Catalytic Oxidizer

Low-temperature and high-efficiency carbon monoxide purification solution

CO Technology Overview

A catalytic oxidizer (CO) is an advanced waste gas treatment device that uses a catalyst to oxidize carbon monoxide (CO) and other volatile organic compounds (VOCs) into carbon dioxide (CO₂) and water (H₂O) at relatively low temperatures (300-500°C). Compared with thermal oxidation, catalytic oxidation technology significantly reduces energy consumption and operating costs, and is particularly suitable for treating low-to-medium concentration, high-volume CO waste gas.

Working Principle

Catalytic oxidation achieves efficient CO purification through four steps:

 

  1. Exhaust gas preheating: Exhaust gas is preheated to the catalyst ignition temperature via a heat exchanger.
  2. Catalytic oxidation: An oxidation reaction occurs on the catalyst surface: 2CO + O₂ → 2CO₂
  3. Heat recovery: The heat of reaction is recovered via a heat exchanger to preheat the inlet gas.
  4. Purified emission: The compliant gas is emitted through a chimney after catalytic oxidation.
CO process diagram

Why choose Catalytic Oxidizer?

 

Core Advantage Comparative Analysis

Advantage Feature

<

Catalytic Oxidizer (CO)

<

Traditional Thermal Oxidizer (TO)

<

RTO

 

<
Operating Temperature 300-500°C 760-1200°C 760-950°C
Energy Consumption Reduced by 40-70% High Extremely low (at high concentrations)
Startup Time 15-30 minutes 1-2 hours 45-90 minutes
Space Requirement Compact, saves 30-50% Relatively large Moderate
Suitable Concentration 100-5,000 ppm High concentration Wide range

 

Our catalytic oxidation system ensures compliance with:

USA

  • EPA Method 25A for CO
  • EPA Method 25 for VOCs

EU

  • EN 13649 sampling standard
  • Compliant with the IED Directive

China

  • GB 16297-1996
  • DB11/501-2017 (Beijing local standard)

Typical Application Scenarios

Automobile Manufacturing and Painting

  • Drying oven exhaust gas: CO concentration 200-800ppm, containing VOCs
  • Welding fumes: Local exhaust treatment
  • Challenges: Large air volume, fluctuating concentration, contains siloxanes
  • Solution: Front-end adsorption concentration + catalytic oxidation system

Printing and Packaging

  • Flexographic and gravure printing exhaust gas: alcohols, esters, solvents, containing CO
  • Complex process exhaust gas: a mixture of multiple pollutants
  • Solution: specialized anti-silicon catalyst, periodic regeneration process

Electronics and Semiconductor Manufacturing

  • CVD process exhaust gas: Contains silanes and CO, easily forming silica.
  • Solution: Two-stage pretreatment + high-temperature catalyst.
  • Special design: Prevents dust ingress, protecting the catalyst.
Automotive painting industry

Chemicals and Pharmaceuticals

  • Reactor exhaust: intermittent emission with large concentration variations
  • Solvent recovery tail gas: low concentration of CO and VOCs
  • Solution: buffer system + adaptive control catalytic oxidation
Chemicals and Pharmaceuticals
Printing and Packaging Industry

Food processing

  • Drying and baking exhaust gas: contains aldehydes and CO, high humidity
  • Challenge: Contains grease and dust, easily contaminating the catalyst
  • Solution: High-efficiency filtration + waterproof catalyst coating
Food processing
Electronics manufacturing industry

Case Studies

 

🏭 Large Automobile Painting Plant Drying Oven Exhaust Treatment

📋 Project Background

Exhaust gas from painting line drying oven in an automobile manufacturing plant

Air volume: 80,000 Nm³/h

🔬 Exhaust Gas Characteristics

  • CO: 300-600 ppm
  • VOCs: 200-400 mg/Nm³ (mainly n-hexane, xylene)
  • Temperature: 120-150°C (partially preheated)
  • Contains trace amounts of siloxanes (from sealants)

🔧 Solution

Pretreatment System:

  • Electrostatic precipitator to remove overspray paint mist
  • Activated carbon adsorption for siloxanes
  • Bag filter for final filtration

Catalytic Oxidation System:

  • Plate heat exchanger with 75% heat recovery efficiency
  • Precious metal catalyst with 240°C ignition temperature
  • Four-zone temperature control for optimized energy consumption

Intelligent Control System:

  • Automatically adjusts burner power based on concentration
  • Catalyst temperature protection logic
  • Real-time energy efficiency monitoring and optimization

Operational Results

  • CO removal efficiency: 99.2%
  • VOCs removal efficiency: 98.5%
  • Energy consumption: 45% more efficient than RTO方案
  • Operating temperature:
    • Inlet preheated to 320°C
    • Reaction temperature 380°C
  • Fuel consumption: 25 Nm³/h natural gas (average)
  • Investment payback period: 1.8 years
  • Annual operating cost savings: $120,000

 

FAQ

 

 

Frequently Asked Questions

Catalytic Oxidation Systems & Emission Control

1. What are the core differences between catalytic oxidation and RTO?

Catalytic Oxidizers (CO) achieve pollutant oxidation at 300-500°C with the help of catalysts, while RTOs perform thermal oxidation at 760-950°C using heat storage ceramics. The core differences are:

  • Energy consumption: CO saves 40-70% in fuel consumption
  • Startup time: CO requires only 15-30 minutes, RTO needs 45-90 minutes
  • Concentration suitability: CO optimally handles 100-5,000ppm, RTO suits a wider range
  • Investment cost: CO systems typically cost 20-40% less than RTOs

Application recommendation: Choose CO for low-medium concentration, intermittent emissions; choose RTO for high concentration, continuous emissions.

2. How do catalysts handle siloxane poisoning?

We employ a three-level protection strategy:

1. Pretreatment interception:
  • Front-end activated carbon adsorption (targeting siloxanes)
  • Electrostatic precipitation + bag filtration (removing dust)
  • Siloxane online monitoring system
2. Catalyst protection:
  • Silicone-resistant formulated catalyst (with silicon scavenger added)
  • Layered design: protective layer + reaction layer
  • Regular high-temperature regeneration procedure (650°C to remove deposits)
3. System design:
  • Bypass system (automatic switching during high silicon levels)
  • Catalyst activity monitoring system
  • Predictive maintenance algorithm

Practical case: A Dutch automotive painting plant using this solution extended catalyst life from 6 months to 3 years.

3. How does the system handle halogen-containing (chlorine, fluorine) exhaust gases?

Special design is required to prevent acid corrosion and dioxin formation:

  • Material upgrade: Reactor uses Inconel 625 or Hastelloy C-276
  • Temperature control: Maintain above 850°C to ensure complete decomposition
  • Post-treatment: Quench tower + caustic washing tower (neutralizing HCl/HF)
  • Monitoring requirements: Continuous monitoring of HCl, HF and dioxin precursors
  • Compliance guarantee: Meets Dutch BAT conclusion documents for halogen-containing exhaust gases

4. How to ensure compliance with the latest requirements of the Dutch Omgevingsdienst?

Our system incorporates four compliance modules:

1. Real-time monitoring module:
  • CO analyzer (EN 15267-3 certified)
  • VOC online monitoring (compliant with EN 13649)
  • Data recording meets NTA 8075 standards
2. Report automation:
  • Automatic generation of quarterly emission reports
  • Automatic alarm and event recording for exceedances
  • Electronic reports directly connected to environmental department systems
3. Compliance verification:
  • Annual third-party performance verification
  • BAT compliance statement documents
  • Complete operation and maintenance records
4. Continuous updating:
  • Regulatory dynamic tracking service
  • Regular software updates
  • Annual compliance audit

5. What Netherlands-specific safety certifications are required for the system?

Required certifications include:

  • ATEX explosion-proof certification (Zone 1 & Zone 2)
  • PGS 28 safety distance compliance certificate
  • CE marking (Machinery Directive, Pressure Equipment Directive)
  • SIL 2 Safety Integrity Level certification
  • NEN-EN-ISO 13702 emergency system certification

Additional service: We provide full certification application assistance, reducing certification time by an average of 60%.

6. What is the catalyst replacement cycle and cost?

Typical economic analysis (30,000 Nm³/h system):

Catalyst lifespan:
  • Normal operating conditions: 3-5 years (24,000-40,000 hours)
  • Severe operating conditions: 2-3 years (with regeneration maintenance)
Cost structure:
  • New catalyst cost: €45,000-€75,000 (approximately 15-25% of system)
  • Regeneration service: €15,000-€25,000 (restores 90%+ activity)
  • Spent catalyst recycling: €5,000-€10,000 return value (precious metal recovery)
Optimization solutions:
  1. Activity monitoring package (3 months advance warning)
  2. Regeneration service contract (extends service life by 50%)
  3. Trade-in program (30% discount on new catalyst)

7. How to handle sharp concentration fluctuations in exhaust gases?

We provide intelligent buffering solutions:

Concentration adaptive control:

At low concentrations (<500ppm):

  • Reduce preheating temperature to 280-320°C
  • Decrease fan frequency
  • Enter energy-saving standby mode

At high concentrations (>2,000ppm):

  • Automatically activate cold air blending
  • Maximize heat recovery
  • Start excess heat utilization system
Physical buffering solutions:
  • Exhaust gas buffer tank (15-30 minutes buffering capacity)
  • Adsorption concentration rotor (concentrates low concentrations 10-20 times)
  • Multi-reactor parallel design (adapts to production fluctuations)

8. What is the system’s energy recovery potential?

Typical energy recovery solutions:

Recovery method options:
  1. Hot air recovery (simplest):

     

    • Temperature: 150-250°C
    • Applications: process preheating, space heating
    • Efficiency: 60-75%
  2. Hot oil system (medium temperature):

     

    • Temperature: 200-300°C
    • Applications: process heating, steam generation
    • Efficiency: 70-80%
  3. Steam generation (high temperature):

     

    • Pressure: 4-10 bar
    • Applications: process steam, power generation
    • Efficiency: 75-85%
  4. Organic Rankine Cycle power generation:

     

    • Power generation efficiency: 8-15%
    • Investment payback period: 3-5 years
    • Suitable for: >10,000 Nm³/h large systems

Economic benefit example:

Processing capacity: 50,000 Nm³/h

Exhaust gas temperature: 400°C reduced to 150°C

Recovered heat: 4.2 MW

Annual benefit: €150,000-€250,000 (subject to natural gas price fluctuations)

9. How to choose a catalytic oxidation solution for automotive manufacturing painting lines?

Based on European automotive plant experience, recommended solutions:

Painting exhaust gas characteristics:
  • VOC: 200-800 mg/Nm³ (contains benzene series, esters)
  • CO: 100-400 ppm
  • Siloxanes: trace amounts (from sealants)
  • Operation mode: intermittent, following production rhythm
Solution comparison:
  1. Direct catalytic oxidation (suitable for small-medium scale):

     

    • Investment: €300,000-€500,000
    • Energy consumption: 25-40 Nm³/h natural gas
    • Features: simple and reliable, easy maintenance
  2. Zeolite rotor + catalytic oxidation (suitable for large air volume):

     

    • Investment: €800,000-€1,200,000
    • Energy consumption: reduced by 60-70%
    • Features: ultra-high concentration processing capacity
  3. Hybrid system (RCO + waste heat utilization):

     

    • Investment: €1,000,000+
    • Features: energy self-sufficient, zero fuel consumption

Success case: A Mercedes-Benz painting plant in the Netherlands adopted solution 2, achieving:

65% energy reduction

VOC removal efficiency >99%

Annual savings of €180,000

Dual certification by German VDA and Dutch environmental authorities