TOKYO - (KRT) - A group of private and academic research institutes is
studying the viability of tackling the gargantuan project of building a seaweed
plantation in the Pacific Ocean to absorb carbon dioxide and produce biofuel.
The group, which includes the Mitsubishi Research Institute, Tokyo University
and Tokyo University of Marine Science and Technology, is studying the viability
of the plantation, which they hope could be vital in the fight against global
warming.
In the atmosphere of primordial Earth, the percentage of carbon dioxide was much
higher than it is today, and the percentage of oxygen was much lower.
The first living organisms - blue-green algae, green algae and other species of
seaweed - converted carbon dioxide into oxygen through internal photosynthesis.
As a result, the percentage of oxygen in the atmosphere eventually rose to
today's level.
"Petroleum was originally fossilized seaweed and other creatures. Therefore, it
makes sense to reduce the amount of carbon dioxide in the air with the help of
seaweed and use the seaweed to produce fuel," professor Masahiro Notoya of Tokyo
University of Marine Science and Technology said.
The plan is to place 100 floating fishing nets in the Pacific Ocean, each
measuring 10 kilometers by 10 kilometers. Seaweed such as sea grape, which can
reach 20 meters in length in a year, will grow from the nets.
If various species of seaweed can be harvested so that at least one of them is
growing at any given time throughout the year, each of the nets could produce
270,000 tons of seaweed a year, according to estimates.
Seaweed discharges hydrogen and carbon monoxide gases when it is exposed to
extremely heated water vapor. Methanol and other biofuel can be synthesized from
the gases.
Because the biofuel is made from carbon hydride, which is created from carbon
dioxide through photosynthesis, no extra carbon dioxide is discharged into the
atmosphere when the fuel is burned. In this sense the fuel holds a very great
advantage over fossil fuels.
Another benefit of the nets is that concentrations of seaweed contain abundant
plankton and attract fish looking for spawning grounds. This in turn will
increase fishery resources.
"Absorbing carbon dioxide is only a small function the seaweed will serve. By
growing seaweed, we can make nature richer," Notoya said.
One of the main problems the institutes face is where to put the nets. Strong
currents run off the Japanese archipelago and the nets could easily be swept
away.
The seas off the coast of the Sanriku region offer a possible solution. The
current there runs in a 300- to 350-kilometer circle. If the area is chosen, it
may be possible to control the nets by tracking them with a Global Positioning
System.
The group is going to research details of currents off the Sanriku region with
observation buoys next summer to confirm the viability of the project.
Tokyo University Prof. Toshio Yamagata and his team have developed a system to
predict sea currents three months ahead of time from water temperatures observed
by satellite.
By combining Yamagata's findings with the GPS technology, it would be possible
to predict and adjust future positions of the nets.
But other hurdles stand in the way of the project. It's size alone might be
enough to scuttle the plan, which calls for 100 of the huge nets floating on the
sea, and a ship to produce the biofuel. The whole system will measure 120
kilometers by 120 kilometers.
Discussions regarding the laws of the sea and other international laws are
essential to prevent the project from obstructing the safe passage of ships
through the area.
It is also necessary to carefully examine what effects the project might have on
the ecosystem.
But to avoid global warming, carbon dioxide emissions must fall by more than 50
percent in the future.
To achieve the goal, solutions must be offered by science, as well as people
changing their ways of thinking and lifestyles.
There are ongoing studies to separate carbon dioxide emitted from thermal power
plants which is then stored underground, and to have carbon dioxide absorbed
into sea water.
Yoshishige Katori, a leading researcher in the huge seaweed farm project and
senior counselor at Mitsubishi Research Institute, said: "Each of the
technologies to be used is not unusually advanced. But combining them for a
specific purpose can contribute to efforts to prevent global warming.
"To make the project a reality, we want to prove the possibility of the plan and
present a vision of a bright future for mankind," he said.