Final Report Summary - OILECLEAR (Development of a safe, compact, highly efficient, economic and fully automatic electrolytic treatment system for separation of emulsified oil from wastewater of ships (bilge) and oil rigs (slop))
Executive Summary:
The global society is supported by a global economy in order to prosper, and the shipping and oil industry are cornerstones that make internationalisation possible. The transport of raw materials, passengers and manufactured products by ships is regulated in order to promote safety, security and environmental protection. Since 1959 IMO has regulated shipping through numerous conventions and codes. The latter is necessary due to the continuous change in jurisdiction a ship needs to comply with due to their intercontinental activities.
The activities of a ship has a huge impact on the environment. For instance, in 1998 a total of 223 cruise ships carried some 10 million passengers to and through sensitive ecosystems. Some of the pollutants generated by cruisers daily include as much as 140 m3 of oily bilge water plus thousands of cubic liters of black water, grey water and ballast water.
If the trade growth of the last 150 years continues, by 2060 the tonnage of cargo in 2010 will grow from 8 billion to 23 billion, with an expansion of the carbon footprint by 300%.
Wastewater from ships and oil rigs has high concentrations of oil. Oil present in the wastewater has its origin in either machinery purposes or because of the drilling process in a rig. Because of the large concentration of oil in water it can be mechanically removed by decanting. However, due to movement and further mixing the oil forms a stable emulsion in water.
The overriding goal of OileClear is to enable ships and offshore rigs, the primary target markets, to meet current and expected regulations regarding oily effluents to the sea. The partners in OilEClear have set an objective to develop an efficient bilge and slop water treatment system which will treat the water to attain concentration of oil below 5 ppm.
Bilge water is common to all ships and is produced from among other cleaning the engine rooms and bilge areas of the ship, deck areas of passenger ships, condensation of atmospheric humidity from the air-conditioning plants and small seepages through the hull. It consists of a varying assortment of oil and grease, oxygen-demanding substances, and organic and inorganic materials including volatile or semi-volatile organic compounds, salts and metals. Slop water is a general term for water contaminated with hydrocarbons as well as other chemicals and wastes produced on offshore oil and gas rigs from cleaning the pipe and drill deck. On rigs for exploration of oil and gas slop water volumes in the North Sea are estimated to 10.000 m3 / year per rig, in sum 1-300.000 m3 a year.
Regulations globally state that no oily water is to be discharged overboard without proper treatment. Release of oily wastewater to the sea is regulated by IMO3, MARPOL, Annex 1, setting a limit to 15 ppm THC or lower at release into the sea, but a lowering to 5 ppm is proposed by the US and Australia. In the North Sea, OSPAR has set the discharge limit to 30 ppm oil in water in slop. Some countries practice stricter regulations in sensitive waters (<5ppm), i.e. US State regulations for rigs operating near shore, and Australian harbor authorities.
The OilEClear system will separate emulsified oil and water by use of a novel three-phase separator design, including self-rinsing and adjustable electrolysis cell, combined floatation and sludge separation unit, explosion proof design, all-enclosed gas phase design, off-gas treatment for minimum air contamination, THC monitor and alarm which cuts the effluent if the effluent level is too high. Effluent data and operation will be managed by intelligent process control system. The Beneficiaries of the project OilEClear are as follows: Coordinator:
Westmatic AB – Sweden; Industrial Partners: OY Imu-tec AB, Finland; Naval Consulting and Management AS – Norway; Stena Line Scandinavia AB – Sweden. RTDs: Teknologisk Institutt AS – Norway; Fraunhofer – Gesellschaft zur Foerderung der Angewanten Forschung E.V.
Project Context and Objectives:
Project objectives
The objective of OilEClear is to develop a treatment system for oily wastewater for ships and oil rigs, enabling these to meet current and future bilge and slop water regulations with regard to oil hydrocarbons (THC), dissolved organics and toxic metals. Specifically, the objectives for Reporting Period 1 is are follows;
Scientific objectives:
- The acquisition of deeper scientific knowledge with respect to the reaction conditions given by design characteristics of existing electrolysis cell constructions, concerning electrolysis and gas formation in relations to design criteria (WP1)
- The acquisition of deeper scientific knowledge with respect to the reaction conditions given by design characteristics of existing electrolysis cell constructions, concerning coagulation and flocculation in relations to design criteria (WP1)
- Global system design criteria (WP1)
Technical objectives:
- Begin the work on development of design specifications for gas and liquid enclosed
electro-coagulation reactor for gas conservation and EX safety, concerning gas and liquid enclosure (WP2)
- Begin the work on development of design specifications for gas and liquid enclosed
electro-coagulation reactor for gas conservation and EX safety, concerning system enclosure and off-gas ventilation and treatment (WP2)
- Begin the development of new conceptual unit designs for simultaneous floc flotation and sedimentation from wastewater, and facilitate design based upon enhanced understanding and modelling of hydrodynamic processes and external forces (WP3).
The technical activities sheduled to be completed in the 2nd Reporting period include:
WP2:
Development of a gas and liquid enclosed electro-coagulation reactor for gas conservation in flocs, off-gas treatment, health and EX safety.
WP3:
Development of a new and an improved unit design for simultaneous floc flotation and sedimentation from wastewater, based upon enhanced understanding and modelling of hydrodynamic processes, particle characteristics and external physical forces. Design, construct and test a full scale separation unit model.
WP4:
Adapt and develop a novel process control unit with appropriate instrumentation and sensor technology, data acquisition and storage, and operational report generator for user-friendly performance surveillance. Integrate the developed process control unit into the OilEClear pilot plant for functionality tests for use in setting particulate and oil effluent quality standards and automatic control.
WP5:
Integrate stand-alone novel prototype with appropriate, optional pre- and post-treatment technology for on board installation, adapted to primary market and end-users.
WP6:
To ensure that project results are formulated and compiled in IPR protectable form including patents.
To develop an Exploitation Strategy, and protection of the Intellectual Property Rights arising from the technological developments
To promote the benefits of the developed technology and foreground beyond the consortium to potential user communities involving other companies through networks of the project end-users and other industrial contacts, trade press and European trade associations as well as websites and extensive distribution of DVDs.
To disseminate foreground and benefits of the developed technology at scientific conferences and workshop events to create reference base for OilEClear in the professional community.
To present the technology at technology conferences, trade fairs and with international organizations to spread the foreground and results of the OilEClear technology and its efficiency in treatment of oily wastewater to create an expectation in the market
Prepare Dissemination and Use Plan (DUP).
WP7:
Overall project management and coordination
Management of project external relations to ensure that all knowledge is created, managed and disseminated in a coordinated and coherent manner, along with all technical activities, legal aspects. Efficient management of time & resource allocation at a consortium level, facilitate and be represented at meetings & general administrative duties, coordination of the Work Packages.
Creating and negotiating IPR ownership and agreements within and outside the partnership. Preparation of, updating and managing the consortium agreement between the participants, obtaining audit certificates
Identification and assessment of potential impact within the project and related to the use and application of results.
The deliverables scheduled for the first period are:
D1.1 - Report on enhanced scientific knowledge of electrolysis, gas formation, flocculation and coagulation
D2.1 – Design specification report of prototype gas, liquid and system enclosures D3.1 – Analysis report on floc characterization
D6.1 - Report on potentially competitive patents and plan for applications [draft month 9] D6.3 - Web page with regular updates throughout the project until end date of the Project.
D6.4 - Press releases, publications and other communication activities.
D6.8 - Interim plan for use and dissemination of knowledge
Deliverables scheduled for the 2nd Reporting period include:
- D2.2: Design specification report of prototype gas, Liquid and system enclosures final.
- D3.2: Report on separation unit fluid dynamics, modelling design, model testing and specifications.
- D4.1: Report on Control system design and manual of process operation.
- D4.2: Report on Control system design and manual of process operation, Final.
- D5.1: Report on global system design, additional Technology evaluation and system integration.
- D5.2: Constructed prototype and report on industrial testing and global evaluation.
- D6.2: Report on potentially competetive patents and plan for Application.
- D6.5: Press release, publication and other communication activities.
- D6.6: Production of a video Clip
- D6.7: Final Wikipedia page on the Project and its results.
- D6.9: Final plan for use and dissemination of knowledge.
Milestones sheduled in theproject period include:
- MS1: Scientific work completed.
- MS2: Coagulation reactor completed.
- MS3: Separation reactor completed.
- MS4: Control and monitoring completed:
- MS5: Verified OileClear.
Project Results:
The Scientific and technological results include:
a) Specification criteria for the ship and oil industry, acquisition of deeper scientific understanding of electrocoagulation.
b) Gas and liquid enclosed electro-coagulation reactor
c) Combined electro coagulation and dissolved air floatation
d) Process control and monitoring, functionality test
e) Fully integrated OilEClear system and functional testing.
Specification criteria:
The foreground related to deeper understanding in the principles of electrocoagulation and DAF will enhance the capability of the SMEs in the project and future licensees for providing consulting and operation and maintenance services to end users. In addition the enhanced understanding will enable the SMEs to further develop or modify the system and make it more competitive in the market. At this point there is no plan of protecting the foreground. Ownership of is equally shared by the 3 SMEs.
Gas and liquid enclosed electro-coagulation reactor:
To fulfil the safety requirements associated with electrolysis of seawater and securing safe working environment around the OileClear system, safety enclosures and management system for potentially hazardous gases has been developed. The enclosures consist of telescopic slide way cover that prevents spilling of wastewater and sludge into the working environment and contact with the rotating electrodes, off gas treatment unit, efficient light source and monitoring of gas concentration with advanced sensors that convey measured values to the intelligent process control system. The set point is recommended to be lower than the threshold value. If the set point is exceeded, the control system closes the electrolysis process combined with alarm to the control room of the vessel or rig.
Potentially, hydrogen and chlorine gases are of important concern and can be generated by the chemical reaction during electrolysis of fresh and salt water. Fraunhofer has performed some initial tests in order to evaluate whether or not hydrogen and/or chlorine gases are generated during operation of the unit. The measurements were performed using Drâger tubes and gas was sampled immediately over the gap between the catode and anode (hot spot). The results show that the level of hydrogen gas varied from 0,04 to 4,8 vol % with an average of 2,25 vol % in air. The explosion limits of hydrogen is 4 - 75 vol % in air. Results from measurement of chlorine show that the concentration is less than the detected limit of the Drâger tubes used i.e. less than 0,2 ppm (equals 0,5 mg/m3).
For monitoring generated hydrogen and chlorine gases. it was decided to include a detector system for hydrogen and chlorine gases respectively as a safety feature and for close monitoring of hydrogen and chlorine gas generation during operation of the electrolysis process.
• Hydrogen: A Drâger gas sensor (catalytic bead) was selected. This is a gas detector for continuous monitoring of flammable gases and vapors in ambient air. The gas concentrations that are detected in a range lower than Lower Explosive Limit is converted to industry standard 4 to 20 mA signal.
• Chlorine: A Drâger Cl2 sensor was selected. This sensor is an electrochemical three electrode sensor for the continuous real-time monitoring of chlorine, fluorine, bromine or chlorine dioxide gas in ambient air.
The readings of the flammable gas sensor (% of Lower Explosive Limit) and chlorine gas sensor ( ppm of Cl2) is displayed in the HMI panel. An alarm system is included based on the monitoring of concentration of flammable gas (hydrogen). The unit is automatically shut off when a flammable gas concentration of more than 10 % of lower explosive limit is registered. At the same time an alarm is shown on the HMI panel reading: “High concentration of hydrogen > 10 % of Lower Explosive Limit”. There is no alarm connected to the chlorine sensor. Both the sensor for flammable gas and chlorine is logged to an internal memory card.
Combined electro coagulation and dissolved air floatation:
During experimentation in early stages during period 1 it was observed that although a floac foam layer is formed, it starts to loose flocs that begin to settle due to release of the electrolysis gases after some time. On a ship, instability of the foam layer due to vibrations strongly decreases the time needed to release the electrolysis gases. Thus, dissolved air flotation (DAF) process was selected and used to remove the oil loaded flocs from the clear phase. This foreground will be owned jointly by Westmatic and IMU-TEC and intend to protect along with the integrated OileClear system.. In addition to being part of the OileClear system marketable to the shipping and offshore oil and gas industries that require efficient and sustainable system for removing of oil in water down to concentrations set by national and international regulations before discharging to the sea, the DAF system can be applicable in other sectors where oil needs to be removed from water. Having generated dissolving gas microbubbles with a multiphase pump, the flotation takes place in a specially designed tank with multiple inlet possibilities, thus offering the possibility to change the inlet position. The clear phase removal pipe has a concave shape to avoid contamination with the floating oil/flocs phase. Additionally the flotation tank has a sampling/drain outlet, a drain for the remaining oil/flocs and the air saturated water inlet. A flocculation column is positioned between the spinning anode and the flotation tank. Two different diameters (23 mm and 50 mm) can be selected to modify the water inlet velocity to the flotation tank. The trials run with the specially designed separation unit has a market potential for separation of oil from water beyond management of bilge water and slop.
Process control system:
The process control system is developed for management of the electrolysis and hydraulic processes for optimum operation of OileClear while attaining the objectives of the project, particularly attaining oil in water concentration of less than 5 ppm. In this regard the control system was developed as modified and more advanced version of the existing control system for the RENAREN based on the Schneider software and hardware platform. Furthermore it is equipped with online monitoring of explosive gases. Thus the control system has a number of automatic functions for management of the separation tank, gas concentrations, oil content, EX-control, multiphase pump that regulates dissolved air saturation, current, service lamps, trend logging functions and human machine interface hardware and software. OileClear can be controlled optionally either in automatic or manual mode. However, with increasingly stringent requirement for management of oil containing waste water before discharge to sea or freshwater recipients, intelligent control of the treatment process will provide more precise management of the waste stream which both the shipping, oil and land based industrial sectors need.
Fully integrated OileClear system
The OileClear system for management bilge water and slop is developed consisting of components that ensure efficient floc generation for entrapping oil, gentle separation of the flocs from the clean phase, safe operation of the electrolysis process and intelligent control of the electrocoagulation and floc separation processes as well as management of EX-control. When emulsion is pumped into the electrocoagulation cell it flows between the anode and the cathode and is dosed with aluminium ions and electrolysis gases. The combination of these three components forms aluminium hydroxide flocs, which attach the free oil droplets, for subsequent removal from the water. The floc separation process consists of DAF and settling of flocs in a specially designed separation tank that enables highly efficient removal of oil entrapping flocs from the clear phase. Electrolysis of seawater has the potential of generating toxic (chlorine) and explosive gases (hydrogen), even though the tests in the OileClear project have shown values that are far less than the threshold levels. However, the integrated system is to be equipped with a venting unit and online measurement sensors that are integrated with the process control system. The intelligent control system shuts off the electrolysis process if the concentration of the gases reaches set point that is lower than the threshold value. Further to this, the electrolysis unit is equipped with a safety enclosure consisting of a telescopic slide way cover. This design has among other benefits that it is sufficiently rigid to support the weight of an operator when the cover is stationary. The cover prevents spilling of wastewater and sludge into the working room and direct contact with the electrodes during operation of the process.
Potential Impact:
The OilEClear system is developed to decrease the oil content in the treated bilge water or slop to less than 5 ppm in the clear phase. The latter ensures that the system is prepared to comply with the new discharge limits set by USA and Australian authorities. The technology will comply also with the current regulations such as the Resolution MEPC 107 adopted on the 18th July 2003 (15 ppm) as well as The US, Baltic and North Sea countries which only permit 15 ppm outside 12 nautical miles from sea shore.
According to the European Community Shipowners’ Associations (ECSA) annual report 2012-2013 in Europe (as 1st June 2013) there were 116 cruises and 2031 ferries from a total fleet of 13587 ships. Regarding oil rigs there are 200 oil rigs reported in Europe (east and North Sea in 2013).
Ships produce around 50000 m3 of bilge water per year and fines due to waste and discharge offenses of around 3 Mio USD with additional conviction (US dep. of Justice 2012) can occur. The technology will ensure that the ships and oil rigs can operate without incurring violations of current and future regulations.
The preliminary market for the OilEClear technology is the Stena Line’s fleet of ships, namely 39 ships in operation at the moment and 24 ferry routes in Scandinavia, UK and Baltics. Exploration rigs are also an objective in which the technology will have a place. A number of demonstration actions have been carried out to this sector by NaCoM in cooperation with Westmatic.
Application of OilEClear in an expanding maritime and offshore oil and gas sectors for reduction of oil in water discharged over board down to 5 ppm will contribute to significant reduction of pollution in European and global seas and protection of the eco sytem. In this connection it has relevance both to existing and future legislations and international conventions. Further to this, manufacturing and supply of OileClear by the industrial partners and their future licensees and distributors can create hundreds European jobs. Further to this, OileClear can contribute to development of standards that may be required for the benefit of the market and impact on the marine ecosystem.
List of Websites:
www.oileclear.com
Contact: Mr. Cal-Olov Persson, Westmatic AB,
Email: carl-olov@wetmatic.se
Phone: +46 570 72 76 03; +46705757958
The global society is supported by a global economy in order to prosper, and the shipping and oil industry are cornerstones that make internationalisation possible. The transport of raw materials, passengers and manufactured products by ships is regulated in order to promote safety, security and environmental protection. Since 1959 IMO has regulated shipping through numerous conventions and codes. The latter is necessary due to the continuous change in jurisdiction a ship needs to comply with due to their intercontinental activities.
The activities of a ship has a huge impact on the environment. For instance, in 1998 a total of 223 cruise ships carried some 10 million passengers to and through sensitive ecosystems. Some of the pollutants generated by cruisers daily include as much as 140 m3 of oily bilge water plus thousands of cubic liters of black water, grey water and ballast water.
If the trade growth of the last 150 years continues, by 2060 the tonnage of cargo in 2010 will grow from 8 billion to 23 billion, with an expansion of the carbon footprint by 300%.
Wastewater from ships and oil rigs has high concentrations of oil. Oil present in the wastewater has its origin in either machinery purposes or because of the drilling process in a rig. Because of the large concentration of oil in water it can be mechanically removed by decanting. However, due to movement and further mixing the oil forms a stable emulsion in water.
The overriding goal of OileClear is to enable ships and offshore rigs, the primary target markets, to meet current and expected regulations regarding oily effluents to the sea. The partners in OilEClear have set an objective to develop an efficient bilge and slop water treatment system which will treat the water to attain concentration of oil below 5 ppm.
Bilge water is common to all ships and is produced from among other cleaning the engine rooms and bilge areas of the ship, deck areas of passenger ships, condensation of atmospheric humidity from the air-conditioning plants and small seepages through the hull. It consists of a varying assortment of oil and grease, oxygen-demanding substances, and organic and inorganic materials including volatile or semi-volatile organic compounds, salts and metals. Slop water is a general term for water contaminated with hydrocarbons as well as other chemicals and wastes produced on offshore oil and gas rigs from cleaning the pipe and drill deck. On rigs for exploration of oil and gas slop water volumes in the North Sea are estimated to 10.000 m3 / year per rig, in sum 1-300.000 m3 a year.
Regulations globally state that no oily water is to be discharged overboard without proper treatment. Release of oily wastewater to the sea is regulated by IMO3, MARPOL, Annex 1, setting a limit to 15 ppm THC or lower at release into the sea, but a lowering to 5 ppm is proposed by the US and Australia. In the North Sea, OSPAR has set the discharge limit to 30 ppm oil in water in slop. Some countries practice stricter regulations in sensitive waters (<5ppm), i.e. US State regulations for rigs operating near shore, and Australian harbor authorities.
The OilEClear system will separate emulsified oil and water by use of a novel three-phase separator design, including self-rinsing and adjustable electrolysis cell, combined floatation and sludge separation unit, explosion proof design, all-enclosed gas phase design, off-gas treatment for minimum air contamination, THC monitor and alarm which cuts the effluent if the effluent level is too high. Effluent data and operation will be managed by intelligent process control system. The Beneficiaries of the project OilEClear are as follows: Coordinator:
Westmatic AB – Sweden; Industrial Partners: OY Imu-tec AB, Finland; Naval Consulting and Management AS – Norway; Stena Line Scandinavia AB – Sweden. RTDs: Teknologisk Institutt AS – Norway; Fraunhofer – Gesellschaft zur Foerderung der Angewanten Forschung E.V.
Project Context and Objectives:
Project objectives
The objective of OilEClear is to develop a treatment system for oily wastewater for ships and oil rigs, enabling these to meet current and future bilge and slop water regulations with regard to oil hydrocarbons (THC), dissolved organics and toxic metals. Specifically, the objectives for Reporting Period 1 is are follows;
Scientific objectives:
- The acquisition of deeper scientific knowledge with respect to the reaction conditions given by design characteristics of existing electrolysis cell constructions, concerning electrolysis and gas formation in relations to design criteria (WP1)
- The acquisition of deeper scientific knowledge with respect to the reaction conditions given by design characteristics of existing electrolysis cell constructions, concerning coagulation and flocculation in relations to design criteria (WP1)
- Global system design criteria (WP1)
Technical objectives:
- Begin the work on development of design specifications for gas and liquid enclosed
electro-coagulation reactor for gas conservation and EX safety, concerning gas and liquid enclosure (WP2)
- Begin the work on development of design specifications for gas and liquid enclosed
electro-coagulation reactor for gas conservation and EX safety, concerning system enclosure and off-gas ventilation and treatment (WP2)
- Begin the development of new conceptual unit designs for simultaneous floc flotation and sedimentation from wastewater, and facilitate design based upon enhanced understanding and modelling of hydrodynamic processes and external forces (WP3).
The technical activities sheduled to be completed in the 2nd Reporting period include:
WP2:
Development of a gas and liquid enclosed electro-coagulation reactor for gas conservation in flocs, off-gas treatment, health and EX safety.
WP3:
Development of a new and an improved unit design for simultaneous floc flotation and sedimentation from wastewater, based upon enhanced understanding and modelling of hydrodynamic processes, particle characteristics and external physical forces. Design, construct and test a full scale separation unit model.
WP4:
Adapt and develop a novel process control unit with appropriate instrumentation and sensor technology, data acquisition and storage, and operational report generator for user-friendly performance surveillance. Integrate the developed process control unit into the OilEClear pilot plant for functionality tests for use in setting particulate and oil effluent quality standards and automatic control.
WP5:
Integrate stand-alone novel prototype with appropriate, optional pre- and post-treatment technology for on board installation, adapted to primary market and end-users.
WP6:
To ensure that project results are formulated and compiled in IPR protectable form including patents.
To develop an Exploitation Strategy, and protection of the Intellectual Property Rights arising from the technological developments
To promote the benefits of the developed technology and foreground beyond the consortium to potential user communities involving other companies through networks of the project end-users and other industrial contacts, trade press and European trade associations as well as websites and extensive distribution of DVDs.
To disseminate foreground and benefits of the developed technology at scientific conferences and workshop events to create reference base for OilEClear in the professional community.
To present the technology at technology conferences, trade fairs and with international organizations to spread the foreground and results of the OilEClear technology and its efficiency in treatment of oily wastewater to create an expectation in the market
Prepare Dissemination and Use Plan (DUP).
WP7:
Overall project management and coordination
Management of project external relations to ensure that all knowledge is created, managed and disseminated in a coordinated and coherent manner, along with all technical activities, legal aspects. Efficient management of time & resource allocation at a consortium level, facilitate and be represented at meetings & general administrative duties, coordination of the Work Packages.
Creating and negotiating IPR ownership and agreements within and outside the partnership. Preparation of, updating and managing the consortium agreement between the participants, obtaining audit certificates
Identification and assessment of potential impact within the project and related to the use and application of results.
The deliverables scheduled for the first period are:
D1.1 - Report on enhanced scientific knowledge of electrolysis, gas formation, flocculation and coagulation
D2.1 – Design specification report of prototype gas, liquid and system enclosures D3.1 – Analysis report on floc characterization
D6.1 - Report on potentially competitive patents and plan for applications [draft month 9] D6.3 - Web page with regular updates throughout the project until end date of the Project.
D6.4 - Press releases, publications and other communication activities.
D6.8 - Interim plan for use and dissemination of knowledge
Deliverables scheduled for the 2nd Reporting period include:
- D2.2: Design specification report of prototype gas, Liquid and system enclosures final.
- D3.2: Report on separation unit fluid dynamics, modelling design, model testing and specifications.
- D4.1: Report on Control system design and manual of process operation.
- D4.2: Report on Control system design and manual of process operation, Final.
- D5.1: Report on global system design, additional Technology evaluation and system integration.
- D5.2: Constructed prototype and report on industrial testing and global evaluation.
- D6.2: Report on potentially competetive patents and plan for Application.
- D6.5: Press release, publication and other communication activities.
- D6.6: Production of a video Clip
- D6.7: Final Wikipedia page on the Project and its results.
- D6.9: Final plan for use and dissemination of knowledge.
Milestones sheduled in theproject period include:
- MS1: Scientific work completed.
- MS2: Coagulation reactor completed.
- MS3: Separation reactor completed.
- MS4: Control and monitoring completed:
- MS5: Verified OileClear.
Project Results:
The Scientific and technological results include:
a) Specification criteria for the ship and oil industry, acquisition of deeper scientific understanding of electrocoagulation.
b) Gas and liquid enclosed electro-coagulation reactor
c) Combined electro coagulation and dissolved air floatation
d) Process control and monitoring, functionality test
e) Fully integrated OilEClear system and functional testing.
Specification criteria:
The foreground related to deeper understanding in the principles of electrocoagulation and DAF will enhance the capability of the SMEs in the project and future licensees for providing consulting and operation and maintenance services to end users. In addition the enhanced understanding will enable the SMEs to further develop or modify the system and make it more competitive in the market. At this point there is no plan of protecting the foreground. Ownership of is equally shared by the 3 SMEs.
Gas and liquid enclosed electro-coagulation reactor:
To fulfil the safety requirements associated with electrolysis of seawater and securing safe working environment around the OileClear system, safety enclosures and management system for potentially hazardous gases has been developed. The enclosures consist of telescopic slide way cover that prevents spilling of wastewater and sludge into the working environment and contact with the rotating electrodes, off gas treatment unit, efficient light source and monitoring of gas concentration with advanced sensors that convey measured values to the intelligent process control system. The set point is recommended to be lower than the threshold value. If the set point is exceeded, the control system closes the electrolysis process combined with alarm to the control room of the vessel or rig.
Potentially, hydrogen and chlorine gases are of important concern and can be generated by the chemical reaction during electrolysis of fresh and salt water. Fraunhofer has performed some initial tests in order to evaluate whether or not hydrogen and/or chlorine gases are generated during operation of the unit. The measurements were performed using Drâger tubes and gas was sampled immediately over the gap between the catode and anode (hot spot). The results show that the level of hydrogen gas varied from 0,04 to 4,8 vol % with an average of 2,25 vol % in air. The explosion limits of hydrogen is 4 - 75 vol % in air. Results from measurement of chlorine show that the concentration is less than the detected limit of the Drâger tubes used i.e. less than 0,2 ppm (equals 0,5 mg/m3).
For monitoring generated hydrogen and chlorine gases. it was decided to include a detector system for hydrogen and chlorine gases respectively as a safety feature and for close monitoring of hydrogen and chlorine gas generation during operation of the electrolysis process.
• Hydrogen: A Drâger gas sensor (catalytic bead) was selected. This is a gas detector for continuous monitoring of flammable gases and vapors in ambient air. The gas concentrations that are detected in a range lower than Lower Explosive Limit is converted to industry standard 4 to 20 mA signal.
• Chlorine: A Drâger Cl2 sensor was selected. This sensor is an electrochemical three electrode sensor for the continuous real-time monitoring of chlorine, fluorine, bromine or chlorine dioxide gas in ambient air.
The readings of the flammable gas sensor (% of Lower Explosive Limit) and chlorine gas sensor ( ppm of Cl2) is displayed in the HMI panel. An alarm system is included based on the monitoring of concentration of flammable gas (hydrogen). The unit is automatically shut off when a flammable gas concentration of more than 10 % of lower explosive limit is registered. At the same time an alarm is shown on the HMI panel reading: “High concentration of hydrogen > 10 % of Lower Explosive Limit”. There is no alarm connected to the chlorine sensor. Both the sensor for flammable gas and chlorine is logged to an internal memory card.
Combined electro coagulation and dissolved air floatation:
During experimentation in early stages during period 1 it was observed that although a floac foam layer is formed, it starts to loose flocs that begin to settle due to release of the electrolysis gases after some time. On a ship, instability of the foam layer due to vibrations strongly decreases the time needed to release the electrolysis gases. Thus, dissolved air flotation (DAF) process was selected and used to remove the oil loaded flocs from the clear phase. This foreground will be owned jointly by Westmatic and IMU-TEC and intend to protect along with the integrated OileClear system.. In addition to being part of the OileClear system marketable to the shipping and offshore oil and gas industries that require efficient and sustainable system for removing of oil in water down to concentrations set by national and international regulations before discharging to the sea, the DAF system can be applicable in other sectors where oil needs to be removed from water. Having generated dissolving gas microbubbles with a multiphase pump, the flotation takes place in a specially designed tank with multiple inlet possibilities, thus offering the possibility to change the inlet position. The clear phase removal pipe has a concave shape to avoid contamination with the floating oil/flocs phase. Additionally the flotation tank has a sampling/drain outlet, a drain for the remaining oil/flocs and the air saturated water inlet. A flocculation column is positioned between the spinning anode and the flotation tank. Two different diameters (23 mm and 50 mm) can be selected to modify the water inlet velocity to the flotation tank. The trials run with the specially designed separation unit has a market potential for separation of oil from water beyond management of bilge water and slop.
Process control system:
The process control system is developed for management of the electrolysis and hydraulic processes for optimum operation of OileClear while attaining the objectives of the project, particularly attaining oil in water concentration of less than 5 ppm. In this regard the control system was developed as modified and more advanced version of the existing control system for the RENAREN based on the Schneider software and hardware platform. Furthermore it is equipped with online monitoring of explosive gases. Thus the control system has a number of automatic functions for management of the separation tank, gas concentrations, oil content, EX-control, multiphase pump that regulates dissolved air saturation, current, service lamps, trend logging functions and human machine interface hardware and software. OileClear can be controlled optionally either in automatic or manual mode. However, with increasingly stringent requirement for management of oil containing waste water before discharge to sea or freshwater recipients, intelligent control of the treatment process will provide more precise management of the waste stream which both the shipping, oil and land based industrial sectors need.
Fully integrated OileClear system
The OileClear system for management bilge water and slop is developed consisting of components that ensure efficient floc generation for entrapping oil, gentle separation of the flocs from the clean phase, safe operation of the electrolysis process and intelligent control of the electrocoagulation and floc separation processes as well as management of EX-control. When emulsion is pumped into the electrocoagulation cell it flows between the anode and the cathode and is dosed with aluminium ions and electrolysis gases. The combination of these three components forms aluminium hydroxide flocs, which attach the free oil droplets, for subsequent removal from the water. The floc separation process consists of DAF and settling of flocs in a specially designed separation tank that enables highly efficient removal of oil entrapping flocs from the clear phase. Electrolysis of seawater has the potential of generating toxic (chlorine) and explosive gases (hydrogen), even though the tests in the OileClear project have shown values that are far less than the threshold levels. However, the integrated system is to be equipped with a venting unit and online measurement sensors that are integrated with the process control system. The intelligent control system shuts off the electrolysis process if the concentration of the gases reaches set point that is lower than the threshold value. Further to this, the electrolysis unit is equipped with a safety enclosure consisting of a telescopic slide way cover. This design has among other benefits that it is sufficiently rigid to support the weight of an operator when the cover is stationary. The cover prevents spilling of wastewater and sludge into the working room and direct contact with the electrodes during operation of the process.
Potential Impact:
The OilEClear system is developed to decrease the oil content in the treated bilge water or slop to less than 5 ppm in the clear phase. The latter ensures that the system is prepared to comply with the new discharge limits set by USA and Australian authorities. The technology will comply also with the current regulations such as the Resolution MEPC 107 adopted on the 18th July 2003 (15 ppm) as well as The US, Baltic and North Sea countries which only permit 15 ppm outside 12 nautical miles from sea shore.
According to the European Community Shipowners’ Associations (ECSA) annual report 2012-2013 in Europe (as 1st June 2013) there were 116 cruises and 2031 ferries from a total fleet of 13587 ships. Regarding oil rigs there are 200 oil rigs reported in Europe (east and North Sea in 2013).
Ships produce around 50000 m3 of bilge water per year and fines due to waste and discharge offenses of around 3 Mio USD with additional conviction (US dep. of Justice 2012) can occur. The technology will ensure that the ships and oil rigs can operate without incurring violations of current and future regulations.
The preliminary market for the OilEClear technology is the Stena Line’s fleet of ships, namely 39 ships in operation at the moment and 24 ferry routes in Scandinavia, UK and Baltics. Exploration rigs are also an objective in which the technology will have a place. A number of demonstration actions have been carried out to this sector by NaCoM in cooperation with Westmatic.
Application of OilEClear in an expanding maritime and offshore oil and gas sectors for reduction of oil in water discharged over board down to 5 ppm will contribute to significant reduction of pollution in European and global seas and protection of the eco sytem. In this connection it has relevance both to existing and future legislations and international conventions. Further to this, manufacturing and supply of OileClear by the industrial partners and their future licensees and distributors can create hundreds European jobs. Further to this, OileClear can contribute to development of standards that may be required for the benefit of the market and impact on the marine ecosystem.
List of Websites:
www.oileclear.com
Contact: Mr. Cal-Olov Persson, Westmatic AB,
Email: carl-olov@wetmatic.se
Phone: +46 570 72 76 03; +46705757958