摘要 |
<p>The process is directed to recovering .epsilon.-caprolactam from a reaction mixture containing .epsilon.-caprolactum and sulfuric acid by separating the caprolactam from the sulfuric acid by an extraction. Extraction includes the steps of neutralizing a part of said sulfuric acid with ammonia, ammonium sulfate, ammonium hydrogen sulfate or mixture thereof, to form an ammonium salt of at least part of said sulfuric acid as a neutralization product, thermally decomposing a part of the ammonium salt formed to produce a gaseous mixture of ammonia and sulfur dioxide and contacting another portion of the neutralization product with said gaseous mixture to produce ammonium hydrogen sulfate, ammonium sulfate or both, and neutralizing at least a part of the sulfuric acid in the reaction mixture with said ammonium hydrogen sulfate, ammonium sulfate or both.</p> |