Liquids from coal. Catalytic hydrogenation of two Spanish subbituminous coals

Chavarria, P.; Martínez, María Teresa; Miranda, JoséL.; Osácar, Jesús

doi:10.1016/0378-3820(86)90059-7

Cited by 9 publications

(2 citation statements)

References 4 publications

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“…In view of these results, 698 K (425 "C) and 723 K (450 "C) would appear to be the optimum liquefaction temperatures, in terms of both efficiency and quality of the products, for Encasur subbituminous coal. Equivalent conclusions are reported in the literature for other subbituminous coals (Mori et al, 1980;Chavarria et al, 1986).…”

Section: Znjluence Of Operating Conditions On Catalytic and Non-catalsupporting

confidence: 68%

Heterogeneously catalyzed coal hydroliquefaction: Screening of catalysts and characterization

Legarreta

Arias

Marco

et al. 1994

Int. J. Energy Res.

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This project is centred upon the study of the activities of different catalysts in one‐step coal liquefaction processes. A series of alumina supported catalysts was prepared by multistep impregnation, including a conventional CoMo/Al2O3 and other preparations containing Zn as a second promoter, and the alumina was acidified with different fluorine contents. These catalysts were extensive physicochemically characterized and their hydrodesulphurization (HDS) and hydrogenation (HYD) activities were tested using a model compound (thiophene). The results obtained indicate that partial substitution of Co by Zn does not affect the HDS and HYD activities and that fluorination diminishes these activities because of textural changes of the carrier. The prepared catalysts were tested in coal liquefaction and their activities were compared to those of cheap iron containing dispersion catalysts such as red mud, Fe2O2 aerosol, and Cottrell and pyrite ashes (by‐products of the sulphuric acid industry). Most of the liquefaction tests were carried out in a magnetically stirred laboratory autoclave for 1 h, at 400 rpm, in the 673 K (400°C) − 748 K (475°C) temperature range, at 17 ± 1 MPa operating pressure, with two different solvents; tetralin and anthracene oil, and using mainly 2/1 and 3/1 solvent/coal ratios. The liquefaction products were fractionated into oils, asphaltenes and preasphaltenes, using pentane, toluene and tetrahydrofurane (THF) as extractive solvents. Prior to the study and comparison of the catalyst activities and exploration of the influence of various operating conditions (temperature, tetralin/coal ratio, type of solvent and operating pressure) on catalytic and non‐catalytic coal liquefaction was performed. The coal used in most of the experiments was a Spanish subbituminous A coal. Additionally in order to contrast results a comparison of all the catalysts was carried out with a standard high volatile (HV) bituminous coal (140 FR 36) from the European Centre for Coal Specimens Stichting Steenkoolbank Nederland (SBN). Supported catalysts present higher activities than iron‐based catalysts. Among these catalysts, red mud proved to be the most active. Catalytic experiments using anthracene oil as solvent and CoZnMo/fluorinated alumina catalysts present maximum yields indicating that Zn as second promoter and carrier acidification to be beneficial in coal liquefaction with solvents similar to those used in real plants.

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Section: Znjluence Of Operating Conditions On Catalytic and Non-catalsupporting

confidence: 68%

Heterogeneously catalyzed coal hydroliquefaction: Screening of catalysts and characterization

Legarreta

Arias

Marco

et al. 1994

Int. J. Energy Res.

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“…On the one hand, at low temperature low oil yield was obtained due to the very weak thermal cracking to produce free radicals. Previous study reported23, 24 that temperature is the most important variable that affects free radicals production, and consequently it has a very great effect on the occurrence of retrogressive reactions. Li et al 1.…”

Section: Resultsmentioning

confidence: 99%

Direct liquefaction of Mukah Balingian low‐rank Malaysian coal: optimization using response surface methodology

Ghani

Ishak

Ismail

2011

Asia-Pacific J Chem Eng

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Coal liquefaction of low-rank coals is of interest because of the formation of a liquid fuel with lower molecular weight and a higher H/C ratio than those of the parent coal, which itself is difficult to use. This study determined the optimum conditions for liquefaction of Mukah Balingian (MB) low-rank Malaysian coal using a supercritical water-tetralin mixture. Response surface methodology (RSM) based on central composite rotatable design (CCRD) was applied to optimize the combination effect of two important reaction variables, i.e. reaction temperature ( • C) and solvent mixture ratios. The reaction was performed via a high-temperature, high-pressure batch-wise reactor system. A total of 13 individual experiments were conducted and the results showed that the RSM based on CCRD is very applicable to the coal liquefaction process studied in this system. The predicted optimum conditions for liquefaction of MB coal was 450• C reaction temperature and 30 : 70 water-tetralin ratio, resulting in coal conversion and an oil yield of 70.6 and 66.1%, respectively. 

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