Reflux condenser

Abstract

Methods, apparatus, and processes are provided for a condenser including flowing a vapor stream including formaldehyde into a tube bundle in a vertical upflow reflux condenser, where a tube in the tube bundle has a length to outside diameter ratio of greater than about 170:1, flowing a cooling fluid on a shell-side of the vertical upflow reflux condenser to condense at least a portion of the vapor stream, where the condensed portion of the vapor stream forms a wetted tube internal surface area on each tube in the generally upright tube bundle; and maintaining the vapor stream velocity at a rate that provides a liquid residence time where formaldehyde condensed on the wetted internal surface area of each tube can react with water to form methylene glycol, removing at least sixty percent (60%) of formaldehyde from the vapor stream fed to the condenser.

Description

technical field [0001] The present disclosure relates to a method and system for removing formaldehyde from a formaldehyde-containing vapor stream. More specifically, the present disclosure relates to an improved process for condensing a formaldehyde-containing vapor feed stream to remove formaldehyde from the vapor feed stream and recover a desired product. Background technique [0002] When ethylene oxide is produced by the silver-catalyzed vapor-phase partial oxidation of ethylene by molecular oxygen, a gaseous reaction effluent is obtained. This effluent can be extremely dilute relative to the desired ethylene oxide product, containing from about 0.3 mole percent to about 5 mole percent of the desired species. [0003] Since the ethylene oxide effluent is very dilute in the gaseous mixture produced by the oxidation reaction, this mixture is subsequently subjected to various treatments (absorption, distillation, flashing, etc.) to obtain pure ethylene oxide. However, th...

AI Technical Summary

Problems solved by technology

On the other hand, in this process, if the overhead stream contains low formaldehyde concentrations, the relative amount of ethylene oxide therein may be in excess, resulting in a loss of yield of the desired purified material

Images