Technologies for Port Air Quality and GHG Emissions Reduction

Technologies for Port Air Quality and GHG Emissions Reduction Introduction

Port operations involves not only ship operation but a lot of other activities such as cargo loading and unloading, ground-level port related transportations and activities of harbour crafts for provision of various services to ports or ships (e.g. dredging, tugs, bunkering, etc.). The main prime mover for most of these vessels, vehicles, cargo handling equipment are diesel engines although move to electrification and use of other technologies are underway. In this section, technological solutions for port area emissions reduction and GHG emissions reductions are discussed. A number of studies has been carried out in the past, the most prominent ones are those by ICCT20 and the IMO. These studies are used as the basis of material in this section and the main outcomes of these studies are highlighted.

ICCT Study on Port Air Quality

Most of the studies performed on port related emissions concentrate on port air quality and not energy efficiency. One of these is reported by ICCT in December 2012. In this report, the ICCT highlights the technologies that could be used in diesel engines as the prime mover for ships and port-side trucks. The main focus is on pollutants including PM (Particulate Matters), carbon monoxide, SOx, NOx and VOC.

The types of technologies identified for reduction of emissions are:

  • Diesel oxidation catalysts: This is a device installed at the back of the engine on the exhaust gases path to oxidize such pollutants as CO, PM and HC.
  • Diesel particulate filter: This is the devise used at the back of diesel engines on the exhaust gases path to trap the particulates and prevent them from leaving the engines.
  • SCR (Selective Catalytic Reduction): This is a very well know technology for significant reduction of NOx emissions. As the name implies, it works via use of agents at the presence of a catalyst to covert NOx beck to N2 and O2.
  • Exhaust Gas Scrubbers: Again, this is a very well-known technology for the back of engines on the exhaust gases path to capture the SOx and prevent them from leaving the engine exhaust.
  • Exhaust Gas Recirculation (EGR): This is a well-known technology that aims to reduce the engine’s combustion temperature and thus reduce NOx via circulating part of the exhaust gas back into cylinder.
  • Shore power: This refers to ship connection to port electricity so that the ship-board engines could be completely switched off.
  • Clean fuels: These include a variety of options such as ultra-low sulphur fuel, LNG, CNG, water-emulsified fuels, biofuels and so on. Most of these options not only reduce SOx but also NOx as well (MariEMS 2017).

Figure 38 below summarizes various options, itemizes potential applications for use at ports, provides estimates for the reduction potential for various pollutants and provides basic cost estimations of each option.

Figure 38: Port air emissions reduction measures according to ICCT December 2012 report (MariEMS 2017).

This shows a significant potential for alleviating air quality issues from ports but they mostly are considered as options for CO2 reduction directly. In fact, most of these options may lead to a small increase in overall fuel consumption as for example NOx control methods most of the time makes engines less efficient.