Gas scrubber and related processes
AssigneeInvista North America S.A R.L.
InventorsClive Alexander HAMILTON, Robert Edward Neate
Life of this patent
Estimating the term…
Abstract
The invention relates to a method for producing a high molecular weight polyethylene terephthalate (PET) via a solid state polymerization system. The method comprises using an acid catalyst to effectuate the conversion of acetaldehyde present within the system to 2-methyl-1,3-dioxolane, which can be readily removed. The invention also relates to PET prepared via this process, which can advantageously exhibit low levels of acetaldehyde.
Claims33
A method for removing impurities from a process gas, comprising:
- introducing a process gas inlet stream comprising a first concentration of acetaldehyde into a gas scrubbing unit;
- introducing an ethylene glycol inlet stream into the gas scrubbing unit;
- contacting the process gas inlet stream with the ethylene glycol inlet stream in the presence of one or more acid catalysts in the gas scrubbing unit, wherein the acetaldehyde reacts with the ethylene glycol to form 2-methyl-1,3-dioxolane during said contacting step, the contacting step producing a purified process gas stream comprising a second concentration of acetaldehyde lower than the first concentration and an ethylene glycol outlet stream containing 2-methyl-1,3-dioxolane;
- and
- removing the purified process gas stream and the ethylene glycol outlet stream from the gas scrubbing unit.
A gas scrubbing apparatus comprising:
- a housing enclosing a chamber adapted to provide contact between a process gas and a scrubbing liquid, the chamber containing one or more solid acid catalysts;
- a supply of process gas comprising acetaldehyde;
- a first inlet in fluid communication with the chamber and in fluid communication with the supply of process gas comprising acetaldehyde and adapted to introducing the process gas comprising acetaldehyde into the chamber;
- a supply of ethylene glycol;
- a second inlet in fluid communication with the chamber and in fluid communication with the supply of ethylene glycol and adapted to introducing the ethylene glycol into the chamber;
- a first outlet in fluid communication with the chamber and adapted to remove an ethylene glycol stream containing 2-methyl-1,3-dioxolane from the chamber;
- and
- a second outlet in fluid communication with the chamber and adapted to remove a purified process gas stream from the chamber.
The system of claim 29, wherein the polymer is a polyester.
The system of claim 30, wherein the polyester is polyethylene terephthalate.
The method of claim 32, wherein the acid catalyst is present at a concentration between 2 kg/tph of ethylene glycol to 10 kg/tph of ethylene glycol.
The gas scrubbing apparatus of one of claim 34, wherein the acid catalyst is present at a concentration between 2 kg/tph of ethylene glycol to 10 kg/tph of ethylene glycol.
Dependencies are inferred from the claim text.