- NATURAL GAS GENERATOR EMISSIONS CONTROL | POWER GENERATION
QNOX™ NSCR System
3-WAY CATALYST + INTEGRATED SILENCER
An integrated Three-Way Catalyst (NSCR) and silencer in a single compact package. Custom engineered for rich-burn and stoichiometric stationary natural gas generators. Standby, prime power, and continuous-duty applications.
99%
NOₓ REDUCTION
98%
CO REDUCTION
97%
HC REDUCTION
BUILT FOR NATURAL GAS
POWER GENERATION
Reliable emissions control for every critical power application.
DATA CENTERS
Mission-critical backup power you can depend on. Zero tolerance for permit risk or downtime.
HOSPITALS
Emergency standby systems where uninterrupted operation is a regulatory and patient safety requirement.
UTILITIES
Peak shaving and grid support where strict emissions permit requirements apply at every site.
MANUFACTURING
Continuous-duty prime power for non-stop industrial operations that can’t tolerate permit disruptions.
SYSTEM OVERVIEW
How the Q-NOX™ NSCR System Works
The Q-NOX™ system uses a single three-way catalyst to treat all three regulated pollutants at once. Closed-loop air-fuel ratio control keeps the engine at stoichiometric, the narrow window where NOₓ, CO, AND HC are converted simultaneously on one catalyst. No filter, no reductant, no separate slip stage.
3-Way Catalysis
NOₓ CO, and HC reduced in a single catalyst. One pass, no separate filter stage.
No Reductant Required
No DEF, no dosing system, no reductant storage. Nothing to refill.
High Efficiency
Up to 99% NOₓ, 98% CO, 97% HC reduction across real-world duty cycles.
Low Maintenance
Long service intervals. Accessible catalyst elements for inspection and replacement
Built for Reliability
Internally insulated. Engineered for standby, prime, and continuous-duty operation.
FREQUENTLY ASKED QUESTIONS
BlueMAX™ PLUS-Series Common Questions
Find quick answers about the PLUS-Series SCR + passive DPF system for stationary diesel power generation.
What catalyst is used for natural gas engines?
Rich-burn (stoichiometric) natural gas engines use a 3-way catalyst, also called NSCR (Non-Selective Catalytic Reduction). It simultaneously reduces NOₓ, CO, and hydrocarbons in single catalyst assembly with no reductant required. Lean-burn natural gas engines instead use an oxidation catalyst or SCR.
How does a 3-way catalyst work?
As exhaust passes through the precious-metal-coated substrate, NOₓ is chemically reduced to nitrogen and water vapor while CO and hydrocarbons are oxidized to carbon dioxide and water vapor. All three reactions happen at once, which is only possible when the engine runes near stoichiometric air-fuel ratio.
How is a NSCR different from a SCR?
SCR injects a urea-based reductant (DEF) to reduce NOx and is used on lean-burn engines. NSCR requires no reductant and works on rich-burn and stoichiometric engines, where the exhaust chemistry lets NOₓ reduction and CO/HC oxidation occur together on one catalyst.
Do I need NSCR or SCR for my natural gas generator?
It depends on your engine. Rich-burn (Stoichiometric) engines use NSCR. Lean-burn engines require SCR, such as NETT’s BlueMAX™ 500 and 520 series. Check your engine’s combustion type or contact us and we’ll confirm the right technology for your unit.
How much does it reduce emissions?
Up to 99% NOₓ, 98% CO, and 97% HC reduction. Actual performance depends on engine type, operating conditions, catalyst sizing, exhaust temperature fuel quality and maintenance.
Is the QNOX™ EPA or CARB verified?
QNOX™ systems are custom engineered to help operators meet EPA, state and local emissions requirements. Verification programs like CARB’s apply to specific product and application combinations; contact us to discuss the compliance pathway for your project and jurisdiction.
Can it be retrofitted to an existing generator?
Yes. QNOX™ systems are available for OEM, retrofit and replacement applications, in standalone catalyst or integrated catalyst-silencer configurations, including compact packages for space-constrained installations.
Still have questions?
Our emissions control experts are here to help.
GET STARTED
Ready to Meet Your Emissions Requirements?
Talk to a NETT Technologies solutions expert about your natural gas generator 3-way catalyst (NSCR) requirements. Scoped, engineered, and delivered as one integrated aftertreatment system.
- Free application review with an emissions solutions expert
- Customized installation & maintenance manuals
- Standalone or integrated configurations available
- OEM and retrofit ready
READY TO SPEC YOUR SYSTEM?
Custom Installation? Not a Problem!
Tell us your engine, site, and compliance requirements. Our engineers will scope the right natural gas generator emission control device for your application.
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