ANTECEDENTES, DEFINICIÓN Y CONTEXTO DEL PROGRAMA DE BENEFICIOS ECONÓMICOS PERIÓDICOS

Booster Treatment System consists of three different components: • SO2 Absorption Enhancer (SAE)

• Mineral Scale Control (MSC) • CO2 NOx Reducer (CNR)

To utilize the ULF treated effect and in the process, improve the pH and the reaction capability of the treated seawater before it is channeled into the abator tower.

Stage 1

Water system starts from the pumping of seawater from the intake of sea chest drawn in by suction pumps. The seawater passes through the SAE before being sprayed. This is shown in Fig. 7 and 8.

pH Exciter System

The pH Exciter (PHX) system through the use of ULF, conditioned the seawater before channeling it into the treatment tank to treat for the use for Stage 2 process. The conditioning of the seawater improves the water absorption capability and also controls scaling in the pipes.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 38 

Water Treatment

The purpose of the water treatment system is to scrub the flue gas in the abator tower efficiently. The water treatment system consists of the PHX system followed by the Ultra Low Frequency Electrolysis System (ULFELS). Through the use of ULF technology, the seawater is first treated by PHX system and directed into the ULFELS treatment tank whereby its pH is raised to between 9.2 and 9.5. The treated seawater is then pumped into the abator tower to remove the GHGs CO2 and NOx. A level sensor is also added into the water treatment system to control the water level in the ULFELS treatment tank. When the water level is higher than the sensor level, a signal will be sent from the level sensor to shut down the suction pump while the booster pump continues to drain the tank. A standby light will be lighted up during this period. When the water level drops to below the sensor level, the level sensor will turn on the suction pump to fill the ULFELS treatment tank. An indicator light will be lighted to show that the suction pump is switched on.

Stage 2

Stage 2 water system starts from the in-line BFC system. The seawater intake pH quality is then monitored and a suction pump is used to pump the water through the PHX system before being channeled into the ULFELS treatment tank for further treatment. A water pressure booster pump is used to pump the ULFELS treated water through the MSC and CNR systems before it is directed into the abator tower. The quality of the ULFELS treated water is monitored just before it is pumped through the MSC and CNR systems and a pressure regulator is used to control the spray from the nozzle into the abator tower. This stage is for removing CO2 and NOx.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 39  Fig. 8: Stages 1 and 2 of CSNOx Ecospec Scrubber Technology [16]

III Abator Tower System

Abator tower serves as a chamber for the reaction between SAE system treated or PHX and ULFELS treated water and exhaust gas removing the three gases from exhaust gas streams.

IV Wash Water System

The wash water treatment system is used for controlling the quality of water discharged into the sea. With this system in place, the discharged water will always have a pH of at least 6.5. This is to ensure that the CSNOx process is both improving the quality of the exhaust gas and enhancing the quality of the discharged water, protecting the marine eco-system.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 40 

V Exhaust Gas Monitoring System

The exhaust gas monitoring system is to observe gas composition, gas pressure, gas temperature and water level sensor. By analyzing the exhaust gas monitoring system parameters, like in Tab. 12 and 13, the change in the exhaust gas from inlet to outlet can be observed clearly.

In the verifications, conducted onboard a 100000 ton oil tanker, at 50% gas load (equivalent to approximately 5 MW engine output), ABS (American Bureau of Shipping) issued a Statement of Fact on the performance of CSNOx system with the following results:

The removal efficiencies of the CSNOx system allows vessels installed with CSNOx to continue using normal heavy fuel and yet meet the 0.1% Sulphur content, as required by the EU Directive effective from 1st January 2010. In other words, there is no need for vessel owners to convert to distillate fuel or modifying the fuel system for switching to distillate. The removal efficiency for NOx is the absolute reduction percentage. After translating this removal efficiency into the NOx emission requirement as per the Tier I, II or III requirements, the CSNOx system is able to remove NOx to such level that vessels installed with it are able to meet even the strictest Tier III requirement. Apart from meeting the SO2 and NOx requirements, there is no other cost effective system currently available to remove CO2 at the rate the CSNOx system is capable of. CSNOx truly is a cost-effective and efficient solution for solving the emission issues faced by the ship owners. In addition, the results also affirm CSNOx scalability and suitability for a normal ship’s operations. CSNOx is extremely efficient in removing SO2, NOx and CO2. Of significance is also the wash water quality, which met all IMO requirements with most parameters surpassing the strict criteria by a large margin.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 41  Hamworthy is a market-leading global company providing

specialist equipment and services to the marine, oil and gas and industrial sectors.

Through a mix of market-led organic development and strategic acquisitions, Hamworthy has built a business that is now regarded as a global leader with enviable expertise, providing specialist equipment and service to a broad range of markets. Their key markets are marine oil and gas. Their marine markets are predominantly for the specialist ship types of oil and gas carriers and cruise ships, although they serve the entire merchant fleet with a wide range of equipment and services. For the oil and gas industry they support

production facilities with systems that address issues of process efficiency and environmental compliance. Although they have a strong marine heritage, many of their products and systems naturally find industrial applications. Headquartered in Poole (UK), Hamworthy has design, development and production facilities in the UK, Norway,

Denmark, Germany, Singapore, and a modern assembly plant in China. In addition, there are sales and service offices in Korea, China, USA, The Netherlands, Spain, India and the Middle East. Wherever they operate, they remain committed to continuous improvement and to their promise to always deliver.

The scrubbing technology

Hamworthy Krystallon has undertaken extensive Environmental Impact Assessment (EIA) studies on a seawater scrubber installed on a 1MW auxiliary engine, on the ferry “The Pride of Kent”.

Hamworthy Krystallon Seawater Scrubber technology will remove more than 98% of Sulphur from exhaust gas emissions along with the majority of PM from a 3.5% Sulphur residual

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 42  fuel, providing compliance under the equivalency section of the IMO regulations. It removes 70% or more of the PM of Carbon present in exhaust gas.

The principle reaction is the neutralization of the SO2/SO42- by carbonates and other compounds existing in the wash water.

The Hamworthy Krystallon Seawater Scrubber (shown in Fig. 9) is based on the same process used in their Inert Gas scrubbers for almost 50 years. The technology is suitable for both, new build and retrofit applications and is a simple, globally accepted and proven solution.

The scrubbing process

The carbonate/Bi-carbonate in seawater neutralizes the SO2 in the exhaust gas, in a three-stage scrubbing process.

1. Venturi section

The exhaust gas enters the venturi section and is cooled down and saturated with a seawater spray. This seawater spray also provides an ejector effect, reducing the total pressure drop over the system.

2. Bubble plate

The gas flow is turned upwards and led through a patented bubble plate arrangement, seen in Pic. 6. This creates a very turbulent mixing of the water and exhaust gas, wetting the particles and absorbing the SO2.

The bubble plate is a unique technology that allows a higher gas velocity through the scrubber, which again leads to a smaller footprint, without an increase in pressure drop.

Fig. 9: Hamworthy Krystallon Scrubber 3D view [19]

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 43  3. Wet filter

After the bubble plate there is a wet filter to polish remaining Sulphur from the gas and a demister to avoid carry-over of water droplets in the cleaned exhaust gas.

In Fig. 10, a schematic of the seawater scrubber and its other different parts are presented.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 44  Plume control

A plume control situated after the scrubber avoids potential steam plume generation. A steam plume is harmless, but still undesirable.

Wash water

The wash water is monitored for pH, PAH (Hydrocarbons), turbidity and temperature when it is pumped up through the sea chest. It is then distributed to the venturi, bubble plate and wet filter sections. The discharge from the scrubber is passed through a hydrocyclone, either by natural gravity or via a booster pump and discharged overboard. The discharge is again monitored and compared to the intake measurements to make sure that it is in line with the discharge criteria.

Sludge

The particulate matter captured in the wash water is transferred to a small sludge tank. The collected sludge is categorized as being non-hazardous, but must be disposed to shore.

Neutralization process

The majority of neutralization is provided by carbonates in the seas, oceans, and coastal waters, however about 4.0% of the neutralization is provided by borates and other ions in low concentrations.

The process of neutralization follows the following generally accepted paths. CO2, pH and carbonates are all related by the following three equations: 1. CO2 + H2O  H2CO3 (Carbonic Acid)

2. H2CO3  H+ + HCO3- (Bicarbonate) 3. HCO3  H+ + CO32- (Carbonate)

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 45  Addition of acids (increasing H+) shifts the equations to the left, which at the end leads to a release of one molecule of CO2 per proton added.

CO2 evolution from the neutralization process

Considering the reactions above in terms of relative SO2 evolution based upon one ton of marine heavy fuel oil with a global average 2.7% S content is as follows:

2.7% S = 27 kg Sulphur/ton of fuel and Sulphur (32 g/mol) = 843.75 Moles S

1 mole SO2 results in 1 mole H2O4 which has 2 protons, therefore creates 2 moles CO2 according to the equations above.

The neutralization of Sulphur can produce 1687.5 moles CO2 = 74.25 kg CO2 if the equilibrium would be shifted all the way.

Taking into account that about 4% of neutralization is undertaken by borates and other compounds the amount of carbonate alkalinity is thus only 96% of the neutralization process. Multiplying the CO2 evolution by this factor of 0.96 from a 100% carbonate process reduces the emission to 71.28 kg CO2. Hence one ton of 2.7% S fuel may evolve 71.28 kg of CO2 through a neutralization process with bicarbonates. Due to the reduction in bicarbonate, some protons will be consumed through reaction 3, producing more bicarbonate. The equilibrium constants are such that this reaction will only occur to a small extent, but this will nevertheless further reduce the amount of CO2 that will effectively be released.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 46 

Marine Exhaust Solutions

Marine Exhaust Solutions Inc. is part of the DME Group (Diversified Metal Engineering Ltd.) of companies.

DME has grown into an international business with clients around the world. DME has recently formed a wholly owned subsidiary, Marine Exhaust Solutions Inc. (MES), which has spent the past six years in research, development and commercialization of an exhaust gas scrubbing technology for marine diesel engines. This technology is called the MES EcoSilencer®.

DME equipment has been installed internationally in locations such as: USA, England, Ireland, Bermuda, Palestine, China, Japan, Colombia, Kazakhstan, Mexico, Turkey, Brazil and more.

The MES EcoSilencer® is a unique product that utilizes advances in seawater scrubbing to achieve dramatic reductions in SO2 emissions.

EcoSilencer seawater scrubbing system is an economic solution which is saving millions of dollars in expected low Sulphur fuel cost premiums, and provides superior reduction rates for SO2 removal over switching to low Sulphur residual fuel.

Up to 90% SO2 exhaust emissions reduction allow you to burn the maximum 4.5% Sulphur fuel and still surpass the regulated reduction to 1.5% Sulphur fuel.

The system is compatible with any engine size from 100 kW to 100000 kW. It’s safe, reliable low maintenance, no reagents, no catalysts, no filters to replace or clean.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 47 

Scrubbing technology 

The principle of operation of EcoSilencer®, presented in Fig. 11, is based on using seawater as scrubbing medium for SO2, NOx, soot and particulate removal. Overboard seawater (cooling water) enters the system through a sea chest and a set of strainers and is pumped by seawater pump into a heat exchanger. After passing through the heat exchanger, the cooling water is discharged overboard.

Before entering the heat exchanger, an amount of overboard seawater is directed into a separate water circulating system (scrubbing water). The scrubbing water is pumped through a bottom part of each installed EcoSilencer®. One EcoSilencer® is provided for each diesel engine. Inside each EcoSilencer® engine exhaust gas passes through a shallow bath of scrubbing seawater. In the process, SO2, NOx, soot and particulate are removed from the exhaust gas.

After scrubbing process, the scrubbing water is pumped out from each EcoSilencer® through a water filtration plant where it passes through a series of primary and secondary hydro- cyclones. Primary hydro-cyclones remove heavy fractions like soot particles and other solids. Secondary hydro-cyclones remove light fractions such as oils. Removed soot, solids and oils are diverted into a settling tank for further separation, by gravity and onshore disposal.

After filtration, a portion of cleaned scrubbing water joins the cooling water line and is discharged overboard. The remaining portion of scrubbing water passes through the heat exchanger, which removes the excess heat from the scrubbing water, before returning back into the water circulating system. The engine size determines the size of the cooling and scrubbing water systems.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 48 

Wärtsilä

Wärtsilä is a global leader in complete lifecycle power solutions for the marine and energy markets. By emphasizing technological innovation and total efficiency, Wärtsilä maximizes the environmental and economic performance of the vessels and power plants of its customers.

Wärtsilä enhances the business of its customers by providing integrated systems, solutions, and products that are efficient, economically, and environmentally sustainable for the marine industry. Being a technology leader in this field, and through the experience, know-how and dedication of their personnel, Wärtsilä is able to customize innovative and optimized lifecycle solutions to the benefit of their clients around the world.

Wärtsilä supports its customers throughout the lifecycle of their installations by optimizing efficiency and performance. It provides a comprehensive portfolio of services and a good service network in the industry for both the power plant and marine markets. Wärtsilä committed to providing high quality, expert support as well as availability of services, wherever customers are, in an environmentally sound way.

Closed Loop Freshwater scrubber system

Water pH elevated with alkali sodium hydroxide ( NaOH ). After exhaust gas enters, stream- bi-Sulphur oxides are captured and neutralized by scrubbing water chemically forming sulfates. Cleaned exhaust gas exits, water and sulphides return to process collection tank.

Closed loop works with freshwater to which NaOH is added for the neutralization of SOX. Closed loop scrubber technology (shown in Fig. 12) means zero discharge and its power requirement about ½ to 1% of the fuel consumption.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 49  Fig. 12: Closed Loop Freshwater scrubber system [15]

Freshwater Makeup

Freshwater

compensates for losses from evaporation and bleed off extraction. Consumption depends on ambient conditions: seawater temperature, exhaust inlet temperature, and chloride content of water; generally about 0.1 m3/ MWh. Fig. 13 shows a freshwater makeup.

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 50 

Seawater Cooling

The seawater cooling, presented in Fig. 14, minimizes freshwater vapor entrapment by cleaned exhaust gases exiting the scrubber to reduce both, plume opacity and freshwater consumption. Cooling does not impact Sulphur removal efficiency from exhaust gases.

Sodium Hydroxide (NaOH) Unit

NaOH is added to the scrubbing water to boost pH and improve Sulphur oxide removal efficiency. Typical 50% concentration of NaOH (Sodium hydroxide, alkaline or caustic soda) is used as alkali. Input data for alkali feed control are Sulphur content and engine load. Alkali consumption depends on concentration level, engine power, fuel Sulphur percentage level and desired SOx reduction. Fig. 15 demonstrates a Sodium hydroxide unit.

Fig. 14: Seawater Cooling [15]

European Project Semester 2011 Study of Exhaust Gas Cleaning Systems 51 

Water Treatment

A small bleed off passes through the water treatment unit (shown in Fig. 16) containing traces of oil and combustion products at neutral pH. Effluent is cleaned from the bleed off, is monitored, and discharged to the sea if satisfactory. Sludge impurities are placed into a holding tank for future disposal in qualified shore side treatment facility.

Fig. 16: Water treatment [15]