Direct liquefaction of vitrinite concentrates obtained by column flotation

Barraza, Juan; Portilla, Alexander; Piñeres, Jorge

doi:10.1016/j.fuproc.2010.09.034

Cited by 19 publications

(6 citation statements)

References 11 publications

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“…As stated by researchers, vitrinite usually has a higher amount of extractable aliphatic hydrocarbons, which are more easily broken during heat treatment than for the inertinite macerals. The oil yields and carbon conversions obtained from this study were lower when compared to values from the literature . The higher values of the oil yields that were reported by other researchers could be attributed to the maceral composition, as the coal sample used by these authors contained vitrinite contents close to 93.0 vol % …”

Section: Resultscontrasting

confidence: 73%

“…The oil yields and carbon conversions obtained from this study were lower when compared to values from the literature. 33 The higher values of the oil yields that were reported by other researchers could be attributed to the maceral composition, as the coal sample used by these authors contained vitrinite contents close to 93.0 vol %. 32 Figure 2 shows the correlation between the surface areas, total reactive macerals, and conversion.…”

Section: Energy and Fuelsmentioning

confidence: 68%

“…This could be attributed to the higher vitrinite contents and low ash yields in the float fractions when compared to the coal fines discards. Barraza et al 33 obtained a higher carbon conversion of about 85 wt % (daf) for density separated samples (float fractions) when compared to carbon conversion of the parent coal. They used a bituminous coal from South America, which contained 92.…”

Section: Energy and Fuelsmentioning

confidence: 99%

“…This trend is consistent with the data from previously reported studies. 15,16,33 The carbon conversion increased for the float fractions when compared to coal fines discards. This could be attributed to the higher vitrinite contents and low ash yields in the float fractions when compared to the coal fines discards.…”

Section: Energy and Fuelsmentioning

confidence: 99%

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Influence of Density Separation of Selected South African Coal Fines on the Products Obtained during Liquefaction Using Tetralin as a Solvent

et al. 2019

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The liquefaction of two South African discarded coal fines and their density separated (float) fractions were carried out under moderate conditions in a laboratory autoclave. Liquefaction tests were carried out on both discarded coal fines and their float fraction samples at temperatures ranging between 380 and 420 °C using tetralin as a solvent and an initial nitrogen gas pressure of 3 MPa. Oil samples produced from the liquefaction of coal fines discards and their float fractions were further characterized using gas chromatography–mass spectrometry (GC–MS) and nuclear magnetic resonance. The liquefaction test results showed that carbon conversions and oil yields were higher for the float fractions when compared to the discarded coal fines samples. The oil yields ranged from 24.4–37.2% (dry ash free (daf)) for the oil produced from the float fractions of the coal fines and 19.1–29.3% for oils produced from the coal fines (daf). The oil and the gas yields of the float fraction samples were higher when compared to those of the coal fines discards. The higher carbon conversion and higher oil yields obtained from the float fractions demonstrated that density separation of the coal fines discards improves the overall carbon conversion and liquefaction yields. Coal fines discards and float fractions achieved 8 wt % (daf) and 10 wt % (daf) PAA yields at 420 °C, respectively, using tetralin as a solvent during liquefaction. The Waterberg and Highveld coal float fractions had carbon conversions of 50.7 wt % (daf) and 52.7 wt % (daf), respectively, in comparison to <42 wt % (daf) carbon conversion of the original discarded coal fines. GC–MS results for the oil samples derived from coal fines discards and their float fractions showed that these oils contained 72 and 81 wt % naphthalene, respectively. Density separation of discarded coal fines is beneficial to produce a float fraction that may be used as feedstock for direct coal liquefaction. The analytical results indicate that density separation of the coal fines may be used to reduce high costs and volumes of discarded coal fines associated with the disposal and handling of discarded coal fines. Environmental problems will also be addressed if discarded coal fines are utilized as feedstock for industrial processes.

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Section: Resultscontrasting

confidence: 73%

Section: Energy and Fuelsmentioning

confidence: 68%

Section: Energy and Fuelsmentioning

confidence: 99%

Section: Energy and Fuelsmentioning

confidence: 99%

See 2 more Smart Citations

Influence of Density Separation of Selected South African Coal Fines on the Products Obtained during Liquefaction Using Tetralin as a Solvent

et al. 2019

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“…Low-rank coal characterized by a high reactivity and low ash content makes it a suitable feed for coal liquefaction . Many studies have pointed out that the maceral composition of the feed has a great impact on the oil yield rate and conversion rate of the liquefaction process. , It is widely believed that vitrinite and liptinite are reactive macerals, leading to a high oil yield and reaction efficiency, while inertinite is considered as an inert maceral, reducing the conversion rate. − Thus, the separation and enrichment of macerals in low-rank coal is the key point in developing and popularizing coal direct liquefaction technique.…”

Section: Introductionmentioning

confidence: 99%

Enrichment Characteristics of Macerals during Triboelectrostatic Separation in the View of Surface Microstructure, Pore distribution, and Typical Electrical Parameters

Sun

et al. 2021

ACS Omega

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Vitrinite and inertinite, respectively, are the reactive and inert macerals for coal liquefaction, which could be effectively enriched in triboelectrostatic separation specialized in particle processing. Inertinite has a higher specific surface area and more pores than vitrinite and a more balanced mesopores distribution, while the mesopores in vitrinite are mainly focused in the 4 nm × 7 nm range. As for electrical properties, inertinite has a higher relative dielectric constant than vitrinite in all granularities, while its resistivity is only higher than vitrinite in the <74 μm fraction, which means inertinite and vitrinite tend to have negative and positive charges, respectively, in their mutual friction, but inertinite (<74 μm) has a stronger ability to maintain surface charge. During triboelectrostatic separation, the 105 μm × 150 μm fraction of clean coal has the highest vitrinite content, whereas inertinite tends to concentrate at tailings <74 μm under the co-effect of separation granularity limit and electrical characteristics of macerals; this conclusion has a certain guiding significance to maceral separation.

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Effect of temperature, solvent/coal ratio and beneficiation on conversion and product distribution from direct coal liquefaction

Barraza

Coley-Silva

Piñeres

2016

Fuel

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Direct liquefaction of vitrinite concentrates obtained by column flotation

Cited by 19 publications

References 11 publications

Influence of Density Separation of Selected South African Coal Fines on the Products Obtained during Liquefaction Using Tetralin as a Solvent

Influence of Density Separation of Selected South African Coal Fines on the Products Obtained during Liquefaction Using Tetralin as a Solvent

Enrichment Characteristics of Macerals during Triboelectrostatic Separation in the View of Surface Microstructure, Pore distribution, and Typical Electrical Parameters

Effect of temperature, solvent/coal ratio and beneficiation on conversion and product distribution from direct coal liquefaction

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