Method for removing SOx from gas using ethylene glycol composite solution

• US 9,815,017 B2
• Filed: 12/03/2014
• Issued: 11/14/2017
• Est. Priority Date: 12/12/2013
• Status: Active Grant

• Current Assignee: Beijing Boyuan Hengsheng High-Technology Co., Ltd., Peking University, Yongfeng Boyuan Industry Co., Ltd., Jiangxi Province
• Original Assignee: Beijing Boyuan Hengsheng High-Technology Co., Ltd., Peking University, Yongfeng Boyuan Industry Co., Ltd., Jiangxi Province
• Inventors: Wei, Xionghui, Zou, Meihua, Wang, Jun, Chen, Li, Li, Lifang, Sun, Yong, Liu, Jiaxu, Hu, Chun, Li, Xiangbin
• Primary Examiner(s): Vanoy, Timothy C
• Application Number:
  US15/102,291
• Publication Number:
  US 20170021304A1
• Time in Patent Office: 1,077 Days
• CPC Class Codes: B01D 2251/70 Organic acids
• CPC Class Codes: B01D 2252/2023 Glycols, diols or their derivatives
• CPC Class Codes: B01D 2252/2026 Polyethylene glycol, ethers or esters thereof, e.g. Selexol
• CPC Class Codes: B01D 2252/602 Activators, promoting agents, catalytic agents or enzymes
• CPC Class Codes: B01D 2257/302 Sulfur oxides
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 2258/0291 from waste incineration plants
• CPC Class Codes: B01D 53/1425 Regeneration of liquid absorbents
• CPC Class Codes: B01D 53/1481 Removing sulfur dioxide or sulfur trioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/507 by treating the gases with other liquids
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Abstract

An ethylene glycol composite solution is used for removing SO_x from a gas. The ethylene glycol composite solution is made by mixing ethylene glycol and/or polyethylene glycol with an organic acid and/or organic acid salt containing no nitrogen atom in a molecule. The ethylene glycol composite solution is brought into contact with the gas containing SO_x to absorb the SO_x in the gas. The ethylene glycol composite solution loaded with absorbed SO_x is regenerated by heating, vacuuming, gas stripping, ultrasonic treatment, microwave treatment, or radiation treatment to release by-products of sulfur dioxide and sulfur trioxide, and the regenerated ethylene glycol composite solution is recycled for use.

Claims

1. A method for removing SO_x from a gas, comprising:

mixing ethylene glycol, polyethylene glycol, or both ethylene glycol and polyethylene glycol with an organic acid, an organic acid salt, or both the organic acid and the organic acid salt to form a composite solution, wherein the organic acid and the organic acid salt are compounds that contain no nitrogen atoms;

bringing the composite solution into contact with the gas containing SO_x to absorb the SO_x in the gas, wherein SO_x is SO₂, SO₃, or a mixture thereof, and

wherein the composite solution contains one or more additives selected from the group consisting of organic amines, amides, sulfones, sulfoxides, and metallorganic compounds.

2. The method for removing SO_x from a gas according to claim 1, wherein the organic acid is an organic monoacid, an organic polyacid, or a mixture thereof;

the organic acid salt is an organic monoacid salt, an organic polyacid salt, or a mixture thereof.

3. The method for removing SO_x from a gas according to claim 2, wherein the organic acid is selected from the group consisting of formic acid, acetic acid, butyric acid, ethanedioic acid, propanedioic acid, butanedioic acid, tannin acid, polygallic acid, citric acid, and mixtures thereof, and

the organic acid salt is a carboxylic acid salt formed by combining the organic acid with one or more selected from the group consisting of sodium ions, potassium ions, magnesium ions, calcium ions, and transition metal ions.

4. The method for removing SO_x from a gas according to claim 1, wherein the composite solution contain less than 50% in mass of water, and less than 30% in mass of the organic acid, the organic salt, or both.

5. The method for removing SO_x from a gas according to claim 1, wherein a mass content of the additives in the composite solution is less than 10%.

6. The method for removing SO_x from a gas according to claim 1, wherein the composite solution absorbs the SO_x in the gas under atmospheric pressure or an elevated pressure at a temperature of −

20 to 80°

C.

7. The method for removing SO_x from a gas according to claim 1, further comprising regenerating the composite solution loaded with absorbed SO_x by heating, vacuuming, gas stripping, ultrasonic treatment, microwave treatment, or radiation treatment at a temperature of 0 to 300°

C. to release SO_x from the composite solution; and

recycling the regenerated composite solution.

8. The method for removing SO_x from a gas according to claim 1, wherein the gas is a flue gas, a waste gas, an industrial raw material gas containing SO_x, or mixtures thereof.

9. A method for removing SO_x from a gas, comprising:

mixing ethylene glycol, polyethylene glycol, or both ethylene glycol and polyethylene glycol with an organic acid, an organic acid salt, or both the organic acid and the organic acid salt to form a composite solution, wherein the organic acid and the organic acid salt are compounds that contain no nitrogen atoms;

bringing the composite solution into contact with the gas containing SO_x to absorb the SO_x in the gas, wherein SO_x is SO₂, SO₃, or a mixture thereof, the organic acid is selected from the group consisting of formic acid, acetic acid, butyric acid, ethanedioic acid, propanedioic acid, butanedioic acid, tannin acid, polygallic acid, citric acid, and mixtures thereof, and the organic acid salt is a carboxylic acid salt formed by combining the organic acid with one or more selected from the group consisting of sodium ions, potassium ions, magnesium ions, calcium ions, and transition metal ions.