| 摘要 |
Phenols from low-temperature or vertical retort carbonization processes are purified so as to eliminate or prevent the formation of red colour, by heating with a small proportion of formaldehyde or substance yielding formaldehyde, and an acid or alkaline catalyst, and distilling. Formalin, paraformaldehyde, trioxymethylene, methylal, and hexamethylenetetramine are specified substances yielding formaldehyde; caustic soda and concentrated hydrochloric acid are specified catalysts. For example, 1 kg. of low-temperature tar acids is heated to 100 DEG C. for 30 min. with 10 gm. of paraformaldehyde and 5 cc. of 2N-caustic soda, steam distilled, separated, and distilled.ALSO:Phenols and neutral tar oils from low temperature or vertical retort carbonization processes are purified so as to eliminate or to prevent the formation of red colour, by heating with a small proportion of formaldehyde, or substance yielding formaldehyde, and an acid or alkaline catalyst, and distilling. Formalin, paraformaldehyde, trioxymethylene, methylal, and hexamethylene-tetramine are specified substances yielding formaldehyde. In examples (1) 1 kg. of low temperature-tar neutral oil is heated to 100 DEG C. for 10 min. with 10 gm. of paraformaldehyde and 10 cc. of conc. hydrochloric acid, then distilled in steam, separated and dried; (2) 1 kg. of low-temperature-tar acids is heated to 100 DEG C. for 30 min. with 10 gm. of paraformaldehyde and 5 cc. 2N-caustic soda, steam distilled, separated and distilled.
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