Gas separation: processes – Liquid contacting – And degasification of a liquid
Patent
1994-07-26
1995-10-31
Spitzer, Robert
Gas separation: processes
Liquid contacting
And degasification of a liquid
95177, 95180, 95184, 95190, 95194, 95237, B01D 5314
Patent
active
054625823
DESCRIPTION:
BRIEF SUMMARY
The present invention concerns a method according to the preamble of claim 1 for separating and/or concentrating liquids of partial or full mutual solubility.
The most frequently employed methods for separating mutually soluble liquids are distillation and a combination of stripping and distillation. A particular problem is presented by azeotropic mixtures, since these cannot be separated into their basic components by conventional distillation. An azeotropic mixture can be separated by distillation only through adding to the mixture an appropriate auxiliary component which forms a new ternary azeotrope with the components of the initial binary azeotrope. The basic components of the binary azeotrope can now be separated by distillation by way of utilizing the difference between the boiling points of the binary and ternary azeotropes and recycling the auxiliary component, which is concentrated by decanting or distillation. Distillation of the azeotropic mixture typically requires from 2 to 3 distillation columns, multiple heat exchangers, vessels and pumps.
Distillation is a relatively expensive separation method due to its high specific energy consumption. The reason for the high energy consumption is related to the fact that, in addition to the component recovered via the column top, energy must also be imported for the evaporation of the recycled component which is mandatory for the operation of the distillation column. Azeotropic distillation has both higher investment and energy costs per distilled mass unit than those of conventional distillation. Energy consumption is further increased by the use of the auxiliary component, number of distillation columns and required recycle circuits. A special drawback of azeotropic distillation are the losses of the auxiliary component resulting in extra costs and frequently environmental problems as well.
Absorption is conventionally employed for separating mixtures of vapours and gases. The greatest drawback of the absorption method is its high specific energy consumption which is caused by the regeneration of the absorbent. It is an object of the selective absorption method according to the present invention to simplify the separation process of mutually soluble liquids, and more specifically, to reduce the specific energy consumption of the separation process. The method according to the invention is in certain cases capable of replacing distillation and stripping either partially or entirely. A particularly advantageous application of the method according to the invention is in the separation of minimum boiling point azeotropes. The specific energy consumption of the method is smaller than that of distillation, because the regeneration of the absorbent is essentially performed by virtue of the heat of absorption and recycle return arrangements are not mandatory. The control of the separation process according to the invention is extremely simple, and the control range covers 0 . . . 100% of the process input capacity. The selective absorption method according to the invention makes the recovery of solvents profitable even for small lots of solvents and those forming azeotropes difficult to separate. Such solvents are used by the paint manufacturers, pharmaceuticals industry and printing houses. The characterizing properties of the method according to the invention are disclosed in the annexed claims.
The method is based on the capability of specific liquids to absorb certain vapours. The same phenomenon is physically utilized in absorption-type heat pumps in which the most commonly employed liquid-vapour pairs are formed by water capable of absorbing ammonia vapour and the aqueous solution of lithium bromide which can absorb water vapour.
The method according to the invention differs from the absorption-type heat pump in that the vapour brought in contact with the absorbent contains two or more components and that the regeneration is essentially carried out with the help of the heat of absorption.
In the selective absorption method according to the invention t
REFERENCES:
patent: 1934029 (1933-11-01), Asbury
patent: 3344585 (1967-10-01), Hollowell
patent: 3590555 (1971-07-01), Wackernagel
patent: 3664091 (1972-05-01), Hegwer
patent: 4548620 (1985-10-01), Albiol
patent: 4636284 (1987-01-01), English et al.
patent: 4692179 (1987-09-01), Mehra
patent: 4979966 (1990-12-01), Rojey et al.
WO, A1, 9006163, Jun. 14, 1990.
Office Action dated May 20, 1992 issued in the corresponding Finnish Patent Application No. 914890.
Office Action dated Jun. 24, 1993 issued in the corresponding Finnish Patent Application No. 914890.
K.H. Innovations Oy
Spitzer Robert
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