LNG applications in marine transport

In recent years more and more focus has been placed on the environmental aspects of ships, because of the great attention to exhaust gas emissions from ships including Nitrogen Oxides (NOX), Sulphur Oxides (SOX) and Carbon Dioxide (CO2) due to their negative effect on global warming. Main purpose of this thesis study is to provide necesserary background information on exhaust emission products and their effects on human health, exhaust emission limits, methods to reduce exhaust emission and conversion of diesel engine to dual fuel engine. Furthermore NOX and SOX exhaust emission limitation according to global and local regulations are decribed and methods on how exhaust emission limits can be reached will be presented. Also this thesis is decribed to measurement methods of exhaust emission on test bend and onboard. International Marine Organization (IMO) introduced restrictions on emissions of exhaust gas for NOX and SOX that came into force in 2015 in the Emission Control Areas and 2020 for the rest of the world. In order to be compliant with these restrictions, ship owners have to take the necessary precautions to make a bussiness in related area. In order to ensure the exhaust emission limits specified in the Regulations, after treatment system or Liquefied Natural Gas (LNG ) as alternative marine fuel must be used. To decrease NOX values in exhaust emission, Selective Catalytic Reduction (SCR) or Exhaust Gas Recirculation (EGR) after treatment system are used or LNG is used as an alternative marine fuel oil. Te decrease SOX values in exhaust emission, Sucrubber system is used or fuel oil which has low SOX is used. A key factor for the success of a gas coversion is finding sufficient space for storing gas onboard the vessel. The second step in the prosess is to check whether or not the existing engines onboard can be converted. If the existing engines aren't suitable for conversion, the only option is to replace them with the new ones. Generally speaking, converting an existing engine is recommended and is economically more feasible than installing new ones. When keeping in mine that a conversion basically brings the same benefits as new engines. For example, the same warranty is granted as for a brand new engine. In addition to which there are also saving to be made on maintenance costs since the running hours are reset. In the Second chapter of the thesis, main engine exhaust emissions are introduced and their effects on environment and human health is indicated. Global and different local regulations have been published to minimize the harmful effects of these exhaust emissions. In this section, these regulations are introduced and the values of the exhaust emissions in these regulations are indicated together with the dates of their implementation. Within the third chapter of this thesis, it is specified which equipment should be used to reduce the exhaust emission values of the fuel types burned on the engines, according to the latest exhaust emission limits specified in the local and global work areas. The equipments to be used and the types of these equipments are specified in detail and the rules for designing of these equipments are specified. In the fourth section of the thesis, LNG is considered as an alternative to the fuels used in the vessels and LNG fuel is explained in detail. In the fifth chapter, the conversion of marine diesel oil (MDO) and heavy fuel oil (HFO) engines to Dual Fuel (DF) engines is discussed. The concept of conversion of HFO engines to DF engines has been discussed and explained in detail. With in the sixth chapter, the parts to be changed on the engine, the parts which will be added on the engine, the modification on existing system and the system which will be added because of the LNG are discussed in detail. The rules and regulations which are used for the determin the design of the parts and systems is given in related sections. And also the documents that must be prepared and approved for the engine and systems must be converted are listed. In the seventh chapter of the thesis, the first marine type engine which was converted from HFO to LNG operation is mentioned in detail. Detailed information of the vessel which has this converted engine and owner of this vessel is given. Also the list of the vessels ,whose engines were converted, is given with their name, owners and conversion year of the engines. Within the eighth chapter of the thesis, exhaust emission measurement methods are mentioned. Detailed information is given on which the emission measurement methods are used for the determine the emissions quantity, under which conditions, and which parameters affect the exhaust emissions values. The measurements methods and rules for these methods are mentioned in detail related section. Which documents has to be prepared after measurement of the exhaust emissions and what kind of information must be included in this document are explained in detail. Finally, within the last chapter named "conclusion", the results achieved within this study will be summarized and recommendation for Karadeniz, Marmara Sea, Istanbul Strait and Canakkale Strait will be put forward in order to achieve ECA Egzost Emission Limits.