Treatment of heavy coal fractions
US4259172A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 23, 1979 |
| Grant date | Mar 31, 1981 |
| Priority date | — |
| Expiry date | Aug 23, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G1/006
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Increased solubility of heavy fractions of coal (e.g., coal liquefaction bottoms and coal solubilization bottoms) is obtained by oxygen-alkylation or oxygen-acylation of weakly acidic protons such as phenolic and carboxylic functionalities by means of a phase transfer reaction. Phenolic and carboxylic functional substituents, which are very polar, are converted to relatively nonpolar ethers and esters, respectively. The O-alkylation or O-acylation is carried out in a binary liquid phase solution (organic and water phases with a solid phase suspended in the medium). A quaternary ammonium or phosphonium salt is reacted with alkali or alkaline earth base to produce the corresponding quaternary ammonium or phosphonium base (an example of a phase transfer reagent). This quaternary base is non-nucleophilic and readily removes the phenolic and carboxylic protons but does little else to the coal structures. After the removal of the weakly acidic protons by the quaternary base, the phenoxides and carboxylates which are produced then undergo O-alkylation or O-acylation. The alkylating or acylating agent comprises a carbon-bearing functionality and a displaceable leaving group. The O-alkylati…
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