Evaluating Thermal & Catalytic Oxidation Technology for VOC, HAP & Odor Abatement John Strey
Experience Installing Quality Equipment Since 1987 Over 3,000 Air Abatement Systems Installed Worldwide Unbiased Approach & Multi Product Platform Process, Permitting & Operating Assistance
Which Technology is Right For My Project? Evaluate Process Site Project Technology
Process Evaluation Process Description Contaminant Of Concern Expected Concentration Mass Balance Required Removal Efficiency Potential Catalyst Poisons
Site Evaluation Space Allocation Overhead Obstacles i.e. Power Lines Natural Gas or Propane Available Stack Height Voltage & Phase Available Noise Issues
Project Evaluation Project Duration Life Cycle Cost Equipment Vendor Selection Ongoing Support
Technology Evaluation Types of Oxidizers Catalytic Oxidizer Electric or Gas Fired VOC & CVOC Heat Recovery Modules Thermal Oxidizer Electric or Gas Fired VOC & CVOC Catalyst Modules Heat Recovery Modules (Recuperative) Regenerative (RTO) Hybrids
Oxidizer Constants Catalytic Oxidizer Maximum 25% LEL Operating Temperature 600-1200 >98% DRE Thermal Oxidizer Maximum 50% LEL Hybrids >50% LEL Operating Temperature 1400-1800 >99% DRE
Advantages Catalytic Oxidizer Compact Electric More Reliable High Uptime Reliable/Safe Less Expensive Operation CVOC Without Dioxin/Furan Thermal Oxidizer Catalyst Poisons no Factor Effective on Greater Range of Organics Higher DRE Modular
Disadvantages Catalytic Oxidizer Catalyst Poisons Low LEL Thermal Oxidizer Larger Footprint Higher Operating Cost CVOC Dioxin/Furan Potential CO2 /NOx Generation Less Reliable
Electric Catalytic Oxidizer Design Electric pre-heater to achieve operating temperature 304 stainless steel construction Plate & frame or tube & shell heat exchanger Externally insulated External painted jacket Available with or without blower Benefits Greater uptime than gas fired oxidizers Lower cost to install and operate Compact footprint saves real estate Operates on multiple voltages & single or three phase Optional automatic restart after power failure Optional remote re-start Removal efficiencies of >98% on gasoline range organics Disadvantages Maximum LEL throughput is 20% Catalyst can be poisoned Catalyst can be plugged (particulate or other) Catalyst can be damaged (temperature or solvent load)
Gas Fired Catalytic Oxidizer Design Burner pre-heater to achieve operating temperature Internal construction is 304 stainless steel Plate & frame or tube & shell heat exchanger Externally insulated External painted aluminized steel jacket Available with or without blower Benefits Compact foot print saves real estate Operates on multiple voltages, single or three phase Removal efficiencies of >98% on gasoline range organics Can be more economical to run based upon utility cost Disadvantages Maximum LEL throughput is 20% with heat exchanger Catalyst can be poisoned Catalyst can be plugged (particulate or other) Catalyst can be damaged (temperature & solvent load) Must be manually restarted after power failure Greater risk of detonation than electric pre-heat
Chlorinated Catalytic Oxidizer Design Burner or electric pre-heater to achieve operating temperature Construction is 304 stainless steel and externally insulated w/painted jacket Plate & frame or tube & shell heat exchanger Available with or without blower Specialty catalyst required Benefits Compact footprint saves real estate Operates on multiple voltages and single or three phase Can be remotely re-stared (not advisable gas fired) Removal efficiencies of >95% on most chlorinated & fluorinated solvents Utility cost is less than thermal oxidizer Operating temperature 650-930 does not form dioxin/furan Heat exchanger lowers exhaust temperature making acid scrubbing more efficient and less costly Disadvantages Maximum LEL throughput is 15% Catalyst can be poisoned, plugged (particulate) or damaged (high temperature or solvent load) Catalyst is expensive (4X cost of standard catalyst) Multiple analytes can cause removal efficiency issues If required, acid scrubbing adds additional maintenance
Gas Fired Thermal Oxidizer Design Burner pre-heater to achieve operating temperature Internally insulated with high temperature light weight refractory Carbon steel painted shell Available with or without blower Primary or secondary burners Benefits Operates on multiple voltages and single or three phase Operates on natural gas or propane Removal efficiencies of >99% on gasoline range organics Not susceptible to catalyst poisons or particulate Catalyst modules and heat exchange modules can be added Concentrations up to 50% LEL High temperature events typically do not cause damage Disadvantages Must be manually restarted after power failure Greater risk of detonation when processing higher LEL levels Higher operating cost to destroy contaminants
Electric Thermal Oxidizer Design Electric pre-heater to achieve operating temperature Painted carbon steel shell Internal tube & shell heat exchanger Internally insulated Operating temperature range 1400-1600 Benefits Greater up-time vs. gas fired oxidizers Energy efficient & lower operating cost vs. gas fired thermal oxidizer Lower cost to install Operates on multiple voltages and single or three phase Optional automatic restart & remote restart capability Removal efficiencies of >99% on gasoline range organics Not susceptible to catalyst contaminants or high temperature events Can be manufactured catalyst ready Disadvantages Maximum LEL throughput is 30-40% Higher capital cost Larger footprint when compared to electric catalytic Recuperative oxidizer has air flow scale issues
Chlorinated Thermal Oxidizer Design Internally insulated with high temperature light weight refractory Mastic coating or exotic materials of construction required Available with or without blower Primary or secondary burners Operating temperatures 1500-1750 Benefits Operates on multiple voltages and single or three phase Removal efficiencies of >99% on most chlorinated & fluorinated solvents Catalyst /heat exchanger module can be added Maximum LEL throughput is 50% More forgiving on multi-constituent/unknown fume streams Disadvantages High exhaust temperature increases cost of scrubber Acid scrubbing adds additional maintenance requirements Operates in temperature range for dioxin/furan formation Heat exchange is expensive due to temperature and materials Metal heat exchangers do not last long at high temperatures High fuel cost to operate without heat exchanger
Thermal Accelerator Design Effective on free product sites Specialty built burner with burner pre-heater to achieve operating temperature Internally insulated with high temperature light weight refractory w/carbon steel painted shell Primary burner with combustion air Tertiary cooling air blower injects air into the combustion chamber Benefits Accelerates clean up time Operates on multiple voltages and single or three phase Safely process fume streams up to 75,000 ppmv Removal efficiencies of >99% on gasoline range organics Not susceptible to catalyst poisons or particulate or damage from high temperature events Catalyst modules and heat exchange modules can be added Passes hazard analysis in tank farm and refinery applications Works well on exhaust of MPE system with free product Disadvantages Must be manually restarted after power failure Higher operating cost to destroy contaminants at lower solvent levels Capital cost higher than traditional thermal oxidizer Larger footprint required
Regenerative Thermal Oxidizer Design Gas or electric pre-heater Ceramic heat exchange Swing bed adsorption/desorption device Internally insulated with carbon steel painted shell 4-way poppet or butterfly valve configuration Operating range 1,400-1,700 Flow reversed/switched every 5 minutes Benefits 95% effective heat recovery reduces energy cost on high volume low LEL fume streams Self sustaining at 5% LEL Not susceptible to catalyst poisons Ceramic heat exchanger media is tough and hard to destroy Electro-mechanical valve drive means less maintenance >98% removal efficiency Electric pre-heat up to 4,000 CFM Disadvantages High LEL fume streams can cause issues High capital cost & large foot print Requires some field erecting
Catalyst Design Can be metal or ceramic Wash coats are applied to provide more geometric surface area Typical VOC catalysts are >75% platinum Sized on Gas Hourly Space Velocity GHSV 40,000 GHSV = 99% removal efficiency 60,000 GHSV = 95% removal efficiency Cell densities from 200-400 per square inch Ceramic Catalyst Wash coat is applied to give more surface area Typical size is 6 x 6 square blocks Glued together for physical size requirements Can be layered Ceramic catalyst is either dip coated or vacuum impregnated with precious metals Operating temperature range 600-1050 Most chlorinated catalyst is ceramic substrate (Typically 10,000 GHSV) Metal Catalyst Metal catalyst is electro plated with precious metals Can be many shapes Operating temperature range 600-1200 Additional Comments Introducing solvent slowly over catalyst prevents thermal degradation Multiple layers(>2) increase risk of catalyst thermal degradation during higher solvent loading Catalyst can become poisoned quickly and removal efficiency can fall quickly when this happens Catalyst min exhaust temperature should always be >650 when sampling for removal efficiency. All ISE oxidizers/catalysts receive a removal efficiency test prior to shipment
Burners Primary Air Burner Fume Stream Directed into Reactor Independent blower provides burner oxygen requirements More energy required to heat combustion air Reactor sized to accommodate combustion air Flame sighting and spark ignitor out of process Flow turndown 4:1, Heat turndown 40:1 Secondary Air Burner Fume Stream Directed Through Burner Minimum oxygen requirement is 16% Flow turndown 2:1 Heavy moisture can cause problems Flame sighting can be an issue Typically a continuous pilot is used
Gas Trains Design Operating gas pressure 2-5 psig Maximum gas pressure 7 psig Built to NFPA & FM specification Sized to deliver max BTU output Gas booster required under 1 psig Components Particle trap & Y-Strainer Main and pilot line Double blocking valve main & pilot Primary & secondary regulator main & pilot Orifice metering valve for pilot Gas control valve Low and high gas pressure switch Proof of closure main blocking valve
Intellishare s Shop Test Quality Control Quality Heat Exchanger Pressure Test (if equipped) Reactor Pressure Test Integrity Reliability Static Control/Instrument Function Test Dynamic Control/Instrument Function Test Destruction Efficiency Performance Test
Safety Standards Controls UL508 & 793 Wiring NEC & NFPA Burners & Gas Trains NFPA 79 & 86 National Fuel Gas Code NFPA 54, FM & IRI Safety Integrity Level (SIL) Vessels & Ductwork, ASTM, SMACNA P.E. Certified All Employees OSHA 40 Hour Certified
Catalyst Deactivation & Poisoning Agents Substance Effect Remedial Action Coating Agents (rust, dirt, inorganic oxide) Glass Forming Coating Agents (organic silicates/esters, silicones, phosphorous) Poisons Heavy Metal Complexes (mercury, lead, zinc, tin, arsenic) Sulfides Halogens (fluorine, chlorine, bromine, iodine, halogenated hydrocarbons) Organic Droplets & Aerosols Covers catalyst active site Non-phosphate detergent washing Factory reactivation or replacement Covers catalyst active site Non-phosphate detergent washing Factory reactivation or replacement Permanent catalyst deactivation Permanent catalyst deactivation Factory reactivation or replacement Non-phosphate detergent washing Factory reactivation or replacement Covers catalyst active site Remove halogen source Lower concentration of halogens Covers catalyst active site Causes catalyst hot spot Factory reactivation or replacement