ARB Research Seminar

This page updated June 19, 2013

Emission Control Technologies for Ocean Going Vessels (OGVs)

Hamid Rahai, Ph.D., Department of Aerospace and Mechanical Engineering, California State University, Long Beach

June 09, 2008
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Research Project


Major California ports such as the Los Angeles-Long Beach ports are among the busiest in the United States, handling more than 43% of the total U.S. seaborne cargo. They are also responsible for nearly a quarter of diesel emissions in the region. Ocean going vessels (OGVs) contribute significantly to the local and regional air pollution. These vessels use residual marine fuel which is one of the cheapest and highly polluting fuels. Different approaches have been proposed for reducing OGVs emissions, including cold ironing, switching to low sulfur fuel during their operation at the port complexes, water-in-fuel homogenization and emulsification (H/E) process, and exhaust gas seawater scrubbing process to name a few. Many innovations in diesel engine designs are also proposed and/or being developed. As expected, each technology has some strength as well as some limitations.

It is imperative for environmental regulatory bodies such as CARB/EPA to stay abreast of these developments and have a clear concise view of various technologies available or planed, their effectiveness as well as their limitations. This project conducted a comprehensive review of diesel emission control technologies that are deemed applicable to existing and new ocean going vessels. The focus was on present technologies and technologies under development by maritime as well as other industries. It encompassed literature searches, other available information sources and surveys of academic, government and industry sources. The information compiled included description of the technologies, their applicability to existing and new OGV's, their strengths, limitations, and corroborating data and documentations when available. The information was evaluated for consistency and organized in a comprehensive concise manner.

Speaker Biography

Hamid Rahai, Ph.D., is professor of Mechanical & Aerospace Engineering and director of the Center for Energy and Environmental Research and Services (CEERS) at California State University at Long Beach. He received his doctorate in Mechanical Engineering from the University of California, Irvine, in 1988. His areas of expertise are Air Pollution and Industrial Aerodynamics, Diesel Emissions Assessment and Control, Renewable Energy, Convective Heat and Mass Transfer and Turbulence.

Dr. Rahai has been teaching, consulting, and performing research in the area of Combustion and Fluid and Thermal Sciences since 1988. He is the coordinator of various undergraduate and graduate courses in the areas of fluid mechanics, thermal sciences and turbulence. He has been the principal investigator on projects related to: turbulent flow in the interaction region of a wing-body junction; distortion of passive scalar by two-dimensional and axsisymmetric objects; the effects of mean strain rate on decay of a temperature variance; dissipation of a passive scalar in the presence of a mean velocity gradient; numerical analysis of turbulent flow past a simplified heart valve prosthesis, development of a high efficiency vertical axis wind turbine; and reducing diesel engine emissions. He is currently working on improving the performance of a SCR filter for reducing diesel NOx and assessment of a combined emulsion system and a scrubbing system for reducing emissions of ocean going vessels (OGVs).

Dr. Rahai has authored or coauthored more than 60 scientific papers, is a member of the American Society of Mechanical Engineers, the Society of Automotive Engineers, and the American Society of Heating, Refrigerating and Air Conditioning Engineers.

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