Conversion of Guanidine Nitrate to Nitroguanidine with Recycle of Spent Acid.

摘要

Hercules Incorporated has designed a production facility to synthesize nitroguanidine and concentrate the spent acid for recycle. The program herein described was undertaken to verify the design criteria set forth by Hercules and to study parameters affecting the nitration and distillation of the spent acid. It was found that a 94-96% conversion of guanidine can be obtained using a sulfuric acid to sulfuric acid plus water ratio of 0.94. Vacuum distillation of the spent acid at 50mm Hg with a hold time of one hour at 100C resulted in good conversion of the dissolved guanidine moiety to guanidine sulfate without decomposition to ammonia. By minimizing the ammonium salts formed, only a 5-10% bleed stream of the recycled acid would be required.