(93e) Standardization of Structured Packing Efficiency Measurements

A major consequence of the ever growing need for bulk-chemicals and the extent of grow of process industries in Far East is that larger and larger equipment is built to stay competitive. The amounts of capital and energy involved require as tight as possible column designs and this posses challenges on scale-up know-how side, which, in turn, relies mainly on efficiency and hydraulics' data obtained from total reflux experiments carried out with much smaller equipment using one of standard test systems, often at conditions different from that of intended application.

Although a lot of experimental work has been done in the past and well established large companies have also collected substantial empirical knowledge from operation of their plants, the design of new as well as redesign of existing columns still encompasses a wide range of concerns. These are mainly related to uncertainties with respect to expected hydraulic and mass transfer performance of novel, performance improving gas/vapor-liquid contacting devices, i.e. trays, random packing, and structured packings, developed and brought to the market mainly by equipment manufacturers. The main stream of such developments is concerned with capacity increase (revamps-retrofits), which implies reaching the capacity increase goal without affecting the separation efficiency adversely, or equipment size reduction (new designs), accompanied (desirable) by energy saving per unit of product (reduction of external reflux). The certainty regarding the hydraulic and mass transfer performance of the G-L contactor considered plays a crucial role for success of such a total cost reduction effort. In order to get this certainty, i.e. to minimize risks associated with building very expensive industrial plants, user companies prefer to have results of dedicated pilot plant scale tests, to be used as basis for validation of own predictive models. Regarding the scarcity and discrepancies among available test installations, establishing standardized testing procedures is considered to be a useful measure to arrive at more confidence in this respect.

With this in mind, and wishing to provide a basis for rising the public knowledge in this respect, this presentation focuses on the uncertainties around experimental characterization of performance characteristics of structured packings, more precisely on clearing the issues associated with usability of total reflux measurements - for (re)design purposes - carried out with some of established test systems using pilot- and semi-industrial scale test installations.