摘要:

Fluid Catalytic Cracking (FCC) is one of the processes applied world-wide for upgrading of heavy petroleum cuts by converting them into lighter products in the gasoline, light, and heavy cycle oil ranges. Catalytic cracking process was developed in the early stages of petroleum refining. It started by utilizing chemically treated natural clays as catalysts. In the early 1960s the introduction of zeolite containing catalysts, mainly the wide pore faujasite family (X-and Y-type) has significantly contributed to the yield as well as FCC process design consideration. The overall process performance is strongly dependent the catalyst characteristics. Therefore, FCC catalyst manufacturers and researchers are continuously searching for modified catalyst characteristics (improved thermal and hydrothermal stability, higher Activity and better selectivity for high barrel-octane gasoline production). This research activity resulted in this introduction of several FCC catalyses with enhanced performance to suit the steadily increasing emand for high quality refined FCC products.

ISSN:0884-3759    

DOI:10.1080/08843759208915983

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Powdered beech wood was heated for 15 min in anhydrous glycerol containing alkaline catalyst (sodium carbonate and sodium hydroxide) and completely converted into liquid products and water -soluble chemicals at 543 K and atmospheric pressure. The most important reaction variables were temperature and weight of the catalyst. The yield of total water-insolubles was 67.4% from beech wood in the presence sodium carbonate at an average temperature of 543 K. 78.2% of lignin in original wood was delignified in the presence 10.0% sodium hydroxide catalyst at 498 K, and a residence of 10 h.

ISSN:0884-3759    

DOI:10.1080/08843759208915984

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A kinetic study of pyrolysis of dried black liquor was performed using a Netzsch 429 Thermogravimetric Analyzer. It was found that as conversion increases from 10 to 45% the apparent pyrolysis activation energy for black liquor increases from 77.20 to 112.74 KJ/mol. For black liquor the order of reaction was found to be first-order. The reaction rate constant was found to be 2.12×109min. These results are in agreement with the data reported by other investigators on biomass pyrolysis.

ISSN:0884-3759    

DOI:10.1080/08843759208915985

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The degradation of middle distillate fuels with increasing time in storage is a continuing problem. Model systems have defined both the scope and the chemical types of molecules that are Implicated in fuel deterioration. To gain insight into a real fuel system, nitrogen-rich extracts have been isolated from a marginally stable shale derived middle distillate fuel and added as a dopant to a stable base fuel in order to induce instability reactions. Alkyl substituted pyridines, tetrahydro-quinolines, quinolines, and indoles were the prevalent classes of compounds present in the extract. The effects of this added extract were examined in terms of sediment formation and peroxide number under accelerated storage stability test conditions. The activity of the extract in inducing fuel instability was correlated with its nitrogen heterocylic composition.

ISSN:0884-3759    

DOI:10.1080/08843759208915986

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Conventional HDS-catalysts consist of Co and Mo supported on Y-Al2O3. The addition of Zn as a second promoter or the alumina acidification with F increase the catalitye activity in HDS of commercial feeds (Fierro et al., 1984; Boorman et al., 1984). In this paper the combined effect of both Zn and F incorporation is discussed. A series of Zn-Co-Mo catalysts supported on fluorinated alumina (0.0 –2.0 wt% F) was prepared and tested for HDS activity using a commercial gas-oil. The data gathered showed a decrease in HDS activity for intermediate F contents (0.4 – 1.0 wt%). This result could be tentatively explained through alumina surface deterioration during impregnation with NH4HF2solutions al low pH.

ISSN:0884-3759    

DOI:10.1080/08843759208915987

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Neyveli lignite and Assam coal were subjected to biodegradation using bacteria and microfungi in the solid state fermentation technique. Neyveli lignite was found to show more biosolubilization than Assam coal. Neyveli lignite was also subjected to biodegradation using liquid state fermentation technique employingcorynebacterium renale, Pseudomonas striata, Escherichia coli, spherotilus natans, streptococcimicrofungi. Solid state fermentation technique yielded better biosolubilization results than liquid state fermentation technique. Extractability of biodegraded coal in chloroform was enhanced. The IR spectral studies indicated oxidation and demineralization of microbially treated coals.

ISSN:0884-3759    

DOI:10.1080/08843759208915988

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A DTA study has been made to investigate the thermal reactivities of five Turkish lignites (Elbistan, Ilgin, Karliova, Xangal, Yatagan) in an air atmosphere. The coal samples exhibited thermal reactivity at temperatures starting from 20 °C and continuing up to 671 °C. Endothermic peaks were observed at the lower end of the temperature range, the highest endothermic peak temperature being 146°C for Elbistan lignite. Exothermic peaks appeared at around 260, 360 and 600 °C. These temperatures are considered to signify the release and combustion of single benzene ring structures and combustion of condensed aromatic rings respectively. Corresponding stages are observed in the TGA traces. After correcting for differences in methodology, the overall heat effects measured by DTA are within greater than 90% of the calorific values of the coal samples determined by bomb calorimetry.

ISSN:0884-3759    

DOI:10.1080/08843759208915989

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Four short-path distillates obtained at different evaporator temperatures (240, 270, 300, and 330° C) and a supercritical fluid extract (with CO2as solvent) of petroleum short residue (North Gujarat Mix) have been separated into saturates and aromatics. Each fraction of all the said samples has been studied by1H- and13C-NMR spectrometry and the distributions of various types of hydrogens and carbons are reported. Several reliable average structural parameters have been computed and their relative variation is discussed.

ISSN:0884-3759    

DOI:10.1080/08843759208915990

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor