Evaluation of dispersed Mo catalysts for direct coal liquefaction
The Advanced Concepts for Direct Liquefaction or Coal program was initiated by the US Department of Energy in 1991 with the objective to develop process concepts that would reduce the cost of producing liquid fuels from coal. The program is intended to develop, in laboratory and bench-scale studies, sufficient technical and economic data on the proposed concepts to justify scale-up to a proof-of-concept operation. This paper presents results from a bench-scale run ALC-2 made at Hydrocarbon Technologies, Inc., during November-December, 1996. This run tested Black Thunder coal impregnated with water-soluble molybdenum precursors in combination with iron and nickel precursors. An objective was to determine the relative activity of the less expensive Mo impregnated catalysts versus the much more expensive oil soluble Mo catalysts at a constant fresh catalyst makeup rate of 100 ppm on coal. A further objective was to determine the effect that co-addition of Fe or Ni catalyst precursors had on coal conversion, product distribution and unit operability. An operating objective was to achieve a high recycle of resid while producing a solids laden reject stream approximately equivalent to the ash concentrate stream produced by the ROSE unit operation at the Wilsonville Pilot Plant. The feed coals, prepared by spraying aqueous solutions of the precursor salts onto pulverized coal, contained only 10% moisture that was only 2% more than contained in the untreated coal. The impregnated coals were processed in a 34 kg/day bench-scale unit at a reactor space rate of 640 Kg/h{sm{underscore}bullet}m{sup 3}, a reactor temperature of 440--450 C and a hydrogen treat gas rate of 20 wt% on feed coal. Sulfiding agents were also used. A solids-rich bottoms stream was separated from the reactor effluent and a portion was further processed for solids removal. The remainder of this solids rich stream along with recovered heavy distillate was used as recycle solvent. Material balances and product distributions were determined for four different impregnated coals. Operational difficulties in the solids separation system caused the resid portion of the recycle solvent to vary during the run thereby complicating data interpretation. However, the average coal conversion for the four catalysts used was 95.0{+-}0.66%. Because resid conversions of the four impregnated catalysts. The data analysis approach and the resulting conclusions will be discussed. In addition, characterization of some difficult to separate solids materials will be discussed.
- Research Organization:
- LDP Associates, Hamilton Square, NJ (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC22-91PC91040
- OSTI ID:
- 20012929
- Resource Relation:
- Conference: 23rd International Technical Conference on Coal Utilization and Fuel Systems, Clearwater, FL (US), 03/09/1998--03/13/1998; Other Information: PBD: [1998]; Related Information: In: The proceedings of the 23rd international technical conference on coal utilization and fuel systems, by Sakkestad, B.A. [ed.], 1164 pages.
- Country of Publication:
- United States
- Language:
- English
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