In order to penetrate the popular 250 m2/m3 structured packing market, a technically superior and commercially viable alternative to Raschig Super-Pak-300 (RSP-300) was developed: the Raschig Super-Pak-250 (RSP-250 wSE). It has a surface area of 250 m2/m3. The rows of sinusoidal waves within vertical packing sheets are surface enhanced to encourage greater turbulent radial spread of thin liquid film flows on the front and back of the waves on each sheet within an element. RSP-250 wSE was tested at SRP, University of Texas at Austin under identical total reflux conditions to RSP-300 [1] on the cyclohexane/n-hepane system at four operating pressures to characterise performance.

The effect of surface enhancement on the mass transfer efficiency of RSP-250 wSE compared to Raschig Super-Pak 300 without surface enhancement (RSP-300 woSE) is significant with consistently lower HETP values. On comparing with the Montz B1-250 and B1-250M [2] as well as F.R.I. tested Sulzer Mellapak M250Y and MellapakPlus M252Y at 0.34 and 1.65 bar (5 and 24 psia) system pressures [3], the hydraulic-efficiency RSP-250 wSE results are outstanding.

For all system pressures, the pressure drop of RSP-250 wSE are consistently lower by an order of magnitude than the 250 m2/m3 surface area standard structured packings and significantly less than the high capacity types at high flow rates. Combined with excellent efficiencies, the pressure drop per theoretical stage is even more impressive.

Given the outstanding hydraulic and mass transfer efficiency performance, the credentials of RSP-250 wSE competing in the 250 m2/m3 surface area structured packing market can now be firmly established.

References [1]Schultes, M., Chambers, S., “How To Surpass Conventional and High Capacity Structured Packings with Raschig Super-Pak”, AIChE Spring National Meeting, Orlando, FL, 23-27 April, 2006. [2]Olujic, Z., Seibert, A.F., Kaibel, B., Jansen, H., Rietfort, T., Zich. E., “Performance of a New High Capacity Structured Packing”, AIChE Spring National Meeting, Houston, TX,22-26 April, 2001. [3]Pilling, M., Spiegel, L., “Design Characteristics and Test Validation of High Performance Structured Packing”, Distillation Symposium, Distillation Honors John Kunesh, AIChE November National Meeting, Reno Nevada, November 4-9, 2001.