Talk to the Engineers Behind Clean Exhaust

A diesel oxidation catalyst (DOC) turns carbon monoxide and unburnt hydrocarbons into CO₂ and water. A diesel particulate filter (DPF) traps soot and burns it off as CO₂. Selective catalytic reduction (SCR) converts nitrogen oxides into nitrogen and water using ammonia made from AUS 32.

Above 56 kW the CPCB IV+ limit is 0.40 g/kWh NOx (0.67 g/kWh above 560 kW) with 0.02–0.03 g/kWh PM. Most engines need urea SCR plus a DPF to reach that. Up to 56 kW the combined NOx + HC limit is 4.7 g/kWh, where a DOC + DPF and sometimes a urea-less SCR is enough.

Urea-less SCR reduces NOx without AUS 32. It suits compact 19–75 kW engines where an AUS 32 tank, its heater and refill logistics are impractical, and it keeps working at low exhaust temperatures.

A small fraction of the fuel burned, depending on engine-out NOx and load. The ATCU doses in closed loop on NOx sensor feedback so you only use what the catalyst needs.

Nitrogen dioxide from the DOC burns soot continuously at normal exhaust temperatures (passive regeneration). When a genset runs cold for long periods, the oxidation booster raises the inlet temperature to burn the soot off (active regeneration). Ash, which does not burn, is cleaned out at service intervals.

A retrofit emission control device is aftertreatment fitted to a DG set that is already installed. Several pollution control boards and the Commission for Air Quality Management require RECDs with at least 70 % particulate capture efficiency on in-use sets, especially in Delhi NCR and large cities.

After a site survey and design, the device is usually fitted in a single shift, followed by commissioning and an emission check for your compliance file.

We size every system inside the engine maker’s backpressure limit, so rated output is maintained. Sizing starts from your engine data and exhaust temperature profile.

Yes. We work with Indian OEMs and build canned substrates, dosing hardware and complete systems to drawing for export partners in Germany, the Czech Republic and the USA from our MEPZ unit in Chennai.

Yes. Urea SCR covers 75–800 kW, Urea-Free SCR System covers 19–75 kW, the compact SCR module covers 15–50 kW and DOC + DPF DOC + DPF covers 50–150 kW, with the ATCU controlling dosing and diagnostics.

It combines particulate filtration, urea-based NOx reduction and ammonia slip control in a single catalyst unit for stationary diesel engines, particularly in the 1,000–10,000 kVA segment. It is designed to be compact, to manage exhaust back pressure and to simplify installation, subject to engine-specific validation, and it supports CPCB IV+ and CAQM Direction No. 76 requirements where applicable.

Yes. Maxmoc develops its own urea dosing pump, injector, After-Treatment Control Module and active regeneration technology. Urea tank modules come from 25 L to 1,000 L with a proprietary level measurement module (designed for ±1 percentage point accuracy under the specified conditions), urea quality measurement and data logging, using sensors we develop and make ourselves.

Maxmoc reports that its retrofit system has been tested at ICAT on selected older-generation CPCB I and CPCB II engines, with test reports available for the relevant configurations. Compliance through retrofit depends on the engine model, rating, duty cycle, installation and applicable approvals, so share your engine data and review the ICAT reports to confirm the exact scope.

At our canning and assembly unit in the Madras Export Processing Zone, Tambaram, Chennai, where every unit is flow, leak and backpressure tested and traceable from substrate to dispatch.

Commissioning, ash cleaning, spares, calibration updates and remote diagnostics through the Aftertreatment controller, with field support across India.