摘要:

We studied the production of ethylene (C2") and propylene (C3") by the decomposition of pure ethane, propane, and n-butane, mixed with steam, in a microwave-irradiated fixed bed reactor packed with silicon carbide. We found that ethylene production was maximized using ethane as the feed, with per pass yields as high as 63% at an ethane conversion level of 74%. With propane and n-butane feeds, more ethylene than propylene was produced, but the propylene amounts were significant. Combined per pass yields of C2" and C3" were 56% at a butane conversion of 99%, and 50% at a propane conversion of 93%. This microwave process appears to be a viable way of producing ethylene and propylene.

ISSN:0884-3759    

DOI:10.1080/08843759608947641

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Unsupported iron Fischer-Tropsch synthesis catalyst, formed to a spherical shape and calcined in air, were carbided at 270°C with CO for 24 hours. Following carbiding, the material retained the shape and size of the calcined metal oxide. During agitation by rolling of a slurry, the average particle diameter decreased by about 50% during 450 hours; the attrited material retained a spherical shape so that size reduction was not due primarily to particle fracture. The average particle size (1/d3) was approximately linearly related to the rolling time, and the particle size distribution was fitted by the Weibull Probability Function.

ISSN:0884-3759    

DOI:10.1080/08843759608947642

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

To meet the growing demand of gasoline, heavier ends of crude are being converted into distillate products through secondary refining processes such as fluid catalytic cracking (FCC), thermal cracking, etc. Present day gasoline in India consists of a mixture of unstable streams such as coker, FCC and visbreaker naphtha besides straight run (SR) naphtha and reformate, affecting the overall quality and stability of the fuel. Out of thirteen refineries in India, nine are equipped with FCC units. In these refineries, gasoline is composed of 50 to 90% of FCC stock. This paper presents data on Indian gasoline quality. Effectiveness of a number of commercially available multifunctional additives on carburettor and intake valve cleanliness was studied on gasolines from different refineries. In addition, the effect of these additives on engine performance and emissions is reported.

ISSN:0884-3759    

DOI:10.1080/08843759608947643

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Solvent extraction of coal results in a coal-derived extract containing the solvent-soluble organic portion of coal free of almost all mineral matter. A residue is also produced and consists of most of the mineral matter. Although a procedure has been developed to manufacture ultra-pure coke precursors for value-added carbon products from coal-derived extracts, treatment/rc-usc of the residue is necessary to make the process economically attractive and environmentally friendly. In this study, a technique has been developed to beneficiate the residue by specific gravity fractionation. It is found that nearly 70 % of the residue can be separated into a fraction containing less than 3.5% ash for a typical WV bituminous coal using an organic liquid having a specific gravity of 1.5. This treatment enables the residue to serve as a low-ash boiler fuel or a suitable precursor for the manufacture of materials such as activated carbons. Consequently, the potential for coal-derived precursors leading to new and non-conventionai marketable carbon products can be realized easily.

ISSN:0884-3759    

DOI:10.1080/08843759608947644

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Solvent transport into coal was studied by proton NMR imaging using pyridine - d5and acetone - d6. Solvent swelling of Fushun bituminous coal was also observed by proton spin density images. From these NMR images, some information on the transport and swelling behavior of coal was obtained.

ISSN:0884-3759    

DOI:10.1080/08843759608947645

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

In this paper an attempt has been made to study the effect of using chemical additives on grinding and flotation of thermal coal containing 40% ash. The mill products are analysed by the new technique of low temperature ashing (LT Ash). The LT ash characterisation are in excellent agreement with the results of sink float and flotation studies. Triethanolamine and Polyethylene glycol have shown many fold enhancement in fine grinding. However, Triethanol amine selectively grinds gangue in comparison to coal, while Polyethylene glycol enhances selective grinding of coat in comparison to gangue. This is supplemented by the results of flotation. There is an increase in recovery of combustibles from 39% in absence of additive, to 83% in Polyethylene glycol grinding. The flotation product contained ash between 22-25%.

ISSN:0884-3759    

DOI:10.1080/08843759608947646

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Photothermal degradation of the latex obtained from Calotropis procera showed enhanced extraction in heptane up to 50%. Treatment of the latex with different concentrations of NaOH resulted in the reduction in heptane extraction of the latex. Treatment of latex with aqueous HC1 coagulated it and thus resulted in an increase in extraction yield. The1HNMR,l3CNMR and FTTR spectral analyses of treated latex showed an increase in the olefinic and carbonyl groups in the latex. Thus, this showed that photothermal treatments rendered the latex more amenable to hydrocracking for obtaining value added chemicals and fuels from the latex.

ISSN:0884-3759    

DOI:10.1080/08843759608947647

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Vacuum Gas Oils (VGOs) from waxy crudes contain appreciable amount of wax. During catalytic cracking of VGO, due to lop sided cracking of n-paraffins, substantial amount of wax is retained in clarified oils. These clarified oils generally find their way in refinery fuel.

ISSN:0884-3759    

DOI:10.1080/08843759608947648

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Solvent extraction is a potential technique for the production of coal-derived extracts which may be suitable as precursors for value-added carbon products. At present. the development of new and non-conventional markets for coal has resulted in the exploration of new applications such as slurry fuels, coal-based graphites, carbon-carbon composites and carbon anodes. However, for carbon products to perform acceptably in such applications, the ash content of the precursor must be less than 0.1%. Although, work to produce a low-ash (ca. 0.2%), low-sulfur coal-derivcd material had begun about a decade ago through solvent extraction using the solvent NMP (N-methyl-2-pyrrolidone), it was practically impossible to produce a coal-dcrivcd extract containing less than 0.2% ash. This is due to the presence of ultra-fine mineral matter particles and solvent soluble inorganic species. The principal objective of the present work was to investigate techniques for the separation of the coal-derived extract from the NMP-coal suspension after solvent extraction and to produce a ultra low-ash precursor. The significant

ISSN:0884-3759    

DOI:10.1080/08843759608947649

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Carbon molecular sieves (CMS) for air separation have been prepared from walnut shells. Walnut shells were first carbonized to produce a microporous char. The char was finely ground and extruded with coal tar and phenol-formaldehyde resin (PF resin) as binder. The extrudate was then heat treated to produce a CMS having good air separation ability. Conditions including carbonization temperature, heat treatment temperature, and amounts of coal tar and PF resin were investigated. The micropore structure of the CMS was investigated by means of gas adsorption. The predominating micropore size distribution of the CMS is 3, 3-4. 0 Å.

ISSN:0884-3759    

DOI:10.1080/08843759608947650

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor