Article
We reduce emissions. We multiply sustainability.
A concise summary of the company’s value proposition across PM, NOx, CO and HC reduction on existing machinery.
Read articleGoal: zero emissions and safer operation
Diesel retrofit for reducing emissions in mining, tunnels and rail
Filter Solutions designs, integrates and installs DOC, DPF and SCR solutions to reduce NOx, particulate matter, CO and HC on heavy machinery, rail equipment, stationary engines and special applications. Our approach combines diesel retrofit engineering and the adaptation of assets to new emission requirements without replacing the whole machine, with particular focus on mining and tunnels, rail and industrial machinery.
Technical summary
Diesel retrofit makes it possible to reduce emissions and adapt to regulation without replacing the full machine.
Filter Solutions integrates DOC, DPF and SCR systems for mining, tunnels, rail and industrial applications where control of NOx and particulate matter is critical.
+90%
Reduction of NOx, PM, CO and HC depending on system and application
360°
Assessment, design, installation, validation and maintenance
Retrofit
Asset adaptation without replacing the full machine
B2B
Solutions for mining, rail, industry and civil works
Applications
Underground mining and tunnels
Dresinas, tampers and profiling machines
Heavy machinery and off-road equipment
Industrial stationary engines
Heavy vehicles and special applications
Engineering, integration, installation, validation and maintenance with a single technical partner.
Engineering company specialised in retrofit and emissions reduction in Spain
Filter Solutions develops solutions for mining and tunnels, rail and industrial machinery, helping companies comply with environmental rules without replacing equipment. Our work focuses on diesel retrofit and on adapting machinery to stricter emission requirements through aftertreatment systems designed for demanding industrial environments. We also work on projects for heavy machinery and applications where the reduction of particulate matter and NOx is critical from a technical, preventive and operational perspective.
Heavy machinery emissions
We study emissions reduction for heavy machinery in industrial applications, civil works, mining and environments with growing environmental restrictions, prioritising retrofit solutions over unnecessary replacement.
Mining machinery emissions and particulate filters
We design strategies for emissions from mining machinery and particulate filters by combining DOC, DPF and SCR technologies according to engine type, available space and reduction target.
Keys to reducing emissions without replacing machinery
A well-planned retrofit strategy makes it possible to act on NOx, particulate matter, CO and HC without completely redesigning the machine. In many projects, the starting point combines integrated solutions such as NOxBUSTER®, feasibility analysis and a review of the applicable regulatory context, especially in environments regulated by RD 427/2021.
Services
From the initial study to system maintenance
Custom assessment
We analyse the machine, engine, available space, temperatures, duty cycle and emissions target before designing the solution, with support from technical and regulatory criteria.
Installation and maintenance
We integrate the aftertreatment system and support the project with technical assistance, maintenance, cleaning and operational follow-up in high-demand industrial applications.
Emissions reduction
We develop DOC, DPF and SCR configurations to adapt to each application and achieve measurable improvements in NOx, PM, CO and HC, from compact layouts to full systems such as NOxBUSTER®.
Telemetry and monitoring
With solutions such as PROCARE Drive, supervision of the system and emissions performance can be integrated into day-to-day operation.
Solutions
Emission-reduction systems and applications
Own technology
NOxBUSTER®
Combined DPF + SCR system for reducing NOx, PM, CO and HC in demanding industrial applications.
- NOx reduction above 90%
- Particulate reduction above 90%
- Strong CO and HC reduction
- Useful for targets aligned with Stage/Tier V references
Own technology
PROAIR®
High-efficiency diesel particulate filter focused on particulate reduction in heavy machinery and industrial diesel applications.
- Particulate reduction above 90%
- Strong CO and HC reduction
- Continuous regeneration approach
- Low-maintenance integration
Own technology
PROCAT™
DOC catalyst for reducing CO and HC and acting as part of a wider emissions-control strategy.
- CO reduction above 90%
- HC reduction above 90%
- Compact and robust DOC solution
- Useful in specific industrial duty cycles
Application
Mining retrofit
Adaptation of underground and mining diesel machinery to reduce emissions without replacing the full machine or redesigning the whole platform.
- NOx and particulate reduction
- Improved underground air quality
- Alternative to full fleet renewal
- Compliance-oriented engineering
Application
Tunnel application
Solutions for enclosed or poorly ventilated environments where occupational exposure, operational continuity and diesel-emission control are critical.
- NOx and particulate reduction
- Air-quality improvement
- Ventilation support
- Engineering tailored to tunnel work
Application
Rail application
Diesel aftertreatment integration for rail maintenance equipment operating in tunnels, depots and other demanding environments.
- Dresinas, tampers and profiling machines
- On-operation emission reduction
- Adaptation without replacing the asset
- Better fit for enclosed rail environments
Sectors
Where retrofit creates the greatest operational value
Mining and tunnels
Aftertreatment solutions for underground diesel machinery where ventilation, occupational exposure and continuity of operation are decisive.
View sector pageRail
DOC, DPF and SCR integration for rail maintenance equipment operating in tunnels, depots and other demanding environments.
View sector pageHeavy machinery
Retrofit for heavy equipment to reduce emissions and extend asset life without unnecessary redesign.
View sector pageStationary engines
Emission-control systems for industrial stationary engines and power-generation applications.
View sector pageCompliance · operation · procurement
A weak emissions strategy can affect operation, compliance and access to projects
If you operate in mining, tunnels, rail or special machinery applications, it is worth reviewing your current fleet and defining which retrofit path best fits each engine, duty cycle and emissions target.
Content reviewed by specialists
The technical information published by Filter Solutions is reviewed by the company’s engineering team and backed by real implementation experience in mining, tunnels, rail and industrial diesel platforms.
Technical blog
We publish regulatory summaries, technical comparisons and case-based articles to help engineering, maintenance and operations teams understand practical diesel emissions decisions.
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Emission limit for mining and tunnels: February 2026
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Read articleFAQ
Frequently asked questions about diesel retrofit and emissions control
Is it legal to retrofit instead of buying a new machine?
Yes. Retrofit is often the most practical route when the machine is still operationally useful but must adapt to stricter emissions targets with less cost and less downtime than full replacement.
Can older machinery be adapted without changing the engine?
Yes. Through DOC, DPF and SCR systems, the impact of older engines can be reduced without replacing the full asset, after a technical review of space, temperature, load and duty cycle.
Which sectors does Filter Solutions serve?
Mainly underground mining, tunnels, rail, stationary engines and heavy industrial machinery.
How can NOx be reduced in diesel machinery?
NOx reduction is usually approached through SCR solutions and combined DOC or DPF configurations defined according to operating temperature, available space, engine load and regulatory target.