Relation analysis on emission control and economic cost of SCR system for marine diesels

In order to meet the IMO Tier III emissions regulations and reduce environmental pollution, many ocean-going vessels have installed the marine SCR system to reduce NOx emissions. However, the investment cost and operation cost of the marine SCR system, as well as the factors affecting the SCR cost are still the problems that need to be studied. In this paper, MAN S46 diesel engine matched SCR system was taken as the research object, and a cost calculation model of Marine SCR system based on cost analysis method has been proposed. The relationship between SCR system cost and some factors such as unit capacity, unit running time and inlet NOx concentration have been analyzed. The research we have done suggests that operating time, NOx inlet concentration, and emission limits are the three main important factors in the operating cost of an SCR system. Among the various secondary costs of operating costs, the reducing agent cost, fuel increase cost, and indirect annual cost account for 60%, 24%, and 7%, respectively. Moreover, the results suggest that the unit denitration cost of the matched SCR system is highly affected by the power of the diesel engine and annual running time. This study demonstrated clearly the relationship between emission control and economic cost of SCR system for marine diesels and was expected to provide a theoretical basis for sustainable development in marine environmental protection policies.