Influence of the transfer line dead volume on the performance of an industrial scale simulated moving bed for p-xylene separation

• Type: Article in International Scientific Journal
• Date: 2003

Authors

Alírio E. Rodrigues (Author) FEUP; Mirjana Minceva (Author) Other

Journal

Title: Separation Science and Technology

Vol. 38 No. 7

Pages: 1463-1497

ISSN: 0149-6395

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 28 Citations

ISI Web of Science

Scopus - 31 Citations

COMPENDEX

Scientific classification

CORDIS: Technological sciences > Technology > Biotecnology > Downstream processing

Other information

Authenticus ID: P-000-KM7

DOI: 10.1081/SS-120019088

Abstract (EN): The modeling and simulation of simulated moving bed (SMB) unit is needed for the choice of its operating conditions; however, it usually does not consider the surrounding equipment (pipe transfer lines, valves, and pumps). The effect of the dead volume on SMB-performance is normally associated with laboratory scale units, where the Volume of the surrounding equipment could represent significant part of SMB unit volume. The presence of the dead volume is also significant in the industrial-scale SMB units applied for production of high purity component; for example, p-xylene. Different techniques are applied in industry to overcome the negative impact of the dead volume on the SMB performance. In this work, the UOP technique for flushing of the transfer lines before withdrawing the extract, applied in Parex process/(industrial scale SMB unit for p-xylene separation) was analyzed. First, the need of the flushing lines was assessed by simulation of SMB unit in presence of the transfer lines' dead volume. The simulated moving bed strategy of modeling was used; the transfer lines' dead volume was introduced into the model through the node mass balances and was assumed as plug flow and continuous stirred tank in different stages of the transfer line use. The transfer lines' dead volume has negative effect on the extract purity. The extract purity falls to 85.54% and 75.22% when the total transfer line dead volume is 0.6% and 1% of the total SMB unit volume, respectively. The advantage of the flushing lines in presence of transfer line dead volume was demonstrated by simulation of Parex unit allowing extract purity above 99.9% and recovery above 98.5%.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 35