1989 international conference on coal science

✍ Scribed by Colin E. Snape

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 261 KB
• Volume: 69
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(90)90331-j

✦ Synopsis

Report

respectively. The corresponding values with microwave heating, 65, 72, 54 and 64% respectively, were significantly higher overall but with a different distribution.

A full comparison with conventional methods has still to be made over the coal series, but microwave heating certainly accelerates both the acetylation and hydrolysis reactions. The higher OH levels found support the contention from ketene acetylation that conventional methods may not succeed in converting all the OH groups in the coal structure. Ketene acetylation of coal is a gas/solid reaction and not amenable to microwave treatment, so the potential effect in this case is unknown; also Halleux et al.' did not refer to the use of reagents involving H,SO, or (CF,CO),O so that no direct comparison is possible via Figure .

Although the microwave heating method clearly requires refinement, particularly as regards control of energy input and reaction temperature, it offers the saving of considerable experimental time, and the results obtained so far encourage further investigation.