- freely available
Energies 2010, 3(9), 1576-1585; doi:10.3390/en3091576
2. Result and Discussion
2.1. Hydro-Conversion of CHLR
|Proximate analysis/wt%||Ultimate analysis(daf)/wt%|
2.2. Hydro-Conversion Kinetic Model Establishment and Solution
- PA: the toluene insoluble/tetrahydrofuran soluble fractions
- A: the n-hexane insoluble/toluene soluble fractions
- HS: oil and gas
- E: Easily reactive part in THFIS
2.3 Verification of the Model
3. Experimental Section
- CHLR obtained from coal hydroliquefaction reactor could be converted to lighter fractions under moderate hydrotreating conditions. At 470 °C and 30 min, HS was enhanced from 14.14% to 40.86% suggesting that the total HS yield in CHL could increase if CHLR is recycled as a co-reactant in CHL. It also indicates that a moderate extension of coal residence time in CHL is beneficial to the increase of oil yield.
- Reverse reactions of PA were not significant under the hydrotreating conditions and the temperature of CHL was almost identical with this hydrotreating condition, which indicated that there could be no severe polymerization caused by recycling of CHLR in CHL.
- Unlike the highly condensed poly-aromatic hydrocarbons and unreacted coal contained in THFIS, mildly condensed PA and A generated in high-temperature separator of the CHL process could easily depolymerize in a short time under the hydro-conversion which was also proved by a kinetic study.
- On the basis of the non-uniform constitution of CHLR, the moderate hydrotreating performance of catalyst and the non-severity of temperature, the kinetics of the CHLR hydrogenation could be conveniently described by a 4-lumped kinetic model.
- Our kinetic study of CHLR hydro-conversion shows that a large quantity of total catalyst consisting of remaining liquefaction catalyst, part of the minerals from raw coal and the Fe-based catalyst additive could considerably reduce the apparent activation energies of hydro-conversion for PA and A, which is beneficial to the recycling of CHLR in CHL.
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