Benzoylation for the recovery of structure directing agent (di-n-propylamine) from the process effluent of aluminophosphate synthesis

Di-n-propylamine (DPA), a structure directing agent for (silico)-aluminophosphate (AlPO4) synthesis, is lost into the mother liquor (ML, 5-6 wt%) from the filtration step. A simple benzoylation reaction could recover DPA as N,N,-dipropylbenzamide (DPBA). The reaction also leads to the recovery of more AlPO4 and a decrease in the pollution caused by the ML.