Begg Cousland Envirotec Limited applications
Air or SO2 is dried with H2SO4 before being fed to the sulphur burner or converter. The Drying Tower can be under pressure or under suction, with the main gas blower being, respectively, in front of or after the tower. The physical limit of drying is 3 mg/SCF of gas as H2O (= 16 mg/SCF as H2SO4) Large particles (>3 microns) are mechanically entrained from the acid distribution system or packing, typically as a load of 500 – 750 mg/m3. As the Drying Tower operates at relatively low temperature, mist is not thermodynamically formed.
Process Information: Case A Conventional H2SO4 Process: In a sulphur burning or metallurgical double absorption H2SO4 plant where no Oleum is produced upstream, SO3 gas exits the third catalyst pass, is cooled down and enters the first ( = intermediate ) absorption tower, where H2SO4 is distributed over ceramic packing to absorb the SO3. When the gas exits the I.A.T. it returns to the converter to go into the fourth catalyst pass after being reheated in a gas/gas heat exchanger. Due to the high inlet gas temperature and the relatively low inlet acid temperature, mist is formed thermodynamically and acid droplets are mechanically entrained from the acid distribution system or packing. In such processes the mist and droplets combine typically as a load of 2,000 – 2,500 mg/m3. The particle size spectrum will be sub-micron to medium sized ( 0.3 to 8 micron )
Tail Gas Scrubber Process Information: The SO2 conversion rate of single absorption plants is lower than double absorption, and many single absorption plants installed tail gas scrubbers to reduce this SO2 content rather than convert the plant to double absorption. Scrubbing the tail gas (tail gas scrubbing) to acceptable SO2 emission values can be done with seawater, caustic, lime slurry, hydrogen peroxide or ammonia. After exiting the absorber tower, the gas enters a tail gas scrubber tower where ammonia (NH3) is injected and contacts the SO2. Ammonium Sulphite and Bi-sulphite are formed and some of these salts are entrained in the exit air. These salts are soluble, but can be emitted in quite large volumes, e.g. 2,000 – 15,000 mg/m3 and are generally < 3 microns in size, with a large amount < 1 mircron.
Electrolysis of brines with chlorine production at the anode and hydrogen together with sodium or potassium hydroxide at the cathode.
Electrolysis of brines with chlorine production at the anode and hydrogen together with sodium or potassium hydroxide at the cathode.
Electrolysis of brines with chlorine production at the anode and hydrogen together with sodium or potassium hydroxide at the cathode.
Process Information: Electrolysis of brines with chlorine production at the anode and hydrogen together with sodium or potassium hydroxide at the cathode.
Process Information: SO3 gas is used in a sulphonation reaction process. Fibre filters which are installed before the sulphonation reactor remove very fine oleum mists. The SO3 gas (6-7%) can contain up to 7,000 mg/m³ of oleum mists, and due to the highly exothermic reaction, it is normal to trace heat and insulate the vessel to prevent oleum freezing.
Process Information: SO3 gas is used in a sulphonation reaction process. Fibre filters which are installed after the sulphonation reactor remove up to 4,000 mg/m³ sulphonated hydrocarbon mist. Due to the high viscosity liquid produced with over sulphonisation, it is recommended (a) to have a stand-by filter unit in parallel, or (b) to have an irrigated demister unit in front of the fibre filters; in any case a Δp metered wash spray system is normal on the candle filters, and the vessel may be trace heated and insulated.
Process Information: Candle Filters can be used in the dry process (electric furnace) described below; the phosphate rock is sintered or nodulized to facilitate escape of phosphorus vapours in the furnace and to prevent the blowing over of dust. After sintering, the material is sized and the fines returned to the sintering machine. Coke and sand are added and the materials charged to the electric furnace. The temperature of the furnace is approximately 2400 ºF.
Phosphor Bronze Processing – Phosphoric Acid / P2O5 Filtration Systems. Process Information: Phosphorous is injected into a bath of molten copper, to produce Phosphor Copper metal. There is then a fume produced from the reaction in the bath, which is extracted by a fan to a filter system, before the cleaned air is then emitted to atmosphere. P2O5 mists are entrained with the fume, and frequently carbon solids are entrained also. (The origin & nature of the Phosphorous is a major factor in the quantity of carbon). Mist Load up to 2,000 mg/m3.
Begg Cousland Envirotec have a close collaboration with Lebracs Rubber in the Phosphoric Acid sector, where the service conditions are stringent with elevated temperature of up to 110 ºC, high pressure and Vacuum service. You can source these materials though us also. Lebracs Rubber has a range of corrosion resistant rubber compounds which meets the Service Conditions of Phosphoric Acid, Slurry, Fluorosilicic Acid and other Corrosive chemicals.
Process Information: Hydrochloric Acid can be emitted from many industrial processes, where it is either used in that form, or generated from the process. HCl will usually be in fine, sub-micron mist form. The gas comes from the process or vapours are drawn to the chimney by a suction fan. Example: In a PVC processes the VCM gas is condensed and the liquid is then fed to a reactor, before passing H2O seal boxes and gas tank stages, prior to compression. At some stage the gas must be neutralised in an absorbing tank of NaOH flakes. HCl mist load typically 50 ppm.
Process Information: Hydrochloric Acid can be emitted from many industrial processes, where it is either used in that form, stored with tank ventilation, or generated from the process. HCl will usually be in fine, sub-micron mist form. The gas comes from the process or vapours are drawn from the tank into a scrubber by a suction fan.
Process Information: Hydrochloric Acid can be emitted from many industrial processes, where it is either used in that form, or generated from the process. HCl will usually be in fine, sub-micron mist form. The gas comes from the process or vapours are drawn to the chimney by a suction fan. In a Titanium Dioxide Chloride process there are emissions of TiO2 dust along with HCl, and after one or more gas scrubbing stages (see also section 18.2), fibre bed mist eliminators are installed to capture the HCl mist.
Process Information: Hydrochloric Acid can be emitted from many industrial processes, where it is either used in that form or generated from the process. HCl will usually be in fine, sub-micron mist form. The gas comes from the process and vapours are drawn into a scrubber by a suction fan. Titanium Dioxide Chloride process – emissions of TiO2 dust and HCl mist.
PROCESS INFORMATION: Most common manufacturing applications are Synthetic Leather (car upholstery, bags, shoes etc.), vinyl coated and linoleum flooring, vinyl coated wallpaper, laminated sheets (special films, belts, tarpaulins) and foam products. Polyvinyl-chloride (PVC) is a thermoplastic and is mixed to additives which improve its properties and enable it to be processed more easily
Process Information: Hydrochloric Acid can be emitted from many industrial processes, where it is either used in that form, stored with tank ventilation, or generated from the process. HCl will usually be in fine, sub-micron mist form. The gas comes from the process or vapours are drawn from the tank into a scrubber by a suction fan. Pharmaceutical plant - general process vent emissions of HCl.