EXHAUST GAS CLEANING SYSTEMS (EGCS)
COMPLIANCE FOR THE ENVIRONMENT
The IMO 2020 regulation is clear: a global limit for sulphur in fuel oil burned by ships of 0.50% from 1 January 2020.
VESSEL OWNERS HAVE TWO OPTIONS:
Burn low sulphur fuel (MGO or 0.50% S Fuel Oil) or install an Exhaust Gas Cleaning System (EGCS) or ‘scrubber’ and continue to use the readily available HSFO fuel.
Scrubber design and installation is a complex and time-consuming series of investigations and decisions because each ship requires a bespoke solution.
Vessel owners must select the most appropriate equipment for their vessel as the decision will affect compliance and long-term value. Avantis can guide you through all the necessary decision points and provide all the services necessary:
- On-board survey to verify available spaces and constraints
- 3D Laser Scan survey & Option analysis
- Feasibility Study
- Installation Planning & Coordination
- Preliminary P&ID of ER and funnel area
- Preliminary list of materials to be supplied and installed
- Reports detailing installation phases of equipment and
- Update Ballast water management plan and required drawings
- Electrical load schedule
COMPLETE ENGINEERING PACKAGE
- Set up access routes to ensure the area is safe to work
- Dismantle and remove silencer and all necessary
- Mount and assemble scrubbers and system
foundations and reconnect exhaust piping
- Install of the exhaust gas monitoring system
- Testing and commissioning
THE SCRUBBER INSTALLATION PROCESS
WET SCRUBBER TYPES
There are three main types of scrubbers available:
Suitable for vessels in waters with adequate alkalinity and/or no discharge restrictions.
Uses seawater as a scrubbing medium. Called open loop because the water is taken from the sea, fed through the scrubber, and then released back into the sea, thus forming an “open loop.”
Suitable for vessels operating in low alkaline waters and/or within zero discharge areas.
Filled with seawater which is recirculated in a “closed loop.” Only a small amount is released into the sea. Discharge water is stored in a tank to ensure a zero-discharge where required. Scrubbing water exchanged with clean water over time to enable efficiency of scrubber.
Suitable for vessels operating in all types of water and/or demanding very flexible operations.
Can run in both open and closed loop mode, enabling ﬂexibility for shipowners operating in both low and high alkalinity areas. Can also refer to other systems, such as an open loop system where caustic soda (NaOH) is added to the water to give an extra boost to the seawater’s alkalinity.
DRY EGC technology uses sodium bicarbonate as an absorbent to clean ship exhaust gas. The absorbent is actively dosed into the exhaust system using proprietary powder handing technology and dry air flow.
BENEFITS OF DRY EGC TECHNOLOGY
- No need for a scrubber tower, pumps, water pipes or engine / boiler modifications
- Quick return on investment for any ship type
- Delivered in a matter of months and installed
without the need for drydocking
- The system produces no toxic chemicals, washwater, or effluents. The output from the system is completely benign and can be recycled
THE ROUTE TO COMPLIANCE
Burning MGO or 0.50% S Fuel Oil is an option for some vessels, but it is expensive and can cause additional maintenance issues for engines designed to run with IFO fuel with sulphur as a lubricant.
The compelling option is to install a scrubber. The fact that SOx dissolves in water makes scrubbing technology possible. In a scrubber, the exhaust gas is sprayed with alkaline water, the sulphur oxides dissolve in the water, and are removed from the exhaust gas with other harmful emissions, such as particulate matter.
The wash water from the scrubber is cleaned to Marpol regulations before being discharged into the sea, and a significant volume of particulates and heavy metals that have been cleaned from the exhaust gas are removed.
The wash water discharge quality standards have been deﬁned in the Marpol regulations and are based on scientiﬁc evaluations of the potential impact on the marine ecosystems.
BENEFITS OF SCRUBBER INSTALLATION
1. REDUCED FUEL COSTS
A scrubber enables a vessel to run on cheaper HSFO rather than expensive MGO or 0.50% S Fuel Oil and will pay for itself in a short time period. The time for payback is a function of the vessel’s fuel consumption and the price differential between HSFO and MGO.
2. ENHANCED ENVIRONMENTAL BENEFITS
Shell Oil conducted a lifecycle analysis to evaluate the use of scrubbers compared to running on low sulphur fuel. It concluded that burning HSFO with a scrubber installed is more beneﬁcial for the environment than running on MGO, as the refining process to make MGO is intensive.
This indicates that scrubbers are a viable option not only from a commercial standpoint, but for the environment as well.