[Emission Control Of Exhaust Gases From Marine Engines]

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Abstract

The main aim of the paper is to identify various technololgy use to conrtol fuel emission in marine ships. Maritime transport has clear environmental advantages: it expends relatively little energy and its infrastructure requirements are small compared to land-based transport modes. Due to low energy need, shipping is a highly carbon-efficient transport mode, i.e. carbon dioxide emissions are low compared to the weight of cargo transported. Shipping can be up to four times more efficient than road transport. Because of relatively small contribution to greenhouse gas emissions shipping is also good in the terms of mitigation of climate change. However, air pollution from ships has been unregulated until recently. As a result, fuel oils with high sulphur content are widely used and emission control technologies are not required. Ships currently produce about half as much sulphur dioxide (SO2 ) as land-based sources and about a third as much nitrogen oxides (NOx ). The International Institute for Applied Systems Analysis (IIASA) estimates that in Europe the amounts of SO2 and NOx emissions from shipping will surpass land-based sources in the 25 EU member states in 2020. Ships emit several hazardous air pollutants such as sulphur dioxide, nitrogen oxides and fine particles. Once emitted, airborne emissions can travel considerable distances so the shipping emissions affect land air quality. Also the emissions from ships during port stays can be substantial contributor to the local air quality.

Table of Contents

ABSTRACT2

CHAPTER 1: INTRODUCTION5

Background study5

Problem Statement5

Research aims and Objectives6

Significance of the study6

Rationale of the study7

CHAPTER 2: LITERATURE REVIEW9

Formation of emissions in marine diesel engines9

Sulphur dioxide emissions10

Nitrogen oxides emissions12

Particulate matter emissions and smoke13

Available scrubbing technologies14

Environmental impacts and other technical considerations18

Scrubbing technologies devices19

Emission Requirements21

Packed bed scrubber22

Flue Gas Treatment27

Air Scrubber29

CHAPTER 3: METHODOLOGY32

Introduction32

Research Design32

Research Approach33

Literature Search33

Nature Of Data33

Generalisability34

CHAPTER 4: DISCUSSION35

Techniques for reducing emissions from ships35

Miller cycle35

In-engine and operational modifications37

After-treatment on-board controls39

Shore-side controls42

Fuel switching44

FGD Technology44

Wet FGD Technologies46

Dry FGD Technologies51

Other Control Technologies58

Approaches for Reducing Diesel Emissions61

Engine Controls62

Exhaust Controls64

Flow-Through Diesel Oxidation Catalysts66

Diesel Oxidation Catalyst67

Filter Regeneration Catalysts68

Impact of Sulfur on Oxidation Catalysts69

CHAPTER 5: CONCLUSION71

Future Directions74

REFERENCES77



CHAPTER 1: INTRODUCTION

Background study

Emissions of acidifying sulphur oxides (SOX) from marine diesel engines have been subject to scrutiny for many years and, as a consequence, new regulations have emerged. From the beginning of 2010, all ships at berth for longer than two hours in ports within the European Union have been required to reduce their sulphur dioxide emissions by switching to marine fuel oil with a sulphur content of 0.1% or less(Flagan, 2012, pp. 236-284). To fulfi l the requirements of upcoming emission regulations, shipowners have two alternatives - switching to costly low-sulphur fuel or treating engine exhaust gases in a sulphur-removing scrubber.

In 2008, the International Maritime Organization (IMO) decided on a progressive global reduction of sulphur oxides emissions from ships. From the current upper limit of 4.5% for the sulphur content of any fuel oil used globally on vessels, the cap on sulphur content is to be gradually reduced to 0.50% by 2020. In special SOX Emission Control Areas (SECAs) such as ...