Dairy farm biogas plant
MTU gas engine, 1,200 kW
98.76% measured NOx reduction
Treats: Nitrogen oxides (NOx)
SCR (Selective Catalytic Reduction) system
Urea-based selective catalytic reduction that cuts NOx in genset exhaust to meet the site emission limit. Closed-loop dosing control, sized for each engine.
- Treats
- Nitrogen oxides (NOx)
- Engines
- Gas and diesel gensets up to 5 MW
- Reductant
- 32.5% urea solution (AUS 32 / DEF)
- Configuration
- One system per engine, or up to 4 engines on one common system
How SCR works
- 1
Urea dosing
A dosing pump feeds 32.5% urea solution to an injector in the hot exhaust, upstream of the catalyst.
- 2
Mixing
A mixer spreads the spray across the duct. In the heat the urea breaks down into ammonia (NH₃).
- 3
Catalytic reduction
On the SCR catalyst, ammonia reacts with NOx and turns it into nitrogen and water vapour.
- 4
Closed-loop control
The control unit reads NOx sensors and exhaust temperature, and adjusts the dosing rate to hold the target and keep ammonia slip low.
What the system includes
- SCR reactor with catalyst
- Urea tank and urea dosing pump
- Dosing injector and mixer
- Control cabinet with NOx and exhaust temperature sensors
- Motorized maintenance bypass, where the site needs one
- Backflow prevention valve when several engines share one system
Where it is used
- Fuels
- Natural gas, food-waste and farm biogas, landfill gas, diesel
- Engines in our projects
- Jenbacher, MTU and Cummins gensets, among others
- Sites
- From a single genset to a site with 14 gas engines
- Combined with
- DOC and DPF on diesel gensets; acoustic enclosure for noise
Biogas and landfill gas can carry siloxanes and H₂S that poison the catalyst. We ask for a gas analysis and the gas pre-treatment details before sizing.
Specifications
Every system is sized for the engine and site, so we do not publish standard sizes. Send your engine data sheet and emission or noise limit, and we reply with a configuration and the values we can achieve.
What we need to size it
- Engine make, model and rating, and number of units
- Exhaust flow and temperature at typical load
- Raw NOx and the NOx limit, with reference O₂
- Fuel type, and a gas analysis for biogas or landfill gas
- Space available and a site layout, if possible
Projects with this product
Landfill site power plant
14 Jenbacher J320 gensets, 14,000 kW in total
85% NOx reduction
CCHP energy station
4 Cummins C1540 N5CC gas engines, 6,000 kW in total
92-93% NOx reduction in operation
Request a quote
Send the engine model, fuel and the emission limit for your site. An engineer replies with a first assessment.
- Engine make, model and number of units
- Fuel type, and a gas analysis for biogas
- NOx limit with reference O₂, and any noise limit
- Site layout or exhaust drawings, if available
Prefer to call or write directly?