An experimental investigation of ultra-low sulfur diesel on ship-based particulate matters and gaseous emissions

Emission of exhaust gases from shipping contribute significantly to the total emissions from the transportation sector. Key compounds emitted from marine diesel engines are carbon dioxide (CO2), carbon monoxide (CO), sulphur oxides (SOx), nitrogen oxides (NOx), volatile organic compounds (VOC), hydrocarbons (HC) and particulate matters (PM). CO, VOC, NOx and PM originated from engine technology whereas CO2, SOx, heavy metals and sulphur compounds become from fuel property. Exhaust gases emitted from ships to atmosphere, they becomes rare interacting with air. While this dilution, chemical compounds are partially reverted and then drop on land and sea. Ultimately, ship source emissions cause many adverse environmental effects as climate change, acidification, deformation of air quality, to name the most important. Considering emissions per transported load and distance, sea transport is the cleanest transportation as far as land and air. However, emission per a ship is rather high. One giant container vessel emits emissions in a year equivalent to fifty million car. Vessel traffic on the Turkish Straits increases dramatically in the last 50 years. When taken into account approximately 50.000 vessel transit from Istanbul Strait per annum near 50 m from land, Istanbul is in danger in terms of both human health and environment. In addition to the environmental effects, there are many adverse effects to human health. For example, emissions of particles may cause the cardiopulmonary disease and lung cancer. Also, additional health impacts of emissions like respiratory illnesses as bronchitis, asthma, and pneumonia can be seen. The International Maritime Organization (IMO) is a central position for the regulations of air pollution from ships. IMO works to develop and adopt new international regulations on different maritime topics, primarily safety, security and pollution prevention. The first rules for regulations to limit airborne emissions from international shipping resulted from the entry into force of the Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL) in May 2005. MARPOL was adopted in its first state in 1973 by the IMO. The Annex VI to the convention regulates several pollutants, including NOx from newly built ships, and SOx. Certain maritime regions are designated emission control areas (ECAs) where the regulated emission levels are lower than in the rest of the ocean. The regulations will become tighter in a stepwise manner and additionally, the number of emission control areas will potentially increase. Turkey became a party of MARPOL Annex VI last February of 2014. In accordance with these general information, ship source emissions are of great importance as measurement of emissions, to improve reduction methods of emissions. The aim of this study is onboard measurement of ship-based exhaust emissions, to determine emission characteristic, to clarify main factors that influence the exhaust emissons, to focus on emissions of particles and to inspect form of particulate matters and to investigate the effects of ultra-low sulfur diesel. The study concentrated on the effects of the ultra-low sulfur diesel fuel on the particulate emissions. In the scope of this thesis, measurements were conducted on-board regarding to regulations of Marpol Annex VI NOx technical code. NOx, SO2, CO, CO2, particulate matters (PM) and hydrocarbons (HC) were measured. Emissions of ultra-low sulfur diesel were compared with other fuels which had different sulfur content. Size distribution of particles named PM2.5 and PM10 is essential to find out health risks. Size of particles and chemical composition of particles are a major parameter for indication of how harmful they are. In addition to measurement of emissions, shaft power measurement, mass flow rate of exhaust, temperature of exhaust and humidity of exhaust were measured. Along with power measurement, emissions were calculated as g/kWh. In this study, effects of engine load, operational conditions and fuel additives on the exhaust gas emissions were investigated. Furthermore, weighted emission factors were calculated and compared with previous studies. The size distributions of particle mass were obtained. The shape of the particles were viewed by scaning electron microscopy. The composition of particles were investigated by using SEM/EDS analysis. Experimental investigation was executed on the ferry under the fleet of İstanbul Deniz Otobüsleri San ve Tic. A.Ş. Experimental investigation of ship's exhaust emission on Istanbul Strait and Marmara Sea is of crucial due to the specific location and ecological condition of the area. As a resulf of this project, adverse effect of ship-based air pollution on environment and human health is aimed to be reduced in the region of Istanbul Strait and Marmara Sea. The ferry was built in 2000 with a tonnage of 1600 GRT and 81 m length. Therefore, it should comply with the NOx emission limits, Tier I. The emission sampling was performed in the stacks of main engine in the engine room at different engine loads. The measurements were done according to the IMO MARPOL Annex VI E2 test cycle for the main engine and D2 test cycle for the auxiliary engine. The concentrations of NOx, SO2, CO, CO2 and HC were measured in raw exhaust gas using Horiba PG-250 gas analyser at the engine loads of 25%, 50% 75%, and 100% for the main engine. The particles were collected by using Tecora Isostack Basic Equipment. Particle mass was collected by using 47 mm glass-micro fibre filters that was analyzed gravimetrically, weighted before and after sampling using a micro balance in the laboratory. The weighted emission factors of NOx, SO2, CO, CO2, HC and PM emissions for the main engine are found to be 11.91 g/kWh, 0.10 g/kWh, 0.67 g/kWh, 611.14 g/kWh, 0.62 g/kWh and 0.079 g/kWh, respectively. For the auxiliary engine, the weighted emission factors of NOx, SOx, CO, CO2 and HC are respectively, 13.01 g/kWh, 0.11 g/kWh, 2.19 g/kWh, 641.69 g/kWh and 1.31 g/kWh. The effects of the fuel additive on the emissions and performance of a marine diesel engine installed on a ferry, experimentally. The fuel additive based on the hydrocarbon solution of cyclic and aliphatic amino compounds. The results indicate that the use of fuel additive reduces the emissions of NOx, SOx, CO, HC and PM. Substantial reductions, especially in PM and HC emissions were obtained. The use of fuel additive resulted in lower emissions of NOx, SO2, CO, HC and PM by 1%, 50%, 5%, 60% and 38%, respectively. However, the CO2 emissions increased by 3.5% when the fuel additive was used. The size distributions of particle mass were obtained for different engine loads and the particle size of PM2.5 were found as the most contributed size for all the engine loads. The shape of the particles were found generally in spherical shape. The composition of particles were investigated by using SEM/EDS analysis. The elemental analysis of particles showed that there are 13 elements in the samples. The carbon was found as the main component of diesel particles comprised approximately 50-60 percent of the total emission composition. The concentrations of detectable elements of Fe and V were found as the most abundant elements and comprised about 8 percent of the total emission composition. Due to the increasing shipping activity at the Marmara Sea in Turkey, ship emissions are becoming the dominant source of the air pollution that should be reduced for adverse health and environmental impacts. Istanbul is the most populated city in the Marmara region so, many people are exposed to the particle emissions that will lead to serious health impacts. The measurements of the ship emissions are required and important to reduce the impacts of marine traffic on the air pollution. Also, it will help to develop new mathematical models and validate the available models. The mass particle size distribution and elemental composition of particles are a major parameter for the indication of negative effects of particle emissions. The present study is devoted to evaluate the effects of ULSD on the formation of particles. As a future work, the effects of various types of fuels on the ship emissions may be investigated for comparison.