Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Technical progress report, July--September 1993
In this quarter, progress has been made in the following two aspects: (1) spectroscopic and chemical reaction studies on the effects of drying and mild oxidation of a Wyodak subbituminous coal on its structure and pretreatment/liquefaction at 350{degrees}C; and (2) effects of dispersed catalyst and solvent on conversion and structural changes of a North Dakota lignite. Drying and oxidation of Wyodak subbituminous coal at 100-150{degrees}C have been shown to have significant effects on its structure and on its catalytic and non-catalytic low-severity liquefaction at 350{degrees}C for 30 min under 6.9 MPa H{sub 2}. Spectroscopic analyses using solid-state {sup 13}C NMR, Pyrolysis-GC-MS, and FT-IR revealed that oxidative drying at 100-150{degrees}C causes the transformation of phenolics and catechol into other related structures (presumably via condensation) and high-severity air drying at 150{degrees}C for 20 h leads to disappearance of catechol-like structure. Increasing air drying time or temperature increases oxidation to form more oxygen functional groups at the expense of aliphatic carbons. Such a clearly negative impact of severe oxidation is considered to arise from significantly increased oxygen functionality which enhances the cross-link formation in the early stage of coal liquefaction. Physical, chemical, and surface physicochemical aspects of drying and oxidation and the role of water are also discussed. A North Dakota lignite (DECS-1) coal was studied for its behaviors in non-catalytic and catalytic liquefaction. Reactions were carried out at temperatures between 250 and 450{degrees}C. Regardless the reaction solvents and the catalyst being used, the optimum temperature was found to be 400{degrees}C. The donor solvent has a significant effect over the conversion especially at temperatures higher than 350{degrees}C.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC22-91PC91042
- OSTI ID:
- 10143986
- Report Number(s):
- DOE/PC/91042--7; ON: DE94010267
- Country of Publication:
- United States
- Language:
- English
Similar Records
Strong promoting effect of H{sub 2}O on coal liquefaction using water-soluble and oil-soluble Mo catalyst precursors
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Technical progress report, December 1992--March 1993
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction
Conference
·
Sat Dec 30 23:00:00 EST 1995
·
OSTI ID:200458
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Technical progress report, December 1992--March 1993
Technical Report
·
Wed Mar 31 23:00:00 EST 1993
·
OSTI ID:10158470
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction
Technical Report
·
Wed Mar 31 23:00:00 EST 1993
·
OSTI ID:6765242