04 By-products related to fuels

a dose of 0.125 mgikg and was more toxic than CT. At a dose of 1 mgikg, 85-100% embryonic deaths occurred in fractions C and D and these two fractions were more potent than fractions A and B. Liver lesions, discoloration of the liver and edema were the main visual toxic manifestations. Both CT and fractionated PAH mixtures were also tested in the Salmonella/microsome plate incorporation assay with Salmonella typhimurium strain TA98 and were evaluated with and without metabolic activation at five dose levels. In the presence of S9, the CT and fractions C, D and E induced a dose-dependent postive response. The CHEST assay results and those from the Salmonellaimicrosome assay were in excellent agreement with each other, indicating that these two bioassays in combination may facilitate the rapid detection and ranking of complex PAH mixtures.

00101854 Nonuniformity of properties of pitch coke Seleznev, A. N. Koks K/h.. 1999. I. 23328. (In Russian) The non-uniformity of properties of pitch coke is studied. An investigation is also carried out into the effects of coal-tar pitch coking conditions on the actual and bulk density, electric resistivity, and compressive strength of the resulting coke as filler for the production of graphite artifacts.

00/01855 Polycyclic aromatic hydrocarbon extraction from a coal tar-contaminated soil using aqueous solutions of nonionic surfactants Paterson, I. F. (‘/lc,,llo.s~phr,rc,. 1999. 38. (I 3). 3095-3 107. The investigation presented focuses on the efficiency and kinetics of surfactant facilitated extraction of phenanthrene and anthracene, which are two exemplar polycyclic aromatic hydrocarbons (PAHs) from a coal tar- contaminated soil. Five different surfactants were used in the study. three of them were ethylene oxide/propylene oxide block copolymers in which the propylene oxide (PO) block was of constant length but the varying lengths of the ethylene oxide (EO) blocks were used. After 50 hours steady state extraction values - for PAH removal -were produced for four of the five surfactants. The extraction efficiency - calculated as the fraction of PAH removed in one washing -is shown to be related to the EO/PO ratio for the block copolymers.

00101856 Preparation and investigation of carbon adsorbents from long-flame coals Dudarev, V. 1. K/h. Twd. Top/. i Mo.wow), iYY9. (I). 36-39. (In Russian) Long-flame coals from Tscheremkhovsk and Kuznetsk basins were used to prepare samples of carbon adsorbents,?which had a mechanical strength 60- 89%, specific surface area 320-620 rn- g and total porosity 0.55-0.67 cm’/ cm2. Iodine and methylene blue sorption capacities of the carbon were 4X0- 860 and 23.0-32.0 mg/g, respectively. The surface areas of the adsorbents can be modified using oxidation, this increases the transient pores which subsequently decreases the pororsity. The decrease of sorption activity to iodine is accompanied by capacity increase to methylene blue.

Wtl’,“57 Preparation of carbon adsorbents from sapropelitic

Kozlov, A. P. Khin~. 71wd. Top/. I Mo.u ow/. 1999. I. 40-44. (In Russian) Standard and non-standard methods of coalification were used to obtain active carbon from sapropelitic coal. The standard method includes semicoking (520’) of starting sapropelite followed by steam activation (850”). Using the non-standard method, the sapropelite is initially modified at a low temperature, then the modified coal is chemically activated with KOH, HsPO.,. or ZnC12 and held in an argon atmosphere at 300-900” for 2 hours. Infrared spectroscopy and thermogravimetric analysis were used to analyse the products. Small-angle X-ray scattering and BET were used to detect the specific surface area of the samples.

00/01858 Preparation of P-type reolite from mineral coal ash Mogica, E. Rcr. SW. Quim. Mcu.. 1998. 42. (4). 186.-188. (In Spanish) P-type zeolite with hot aqueous sodium hydroxide, can be prepared from coal ash, which is a waste product from coal combustion and contains a large proportion of quartz and mullite.

00101859 Preparation of zeolites by hydrothermal decomposition of ash and fly ash Kolousek, D. Czech Rep. CZ 282,132 (Cl. COlB39/02), 14 May 1997, Appl. 4,530, 18 Sep 1990. 4. (In Czech) Power plant ash or fly ash with SiOzAlz03 molar ratio of 2.2-4.8 is used in the preparation of zeolites using hydrothermal decomposition. The process of hydrothermal decomposition of the ash, involves the ash being modified in an aqueous solution of alkali metal hydroxides at 80-160” for l-168 hours. Prior to the modification step, the ash of fly ash may be treated by magnetic separation or chemical leaching with hydrogen chloride. The obtained zeolites with high sorption capacity are suitable for use in chemical industry.

00/01860 Process development for production of hard pitch from coal tar for electrode industries Chaudhuri, A. I. /SlJ Inr.. 1999. 39. (I). 10-14. The residue of coal tar distillation is coal tar pitch. Coal tar pitch can be suitably processed to produce hard pitch of desired quality in terms of softening point (SP), benzene insolubility (BI), quinoline insoulbility (01) &resin and coking value (CV). As per customer requirement, these

properties could be achieved by controlling coal tar quality, different parameters during distillation of tar and processing of soft and medium pitch. Coal tar pitch with CV in the range of 55-584, BI content of 30- 32%, QI content of 13-16% and SP of 9S-105°C. finds its use as a binder for the manufacturing of electrodes. During 1993, Bokaro Steel Plant (BSL), SAIL coal tar pitch of a poor quality with high BI and Ql content in it owing to poor health of coke oven batteries. The by-product plant, found it difficult to produce hard pitch to the specification of aluminum and electrode industries. The R requirements. The electrode industries buy approximately 3000 t/year of hard pitch that the Bokaro Steel Plant produces.

00/01561 Process for refining p-methylnaphthalene from coal- tar crude methyl naphthalenes Hong, H. Faming Zhuanli Shenqing Gongkai Shuomingshu CN I ,I 72.096 (Cl. CO7C15/24), 4 Feb 1998. Appl. 9h,ll7,039, 20 Jul 1996. 4. (In Chinese) The process for refining $methylnaphthalene from coal-tar crude methyl naphthalenes consists of three steps: (i) the distillation of crude methane naphthalenes (prepared by the distillation of coal tar and the removal of quinoline by acid leaching) to obtain an enriched fraction of 1. methylnaphthalene. (ii) the addition of 30.-50 wtCir diethylene glycol to the enriched fraction for azeotropic distillation to obtain an intermediate fraction of ij-methylnaphthalene. and (iii) the removal of diethylene glycol from the intermediate fraction after standing and rectification of the i- methylnaphthalene fraction to yield .i-mcthylnaphthalene

00/01862 Processing stoichiometric silicon carbide fibers from polymethylsilane. Part 1 - Precursor fiber processing Zhang, Z-F. J. Muter. Chew.. 1998. 8. ( 12). 2715. 2724. Polymethylsilane (PMS). -[MeSiH],[MeSi],- in a highly br;mched from. has been synthesized and successfully processed into infusible precursor fibre\ approximately 30-100 Ilrn in diameter. These precursor fibres were converted into stoichiometric, nanocrystal SiC fihres, 20-70 I’m in diameter. by pyrolysis in an inert atmosphere at ramp rates up to 20°C min ’ to 1000°C. Descriptions of precursor synthesis. fibre processing, fibre curing and pyrolytic processing are also presented Thermo-gravimetric analysis. differential thermal analysis. chemical analysis and X-ray diffraction were used to characterize the bulk materials.

00/01863 Production of activated carbon from bituminous coals Dongel, B. Itr~ro~rio~i.t Mirror. Cool ,w,,c (c\.\. PI (I( I,rt Miner Pl-,,r~l5, Symp., 71/r. 1998. 357-360. Edited by Atak S (21 or/ Presented in this paper is the production of activated carbon from bituminous coal having a wide spectrum of raw materials. First, three different coal samples used in the experiments have been carbonized after different pre-treatment processes, namely, size reduction and enrichment and then activated with steam. The activated sample was analysed and carbon tetrachloride adsorption and iodine number were detected.

00101064 Production of activated carbons from brown coal and waste products (bioproducts). Importance of raw material properties for quality of activated carbons Meyer, B. Ear. Cornrn.. [Rep./ El/R. 1999. I- 70. (In German) The production of activated carbon is described in detail. The suitability of wood (oak and beech), nutshells, such as walnut. hazelnut. coconut and Brazil, fruit stones (apricot, cherry, olive, plum and peach) and brown coal for the manufacturing of activated carbon and the most suitable production and activation conditions were studied. The temperature for pyrolysis. heating-rate and rinse gas environment as well as the reaction temperature in the activation stage was detected. For the activation process an H-N mixture was used. The activated carbon from the bioproducts. which includes the fruit stones and the nuts had a higher value than that from brown coal.

00/01865 Property control of carbon materials by fluorination Touhara. H. and Okino, F. C‘tr&~/r. 2000. 3X. (1). 141 267 Fluorination is one of the most effective chemical method to modify and control physicochemical properties of carbon material\ The method i\ rather straightforward, but the interpretation of the results is not necessarily facile. The complication lies in the diversity ot carbon material\ and the wide-range C-F bond nature. This (conversely gives an opportunity to control properties of carbon materials in a wide range, either gradually or drastically. In this review, recent topics in the field of fluorinated carbon materials are focused on.

00/01866 Quantification of fusion in ashes from solid fuel combustion Hansen, L. A. ~/~r~uoc~hr~. Ac,/o. 1999. 326. (I 2). 105- I17 During solid fuel combustion ash is produced and fusion of the ash particle\ greatly affects their tendency to cause operation difticulties in utility: boilers. In this paper, a novel laboratory method for assessing the fusion trt ashes based on simultaneous thermal analvsis (STA). is described. Using STA, melting is detected as an endothermic reaction involving no change in mass. A fusion curve is composed from the measurement signals that show the melt fraction in the ash as a function of temperature. This is done either by a simple comparison of the energies used for melting in the variou\ temperature ranges or by accounting for the relevant melting enthalpies. The repeatibility of the method is sound, melting onset detections and

Fuel and Energy Abstracts July 2000 209