Direct Amination Of Light Olefins

The effects of catalyst kinds and catalyst carrier acidity and reaction conditions on the catalytic performance of direct amination of light olefins were studied in a small fixed bed reactor. Combined with some catalyst characterization means such as XRD, NH3-TPD and NH3-FTIR, the following results are obtained:(1) For the direct amination of ethylene, different Iron-based catalysts have different catalytic performance. The trend of activity of catalyst is Fe2N>Fe> Fe2O3. The study of Fourier Transform Infrared spectroscopy (FTIR) by using NH3as probe molecule reveals that there are two active centers in catalyst Fe2N (N and Fe). The existence of intermediate species of Fe-NH2and N-NH2on the surface of catalyst Fe2N is the main reason to cause the high reaction activity on direct amination of ethylene. In addition, acidity of catalyst carrier has some effect on the direct amination of ethylene too, which is beneficial to the reaction. While alkaline catalyst carrier is unfavorable to the reaction.(2) Compare with Fe2N catalyst, Co and Ni catalysts have high activity at low temperature. Owing to the low conversion of ethylene on Cu catalyst, Cu catalyst is unsuitable for direct amination of ethylene.(3) IBA-01catalyst shows high conversion of ethylene and high selectivity of amine on the direct amination of isobutylene. The good catalytic performance of this catalyst may be related with the acidity of catalyst.(4) The reaction condition has obvious influence on the direct amination of light olefins. For ethylene, the appropriate reaction condition is temperature400-450℃; reaction pressure-0.01MPa; the GHSV280h-1; raw materials ratio (amine:light olefins)5. For isobutylene, the appropriate reaction condition is temperature300℃; pressure3MPa; raw materials ratio2; GHSV1h-1.