Retrofit Emission Control Devices for DG Sets

By Aceget Private Limited 07-05-2026 86

In India’s rapidly urbanizing and industrializing landscape, diesel generator (DG) sets remain a critical backup power source. From residential complexes to hospitals and industrial units, DG sets ensure uninterrupted operations during power outages. However, this reliability comes at a cost of significant air pollution. Emissions from DG sets contribute to particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HC), all of which degrade air quality and impact human health.

To address this growing environmental concern, regulatory authorities such as the Central Pollution Control Board (CPCB) have introduced stringent emission norms. One of the most effective solutions to meet these norms, especially RECD for DG set is the adoption of Retrofit Emission Control Devices (RECDs).

Understanding DG Set Emissions and Their Impact

Diesel generators operate by burning fuel, which produces exhaust gases containing harmful pollutants. In densely populated regions like Delhi-NCR, DG sets are considered a major contributor to localized air pollution, particularly during power shortages or peak demand periods.

The primary pollutants emitted include:

Particulate Matter (PM): Fine particles that penetrate deep into lungs
Nitrogen Oxides (NOx): Contribute to smog and respiratory issues
Carbon Monoxide (CO): A toxic gas affecting oxygen delivery in the body
Hydrocarbons (HC): Lead to ground-level ozone formation

Given these risks, regulatory intervention has become essential.

CPCB Emission Norms for DG Sets

The CPCB, under the Ministry of Environment, Forest and Climate Change, has established emission standards to regulate DG set pollution. These norms have evolved over time and are becoming increasingly stringent.

Key Features of CPCB Norms

Emission Limits:
DG sets must comply with specified limits for PM, NOx, CO, HC, and smoke opacity.
Implementation Timeline:
Updated norms are expected to be mandatory for new gensets from July 2025 onward.
Stack Height Requirements:
Proper exhaust and stack height must be maintained to ensure dispersion of pollutants.
Certification and Testing:
DG sets must be tested and certified by authorized agencies such as ARAI or ICAT.

What is a Retrofit Emission Control Device (RECD)?

A Retrofit Emission Control Device (RECD) is an add-on pollution control system installed on existing DG sets to reduce harmful emissions without replacing the generator.

These devices are particularly useful for older DG sets that were manufactured before stricter emission norms came into force.

Key Functions of RECD

Reduces particulate matter and gaseous pollutants
Improves combustion efficiency
Ensures compliance with CPCB standards

RECDs can reduce emissions by up to 70-96% depending on technology and operating conditions.

Working Principle of RECD

RECD systems use a combination of filtration and catalytic processes to clean exhaust gases:

Filtration:
Diesel particulate filters (DPF) capture soot and fine particles
Oxidation:
Catalysts convert CO and HC into less harmful substances
Reduction:
Advanced systems reduce NOx emissions
Regeneration:
Self-cleaning mechanisms burn accumulated particles to maintain efficiency

Types of RECD Technologies

Depending on the DG set capacity and application, different RECD technologies are used:

Dry Type Systems: Use catalytic converters and filters
Wet Type Systems: Use scrubbing solutions to remove pollutants
Hybrid Systems: Combine multiple technologies for enhanced performance

These systems can be installed across a wide range of DG capacities, typically from 25 kVA to over 2500 kVA.

Importance of CPCB Approval

Using a CPCB-approved RECD ensures:

Verified emission reduction performance
Compliance with regulatory standards
Acceptance during inspections by pollution control boards

Benefits of Retrofit Emission Control Devices

1. Environmental Benefits

RECDs significantly reduce air pollutants, contributing to improved air quality and reduced health risks.

2. Regulatory Compliance

They help organizations meet CPCB norms and avoid penalties or operational disruptions.

3. Cost-Effective Solution

Retrofitting is far more economical than replacing an entire DG set with a new compliant model.

4. Extended Equipment Life

Improved combustion and reduced soot buildup can enhance the lifespan of DG sets.

Challenges in Implementation

Despite their benefits, RECD adoption faces certain challenges:

Initial Investment: Installation costs may deter small operators
Awareness Gaps: Many DG set owners are unaware of updated norms
Compliance Monitoring: Enforcement remains inconsistent in some regions
Technical Compatibility: Not all DG sets are easily retrofitted

However, increasing regulatory pressure and awareness are gradually overcoming these barriers.

Conclusion

Retrofit Emission Control Devices (RECDs) represent a practical and effective solution to reduce emissions from existing diesel generator sets. As CPCB norms become stricter and enforcement intensifies, industries and institutions must proactively adopt these technologies to ensure compliance.

Beyond regulatory obligations, RECDs contribute to a larger environmental mission reducing air pollution and safeguarding public health. In a country where energy reliability and environmental sustainability must coexist, retrofitting DG sets is not just a compliance requirement but a responsibility toward cleaner air and a sustainable future.

Tags : recd RECD for DG Set CPCB CPCB-approved CPCB-compliance Retrofit Emission Control Device Aceget Private Limited

Share on social media