无烟煤碱氧氧化及选择性脱羧制取均苯四甲酸

Alkali Oxygen and Selectively Decarboxylated of Anthracite to Prepare Pyromellitic Acid

以陕西无烟煤为原料,在氢氧化钾碱性溶液及氧气中碱氧氧化得到水溶酸,再将水溶酸在硫酸氢钾和浓硫酸混合介质中进行选择性脱羧,进而采用溶剂重结晶法制取均苯四甲酸。考察了不同反应条件对水溶酸脱羧产品粗均苯四甲酸产率的影响,得到最佳脱羧条件是:反应温度330℃,水溶酸:浓硫酸:硫酸氢钾=1:2:5,反应时间1.5h。在用溶剂重结晶法制取纯均苯四甲酸的步骤中,最佳溶剂是2-戊酮。

Shanxi anthracite has been subjected to oxygen-oxidation at 260~C in all aqueous solution of potas- sium hydroxide to produce water-soluble coal acids （CA）, then the water-soluble coal acids have been selec- tively decarboxylated in the mixed medium of KHSO, and H2SO, to produce crude pyromellitic acid （PA）. The study has obtained the best decarboxylated conditions： reaction temperature 330℃ ; CA：H2SO4·KHSO4 = 1：2：5 and the reaction time is 1.5h. Pure PA is obtained by solvent recrystallization method and the best sol- vent was 2-pentanone.