Chapter 33
Downloaded by UNIV OF CALIFORNIA SAN DIEGO on June 5, 2015 | http://pubs.acs.org Publication Date: August 29, 1989 | doi: 10.1021/bk-1989-0406.ch033
Selection of Components for Commercial Supercritical Fluid Food Processing Plants Rodger T. Marentis and Samuel W. Vance Pitt-Des Moines, Inc., Neville Island, Pittsburgh, PA 15225 Criteria for selection of equipment and components for commercial supercritical fluid processing plants for the food processing industry are listed and discussed. Unique features and designs for SCF food processing are specified. Requirements for vessels, heat exchangers, instrumentation, piping, fluid transport devices and typical ancillary equipment are reviewed. Supercritical fluid (SCF) food processing plants have become one of the more robust technologies for new applications within the food industry in recent years. The announcement of the construction and start up of a coffee decaffeination plant in Houston, Texas (1) has markedly heightened interest, resulting in increased awareness of the unique factors that apply to the design of the SCF processing plant and, more importantly, the considerations necessary to select equipment and components for installation in a SCF processing plant. Figure 1 shows a flow schematic for such a plant and process. The major equipment items are extraction vessels, separation vessels, heat exchangers and pumps or compressors which are interconnected with piping, flanges and couplings. Valves specially designed for the operating conditions permit sequencing of flows and control of process variables. Α· data acquisition and logging system and process control loops make the process far more workable and efficient. Figure 2 reveals the increase in piping complexity and valve quantity required for multiple extractor vessels, with an increase in valve quantities to include the necessary diverting valves for efficient system operation. Only two valves are required for a one extractor vessel system, but 22 valves are required for a four extractor vessel system. In addition, process plants need utilities and auxiliaries, such as cooling water, a refrigeration system, steam, hot water and compressed air. These items may be available at an existing plant site, may be added for a new plant site, or may be expanded if existing units do not provide the needed quantities and qualities of utilities for the supercritical fluid process. 0097-6156/89/0406-0525$06.00A) o 1989 American Chemical Society
In Supercritical Fluid Science and Technology; Johnston, K., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1989.
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SUPERCRITICAL FLUID SCIENCE AND TECHNOLOGY
Extract Product
Makeup Entraîner System
C0 Recycle System
Separator
2
Figure 1. P D M pilot plant unit schematic diagram. (Reprinted from ref. 9. Copyright 1988 American Chemical Society.)
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