Near Shore Recovery of Spilled Oil
The recovery of oil on water near shore is currently a gap in the oil spill response model. Shallow waters
prevent large vessels from operating effectively, and shore-based techniques can only be deployed within
metres of the shoreline. RESTCo proposes an innovative small boat which can operate effectively in this
region with a number of key features.
The near-shore waters are often environmentally rich, and can support substantial aquaculture such as
clams, scallops, mussels, marine plants like kelp and more that cannot swim away from an oil spill,
and which are frequently key resources for local communities.
They are also sensitive to oil spills which can destroy productivity for years or decades. Therefore,
we see it as appropriate that the first response capability, especially for small and emerging spills,
should reside in those communities to enable rapid response.
An earlier version of the proposed vessel featuring the oil separation pyramid in the centre of the deck
Dedicated spill response boats and crews are an expensive approach to preparing
for an event which is rare, so we propose a work boat which can earn its keep in a 'day-job', while
remaining capable of effectively recovering spilled oil from the water surface with a few minutes
of equipment reconfiguration. The same workers that crew the boat in normal operations can be
trained to carry out the spill response operations, preferred because they know the local waters.
The patented Canadian gravity oil recovery system has been tested by RESTCo in our test tank,
and with oil proxies on open water on our test boat.
A one-tenth scale model of the proposed workboat in its fully decked general purpose mode
A portion of that deck can be removed and the gravity separation tower dropped into the vessel's moon pool
It has also been independently evaluated on a 12-metre test
platform at Ohmsett. The integrated tower and hull design was shown to operate with high collection efficiency
of the oil on the water on both calm water and in waves (better than 90% collection). By pumping out
collected oil from the top of the tower, almost no water is taken up with the oil.
Oil collection gravity tower on 12-metre test platform at Ohmsett trials - collecting oil in waves
(Ohmsett is an independent testing facility funded by the U.S. government, located in New Jersey)
Most oil skimmer equipment in use today (booms, bow sweeps, and
various sorts of disk, brush, drum and mop skimmers) are ineffective in waves or inclement weather.
Construction of the test rig used at Ohmsett was funded by the Government of Canada as part of an innovation
awards program (CICP).
Aquatic weeds in pump discharge view tube Aquatic weeds and algae in drain box
Testing by RESTCo shows that the patented gravity oil recovery system will also work to pick up
seaweed, (micro)algae, floating plastic and other pollution.
RESTCo is in the process of validating our new conveyor pick-up system which can collect algae,
microplastic, floating pollution, seaweed and oil on the water surface.
Proof-of-concept conveyor ready for installation on test boat
Tank tests of the innovative conveyor system shows it can pick up floating plastic pollution,
microplastics and algae. Spilled oil recovery testing should take place before the end of 2020.
In the videos, note that water drains through the patented conveyor belt fabric, while microplastics and
microalgae do not. This adsorbent (vs. absorbent) does not let oil drain through.
RESTCo conveyor picking up microplastics (10-50 microns diameter) in test tank
(The yellow beads are calibrated microspheres for testing and tracking microplastics for research.
They are sufficiently expensive that we collect and dry them for re-use. They don't get released
into drains or waterways.)
RESTCo conveyor picking up microalgae in the test tank
Microalgae grows within the water column, and is food for small aquatic zooplankton and fish. However,
when algae overproduces due to warming water and oversupply of nutrients (e.g., phosphorus and nitrogen),
it starts to collect on the surface, blocking light from reaching deeper in the water, affecting the
health of other organisims in the water. Some algae blooms even contain toxins.
RESTCo conveyor picking up floating plastic pollution in the test tank
Plastic pollution in our wild waters is a global, and growing, problem. That includes macro- and
meso-plastic pollution, which typically degrades over decades into microplastics and greenhouse gases.
In real-world operation, the forward motion of the boat or water current would push the plastic
pollution to the front edge of the conveyor.
The key innovation here is that one device can be used to pick up floating litter, plastic pollution
(even microplastics), microalgae, aquatic weeds and spilled oil without having to change out belts or
other parts. One adsorbent filter material (patented) can recover and capture all of them. This is important for
reducing downtime during recovery operations, but also allows for capture of oil which may be mixed
with floating wood debris or aquatic weeds or other foreign matter. A second mesh filter in the
capture tank can allow only the oil - already separated from the water - to go to the oil storage.
Both the gravity recovery tower and the conveyor units are made to be removable when not needed for
daily operations, but can be fitted to the boat in minutes when needed. The conveyor can be used to
harvest floating seaweed.
In most applications, the collected material in the gravity tower will be removed using an innovative,
efficient low speed displacement pump, which is also a patented Canadian technology.
Patented Canadian low speed high volume pump
Once initial spill recovery operations are completed, the RESTCo workboat can be used to deliver
equipment and personnel to specific regions, install and collect adsorbent water fences, spray
bioremediant on areas requiring more attention, or collect and tow bladders, oil storage barges and
booms, and carry out post-event water and shoreline monitoring. The boats can be fitted with bow
sweeps to increase the area cleaned per hour, when water conditions permit. When water conditions
are rough, the boats can operate without sweeps, when other conventional oil spill response
technologies cannot operate or are completely ineffective.
RESTCo sees the combination of these innovative technologies as enabling a new spill response arena:
community-based vessels designed to protect the local near-shore and inland waters with a range of
of capabilities, as well as typical workboat tasking so the boat can earn its keep daily, while also
being able to shift to emergency response operations very quickly to enable rapid response before
spilled oil spreads to cover many square kilometres of water surface. The vessel can support additional
spill response and remediation equipment. Electric drive systems can be fitted to reduce impact of
gasoline and diesel exhaust, spills and noise on
shellfish and other local marine life. Constructed primarily from aluminum, the boat can even be
recycled at end of life.
Because this is a new niche in the spill response regime, we see potential demand from spill response
organizations, community-based first responders, aquaculture operators who want to protect their
product from oil, algae blooms, pollution or even the exhaust and noise from outboard motors on conventional workboats. Similarly,
tourist destinations will want quiet workboats which can keep their water areas pristine on a routine
basis, but also respond rapidly to potentially devastating oil or fuel spills.
The boats are sized to allow trailering so that boats from other communities can be moved to a spill
location within hours, putting more response capability on the water in short order if required (swarm).
Once proven in Canada, we envisage a large export market for this product and its complementary
technologies, creating jobs in aluminum making, boat building, pump, tower and conveyor manufacture,
and specialized fittings for aquaculture and water tourism protection.