Purified Terephthalic Acid Catox & Scrubbing Systems Brochure (PDF 1.14 MB)

Purified Terephthalic AcidCatox & Scrubbing SystemsBETTER AIR IS OUR BUSINESSHigh & Low PressureCatox SystemsStandardScope of Supply• Steam Preheater• Gas Preheater• Hot Gas Generator• Recirculating Fan• Catalytic Reactor• Catalyst• Main Recuperative Heat Exchanger• Bypass Valves• High Pressure HBR Scrubber• Process Gas Drier• Process InstrumentationSimple Process, High EfficiencyPurified terephthalic acid (PTA) is a raw material used inthe production of Polyester and other synthetic materials.In the production of PTA, exhaust gases from the reactorcontain such contaminants as acetic acid, bromine andother volatile organic compounds which must be oxidizedin a catalytic oxidizer (catox) before the gas can be usedin the plant through an expander, used for material con-veying or vented to atmosphere.AirScience is a known provider of catox systems to thePTA industry. The company has supplied high pressurecatox systems with external hot gas generators and heatexchangers as well as high pressure catox systems withinternal flameless catalytic burner section. AirScience has also supplied multiple low pressure Catoxsystems with associated water seal, heat exchangers andexhaust stack.Catalyst selection and material of construction are key tobuilding an efficient catox system which will resist thecorrosive environment of the PTA vent gases.steamprocess gassteampreheaterfuelhot gasgeneratorrecuperativeheatexchangergas preheaterheat exchangerPTA catalyticreactorrecirculatingfanpurgeexhaustcoldbypassTo High Pressure HBr Scrubber& Process Gas Dryer Indirect Heating - High PressureCatox SystemTo High Pressure HBr & Process Gas Dryer for material conveying system burnercatalyst steamprocess gasfuelPTAcatalyst To Low Pressure HBr Scrubbing System and stackgas expandergas mixersteampreheaterDirect Heating - High PressureCatox Systemprocess gasfueldirect gaspreheaterrecuperativeheatexchangerPTA catalyticreactorsteamsteampreheatercoldbypassTo Low Pressure HBr Scrubberand stackvent to atmospherewatersealStandardScope of supply• Steam Preheater• Catalytic Reactor• Internal Flameless Burner• Gas Mixing Devices• Catalysts• High Pressure HBR Scrubber• Process Gas Drier• Low Pressure HBR Scrubber• Process InstrumentationDirect Heating - Low PressureCatox SystemStandardScope of supply• Water Seal• Steam Preheater• Main Recuperative Heat Exchanger• Direct Gas Preheater• Catalytic Reactor• Catalyst• Bypass Valves• Low Pressure HBR Scrubber• Process Instrumentation Desiccant Air DryersWell Proven HeatlessDrying TechnologySimple Process, High EfficiencyWet process gas enters a coalescing pre-filter, then passesthrough the inlet valve assembly and is directed towards chamberI where the clean gas passes upward through the desiccant. Gasdrying takes place by adsorption. Dry gas from chamber I outletthen passes through the outlet valve assembly and through theafter-filter to the dry gas receiver tank.While gas is being dried in chamber I, the desiccant in chamberII which has been humidified in the previous cycle, is beingsimultaneously regenerated. Chamber II is de-pressurized, in thedownward direction, and the vent gas is released to atmospherethrough a purge valve. A controlled portion of dry gas is used toflush out the desorbed moisture from chamber II desiccant.When the regeneration is complete, the purge valve is closed andchamber II is slowly re-pressurized to line pressure for a smoothchangeover. A drying period of 5 minutes provides an efficientdew point of -40°C or better (at atmospheric pressure). In regen-eration process approximately 60 seconds are required for re-pressurization.Simple Installation, High SatisfactionAirScience Process Gas Heatless Desiccant Dryers are factoryskid-mounted and pre-commissioned. They are fully automatic andrequire no operator. All operations take place automatically andGas Purity remains consistent. StandardScope of supply• Moisture separator with automatic drain• Replaceable cartridge type pre-filter• Twin vessel desiccant gas dryer with PLC controlled change-over valves• Vent exhaust silencer• Replaceable cartridge type after-filter• Pressure release safety valve• Pressure indicators and transmittersAPPROX. SPACE REQUIREMENT (MM)M)Factory Skid-ounted & Pre-commissioned Air Dryer Model ListPIPE LINE MODEL M3/HR CFM SIZE (MM) L W HANHLD-09 500 300 40NB 1200 1200 2400ANHLD-10 700 400 50NB 1200 1200 2400ANHLD-11 850 500 50NB 1400 1400 2400ANHLD-12 1000 600 50NB 1400 1400 2400ANHLD-13 1300 750 80NB 1500 1500 2500ANHLD-14 1700 1000 80NB 1600 1600 2600ANHLD-15 2125 1250 80NB 1600 1600 2600ANHLD-16 2550 1500 100NB 2000 2000 3000ANHLD-17 3400 2000 100NB 2000 2000 3000ANHLD-18 4250 2500 100NB 2000 2000 3000ANHLD-19 5100 3000 125NB 2000 2000 3000ANHLD-20 5950 3500 150NB 2000 2000 3000ANHLD-21 6800 4000 150NB 2000 2000 3000AfterFilterDry Air ReceiverControlPanelDesiccantAir DryersPreFilterHeatless Type Desiccant Drying TechnologyHigh and Low PressureHBr SystemsSimple Process, High EfficiencyPTA process gases ventedfrom the catox systems contain bromine which hasto be removed from the gas stream prior to any further use or venting toatmosphere.HBr scrubbers as they are commonly called are foundon the low pressure as wellas the high pressure vent gas lines. Typicallythe low pressure scrubbers will be highvolume flow and will be built out of fiberglassreinforced plastic (FRP). The high pressurescrubbers are small actual gas flow andare typically polymer lined carbon steel.As the process gas contains carbon dioxideand hydrogen bromide, caustic based reagentwill react preferentially with carbon dioxide.To remedy this situation AirScience hasdeveloped a specific reagent mix thatensures optimum reduction of hydrogenbromide without parasitic reaction withcarbon dioxide. bromine absorber clean gasto atmospherevent to atmospherewater sealbromine absorber High PressureHBr Scrubbing TechnologyLow PressureHbr Scrubbing TechnologyStandardScope of Supply• Water Seal and Stack• Scrubber Vessel and Stack• Recirculating Pumps• Spray Header and Nozzles• Demister Pad and Backwash System• Random Packing• Level, Temperature, Pressure Drop ControlsStandardScope of Supply• Scrubber Vessel with Internal Lining• Random Packing• Spray Header and Nozzles• Demister Pad and Backwash System• Recirculating Pumps• Level, Temperature, Pressure Drop ControlsCANADA1751 Richardson, suite 3525Montréal, Québec H3K 1G6Phone:(514) 937-4614Fax: (514) 937-4820EMail: sales@airscience.netINDIA410 - 4th floor, Sarthik SquareBodakdev, Ahmedabad, 380054Gujarat, IndiaTel: 91 79 40029591Fax: 91 79 40029595Dubai OfficeTel: 971 50 6508434Fax: 971 43 970533EMail: sales@airscience.netMEXICOAndes 93-ACuarta seccion lomass verdesNaucalpan de JuarezEdo. de MexicoPhone: (52) 55 5343-7480(52) 55 5344-7157(52) 55 5344-7158Fax: (52) 55 3623-4320EMail: sales@airscience.netwww.airscience.ca