Fractionation and structural characterization of coal liquids

Farcasiu, M.

doi:10.1016/0016-2361(77)90034-5

Cited by 163 publications

(69 citation statements)

References 5 publications

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“…Comprehensive analysis of emission characteristics of synthetic and conventional fuels have been compared by others [43,44]. DCL products are typically rich in polycyclic aromatics and heteroatoms [45][46][47][48], while ICL has lower aromatics content. High temperature FT-synthesis yields branched products and contains aromatics, whilst these are virtually absent in low temperature FTsynthesis [49].…”

Section: Emission Propertiesmentioning

confidence: 99%

A review on coal-to-liquid fuels and its coal consumption

Höök

Aleklett

2009

Int. J. Energy Res.

150

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Continued reliance on oil is unsustainable and this has resulted in interest in alternative fuels. Coal-to-Liquids (CTL) can supply liquid fuels and have been successfully used in several cases, particularly in South Africa. This article reviews CTL theory and technology. Understanding the fundamental aspects of coal liquefaction technologies are vital for planning and policy-making, as future CTL systems will be integrated in a much larger global energy and fuel utilization system. Conversion ratios for CTL are generally estimated to be between 1-2 barrels/ton coal. This puts a strict limitation on future CTL capacity imposed by future coal production volumes, regardless of other factors such as economics, emissions or environmental concern. Assuming that 10% of world coal production can be diverted to CTL, the contribution to liquid fuel supply will be limited to only a few Mb/d. This prevents CTL from becoming a viable mitigation plan for liquid fuel shortage on a global scale. However, it is still possible for individual nations to derive significant shares of their fuel supply from CTL, but those nations must also have access to equally significant coal production capacities. It is unrealistic to claim that CTL provides a feasible solution to liquid fuels shortages created by peak oil. For the most part, it can only be a minor contributor and must be combined with other strategies.

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Section: Emission Propertiesmentioning

confidence: 99%

A review on coal-to-liquid fuels and its coal consumption

Höök

Aleklett

2009

Int. J. Energy Res.

150

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“…To investigate the effects of light in asphaltenes isolated from Blend Arabian Light crude oil, samples were fractionated by sequential elution solvent chromatography [14]. This technique, suitable for liquid coals [15][16], and adapted to crude oil asphaltenes [17] was selected, for it separates compounds according to functionalities.…”

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confidence: 99%

A fraction to fraction study of photo-oxidation of BAL 150 crude oil asphaltenes

et al. 1998

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IntroductionAmong several intricate physical, physico-chemical, and biological factors, natural light plays an important role [1][2][3][4][5][6] in the mitigation of oil spills at sea or ground surface. Nevertheless, little is known about the contribution of photooxidation to the lengthy degradation of asphaltenes [7][8][9][10][11], the most recalcitrant fraction to weathering processes. Their extremely complex composition probably accounts for this lack of data, by making gradual changes outstandingly difficult to investigate.The chemical nature of asphaltenes is poorly defined. In fact, they correspond to a solubility class of constituents: these precipitated from crude oils by adding at least 40 volumes of normal alkanes (nC 5 to nC 7 ). Asphaltenes contain lamellar macromolecules resulting from the condensation of polyaromatic, naphthenic and heterocyclic nuclei, bearing alkyl side chains and sometimes functionalized. Their molecular weight varies from several hundreds to several thousands [12,13]. Cross linked by alkyl, sulphur and oxygen bridges, the polycyclic sheets constitute a matrix that traps various aliphatic hydrocarbons, and form micelles spread among the other petroleum constituents (hydrocarbons and resins).Addressing chemical changes in such structures is a technical challenge, and hence separating samples into different fractions is an unescapable step before analysis. To investigate the effects of light in asphaltenes isolated from Blend Arabian Light crude oil, samples were fractionated by sequential elution solvent chromatography [14]. This technique, suitable for liquid coals [15][16], and adapted to crude oil asphaltenes [17] was selected, for it separates compounds according to functionalities. Subsequent analyses involved gravimetry, elemental analysis, NMR, UV-fluorescence and chiefly FTIR spectroscopy. Materials and methodsThe effects of light exposure were studied in asphaltenes separated from Blend Arabian Light topped at 150°C (BAL 150). In addition, a number of asphaltenes from several other crude oils (Rospo Mare, Ekofisk, Oman, Handil, Irak, Saoudian (PBS), Kuwait, Shengli, Bach Ho, Zarzaïtine, Blend Arabian Medium and Bunker C) were fractionated and investigated to elucidate some FTIR data. Precipitation of asphaltene fractionsAsphaltenes were precipitated in compliance with the NFT 60-115 AFNOR standard [18]. Crude oil (5 g) was mixed to n-heptane (200 mL) in a 250 mL round bottom flask, heated to reflux (90°C) under agitation during 2.5 hr, and then allowed to settle for 12 hr at room temperature. This solution was filtered on a glass microfiber filter (Whatman GF/A, porosity 0.45 µm). Warm heptane was used to drain out the precipitate coating the flask wall, and to thoroughly rinse the solid collected on the filter. The solid was dissolved with dichloromethane; the solution was then concentrated in a rotary evaporator and dried under nitrogen flow up to complete solvent elimination. In the case of BAL 150 crude oil, this technique yielded an asphaltene fraction of about 3%. ...

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“…The SESC results reported in Table 3 are normalized to 100%. With a few samples from runs at low severity 7 we had significantly less than 100% recovery.…”

Section: Sesc Profiles Of Wood Oilsmentioning

confidence: 96%

“…found tn each fraction of th_e oi_ls tested, typtcal average111olecular weights, the typical percentage of oxy-gen tn the fractton and an average molecula-r formula, According to Farcasiu [7], the constituents of having greater than 10 wt% heteroatoms. In the case of wood oil, F6 would seem to be polyphenolic material, perhaps partially degraded lignin.…”

Section: Characterization Of Sesc Fractionsmentioning

confidence: 99%