Chimney for plume reduction in a CO2 capture installation
The vent stack design addresses the visibility issue of NO2 plumes in CO2 capture plants by diluting the gas with ambient air, achieving complete plume invisibility by mixing it with atmospheric air to reduce NO2 concentration below 10 ppm.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Utility models
- Current Assignee / Owner
- LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE
- Filing Date
- 2025-05-23
- Publication Date
- 2026-05-01
AI Technical Summary
Existing chimney designs for CO2 capture plants fail to effectively reduce the visibility of NO2-induced reddish plumes due to insufficient gas dilution, which becomes visible when NO2 concentration exceeds 10 ppm.
A vent stack design that dilutes the evacuated gas with ambient air by using a venturi or fan to mix it with atmospheric air, reducing NO2 concentration to below 10 ppm before release, thereby eliminating plume visibility.
The design completely eliminates the visibility of NO2 plumes by ensuring the gas is diluted to a concentration below 10 ppm, making the plumes less noticeable.
Abstract
Description
Title of the invention: Chimney for reducing plumes in a CO2 capture installation
[0001] INTRODUCTION
[0002] The object of the present invention is to propose a chimney design capable of reducing the visibility of the plume from the chimneys of CO2 capture plants, and in particular the red coloration due to a high NO2 content in the gas released into the air by the chimney.
[0003] STATE OF THE ART
[0004] The chimneys of industrial emitters are essentially designed by choosing an appropriate chimney height, diameter and material, in order to resist erosion / corrosion due to the evacuated gases and to ensure that, under all conditions, the evacuated gases have an outlet velocity high enough to ensure good dispersion of pollutants, but low enough to avoid generating excessive noise.
[0005] The height of the chimney is chosen according to the dispersion of pollutants and depends at least partially on the speed of the evacuated gases.
[0006] In some cases, steam may be injected into the gas vented from the chimney in order to correct the colour of the plume of gas vented to the air, to make it more aesthetically pleasing and / or less visible.
[0007] PROBLEM SOLVED BY THE INVENTION
[0008] This invention proposes a new design aimed at eliminating the colouring of the evacuated gas, and is particularly useful when applied to CO2 capture plants which may have a high NO2 content in the evacuated gas, resulting in a reddish colour plume.
[0009] DESCRIPTION OF THE INVENTION
[0010] It is known that the red colouring of the plume of gas released to the air can become very visible when the concentration of NO2 in the gas released to the air is greater than 10 ppm.
[0011] As the evacuated gas disperses into the atmosphere and the concentration of NO2 decreases, the plume gradually becomes less visible.
[0012] The present invention relates to a vent stack for a gas from a CO2 capture installation comprising an elongated hollow body open at the top to the atmosphere and means for bringing the gas containing NO2 into the elongated hollow body, the body comprising means for diluting the gas before venting it to the atmosphere by mixing it with atmospheric air. The capture installation comprises means for separating a gas comprising CO2 and NO2 for produce a gas or liquid enriched in NO2 which must be released into the air by sending it to a chimney open to the atmosphere and comprising an elongated hollow body.
[0013] This invention aims to completely eliminate the visibility of the plume before it exits the chimney, by diluting the evacuated gas with ambient air.
[0014] This objective can be achieved in different ways: • If the gas network upstream of the chimney has sufficient pressure, a venturi can be constructed inside the chimney to accelerate the gas sufficiently to avoid negative pressure at the venturi throat; by design, the venturi throat can be open to the atmosphere and allow enough air to enter so that the mixture with the gas to be evacuated dilutes the NO2 to a concentration < 10 ppm and thus eliminates the visibility of the plume. • If the gas network upstream of the chimney does not have sufficient pressure to push the gas through a venturi, a fan can be installed at the chimney inlet to provide the necessary pressure. • Another solution would be to install a fan at the chimney inlet which would directly push air to mix with the gas in the chimney and dilute the NO2 to a concentration < 10 ppm, thus eliminating the visibility of the plume, or at least reducing the red colour.
Claims
[Claim 1] Demands Venting stack for a gas from a CO2 capture installation comprising an elongated hollow body open upwards to the atmosphere and means for bringing the gas containing NO2 inside the elongated hollow body, the body comprising means for diluting the gas before sending it to the atmosphere by mixing it with atmospheric air.