(560d) The Green Production Process of ?-Caprolactam with Vapor-Phase Beckmann Rearrangement
AIChE Annual Meeting
2019
2019 AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Poster Session: Catalysis and Reaction Engineering (CRE) Division
Wednesday, November 13, 2019 - 3:30pm to 5:00pm
The Green Production Process
of ¦Å-caprolactam with Vapor-Phase
Beckmann Rearrangement
Research Institute of Petroleum Processing (RIPP), SINOPEC, Beijing 100083, P. R. China ¨C wanghao.ripp@sinopec.com;
Keywords: ¦Å-caprolactam, vapor-phase, Beckmann rearrangement
1Introduction Vapor-phase Beckmann rearrangement is a
green, free-ammonium sulfate ¦Å-caprolactam production process. With the increasing demand for
¦Å-caprolactam, this process has been widely concerned. The existing liquid-phase
method, as shown in Eq.(1), uses sulfuric acid as a
catalyst, and produces about 1.5 tons of ammonium sulfate per ton of ¦Å-caprolactam,
which will be a great burden of ¦Å-caprolactam enterprises in the future. Compared with the
existing processes, the vapor-phase rearrangement process, as shown in Eq.(2), has the advantages of low equipment corrosion, low
waste water discharge, high product quality, safe and stable operation, and
thus has a broad market development prospect as a new generation of ¦Å-caprolactam
production process. 2
The production process of ¦Å-caprolactam with vapor-phase Beckmann rearrangement The process consists of vapor-phase Beckmann rearrangement reaction unit and crystallization refining unit. The determined process conditions and process flow are quite
different from those of the existing HPO process. The vapor-phase Beckmann rearrangement process is
a gas phase reaction process, which requires cyclohexanone oxime to
participate in the reaction with gas phase. However, due
to its heat-sensitive characteristics, its vaporization problem is the primary
problem in the development of vapor-phase
Beckmann rearrangement process. Secondly, since
the reaction proceeds at a high temperature, the product distribution
characteristics determine that the refining process requires a crystallization
method with high-efficiency separation method. In the process
of crystallization process development, the high quality product was been obtained. RIPP-SINOPEC relies on 800
tons/year cyclohexanone oxime vapor-phase Beckmann rearrangement pilot equipment
device
to solve lot problems after years of process
development. A total of 5000 hours of experimental investigation was completed
in this device. Time-on-stream of the catalyst was
greater than 700 hours, the conversion of cyclohexanone oxime was greater than
99.9%, and the selectivity of caprolactam was greater than 96.5%. Meanwhile, the high quality ¦Å-caprolactam was
produced with crystallization refining in this pilot
plant.
At present, the process has already been industrialized and promoted. 3
Conclusion
Vapor-phase Beckmann rearrangement process of
produced ¦Å-caprolactam was developed by RIPP-SINOPEC, which is a green process
and high atom economic. The technology has completed pilot plant verification and
will realize industrial production in recent years.