Highly active limonite catalysts for direct coal liquefaction

Kaneko, Takao; Sugita, Satoru; Tamura, Masahito; Shimasaki, Katsunori; Makino, Eiichiro; Silalahi, Lambok Hlarius

doi:10.1016/s0016-2361(02)00079-0

Cited by 29 publications

(25 citation statements)

References 16 publications

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“…The composition is in agreement with literature data. 38 , 41 In addition to iron (51.5 wt %), the catalyst also contains Ni (1.4 wt %), Cr (2.0 wt %), Al (4.2 wt %), and traces of Co, Mg, Ca, and S. Besides limonite, other iron-based catalysts (goethite and iron disulfide) were also tested, as well as a conventional hydrotreatment catalyst (CoMo/Al 2 O 3 ). The BET surface areas of limonite, goethite, and CoMo/Al 2 O 3 were determined and are 158, 58, and 140 m 2 /g, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Limonite ores contain both hematite (α-Fe 2 O 3 ) and goethite (α-FeOOH). 38 XRD analyzes were performed to investigate the types of phases in the limonite catalyst used in this work. As can be seen in Figure 2 , the XRD patterns for limonite and goethite catalysts consist predominantly of α-FeOOH, which is in agreement with literature.…”

Section: Resultsmentioning

confidence: 99%

“… 31 − 37 An example is limonite ore, which contains hematite (α-Fe 2 O 3 ) and goethite (α-FeOOH). 38 The hydrotreatment activity of such Fe-based catalysts for coal liquefaction is suggested to be due to the transformation of iron phases (α-Fe 2 O 3 /α-FeOOH) into an active pyrrhotite (Fe 1– x S) phase upon sulfidation of the catalyst. 36 , 38 It is suggested that hydrogen dissociation occurs on these Fe 1– x S clusters.…”

Section: Introductionmentioning

confidence: 99%

“…In fact, the use of limonite as a catalyst for coal liquefaction is known. 38 Performance of the limonite catalyst is compared to that of other iron-based catalysts (FeS 2 , FeOOH, Fe 2 O 3 , and Fe 2 O 3 –NiO) as well as a commercial CoMo catalyst, a well-known hydrotreatment catalyst. Catalyst stability was probed by performing recycling experiments.…”

Section: Introductionmentioning

confidence: 99%

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Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts

Agarwal

Chowdari

Hita

et al. 2017

ACS Sustainable Chem. Eng.

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Limonite, a low-cost iron ore, was investigated as a potential hydrotreatment catalyst for kraft lignin without the use of an external solvent (batch reactor, initial H2 pressure of 100 bar, 4 h). The best results were obtained at 450 °C resulting in 34 wt % of liquefied kraft lignin (lignin oil) on lignin intake. The composition of the lignin oil was determined in detail (elemental composition, GC-MS, GC×GC-FID, and GPC). The total GC-detectable monomeric species amounts up to 31 wt % on lignin intake, indicating that 92 wt % of the products in the lignin oil are volatile and thus of low molecular weight. The lignin oil was rich in low-molecular-weight alkylphenolics (17 wt % on lignin) and aromatics (8 wt % on lignin). Performance of the limonite catalyst was compared to other Fe-based catalysts (goethite and iron disulfide) and limonite was shown to give the highest yields of alkylphenolics and aromatics. The limonite catalyst before and after reaction was characterized using XRD, TEM, and nitrogen physisorption to determine changes in structure during reaction. Catalyst recycling tests were performed and show that the catalyst is active after reuse, despite the fact that the morphology changed and that the surface area of the catalyst particles was decreased. Our results clearly reveal that cheap limonite catalysts have the potential to be used for the depolymerization/hydrodeoxygenation of kraft lignin for the production of valuable biobased phenolics and aromatics.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts

Agarwal

Chowdari

Hita

et al. 2017

ACS Sustainable Chem. Eng.

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show abstract

“…An Australian limonite was used as a catalyst precursor in the present study, because it was reported to be transformed into a highly dispersed Fe catalyst [14]. The as received limonite is composed of about 90 mass% of a-FeOOH, and the metal composition on a dry basis is: Fe, 55.6; Si, 2.3; Al, 1.4; Ca, 0.2; Mg, 0.1 mass%.…”

Section: Catalyst Materials and Preparationmentioning

confidence: 99%

High Catalytic Performance of Fine Particles of Metallic Iron Formed from Limonite in the Decomposition of a Low Concentration of Ammonia

2005

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Catalytic NH 3 decomposition with limonite rich in a-FeOOH has been studied as a hot gas cleanup method to remove a low concentration of NH 3 from fuel gas produced in coal gasification. Fine particles of metallic Fe formed from a-FeOOH achieve the almost complete decomposition of 2000 ppm NH 3 to N 2 at 500°C under a high space velocity of 45,000 h )1 and show the stable catalytic performance for 50 h. The predominant catalytic mechanism involving the formation and subsequent decomposition of Fe nitrides may be proposed on the basis of the XRD and TPD results.

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Hexavalent Chromium Removal from Solutions: Surface Efficacy and Characterizations of Three Iron Containing Minerals

Baig

Wang

Zhuoxing

et al. 2014

CLEAN Soil Air Water

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In the present study, coupled reduction–sorption of Cr(VI) using three iron containing minerals (magnetite, hematite, and pyrrhotite) in aqueous solutions was investigated as a function of solution pH, contact time, and particle size. Detailed characterizations were performed using Brunauer–Emmett–Teller (BET), environmental scanning electron microscopy, and X‐ray diffraction (XRD) techniques. Results demonstrated that over 99% of Cr(VI) removal was achieved just after 1 min of the reaction using pyrrhotite with particle size (100–200 mesh). In comparison, removal efficiency of hematite and magnetite against Cr(VI) was below 40% after 2 h of the reaction. Acidic aqueous medium proved effective for Cr(VI) removal and nearly 100% Cr(VI) removal was achieved at pH 3 using pyrrhotite (30–40 mesh), while the surface efficacy of hematite and magnetite has also improved in acidic solution. In terms of removal efficiency, the three minerals followed the order: pyrrhotite > magnetite > hematite. However, no significant difference in the BET specific surface area was recorded among these minerals, but the mineralogical compositions played an important role for removing Cr(VI) in aqueous solutions. Analysis of XRD pattern revealed that iron contents produce Fe3FeSiO4(OH)5 and FeCr2O4 after the reaction with soluble Cr(VI) and precipitated. This study suggested that high ferrous ions‐based minerals can effectively remove Cr(VI) from contaminated water environments.

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Highly active limonite catalysts for direct coal liquefaction

Cited by 29 publications

References 16 publications

Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts

Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts

High Catalytic Performance of Fine Particles of Metallic Iron Formed from Limonite in the Decomposition of a Low Concentration of Ammonia

Hexavalent Chromium Removal from Solutions: Surface Efficacy and Characterizations of Three Iron Containing Minerals

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