Prospectus

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DSP-26 Improved Understanding of Impact of Bed Depth on Random and Structured Packing Efficiency Expected Benefit toMembers: Ability to reduce costs of new facilities by installing deeper packed beds. Present Situation and Proposed Research: FRI currently uses the same correction for bed depth for both random and structured packing: HETP avg = HETP * (0.8 + 0.04 * (H/ HETP) 0.7 . The correlation was developed from only five data points for structured packing (two systems, 5 FT, 12FT & 19FT) and two data points for random packing (one system, 12 and 19). In TR-143, it is noted that the empirical parameters in Equation (30) may need to be adjusted when more experimental data are available. The effect of bed length on the HETP may also be related to the liquid and vapor loadings and system physical properties. However, these factors are not included in Equation (30) due to limited experimental data. TR-152 for random packing efficiency has a similar disclaimer, but it has disappeared from more recent efficiency reports like TR-209. There is very little information in the literature on just how bad efficiency loss is from deep beds of random and structured packing, and the information that does exist is conflicting. Rukovena and Koshy (Ind Eng. Chem Res. 1993, 32, 2400-2407) report data on structured packing at packed depths up to ~38FT with no appreciable change in HETP, and cite case studies of even deeper beds working efficiently. The proposed research comprises two phases: 1. Review existing data: FRI Staff to review experimental results since 2002, including recent insights into short beds from the DSP-1 Intermediate Bed Limiter work, to see what additional data we might have that would let us refine the correlation. Staff also to review any results from well-documented publications (the Rukovena-Koshy paper and any other more recent papers), for possible insights that would allow refining the correlation. Staff also to explore getting access to unpublished SRP results on bed depth effects, perhaps in trade for FRI data pertinent to this topic. Staff to give thought as to a less-empirical model structure for efficiency loss with packed depth. Developmental Research Idea

PROSPECTUS

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