摘要:

Results of a study conducted to convert coal to C2-C4hydrocarbons in a two-stage reactor system are presented. Coal was converted to liquids at 440° C in a stirred batch autoclave using tetralin as the hydrogen donor solvent. The liquids produced were separated from the unreacted coal and ash by filtration. The liquids were then fed into a second stage fixed bed reactor containing sulfided Ni-M0/AI2O3and Si02-AbO;5 catalyst. The liquids were hydrocracked on the dual-functional catalyst giving high yields of C2-C4hydrocarbons. The pressure was 1800 psig and the temperatures were in the range of 425 to 500° C. Reaction mechanisms of conversion of coal derived liquids to C2-C4hydrocarbons are presented. The kinetic parameters of the conversion of coal liquids to gases were determined. The activation energy was determined to be 23.9 Kcal/mol Cracking reactions involving C-C bonds appear to be rate-controlling.

ISSN:0884-3759    

DOI:10.1080/08843759608947633

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The direct use of coal for power generation may cause pollution from the generation of fly ash and toxic mineral matter contents and due to the green house house effect, if not controlled. There is a need to further develop efficient and cost- effective techniques of coal cleaning. However,it is important to analyse the coal mineral matter directly to understand its chemical nature. The nature of bonding and association been organic matter of coal and various constituents of mineral matter may be understood. The state of aggregation of mineral matter and the studies of associative forces between mineral matter components might help in developing reagents to clean coal. Swelling behaviour of coal and its effect on dissociation of mineral matter may be studied. A real break- though in the development of efficient and cost- effective coal cleaning technologies may be expected only after studying the nature of mineral matter constituents of coal and their interaction with coal swelling reagents when present in micro-quantities in water, CO2etc. medium.

ISSN:0884-3759    

DOI:10.1080/08843759608947634

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Kinetic measurements were carried out for the catalytic cooxidation of mixed 1-butancthiol,1-octanethiol and 2-methyl-2-pro-panethiol in gas-liquid system. A mechanism which can explain the enhancement of the oxidation of 2-methyl-2-propanethiol by normal thiols and agree well with the experimental results was set up, and the Michaelis-Mentcn type kinetic equation was derived accordingly. Researches also demonstrate that the interactions between different thiol molecules during the catalytic cooxidation of mixed thiols in the sweetening process are the general role.

ISSN:0884-3759    

DOI:10.1080/08843759608947635

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Asphaltenes precipitated from an Arabian Mix vacuum residue were hydro-cracked in a batch autoclave at 435 and 460°C for 5-90 min. Experiments without catalyst, with modified red mud and with an industrial Co Mo/Al203catalyst were compared. The products were fractionated into gas, naphtha, oil, asphaltenes and coke. Feed asphaltenes and several product fractions were characterised by elemental analysis, by average molecular mass and by1H n.mr. Due to the hydrogenation activity, both catalysts caused - with similar efficiency - the decrease of coke formation and the increase of quantity and quality of oil.

ISSN:0884-3759    

DOI:10.1080/08843759608947636

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This paper gives a new correlation for finding viscosity of Bingham coal-water mixtures at any shear rate. Coal water mixtures of ash content varying from 8 to 40% by weight show Newtonian behaviour and Bingham plastic nature depending upon slurry concentration. It has been observed that the yield stress successively increases with ash content. A correlation predicts the viscosity at infinite shear rate n∞ I.The apparent viscosity of the slurry is obtained from the different measured parameters and the value of n∞

ISSN:0884-3759    

DOI:10.1080/08843759608947637

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An evaluation of eastern shale oil (ESO) residue as an asphalt additive to reduce oxidative age-hardening and moisture susceptibility was conducted. The ESO residue, having a viscosity of 23.9 Pa"s at 60°C (140°F) was blended with three different petroleum-derived asphalts, AAD-1, AAK-1, and AAM-1, that are known to be very susceptible to oxidative aging. Rheological and infrared analyses of the unaged and aged asphalts and the blends were then conducted to evaluate oxidative age-hardening. In addition, the petroleum-derived asphalts and the blends were coated onto three different aggregates, Lithonia granite (RA) a low-absorption limestone (RD) and a silicious Gulf Coast gravel (RL) and compacted into briquets. Successive freeze-thaw cycling was then conducted to evaluate the moisture susceptibility of the prepared briquets. The abbreviations used above for the asphalts and the aggregates are part of the Strategic Highway Research Program nomenclature.

ISSN:0884-3759    

DOI:10.1080/08843759608947638

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Experiments were conducted to study the effectiveness of a hydrogen donor solvent (tetralin) in a supercritical phase in controlling agglomeration and adhering tendency of a caking coal. It was observed that supercritical tetralin was as effective as tetralin in the liquid phase in controlling agglomeration and adhering tendency.

ISSN:0884-3759    

DOI:10.1080/08843759608947639

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A significant decrease in pyrite dissolution rate can be achieved by subjecting it to a humic acids treatment. In this study, the following two sources of pyrite were used: (I) an acid refuse (coal slurry) sample, and (ii) a coal pyrite sample. In addition to pyrite dissolution rate measurements, column studies also were carried out. The leachate iron, sulfur, chromium, vanadium and cadmium metal contents were determined. Pyrite passivation was also studied using some model compounds of humic acids. The data obtained suggest that catechol and 4-aminophenol addition to pyrite can result in a significant suppression of pyrite dissolution under nitrogen and air atmospheres whereas oxalic acid addition enhances pyrite dissolution. In a related research work, it is shown that lignin addition also results in a decrease in pyrite dissolution rate.

ISSN:0884-3759    

DOI:10.1080/08843759608947640

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor