Aldol condensation of refluxing acetone on CaC2 achieves efficient coproduction of diacetone alcohol, mesityl oxide and isophorone

Efficient production of diacetone alcohol (DAA), mesityl oxide (MO) and isophorone (IP) is important for the high value utilization of acetone. For this, a novel process is proposed for the aldol condensation of acetone by refluxing on CaC2, whereby 95% of total selectivity of (DAA, MO and IP) and 85% of acetone conversion are achieved simultaneously under mild conditions (56 degrees C, 100 kPa). This result is superior to the previously reported ones, which may be ascribed to the extremely high catalytic capacity of CaC2 for the aldol condensation and instant separation of the target products from the catalyst to suppress the unwanted successive condensations. Moreover, the target products may be adjusted by operation conditions. Lower temperature and higher reflux rate favour the production of DAA and MO; MO and IP are favoured otherwise. The present process integrates several functions into one unit, i.e. the basic catalysis of calcium carbide, aldol condensation of acetone, instant distillation separation of the condensates, and the hydrolysis of CaC2 to C2H2, which makes it feasible to coproduce C2H2 and high value derivatives of acetone simultaneously.