Liquid separation by membrane assisted vapor stripping process

Inactive Publication Date: 2009-03-05
VANE LELAND +1
View PDF6 Cites 55 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Further, standard distillation is only able to reach the ethanol-water azeotrope—about 5 wt % water.
Such a process would also be useful for recovering ethanol from dilute process or waste streams not currently attractive due to the inefficiency of distillation, particularly in smaller installations in which the economies of scale do not favor distillation.
Unfortunately, the inert gas dilutes the volatile product, making recovery of the product by condensation more energy intensive.
However, in situations where the components are fully miscible and the VLE behavior is not highly favorable, stripping and overall separation efficiencies decrease.
In addition, lower alcohols are fully miscible with water in the overhead condensate.
Although it acts to improve the separation performance of most distillation columns, return of reflux condensate to the column increases the heat required in the reboiler.
However, below 3 wt %, the energy of distillation rises rapidly and wi

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Liquid separation by membrane assisted vapor stripping process
  • Liquid separation by membrane assisted vapor stripping process
  • Liquid separation by membrane assisted vapor stripping process

Examples

Experimental program
Comparison scheme
Effect test

example 1

Effect of Non-Condensable Gas on Vapor Stripper, Compressor, and Membrane Systems

[0085]As noted previously, the use of non-condensable gases to strip organic compounds from water followed by the recovery and reuse of the gas has been taught in prior art. In order to test whether the absence of non-condensable gases is advantageous according to the present invention, the efficiency and cost of the compressor and membrane systems required in the process for a hypothetical overhead vapor as a function of non-condensable gas content were estimated. The ethanol-water binary mixture was chosen as the model system. The chemical process simulation program ChemCAD 5.4 (ChemStations, Houston, Tex., USA) was used to perform steady state calculations. ChemCAD was also used for most equipment sizing and costing. Exceptions were liquid pumps, liquid storage tanks and distillation / stripping towers, for which literature sizing / costing relationships were used. Column height was based on an assumptio...

example 2

Production of Fuel-Grade Ethanol from Dilute Fermentation Broths

[0099]The energy usage and capital / operating costs according to the present invention were estimated for the recovery of ethanol from aqueous fermentation broths containing 1 or 5 wt % ethanol. The schematic diagram of the standard configuration of the present invention considered in this example is shown in FIG. 5, which is a schematic diagram of a process according to the present invention in which permeate from the first membrane stage is returned as vapor to act as stripping vapor in the stripping column. Permeate from second stage membrane is directed to the suction side of the overhead compressor. Retentate vapor is optionally condensed by heat exchange with the reboiler.

[0100]Referring with particularity to the drawings, in FIG. 5 there is the feed liquid stream, 43, which feeds into the stripping column, 44. A stream of bottoms liquid or treated liquid, 45, exits the bottom of the stripping column. Said bottoms ...

example 3

Effect of Stripper Pressure and Compressor Discharge Pressure on Energy Usage

[0126]In example 2, the calculated energy benefits of the present invention relative to that of distillation were presented for the separation of ethanol / water mixtures. In that example, the operating temperature of the stripping column for the present invention was fixed at 55° C. In this example, the effect of stripper temperature (which determines the stripper pressure) and of the overhead compressor discharge pressure (which is the same as membrane feed pressure in the present invention) on energy usage for the present invention are calculated for ethanol-water mixtures of 1 and 5 wt % ethanol. The general basis assumptions are the same as those in Example 2 and generic schematic diagrams for the 2- and 3-membrane systems for this example are the same as those in Example 2 and are presented in FIGS. 5 and 11. Raising stripper operating temperature also raises the operating pressure of the stripper, ther...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Fractionaaaaaaaaaa
Fractionaaaaaaaaaa
Temperatureaaaaaaaaaa
Login to view more

Abstract

An improved process for separation of liquid mixtures involves vapor stripping followed by mechanical compression of the vapor which is then exposed to a permeation membrane for separation of the compressed vapor.

Description

FIELD AND BACKGROUND OF THE INVENTION[0001]This invention relates to the field of separation of liquids using stripping means. The process of the invention involves vapor stripping followed by mechanical compression of the vapor which is then exposed to a permeation membrane for separation of the compressed vapor.[0002]Distillation is the most common separation unit operation for miscible liquid mixtures in the chemical industry, including facilities producing ethanol. Although distillation has proven to be a robust and efficient method for removing and concentrating ethanol (EtOH) from fermentation broths, the energy efficiency of distillation declines dramatically below an ethanol concentration of 5 wt %. Processes proposed for the conversion of lignocellulosic biomass and waste materials to ethanol may deliver ethanol concentrations less than 5 wt %. As a result, processes which recover ethanol from water more efficiently than distillation at low concentrations will make lignocel...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C07C29/80B01D3/26C07C45/82B01D61/56
CPCB01D1/28B01D3/002B01D3/145B01D3/38B01D61/36B01D2311/04C07C45/786C07C29/76C07C29/80B01D2311/26C07C31/04C07C31/08C07C31/12B01D61/363
Inventor VANE, LELANDALVAREZ, FRANKLIN R.
Owner VANE LELAND
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap