tailieunhanh - Origin of NOx emission from ships inside major bays in Japan
The amount of NOx emission from ships inside the major bays in Japan, ., Tokyo Bay, Osaka Bay and Ise Bay, are analyzed and the strategies in the reduction of NOx emission are discussed. Normally each ship has three sources of NOx emission, ., main engine, auxiliary engine and auxiliary boiler. Since wide range of ships are in operation in these bays, each of the ships are categorized in 4 ranks by the size of each ships. | TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 18, SOÁ K7- 2015 Origin of NOx emission from ships inside major bays in Japan Akihiko AZETSU Tokai University, Japan (Manuscript Received on July 13th, 2015; Manuscript Revised October 16th, 2015) ABSTRACT The amount of NOx emission from ships inside the major bays in Japan, ., Tokyo Bay, Osaka Bay and Ise Bay, are analyzed and the strategies in the reduction of NOx emission are discussed. Normally each ship has three sources of NOx emission, ., main engine, auxiliary engine and auxiliary boiler. Since wide range of ships are in operation in these bays, each of the ships are categorized in 4 ranks by the size of each ships. The amounts of NOx emission from each source and each rank of ships are estimated separately and compared with each other to understand the origin of NOx emission inside these bays. From the systematic calculations, it was explored that more than half of the amount of NOx was emitted from the auxiliary engines during the anchorage period. Especially the influence of the NOx emission from auxiliary engines of larger sized ships of rank 4, the largest category, is the largest. This should be mainly due to the longer anchorage and cargo work time necessary for handling the larger amount of cargo of larger sized ships. On the other hand the NOx emission from main engines is mainly emitted from the small sized ships of rank 1. Same tendencies are obtained through the NOx emission calculations of three major bays in Japan. From these results, it is suggested that the usage of land electricity in larger sized ships is effective in the reduction of NOx emission in major bays. Key words: Emission, NOx, Ship, Main engine, Auxiliary engine. 1. INTRODUCTION To maintain air quality and to preserve both of global and regional environment, the reduction of pollutant emissions from ships should be one of the key issues [1]. From this point of view, the stringent regulations for NOx and SOx emissions from ships .
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