Heats of interaction between coal-liquid fractions and acids or bases. application of the bolles—drago approach to mixtures
✍ Scribed by K.C. Tewari; P. Stein; N.C. Li
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 205 KB
- Volume
- 63
- Category
- Article
- ISSN
- 0016-2361
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✦ Synopsis
In summary, these results clearly demonstrate the value of cross-polarization n.m.r. methods in studies of coal-solvent interactions. They show that sorbed solvent molecules in coal-solvent systems retain a degree of molecular freedom, which is great enough to remove chemical shift anisotropy but insufficient to reduce cross polarization to a level similar to that present in solution. Some loss of conformational rigidity of coal molecules was observed when coal was soaked in pyridine. Magnetic spin diffusion between coal and solvent protons is much slower than between individual coal protons, as shown by the different 7& values of the coal and sorbed solvent.
Practical applications of cross-polarization studies of solid-solvent interactions may include the study of coal slurries, coal surfaces and mineral matter or catalyst interactions with solvents during coal liquefaction processes.