Carbon dioxide for pH control CO2 Clean technology for pH reduction airliquide.ca food.airliquide.com CO2 VS Acids For many years, strong acids were used to control pH levels in water treatment facilities, most commonly, sulfuric acid. Acid products do the job, but have many potential problem: acids are difficult to control and are potentially dangerous to store and handle; safety showers have to be installed and made available for operating personnel, who must also wear special protective clothing. Comparative neutralization curve of mining effluent (660 mg/l CaCO3) Corrosive acid requires special materials for equipment and piping. Maintenance of systems demands frequent component repairs and replacement. Carbon dioxide (CO2), on the other hand, is safe to handle, easy to apply, efficient, and ecologically safe. H2SO4 CO2 When pH control is critical to your process or effluent quality, you can trust the CO2 solution. Acid added (mg/l) Description: When dissolved in water, CO2 forms a weak acid: carbonic acid. This substance reacts immediately with alkalis such as caustic soda, sodium carbonate, and dissolved lime, turning them into neutral carbonates and bicarbonate salts. CO2+H2O H2CO3+2NaOH H2CO3+Na2CO3 H2CO3 Na2CO3+2H2O 2NaHCO3 + – Carbonic acid is a mild acid present in water as ions H and HCO 3 , which are highly reactive. They will immediately react with the CO32-- and OH ions that are responsible for the alkalinity of water. Adding more CO2 forms bicarbonate ions with a pH of 8.3. Under lower pH, free CO2 starts to form with a lower technically feasible pH of ~5.2 under pressurized conditions. pH Control: CO2 is introduced into high-pH water by means of a diffuser and/or venturi nozzle, which are installed in an existing pressurized pipe, a recirculation loop, or at the bottom of a basin. Fine CO2 bubbles are released by the diffusers and/or venturi and dissolved into the high-pH water. A pH probe is installed downstream of the gas injection point, measuring the pH of the water after the absorption of CO2. A pH control manifold automatically adjusts gas flow and achieves high efficiency and reliability with little supervision from plant personnel. Advantages: There is no secondary pollution introduced into the treated water by salts such as chlorides (from HCl) or sulfates (from H2SO4). The introduction of CO2 will contribute to the chemical equilibrium of water by forming carbonates and bicarbonate compounds. Supply Modes: For small requirements, carbon dioxide can be supplied in liquid cylinders. Larger volumes will be delivered by truck and stored on-site in a bulk CO2 storage tank supplied by Air Liquide. Typically, CO2 is available at a pressure of up to 300 psig and so doesn't require any pump for its transfer into your process. Applications: CO2 is used in various industrial waste water processes: • Pulp and paper • Textiles • Cooling towers • Food plants (cheese, dairy, slaughtering) • Bottling • Potable water solids removal and recarbonation • SAGD boiler blow-down water, tailings, mining • Dissolved air flotation AIR LIQUIDE PROPOSES: A pH control system that is safe for the environment • CO2 is inert and non-corrosive • CO2 dissipates safely into the atmosphere, leaving no residue to be neutralized • Acid leaks must be neutralized with alkaline solutions to prevent damage to equipment or the environment • No special alloy or plastic distribution piping is required for the CO2 system Regulation: • Eliminate risk of over-acidification No maintenance: • Components of the system are installed and maintained by Air Liquide’s experienced technical team Flexibility: • Liquid CO2 can treat streams pH as high as pH 14 These features ensure efficient control and quick reaction to any process pH change or flow variation. FINDING SOLUTIONS IS IN OUR NATURE AIR LIQUIDE CANADA INC. Head Office 1250, Rene-Levesque Blvd West Suite 1800 Montreal, Quebec H3B 5E6 Telephone: (514) 933-0303 Fax: (514) 846-7700 Contact one of Air Liquide 11201 Ray-Lawson Blvd. Anjou, Québec ALTEC Group – Environnement H1J 1M6 Phone: 514 356-7647 Telephone (514) 356-7600 Fax:Fax: 514(514) 351-0531 351-0531 Québec Customer Centre 225 Fortin Vanier, Québec G1M 3M2 Telephone (418) 683-1917 Fax: (418) 683-4906 Lake Ontario Customer Centre 5315 North Service Road Burlington, Ontario L7R 4L8 Telephone (905) 335-4877 Fax: (905) 335-0301 Northern Ontario Customer Centre Canada’s food specialists: 1297 Kelly Lake Road Ontario, Quebec and Atlantic: 416 702-8107 ALTEC Group - Environment Western Canada: 780 410-8851 Telephone: (450) 641-6218 food@airliquide.com Fax: (450) 641-6239 www.food.airliquide.com / www.airliquide.ca Air Liquide Canada inc. Head Office Atlantic Customer Centre 280 John Street 1250 Rene-Levesque Blvd West Moncton, Suite 1700 New Brunswick E1C 9W3 Montreal, Quebec H3B 5E6 Telephone (506) 857-3280 Phone: 514 933-0303 Fax: (506) 857-9734 Fax: 514 846-7700 airliquide.ca Montréal Customer Centre Southwestern Ontario Customer Centre 351 Eleanor Street London, Ontario N5W 6B7 Telephone (519) 455-3990 Fax: (519) 455-3828 Sudbury, Ontario P3E 5P5 Telephone (705) 674-7777 Fax: (705) 674-0517 Midwest Customer Centre 58 Weston Street Winnipeg, Manitoba R3E 3H7 Telephone (204) 989-9353 Fax: (204) 779-1047 Calgary Customer Centre 3004 54 Avenue S. E. Calgary, Alberta T2C 0A7 Telephone (403) 777-4700 Fax: (403) 777-4727 Edmonton Customer Centre 10020 56 Avenue Edmonton, Alberta T6E 5Z2 Telephone (780) 438-5600 Fax: (780) 438-2801 Pacific Customer Centre 23231 Fraserwood Way Richmond, British Columbia V6V 3B3 Telephone (604) 676-3900 Fax: (604) 676-3901 World leader in gases, technologies and services for Industry and Health, Air Liquide is present in 80 countries with more than 50,000 employees and serves more than 2 million customers and patients. Oxygen, nitrogen and hydrogen have been at the core of the company’s activities since its creation in 1902. Air Liquide’s ambition is to be the leader in its industry, delivering long-term performance and acting responsibly. NOTE: This document is intended for general information purposes only and is not intended as a representation or warranty of any kind, or as a statement of any terms or conditions of sale. The specifications are solely for informational purposes and shall be subject to change at the sole discretion of Air Liquide Canada Inc. at any time. The specifications and information are believed to be correct, but are not warranted for correctness or completeness, or for applicability to any particular customer or situation. Air Liquide Canada Inc, its affiliates and subsidiaries, as applicable, disclaim all liability directly or indirectly in connection with the use of any Note: This brochure is intended for general information or specification provided herein. information purposes only and is not intended as a representation or warranty of any kind, or as a statement of any terms or conditions of sale. The information herein is believed to be correct, but is not warranted for correctness or completeness, or for applicability to any particular situation. © 2015customer Air LiquideorCanada inc.The terms and conditions of any sales transactions that may occur between Air Liquide and any customer shall be set forth in the agreement by theofparties. ASPAL issigned a trademark L’Air Liquide, Société Anonyme pour l’étude et l’exploitation des procédés Georges Claude
© Copyright 2024