Method of processing liquid containing ammonia nitrogen from semiconductor fabrication machine

Patent metadata

Field	Value
Publication number	US-12459841-B2
Application number	US-202217818297-A
Country	US
Kind code	B2
Filing date	Aug 8, 2022
Priority date	Aug 8, 2022
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

The present disclosure provides a method of processing a liquid containing ammonia nitrogen from a first semiconductor fabrication machine. The method includes: adsorbing a plurality of ammonium (NH4+) ions in the liquid; desorbing the plurality of NH4+ ions to a solution; converting a fraction of the plurality of NH4+ ions into a plurality of ammonia (NH3) molecules; and electrolyzing the plurality of NH3 molecules to become a plurality of hydrogen (H2) molecules and a plurality of nitrogen (N2) molecules.

First claim

What is claimed is:

1 . A method of processing a liquid containing ammonia nitrogen from a first semiconductor fabrication machine, the method comprising:
adsorbing a plurality of ammonium (NH 4 + ) ions in the liquid; transferring the plurality of adsorbed NH 4 + ions to an aqueous solution which is substantially neutral; adding sulfuric acid to the aqueous solution to desorb the plurality of adsorbed NH 4 + ions by forming a plurality of ammonium sulfate ((NH 4 ) 2 SO 4 ) molecules in the aqueous solution; adding an alkaline solution to the aqueous solution to convert a fraction of the plurality of ammonium sulfate molecules into a plurality of ammonia (NH 3 ) molecules; and electrolyzing the plurality of NH 3 molecules to become a plurality of hydrogen (H 2 ) molecules and a plurality of nitrogen (N 2 ) molecules.

2 . The method of claim 1 , further comprising collecting the liquid from the first semiconductor fabrication machine before the adsorption of the NH 4 + ions in the liquid.

3 . The method of claim 1 , further comprising adjusting a pH value of the solution to be greater than 11 at room temperature.

4 . The method of claim 1 , further comprising transporting the plurality of H 2 molecules to a hydrogen supply system for supplying hydrogen gas to a second semiconductor fabrication machine different from the first semiconductor fabrication machine.

5 . The method of claim 1 , wherein the plurality of NH 4 + ions are adsorbed by a zeolite or an aluminum oxide (Al 2 O 3 ) compound.

6 . The method of claim 1 , wherein after the desorption of the plurality of NH 4 + ions to the solution, a concentration of the plurality of NH 4 + ions in the solution is greater than a concentration of the plurality of NH 4 + ions in the liquid.

7 . The method of claim 1 , wherein before the electrolysis of the plurality of NH 3 molecules, the fraction is greater than 90%.

8 . The method of claim 1 , wherein the plurality of ammonium sulfate ((NH 4 ) 2 SO 4 ) react with the alkaline solution in the aqueous solution.

9 . A method for producing hydrogen gas from a liquid containing ammonia nitrogen, the method comprising:
collecting the liquid from a semiconductor fabrication machine; adsorbing a plurality of NH 4 + ions in the liquid; transferring the plurality of adsorbed NH 4 + ions to an aqueous solution which is substantially neutral; adding sulfuric acid to the aqueous solution to desorb the plurality of adsorbed NH 4 + ions by forming a plurality of ammonium sulfate ((NH 4 ) 2 SO 4 ) molecules in the aqueous solution; increasing a temperature of the aqueous solution to be greater than 40° C.; adding an alkaline solution to the aqueous solution to convert the plurality of ammonium sulfate molecules into a plurality of ammonia (NH 3 ) molecules; and decomposing the plurality of NH 3 molecules into a plurality of H 2 molecules and a plurality of N 2 molecules.

10 . The method of claim 9 , further comprising supplying the plurality of H 2 molecules to a semiconductor production tool through a hydrogen storage system or a gas transport system.

11 . The method of claim 9 , wherein a first concentration of the plurality of NH 4 + ions in the liquid containing ammonia nitrogen is increased to a second concentration of the plurality of NH 4 + ions in the aqueous solution after the adsorption and the desorption of the plurality of NH 4 + ions.

12 . The method of claim 9 , wherein the adsorption of the plurality of NH 4 + ions in the liquid containing ammonia nitrogen includes using a cation exchange resin.

13 . The method of claim 9 , wherein before the decomposition, a fraction of the plurality of NH 3 molecules in the aqueous solution is greater than 90% by adjusting the pH value of the aqueous solution and maintaining the temperature of the aqueous solution.

14 . The method of claim 9 , wherein the alkaline solution includes sodium hydroxide (NaOH) and potassium hydroxide (KOH).

15 . The method of claim 9 , wherein the plurality of NH 3 molecules are decomposed by electrolysis.

16 . The method of claim 9 , wherein before the decomposition of the plurality of NH 3 molecules, in the solution, an amount of the plurality of ammonia molecules is controlled to be greater than 9 times an amount of the plurality of ammonium ions.

17 . A method for providing hydrogen gas to a semiconductor production tool, comprising:
providing an aqueous medium having a first concentration of NH 4 + ions; passing the aqueous medium through a zeolite to trap the NH 4 + ions by the zeolite; transferring the NH 4 + ions trapped by the zeolite to an aqueous solution which is substantially neutral; adding sulfuric acid to the aqueous solution to release the NH 4 + ions from the zeolite by forming ammonium sulfate ((NH 4 ) 2 SO 4 ) molecules in the aqueous solution; increasing a pH value of the aqueous solution to be greater than 11 at room temperature to convert a fraction of the (NH 4 ) 2 SO 4 molecules into NH 3 molecules; electrolyzing the NH 3 molecules to produce H 2 molecules and N 2 molecules; and providing the H 2 molecules to the semiconductor production tool.

18 . The method of claim 17 , wherein the zeolite includes clinoptilolite.

19 . The method of claim 17 , wherein the electrolysis of the NH 3 molecules is performed under a condition that keeps the pH value of the solution greater than 11 at room temperature.

20 . The method of claim 17 , wherein the NH 3 molecules are electrolyzed under a condition of pH value greater than 10 at or temperature greater than 40° C.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Lin En Tian
• Weng Chiao-Ling

Classifications

• C02F1/586

  by removing ammoniacal nitrogen (for biological methods C02F3/00) · CPC title

• C02F2001/425

  using cation exchangers · CPC title

• C02F2103/346

  from semiconductor processing, e.g. waste water from polishing of wafers · CPC title

• C02F2101/16

  Nitrogen compounds, e.g. ammonia · CPC title

• C02F1/42

  by ion-exchange (ion-exchange in general B01J) · CPC title