03499 Origin and fate of sulfur in Spanish coals

03499 Origin and fate of sulfur in Spanish coals

0 1 Solid fuels (sources,winning, properties) 96103497 A model structure of Zso Zhuang bituminous coal Takanohashi, T. er al., Coal SCL Technol...

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0 1 Solid fuels (sources,winning, properties) 96103497

A model

structure

of Zso Zhuang

bituminous

coal

Takanohashi, T. er al., Coal SCL Technol., 1995, 24, (I), 55-58. A model structure of Zao Zhuang (Chinese bituminous, 86.9 wt% C) coal was based on the structural analyses and the computer simulation. The model structure as associations of coal molecules which have a continuous distribution of molecular weight. Coal model molecules were placed in a basic cell randomly, and CAMD (computer aided molecular design) was applied for the construction of the raw coal model using periodic boundary condition. 96103490

bituminous

Nature coals

of high

oxyreactivity

of oxidative

altered

Taraba, B. et al.. Coal Sci. Tecltnol., 1995, 24, (I), 465-468. The paper discusses the effects of aromaticity, free radical concentration, functional groups, porosity, heat of wetting, and He diffusion on the spontaneous heating propensity of unaltered and post-sedimentary oxidatively altered bituminous coals from the Upper Silesian Basin. 96103499 Origin and fate of sulfur in Spanish coals Gorchs, R. ef al., Coal Sci. Technol., 1995, 24, (2), 1657.1660. The paper discusses a study made of the distribution of Fe and S in Spanish low-rank coals with a high amount of organic sulphur. Organic sulphur compounds of the Mequinensa lignite along with its depositional paleoenvironment and coalification are described

The role of moisture

Oxidation

of coal macerals

under

pressure

Barman, B. and Roy, M. Indian Chem. Eng. Sec. A, 1995, 37, (1) 73-75. Oxidation of coal macerals was carried out under pressure and the oxidation product was extracted with Me Et ketone. The extraction was fractionated using ether, pentane and acetone. The different extractions were then chromatographed. The macerals contained condensed aromatic structure; fusinite was more condensed than vitrinite and exinite may be the least condensed.

Phenolic 96103501 ing walls of mines

resin foam for the sealing

of loose hang-

Bichler. W. and Simon. 1~. G/ltrckarcl, 199. 131, (9). JX-427. (In German) Discusses the \ealing of loose hangtng walls in hard coal mine\ with ?component resin Rocsil I.

Porosity of Polish coals 96103502 Ceglarska-Stefanska, G. er al.. Arch. ,Mirt. SC!., 1995, 40. (3). 303-315 Describes a study of the relationships between coalification rate, pore volume, and porosit,y for 14 coals extracted from different Polish beds. Investigations involving Hg porosimetry, He density, and apparent density methods showed that the dependence of total porosity on the rake of metamorphism was maximum for coals containing 85.87% C. 96103503

conversion

Possible technology

impacts

of coal

properties

on the coal

Okada. K. Coal SC;. TecIi~roI., 1995. 24, (2), 1247-1250. A classification svstem was devised IO better cla\sifv liquefaction suitabilitv based on H-Catmosphere ratio and inertinite contcnt.~ Under this recla\\iitcation, coal with a high H-C atmosphere ratio and low inertinite conten would be considered ‘light’; coals with a low H-C atmosphcrc ratio and high inertinite content would be regarded as ‘hea\,!‘, and intermediate coals would be called ‘middle’.

Reflectance and surface energy of hard coals 96103504 Sahlik, J. and Roy, I_. Fizykochem. Prohl. Mvrerahrgit, lYY5, 29. 39-46. (In Polish) Rctlectance of vaitrinite was used as a parameter to characterize and classify coals and consequently predict the way of their utilization. Assuming that the mean value of the critical surface energy -. of coal could be applied in the came vvay, the reflectance and critical surface energy measurements were conducted using bituminous coal samples of different degrees of coalification. 96103505

location

Regularities of chlorine in Russian coals

concentration

and

96103508 supported

The relationship between sition and some chemical properties Iignites, Greece

the petrographic compofor the Ptolemais Basin

Va1cev.a. S. er al., Con/ SC{. I‘ec/i,rol.. 19Y.5. 24, (I). The maceral composition of Iignites and reflectance \tudled

25%262 of m,iceral\

Simple desulfurization in coal briquette

technology

using limestone

Uemiya, S. er al., Coal Sci. Techno/., lYY5, 24. (2) 1835-1838. Describes a study of sulphurous acid gas emission from a coal briqeutte consisting of high-sulphur coal and limestone. The sulphur retention was affected by Cal& surrounding temperature, and heating rate during combustion. The suitable temperature for efficient sulphur capture was 973. 1073 K, while sulphur retention was not improved by the further addition of limestone beyond Ca/S of 2.

Sorption

investigation

of methane

on coal

Ceglarska-Stefanska, G. Coal Sci. Techno/., 1995, 24, (l), 27-30. The sorption studies carried OUI under various experimental conditions (dry and wet coals, as well as the coals of a limited freedom of variations in their outer dimensions) indicate that methane diffusion in the coal matrix is inhibited also by sorptive deformation. It should affect the permeability of coal beds and the occurrence of additional stresses in the bed considerably.

96103510

Spontaneous

heating

in New Zealand

coals

Clemens. A. H. and Matheson. T. W. Conl Sci. Technol., 1995, 24, (I), 481.484. The self heating of coal mainly involvres exothermic reactions between the coal and oxygen and the moderating or enhancing effect that water has on these reactions. To study them the chemical and thermal responses of dried low rank coals on exposure to a flow of oxygen or air were monitored and it was found that over the temperature range 30 to 180” only one exothermic oxidation reaction was responsible for self heating. To study the influence of moisture the thermal and chemical responses of dried and partially dried samples of the low rank coals were studied.

96103511 Studies on the coals and their lithotypes

swelling

and

extraction

of hard

Jasienko. S ef nl., Coal Ser. Tehoi., lYY5, 14, (I). 389-392. Describes a study of the colloidal structure of coals, a flame coal, an orrhocoking coal and an anthracite and separated lithotype which were treated with vapour and liquid methanol, pyridine and N-methyl-2-pyrrolidinone at 25°C. Also investigated was the extraction with boiling Nmethyl-7.pyrrolidinone.

96103512

The sulfur

geochemistry

of some Australian

brown

coals Song. Z. rr tri., Cool Sri. Tech~ioi., 1995, 24, (2). 1661-1664. Discusses the major differences observed in response of sulphur-containing coals to hydrous pyrolysis. In the Lochiel coal, sulphur is generally in a highly reactive form, and unreactive hulphur forms were observed in very lo\r concentrations. Explanations for the lower reactivities of the other coal5 were advanced. Sulphur isotopic data, although illustrating differrnces between coals, appears at this stage to be of limited value in the Interpretation of hydrous pyrolysis data, but they do indicate the possibility of a single source of sulphur for each coal.

Sulfur in Assam coal 96103513 Barooah, P. K. and Baruah, M. K. Fried Process. Techno/., 81-97. The papet discusse\ sulphur forms in Assam cs.)als

1995, 46, (2)

form

Zh,irov,. 1 N. Coni SC!. Tecirrrol.. lYY5. 24, (2), 1705-1708 Some generalizations were made on the CI content in Russian coals, the origin of Cl, and possible associations with other elements, notably Na and K. In spite of its biogenic accumulation, the high mobility of Cl usually does 1101 lead to selective accumulation at different staees of neatification
of low-rank

Clemens, A. H. and Matheson, T. W. Fuel, May 1996, 75, (7), 891-895. The self-heating of coal mainly involves exothermic reactions of oxygen at reactive radical sites within the coal and the enhancing or moderating effect that water has on these reactions. The thermal response of samples of low-rank coals, dried by heating under nitrogen flow at 105’C and exposed to dry oxygen, is similar to or slightly less than that observed when they are flow-dried at 30°C and tightly bound moisture remains. The most likely reason is that moisture affects the nature of the radical sites where oxidation occurs. By hindering the formation of stabilized radicals, it encourages faster oxidation which may lead to enhanced thermal response, although some of the extra heat may be taken up by the residual moisture.

96103509 96103500

in the self-heating

were

96103514

Thermal

analysis

of sapropelic

coals

Bodoev. N. V. er al.. Analusis, 1995, 2.1. (6). 274-276. Discusses the investigation of eight sapropelic coal samples of various ranks using thermogravimetry, derivative thermogravimetry and differential thermal analysis methods.

Thermal behavior of macerals in low-rank coals 96103515 lYY5, 24. (I), Coni Srt Tr~/lflO/., Gagarin. S G and Ulanov. N N. 29Y-302. The paper describes the investigation of the thermal hehaviour of 16 coal samples using TGA/DTA and centrifugal field pyrolysis. The average effects of ltptinite and inertinite and rank dependent effects of vitrinite were estimated by means of regression analysis. An approximate additivity at the macerals effects for thermal propertie\ ot petrographic inhomogeneou\ coals was observed

Fuel and Energy

Abstracts

July

1996

251