Study On Quantification Of Exhaust Emissions From Ships

Maritime transport has always played an important role in sustainable transport and has made great contributions to economic and social development.However,maritime transport has contributed a great quantity of air pollutants and greenhouse gas at the same time.Compared with foreign countries or regions,there are still large gaps for evaluation,management,control and policies-making relevant to maritime emissions in China.Quantitative research and characteristics analysis on exhaust emissions?including ship emissions such as NO_x,CO,HC,CO₂,SO₂ and PM?of coastal regions and marine fleet could provide environmental managers and shipping stakeholders with accurate and effective decision-making basis for developing emission control measures.Therefore,it has very important significance for sustained reductions in harmful emissions from ships and safeguarding atmospheric environment.Due to poor applicability and lack of basic data to specific research objectives,traditional fuel consumption-based and ship activity-based emissions calculation models bring about great uncertainties to estimating results.Thus,based on the statistical analysis of Clarksons and CCS ship database,the relationships of main engine rated power,auxiliary engine rated power and ship design speed against ship's gross tonnage were established.Based on statistical analysis on Parent Engine emission test reports of 76 and 113 marine diesel engines manufactured by China's engine makers in accordance with IMO NO_x Tier ? and Tier ? standards respectively as defined in MARPOL?Intemational Convention for the Prevention of Pollution from Ships?Annex?,fuel-based emission factors and energy-based emission factors for marine diesel engines were determined respectively according to engine types.Through the classification of ship activities in detail,ship emissions were divided into two parts spatially:sea route emissions under constant operating conditions and near port emissions under variable operating conditions.Combined with ship arrival/departure statistics and AIS statistical data from China Maritime Safety Administration,an applicable ship activity-based bottom-up model was established for the estimation of local and regional emissions from ships.In addition,combined with regression analysis between waterborne transport turnovers and China's GDP,a transport turnovers-based bottom-up approach was employed to establish a estimationmodel for the prediction of fuel consumption and exhaust emissions from China's waterborne transportation sector.Calculation methods and related conclusions could provide a reference to the quantification and policy-making for ship emissions in China.Fuel consumption-based model,ship activity-based model and transport turnovers-based model are based on overall and macroscopically data to estimate ship emissions.Due to several simplifications and assumptions,there are probably great uncertainties for the estimating results and it is difficult to reflect the individual characteristics of a particular ship emissions.Thus,the next effort of the international shipping industry should position at establishing an effective mechanism to monitor,report,collect and verify ship operational data.