the coal-finery Schobert, H. H. Preprints of S.vmposin - Amwicnn Chemical Society Disi.~ion of Fue/ Chmistrr. 2003. 48, (1). l53m-154. In a review the progress in the conversion of coal into synthetic liquids, phenols, coke and other compounds for chemical feedstocks is presented.
03/02136 Prospect for development of technology of Coal chemical industry in the 21st century Gao, J.-S. et nl. Mei Huagong, 2002, 30, (5). 3-8. (In Chinese) Coal is one of the important backbones for the economic development in the world. There are three problems in coal conversion which should be considered, i.e. high efficiency, cleanness and economics. The integration of energy, resource and environment should be considered in solving the above problems. The coal chemical industry will progress greatly in the 21st century, but the prospect is not so optimistic due to the special characteristics of coal itself.
03/02137 Transforming coal into premium carbon products: an outlook Andresen, J. M. ct al. Preprints of Symposia -. American Chemical Society, Di~~ision of Fuel Chemistry, 2003, 48, (I), 22-23. In a review the transformation of coal into premium carbon products is highlighted. Topics were the production of carbon fibres, activated carbon and its combustion byproducts, and carbon binders and fillers.
Derived solid fuels
;;:;;:8 Carbon nanotube synthesis upon stainless steel
Vander Wal, R. L. and Hall, L. J. Carbon, 2003, 41, (4), 659-672. This paper reports and interprets the effectiveness of different bulk metal catalyst preparations and of various components within reactive gas mixtures for carbon nanotube (CNT) synthesis. The combined catalyst precursor and supporting material is type 304 stainless steel mesh. The steel mesh keenly illustrates the net effect of different pretreatments upon the catalyst because of its resistance to oxidation. These preparative treatments include oxidation, reduction, and their combinations. Finally the utility of the different components within the reactive gas mixture are illustrated by synthesis tests in their individual absence. The effect of catalyst preparation and gas mixture on CNT synthesis is judged on the basis of the relative surface density and morphology of the CNTs (as observed via SEM) and their graphitic structure (as observed via TEM).
it/O0139 Clean production of coke from carbonaceous
Eatough, C. N. et al. U.S. Pat. Appl. Pub]. US 2003 57,083 (Cl. 201-21; ClOB57/04), 27 Mar 2003. Appl. 954,603. Closed apparatus and processes by which a carbon feedstock is composed of a mixture of non-coking coal fines and another carbonaceous material, such as waste coke fines are disclosed. The coal and coke fines are mixed together and may be formed into solid pieces. The mixture alone or as solid pieces is fired through pyrolysation into solid pieces of coke, with solid and gaseous byproducts of pyrolysation being recycled for use within the coke- producing closed system, thereby reducing or eliminating release of undesirable substances to the environment. A char-forming binder may
or may not be added to the carbon mixture prior to pyrolysation. fhc pyrolysis tar may act as the binder and the evolved gases used as fuel for the pyrolysis operation.
03/02140 Coke produced from blends of high volatile bituminous coal and soft brown coal as a prospective domestic fuel Karcz, A. PZ cl/. Ktrrho. 2002, 47. (Y), 256 261. (In Polish) The paper presents the examination results of physical. chemical and mechanical properties of domestic coke. This coke was produced on a semi-commercial scale from blends of high volatile bituminous coal and soft brown coal. The obtained results, which are in accordance with the results of earlier laboratory tests, lead to a conclusion that it is possible to produce domestic coke from a blend containing 90% of high volatile bituminous coal and 10% of soft brown coal. The coke produced from such blend is characterized by high reactivity. good mechanical properties as well as proper size distribution, and therefore can be utilized as the smokeless domestic fuel. The emission rates of air pollutants and the combustion efficiency were evaluated for the obtained coke, as well as for the size-grade hard coal with the use of the standard laboratory equipment for solid fuels conformity certifica- tion. These tests showed that the combustion efficiency was similar for both fuels, while rhe emission of air pollutants was much lower for the coke. To conclude. a conventional coke plant can produce a high quality domestic coke. It is possible to substitute such coke for hard coal, which would lead to a reduction of air pollutant emission.
03/02141 Curing temperature effect on mechanical strength of smokeless fuel briquettes prepared with humates Bless, M. J. ef a/. Energ.~ & Fu&. 2003. 17. (2). 419.-423. The effect of curing temperature on smokeless fuel briquettes was studied by FTIR spectroscopy (FTIR), mass spectrometry (MS), and temperature programmed decomposition (TPD). These techniques help to predict the final properties of these briquettes which were prepared with a low-rank coal, sawdust, and olive stone as biomasses and humates as binder. The best mechanical properties are reached with both the mildest thermal curing at 95 and the cocarbonized at 600 of Maria coal (M2) and sawdust (S) due to the fibrous texture of sawdust. The temperature of curing causes the release of a certain amount of oxygenate structures and the decrease of the mechanical resistance.
03/02142 Effect of inorganic matter on reactivity and kinetics of coal pyrolysis Liu, Q. ef (I/. Preprints of Sympo.\itr Amcvicarf Chemiutl Society. Division of Fud Chemistry. 2003. 48, (I), 368-369. Coal samples were demineralized by treatment with HCl/HF and impregnated with alumina, CaO and KzC03. The raw coals and the such-prepared coals were pyrolysed in a thermogravimetric device, and it was demonstrated that the inherent minerals in he coal had no effect on the kinetics of coal pyrolysis, by the addition of CaO, alumina or K2C03 enhanced the reactivity in coal pyrolysis. The coal pyrolysis could be described by a multi-step first order model, and addition of inorganic matter decreased the activation energy for coal pyrolysis.
03/02143 Mineral reaction and morphology change during gasification of coal in CO* at elevated temperatures Liu, H. et al. Fuel. 2003. 82, (5), 523-530. Studies of the gasification of char in CO2 at elevated temperatures are necessary for the development of IGCC technology. Experiments at high heating rates and elevated temperatures revealed that the temperature dependence of gasification reactivity was very different for low compared with high temperature ranges. To elucidate these mechanisms, the reaction of mineral matter and the change in morphology during gasification of a char at elevated temperatures were examined by char characterization. CO2 gasification experiments showed a large difference in gasification rate for chars prepared at higher temperatures compared to those prepared at lower tempera- tures. Changes in char particle morphology and mineral matter during gasification are also quite different. At higher carbonization tempera- tures, mineral reactions during pyrolysis, which occurs in addition to ash fusion, appear to be one of the factors accounting for these differences. Certainly, a change of mechanism is involved. Graphite enrichment may also contribute to the decrease in char reactivity.
03/02144 Needle penetrometry with variable force loading for measuring viscosity of pelletized coal upon heating Hayashi, J. et al. Furl, 2003, 82, (5), 487T500. A needle penetrometry was performed loading steady force in a range from 1x10- to 2 N to pelletized coal upon heating via a cylindrical needle. From the observed effects of shear rate on apparent viscosity of softening coal pellet, defined as the shear-rate to shear-stress ratio, it was found that the pellet behaved as a Newtonian fluid for shear rates lower than a critical one while as a pseudo-plastic fluid for higher shear rates. The penetrometry was also carried out varying the force with
358 Fuel and Energy Abstracts November 2003