Commercial Extraction Equipment

Abstract

THE literature on liquidliquid extraction deals mainly with phase relationships, stage calculations, and discussion of the mechanism of mass transfer between two liquid phases.The published information on commercial extraction equipment, particularly the types used and performance data, is rather limited.Hunter and Nash {24) have written several papers containing brief notes on extraction equipment. Two reviews by Waeser {45,46) written in Germany during the war have become available in this country. Green {19) in England reported on solvent extraction with special reference to fine chemical manufacture.However, the best discussions to date have been those of Elgin in Perry's Handbook {38) and his several annual reviews {10,11) published since that time.This paper is an attempt to summarize all of the information available to date on commercial extraction equipment. The sources have been the general literature, patent literature, and data from manufacturers and operators of extraction equipment. The review of the patent literature is presented because it is a tedious process for an individual engineer and not very informative unless the reviewer goes back to the original patents. The INDUSTRIAL AND ENGINEERING CHEMISTRY Vol. 42, No. 6 Table I. Major Commercial Applications of Liquid-Liquid Extraction Processes I. Petroleum Refining A. Separating high purity products Toluene Butadiene Olefins B. Separating one or more groups of compounds from cuts of wide boiling range 1. Treatment of kerosene, Edeleanu (98) 2. Lubricating oils treated with selected solvents Edeleanu (liquid SO2) Chlorex [bis(2-chloroethyl)etherj Duo-Sol Furfural Nitrobenzene Phenol C. Dewaxing, deasphalting, and decarbonizing operations II. Extraction of Acetic Acid A. Wood distillation B-Recovery of acetic acid from dilute solutions from cellulose acetate, etc. III. Phenol Recovery A. Raschig process, primary phenol production B. Gas works liquids, recovery and by-product phenols C. Recovery of phenol from a wide variety of solutions IV. Chemical Processes with Liquid-Liquid Contacting A. Nitration /Here the value of countercurrent operations may be B. Sulfonation (questioned because of the danger of over-reaction V. Vitamins and Antibiotics VI. Vegetable Oil Refining VII. Fischer-Tropsoh Synthesis of Liquid FuelsA. Separation of water-soluble by-products B. Separation of oil-soluble oxygenated by-products 2. Solvent loss. (This varies considerably.) 3. Capital and labor charges of the distillation equipment.4. Capital, labor, and power for extraction equipment.

Additional Staged Operations

“…P is total gas pressure and p is the average molar density of the liquid. If we also use a mass balance, then -d(GMY) = NAavdh = -GMdY -YdGM for only one component's flux dGM = -NAaVdh (13)(14) or…”

“…(1 3-25) (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26) Similarly, for the liquid side we obtain (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28) (1 3-29)…”

“…In [ ; ; 1 ; : ; ; I (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) The same is true for the liquid side: (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32) ( X * -X ) , -( X * -X ) 2 ( X -X*)lrn = In [ ; ; : I % ( ; I Another simplified method uses the concept of a dilute gas so that Likewise the Noc and N O L values become r, -mX, Y, -m X , where K = mG,/L, and K' = L,/mG,. These expressions can be related in a plot as per Complicated systems (high concentrations, heat effects, curved equilibrium lines, multicomponents, etc.)…”

“…As seen, the behavior for bubble cap and valve trays is not very sensitive to capacity, in contrast to sieve trays and packed columns. Various studies of stage efficiencies of liquid-liquid extraction systems found that many operations had values from 71 to 79 percent (5,(13)(14)(15)(16). In addition, some systems ranged from 95 to 100 percent (5,13,14,16).…”

Countercurrent Liquid-Liquid Extractor

“…This operation becomes laborious and time consuming if carried out in equipment such as individual separatory funnels. To simplify this process many continuous and intermittent countercurrent flow liquid-liquid extractors have been designed to operate on a laboratory or on a commercial scale (14,18).…”