| 摘要 |
FIELD: chemistry.SUBSTANCE: invention relates to a method of producing purified terephthalic acid, in which it is produced without using a dryer, wet crystals of crude terephthalic acid are purified in the form of a suspension with the help of an aqueous liquid without drying damp crystals to a crystalline powder. Here take place stages of washing of wet crystals of crude terephthalic acid with water and regeneration of acetic acid, contained in waste flush fluid is effectively made in the energy saving mode. More specifically, after the crystals are separated from the suspension of crystals of crude terephthalic acid and washed, crystals containing no acetic acid are collected essentially, waste flush fluid is collected separately brought out during the water washing. Then, acetic acid is extracted from used flushing fluid using the extracting solvent, without dehydration distillation usage, and water is separated. After that acetic acid extract is supplied into the column for acetic acid dehydration distillation to extract acetic acid.EFFECT: it is found that there is a significant correlation between content of acetic acid in the spent flushing fluid and the extracting solvent (i/e relative flow of solvent), and a really executable method of water washing is developed to reduce power consumption and losses of acetic acid.9 cl, 5 dwg, 4 tbl, 3 ex |
