CE Delft has prepared report for NABU which provides an economic and ecological assessment of scrubbers.
CE Delft has analysed the economic and ecological aspects of using scrubbers as a means for ships to meet the SECA fuel sulphur requirements. The study was launched in Hamburg on 13 March during a seminar organised by the German NABU (Nature and Biodiversity Conservation Union), which commissioned the study. The study focuses on the current and future market, the ecological impact of increased use of scrubbers in coastal areas and the business case for ship-owners
Scrubber types Four different scrubber types are available today: 1. Seawater scrubbers (open loop) utilize untreated seawater, using the natural alkalinity of the seawater to neutralize the sulphur from exhaust gases. The negative characteristic of an open loop system is its greater energy consumption compared to a close loop system, but there is no need for chemical additives like caustic soda in a closed loop system. 2. Freshwater scrubbers (closed loop) are not dependent on the type of the water the vessel is operating in, because the exhaust gases are neutralized with caustic soda, which is added to freshwater in a closed system. Circulating water is processed after the scrubber and dosed with caustic soda in order to restore the alkalinity of wash water. The amount of the water which is needed in a closed loop process is about half of the flow in an open loop system. 3. Hybrid scrubbers give the possibility to either use closed loop or open loop technology. Hybrid scrubbers are generally used as an open loop system when the vessel is operating in the open sea and as a closed loop system when operating in harbour or estuaries, where water discharge is prohibited. Among the different types of scrubbers a hybrid scrubber is becoming increasingly common because of its flexibility and restrictions. 4. Dry scrubbers do not use any liquids in process but exhaust gases are cleaned with hydrated lime-treated granulates. There is not any discharge to the sea from the system. As a result of the process a gypsum, which is used to manufacture wallboard, is generated. An advantage of a dry scrubber is its lower energy consumption compared to a wet scrubber.
|
Development of the world fleet with scrubbers installed
The number of scrubbers installed on vessels has increased significantly in recent years. About 80 scrubbers are currently installed, most of which are hybrid or open-loop scrubbers. At the time of writing, the number of units ordered stands at approximately 300. Although the IMO wash-water criteria for scrubbers are generally met, if there is insufficient dilution, scrubbers may have a negative impact on the marine environment in the form of acidification, eutrophication and accumulation of hazardous hydrocarbons and heavy metals, particularly in ports and coastal areas.
The long-term impacts of use of open-loop scrubbers, especially in vulnerable coastal areas with reported moderate water quality, therefore needs to be systematically investigated by measuring and modelling water quality. Based on the results, it should be assessed whether scrubbers can be used in accordance with the European Water Framework Directive and Marine Strategy Framework Directive, which set maximum concentrations for certain hazardous pollutants, prohibit deterioration of water quality and aim to achieve ‘good environmental status’, respectively.
Conclusions
Although the IMO criteria are met, scrubbers may have an impact on acidification and accumulation of hazardous substances like heavy metals and PAHs, especially in vulnerable coastal areas where dilution is limited and the water quality is reported to be moderate. Increased use of scrubbers may lead to a deterioration of the water quality. The long term impacts of the use of open loop scrubbers should be further investigated systematically by measuring and modelling in order to prevent negative cumulative environmental impacts of scrubber waste water discharge. It should be evaluated if scrubbers can be used in accordance with the European Water Framework Directive that sets maximum concentrations for certain hazardous pollutants, especially in the near of dense shipping routes and vulnerable estuaries.
The installation of scrubbers requires significant investment costs. Typical installation costs range between 200 and 400 EUR/kW, which imply an investment of several millions, depending on a ship’s engine power.
According to the study, it is hard to draw firm conclusions on the profitability of using scrubbers, as this depends on the vessel’s operational profile, the differential between HFO and MGO prices, and the time sailed in SECAs. Between January 2014 and February 2015 the HFO/MGO fuel price differential ranged from 240 to 300 $/ton. Scrubbers are more often profitable when this difference in high than when it is low.
Read the analysis on the economic and ecological assessment of scrubbers by clicking on the image below:
Source: CE Delft
In the origin, I was forthright with you propecia before and after has changed my being. It has become much more fun, and now I have to run. Just as it is improbable to sit.