Browse Prior Art Database

Method of extracting a salty wastewater stream of the MDA production process

IP.com Disclosure Number: IPCOM000246890D
Publication Date: 2016-Jul-12
Document File: 2 page(s) / 97K

Publishing Venue

The IP.com Prior Art Database

Abstract

The salty wastewater stream of the diamino diphenyl methane (MDA) production process hereinafter referred to as "brine" contains high boiling organics like Aniline and MDA which are difficult biodegradable and cannot be easily removed from the brine by standard stripping processes. Some other impurities like phenol, Ammonium, and methanol cam be removed by standard stripping processes. The process is based on extracting the wastewater with a continuous liquid/liquid extractor using toluene. The toluene is sent to a rectification column where it is separated from the heavier boilers (aniline and MDA). The toluene is reused and also the recovered aniline and MDA are reused. The brine solution leaving the liquid extractor is free of high boiling organics but contains toluene. Toluene can easily be stripped from the brine by using standard stripping technologies like nitrogen or live steam stripping.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 51% of the total text.

Page 01 of 2

Method of extracting a salty wastewater stream of the MDA production process Summary

The salty wastewater stream of the diamino diphenyl methane (MDA) production process "here after referred to as brine" contains high boiling organics like Aniline and MDA which are difficult biodegradable and cannot be easily removed from the brine by standard stripping processes.

Some other impurities like phenol, Ammonium, and methanol cam be removed by standard stripping processes.

The process is based on extracting the wastewater with a continuous liquid/liquid extractor using toluene. The toluene is sent to a rectification column were it is separated from the heavier boilers (aniline and MDA). The toluene is reused and also the recovered aniline and MDA are reused.

The brine solution leaving the liquid extractor is free of high boiling organics but contains toluene. Toluene can easily be stripped from the brine by using standard stripping technologies like nitrogen or live steam stripping.

Extraction process

The extraction of brine is done in an Liquid/Liquid extraction column packed with random packing, structured packing or trays like sieve trays or dual flow trays. Preferable non-fouling or cleanable internals are used in this application.

The extraction is done in the temperature range of 40C to 110C but preferable between 60C and 80C. The mass ratio of toluene to brine is in the range of 0.1~0.2 to 1 but preferable
0.12 ~ 0.16 to 1.

The ratio of the toluene to brine is mainly determined by the strength (NaCl% in brine) higher NaCl concentration will require lower mass ratio of toluene to brine since the solubility of aniline and MDA is lower at the higher NaCl concentrations.

With an optimized design it is possible to achieve very low levels of high boilers in the bottom stream of the Liquid/Liquid extraction tower...