# US 2014/0193319 A1 · Flue gas treatment method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0193319 A1 - Document ID: US20140193319A1 - Status: Published application - Kind: A1 - Application number: 14/150,005 - Filed: 2014-01-08 - Published: 2014-07-10 - Earliest claimed: 2013-01-09 - Assignees: ALSTOM Technology Ltd - Applicants: ALSTOM Technology Ltd - Inventors: Michael Charles BALFE; Peter Kniesburges - Web page: https://patentgrep.com/patent/US20140193319A1 ## CPC - B01D 53/62: Carbon oxides - B01D 53/1406: {Multiple stage absorption} - B01D 53/1475: {Removing carbon dioxide} - B01D 53/501: {by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound} - B01D 53/502: {characterised by a specific solution or suspension} - B01D 53/64: Heavy metals or compounds thereof, e.g. mercury - B01D 53/80: Semi-solid phase processes, i.e. by using slurries - B01D 2251/304: of sodium - B01D 2251/404: of calcium - B01D 2251/604: Hydroxides - B01D 2252/102: Ammonia - B01D 2252/103: Water - B01D 2257/302: Sulfur oxides - B01D 2257/504: Carbon dioxide - B01D 2257/60: Heavy metals or heavy metal compounds - B01D 2258/0233: from cement factories - B01D 2258/025: from metallurgy plants - B01D 2258/0283: Flue gases - F23J 2215/50: Carbon dioxide - Y02C 20/40: of CO2 - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - F23J: REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES (combustion apparatus for consuming smoke or fumes, e.g. exhaust gases, F23G7/06) - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] ## Abstract The present invention relates to a method and system for cleaning a process gas containing carbon dioxide and contaminants, by bringing the process gas into direct contact with an alkaline solution or slurry, and capturing in the alkaline solution or slurry at least a part of the contaminants of the process gas; and bringing the process gas, depleted in contaminants, into direct contact with a cooling liquid to form a cooled process gas; wherein said alkaline solution or slurry is separate from the cooling liquid. ## Claims ### Claim 1 A method of cleaning a process gas containing carbon dioxide and contaminants, said method comprising: bringing the process gas into direct contact with an alkaline solution or slurry, and capturing in the alkaline solution or slurry at least a part of the contaminants of the process gas; and bringing the process gas, depleted in contaminants, into direct contact with a cooling liquid to form a cooled process gas; wherein said alkaline solution or slurry is separate from the cooling liquid. ### Claim 2 (depends on 1) The method according to claim 1, further comprising: bringing the cooled process gas into direct contact with an ammoniated solution or slurry to remove, at least partly, carbon dioxide from the process gas, and to form a process gas containing ammonia; and bringing the process gas containing ammonia into direct contact with a wash liquid to remove, at least partly, ammonia from the process gas. ### Claim 3 (depends on 1) The method according to claim 1, wherein the alkaline solution or slurry comprises NaOH or Ca(OH)2. ### Claim 4 (depends on 1) The method according to claim 1, wherein the alkaline solution or slurry has a pH-value of 8 or higher. ### Claim 5 (depends on 1) The method according to claim 1, wherein the step of bringing the process gas into direct contact with an alkaline solution or slurry is performed at a temperature above the dew point of the process gas. ### Claim 6 (depends on 1) The method according to claim 1, wherein the contaminants include sulfur dioxide, heavy metals and particulate material. ### Claim 7 (depends on 1) The method according to claim 1, wherein the process gas is generated by a cement production facility or a steel production facility. ### Claim 8 (depends on 1) The method according to claim 1, wherein the alkaline solution or slurry containing contaminants captured from the process gas is, at least partly, returned to the process in which the process gas was generated. ### Claim 9 (depends on 8) The method according to claim 8, wherein particulate material captured from the process gas or formed in the alkaline solution or slurry is, at least partly, separated from the alkaline solution or slurry. ### Claim 10 A gas cleaning system for cleaning a process gas containing carbon dioxide and contaminants, said gas cleaning system comprising: an alkaline cleaning system comprising a gas-liquid contacting device operative for removing, at least partly, contaminants from the process gas, by bringing the process gas into direct contact with an alkaline solution or slurry, and capturing in the alkaline solution or slurry at least a part of the contaminants of the process gas; and a cooling system comprising a gas-liquid contacting device operative for cooling the process gas depleted in contaminants by bringing the process gas depleted in contaminants into direct contact with a cooling liquid; wherein said alkaline solution or slurry is separate from the cooling liquid. ### Claim 11 (depends on 10) The gas cleaning system according to claim 10, further comprising: a CO2-absorber comprising a gas-liquid contacting device operative for removing, at least partly, carbon dioxide from the process gas by bringing cooled process gas into contact with an ammoniated solution absorbing at least a part of the carbon dioxide; and an ammonia removal system comprising a gas-liquid contacting device operative for removing, at least partly, ammonia from the process gas, which has been treated in the CO2-absorber and which comprises ammonia, by bringing the process gas containing ammonia into direct contact with a wash liquid. ### Claim 12 (depends on 10) The gas cleaning system according to claim 10, wherein the contaminants include sulfur dioxide, heavy metals and particulate material. ### Claim 13 (depends on 10) The gas cleaning system according to claim 10, wherein said gas cleaning system is integrated with a cement production facility or a steel production facility. ### Claim 14 (depends on 10) The gas cleaning system according to claim 10, wherein the alkaline cleaning system is configured to return, at least partly, alkaline solution or slurry containing contaminants absorbed from the process gas to the process in which the process gas was generated. ### Claim 15 (depends on 14) The gas cleaning system according to claim 14, wherein said alkaline cleaning system further comprises a liquid/solid separator operative for separating, at least partly, solids formed in the alkaline solution or slurry from the solution.