Flow Analysis of Ship Scrubber Effluent

Abstract

Lee, K.-W.; Byun, T.Y., and Kim, M.-C., 2021. Flow analysis of ship scrubber effluent. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 564–568. Coconut Creek (Florida), ISSN 0749–0208. Sulfur oxide is one of the three major air pollutants that cause acid rain. Ships contribute to approximately 13% of sulfur oxide emissions. Due to this, concerns have been raised regarding the poor air quality in port cities. Hence, the problem of sulfur oxide emission must be solved on priority. The International Maritime Organization (IMO) under the United Nations decided to significantly strengthen the regulation of sulfur content standards for marine fuel oil. The percentage of sulfur in oil should be reduced to below 0.5% from the previous value of 3.5% by the year 2020. Liquefied Natural Gas (LNG) might be a good option for the reduction of sulfur initially; however, the abrupt change from diesel to LNG is difficult due to its cost. Scrubber is another comparatively economical option to remove sulfur through chemical reactions. There is, however, a side effect: when sulfur oxides are mixed with washing water, they cause the water to turn acidic. The acidity (pH) of the discharged water is regulated by MEPC.259(68), as this acidic washing water might affect marine organisms. This study investigates the extent of effluent dilution due to variation of outlet pipe size, angle, and presence of different diffusers using computational fluid dynamics analysis.