A Seawater Scrubber is designed to remove the first two waste products of SOx and particulates. In the process a small amount of the NOx, CO2 and H2O are also removed but that is not the primary purpose of the scrubbing system.
The combustion of fuel in a marine engine produces unwanted emissions that can be summarised as:
SOx – oxides of sulphur mainly SO2 with around 5% SO3
Particulates – carbon, fuel and lubricant ash, hydrocarbons, sulphates
NOx –oxides of nitrogen mainly NO but some NO2 and higher oxides
CO2 – carbon dioxide from combustion of carbon in the fuel
H2O – water from combustion of hydrogen in the fuel
A Seawater Scrubber is designed to remove the first two waste products of SOx and particulates. In the process a small amount of the NOx, CO2 and H2O are also removed but that is not the primary purpose of the scrubbing system.
So what is the basic concept?
SOx – sea water and indeed hard estuarine and river water is alkaline caused mainly by calcium based salts in solution. SO2 and SO3 is transferred from the exhaust gas to the scrubbing water. The SOx reacts with, and is neutralized by, these alkaline salts. Once all the salts are reacted then the pH of the water falls and any remaining SOx is held in solution. Further sea water may be added after the Scrubber to provide additional alkali to neutralise this remaining SO2.
Particulates – the Scrubber drops the temperature of the exhaust to near ambient. This causes any hydrocarbons to condense on soot particles in the exhaust. Water and extreme mixing causes them to stick together and become trapped in the water spray. Particulates then pass out of the scrubber suspended in the drain water. An efficient wash water cleaning system then removes nearly all solid mater before the water returns to the sea. In this way the scrubber system traps the hydrocarbons, fuel ash and any harbour sediment for safe disposal ashore.
Monitoring - the Hamworthy Krystallon system is designed for compliance under Scheme B of the IMO Sea Water Scrubbing Guidelines. What does this mean? Scheme B allows for continuous monitoring of both the exhaust outlet and water outlet to verify and record that the Scrubber is working at its full operational efficiency. For this application, we have developed cutting edge solutions unique to Hamworthy Krystallon. The Scrubber performance is verified in a continuous basis providing peace of mind throughout the life of the ship.
License to operate - Hamworthy Krystallon have 4 years of independent Environmental Impact Assessment studies to back the technology. We have 40 years of experience in scrubbing through the supply of Hamworthy Moss Inert Gas systems. Our solution is unique in a proven ability to operate with No Harm to the environment either air or water.
History
Sea water scrubbing has been an accepted technology used in land based power plant since the 1930’s. The first operational system was used on hard brackish river water at Battersea on the Thames in London, the latest we know of was commissioned at Vassilicos in 2006 on a steam turbine boiler plant operated on the coast of Cyprus. Sea water scrubbers have been used at sea since the 1960’s; they are called Inert Gas generators and are supplied by our parent company, Hamworthy Moss.
Hamworthy Moss first started developing sea water scrubbing systems in a project with Shell mid 1990’s. Krystallon began their designs in 2002 with a project on MV Pride of Kent. The project was to prove that sea water scrubbing could be adapted for use on an operating marine diesel engine. The first Krystallon system was commissioned in 2005 with a larger system fitted as replacement for the first experimental unit on Pride of Kent in 2006. That system has now operated for over 30,000 hours scrubbing over 98% of all SOx from a 1MW engine with no major operational problems.
2006 saw commissioning of the first operational water treatment plant. In 2007 the technology was developed with a further 2 installations in the first half of the year and a design envelope now extended from 0.5 through 10MW engine capacity. 2008 saw commissioning of a further unit, our first in Asia Pacific and type approvals for major sub assemblies.
In June 2007 the hard work of Krystallon supported by P&O Ferries was recognized by the marine industry with a prestigious Sea Trade Award for the Protection of the Marine and Atmospheric Environment.
Krystallon became part of the Hamworthy Group of companies late in 2009. As Hamworthy Krystallon we now have the manufacturing, product support and worldwide presence to make Sea Water Scrubbing a practical, cost effective and reliable marine technology.
