Retrofitting Compact SCR™ and      Diesel Particulate Filters to a Passenger Ferry        

This page updated April 19, 2007.

Engine, Fuel and Emissions Engineering, Inc. 

Retrofitting Compact SCR and
Diesel Particulate Filters to a Passenger Ferry

Technology and Innovation
The emission control system to be demonstrated would combine a simplified, Compact SCR™ system with a catalyst-coated silicon-carbide diesel particulate filter (DPF). The DPF is designed for passive regeneration under normal vessel cruise conditions, with a manually-activated active regeneration system as a backup. An exhaust bypass is provided to protect the SCR™ catalyst from thermal damage during DPF regeneration, and to ensure that vessel propulsion power is not lost even in the event of system failure.

The compact SCR™ system is designed to be retrofit to existing diesel engines, especially in applications that are constant speed (e.g. gensets, pumps) or that undergo limited transient variations in speed (e.g. vessel propulsion engines). The SCR™ catalyst is a Ti-V-W formulation located in the exhaust. When catalyst temperature exceeds 200oC, the system injects aqueous urea solution into exhaust upstream from the catalyst. Key innovations are: (1) use of compact, high cell-density monolithic SCR™ catalyst -- about one-fifth the size and weight of comparable SCR™ systems using conventional catalyst technology designed for stationary sources; (2) use of an innovative, compact mounting system for the array of multiple parallel DPF and SCR™ catalyst elements required to achieve acceptable catalyst space velocities and exhaust backpressures for large marine engines (3) use of a simplified, open-loop control system suitable to the restricted range of RPMs / transient activity in the target engine population; (4) provision of a bypass system to assure against loss of engine propulsion in the event of a malfunction leading toÏoverloading of the DPF; and (5) use of the RAVEM portable emission measurement system to calibrate the urea injection system in-situ for optimal NOx reduction while meeting ammonia slip targets, thus eliminating the need for expensive “mapping” in an emission laboratory. 
Emission Benefit
A simple, compact, retrofit SCR™ + DPF technology would make it possible to cost-effectively reduce NOx, PM, VOC, and toxic emissions from existing diesel engines in harbor craft, fishing craft, gensets, cranes, dredges, etc.; thus, meeting emission reduction goals, and / or reducing the air quality impacts of construction projects and maritime projects such as harbor dredging, and bridge construction. This would enable harborcraft to comply with ARBs proposed diesel ATCM without having to replace their engines.
Project Description
The demonstration SCR™ + DPF systems would be installed on the main engine exhausts in the engine room of M.V. Bay Monarch, a Blue and Gold Fleet passenger vessel operating out of Pier 41, San Francisco. Preliminary designs would be reviewed with Blue and Gold Fleet engineering, and then with the U.S. Coast Guard. Final designs satisfactory to both reviewers would be developed, procured, assembled, and tested in the laboratory. Once satisfactory operation is demonstrated in the laboratory, they will be installed in the vessel. In-situ emission measurements and fine calibration will be conducted after 25 hours of operation to allow for de-greening. Subsequent emission measurements will be made at 500 and 1,100 hours, and after one year (aprox. 2,400 hours). An application for ARB verification will be prepared and submitted based on the 1,100 hour data.

Funding Source

Funding Amount




$  66,400

Blue and Gold Fleet, Pier 41

$  85,000

ICAT Funded Projects