Dissertation/Thesis Abstract

Analytical framework to evaluate emission control systems for marine engines
by Jayaram, Varalakshmi, Ph.D., University of California, Riverside, 2010, 186; 3433860
Abstract (Summary)

Emissions from marine diesel engines are mainly uncontrolled and affect regional air quality and health of people living near ports. Many emission control strategies are evolving to reduce these emissions and their impacts. This dissertation characterizes the effectiveness of new technologies for reducing NOx and PM2.5 emissions from a range of marine diesel engines. Researchers, regulators and policy makers require these characterizations to develop emission inventories and suitable mitigation strategies.

Three NOx control technologies were analyzed: injection timing retard, water in fuel emulsion, and selective catalytic reduction (SCR). Each significantly reduced NOx emissions. The SCR, however, increased PM2.5 emissions by 150–380% indicating a need for technology modification before implementation. Additionally, two fuel control strategies for PM2.5 based on cleaner burning fuels were evaluated: the effects of switching from high-sulfur heavy fuel oil to lower-sulfur marine distillate oil and switching from diesel to biodiesel blends were tested. Results showed significant PM2.5 reductions with minimal change in NOx; however, the biodiesel fuel increased formation of nucleation mode particles.

In-use emission benefits of a diesel-electric hybrid tug were characterized. Activity data showed that the average load factors of tug boat engines were up to 83% lower than that specified in the certification cycles typically used for developing emission inventories. Reductions of 73% for PM2.5 , 51% for NOx and 27% for CO2 were seen in comparison to a similar conventional tug. The majority of these reductions were attributed to the hybrid tug’s energy management system, which directs use of auxiliary power for propulsion. Additional in-use harbor-craft measurements showed significant ocean current effects with a three to six fold increase gaseous and PM 2.5 emissions.

Overall this research showed that (1) new control technologies should be evaluated in the pilot stage to ensure that they do not increase emissions, (2) use of certification cycle load factors can significantly overestimate emissions from marine applications, and (3) actual in-use measurements are needed for accurate localized inventories. Finally, a new activity and emissions based protocol was developed to establish emission benefits of a multi-powered diesel-electric hybrid system.

Indexing (document details)
Advisor: Cocker, David R.
Commitee: Miller, J. Wayne, Norbeck, Joseph
School: University of California, Riverside
Department: Chemical and Environmental Engineering
School Location: United States -- California
Source: DAI-B 72/02, Dissertation Abstracts International
Subjects: Naval engineering, Environmental engineering
Keywords: Biodiesel, Emission control, Heavy fuel oil, Hybrid engines, Selective catalytic reduction, Ship emissions, Water in fuel emulsions
Publication Number: 3433860
ISBN: 978-1-124-40017-4
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