São Paulo – Next November, Dubai, United Arab Emirates will host the U.N. climate summit, COP28, when representatives of the countries that are members of the United Nations Convention on Climate Change (UNFCCC) will gather to discuss urgent environmental issues of global importance. The UAE’s COP28 President Sultan Ahmed al-Jaber has argued that besides cutting back emissions, the world should use new technologies to remove carbon from the atmosphere in order to slowdown the global warming.
Claudio Oller, who’s a professor at the Chemical Engineering Department of the Polytechnic School of the University of São Paulo (USP) and coordinator of its High Pressure Laboratory that opened last year, share this view. “The processes of capture and transformation of CO2, the leading cause of global warming and climate change, need to be updated.” This is one of the goals of the laboratory he manages, which is part of the Research Center for Greenhouse Gas Innovation: finding new, more sustainable and affordable solutions by using chemical and biological resources under high pressure.
Starting in the Industrial Revolution in the 19th century the use of fossil fuels like coal, natural gas, and oil derivatives like gasoline, diesel oil, fuel oils, and others rose sharply. The use of such resources releases greenhouse gases into the atmosphere. This also happens when forests are teared down for the agricultural expansion. The carbon, which has been stored in solid form inside the plant biomasses is then released as a gas when the plant is burned.
According to figures from the global IPCC panel which informs policymakers about the climate, over the past 270 years the humankind has released some 1.5 trillion tonnes of carbon dioxide into the atmosphere. These work as a lid that traps heat on the planet. This phenomenon has accelerated global warming, thus resulting in large-scale environmental disasters like changes in atmospheric winds, ocean currents and rain regimens across the world. Consequently, the world has experienced extreme heat waves, extended droughts, ocean acidification, and sea level rise, which threatens ecosystems and coastal communities. The CO2 is deemed the leading source of the greenhouse effects not only because it retains more heat but because it exists in greater abundance than other gases like methane, nitrous oxide, and water vapor.
Oller believes that the humankind will still rely on petroleum and its derivatives for many years to come – “I’m going to guess at least 50 years” – since it’s the leading fossil fuel used around the world and no equivalent replacement has been found yet. “Oil is wonderful, and it’s the raw material for thousands of other products. Burning it is a waste,” he says. Under his lead, researchers have studied the bioconversion of CO2 in a supercritical state by bacteria from Antarctica. Working with sediments taken out from the bottom of the Antarctic Ocean that are rich in microorganisms, the scientist managed to wake up dormant bacteria from approximately 20,000 years ago. Now they want to know how these microorganisms, behave under extreme conditions. In wide pressure ranges, without light, and in the presence of CO2 in a supercritical state, which means a at a temperature and pressure above its critical point,” said Oller.
These so-called extreme conditions found in underground caverns under the sea like the ones that’ll be created from the pre-salt exploration. The idea is to store in these salt caves the CO2 that comes from oil production in a supercritical state so that it occupies less volume. Oller says that this is one of the most effective ways to cut back greenhouse gas emissions but warns that “we still don’t know the long-term consequences that these carbon reservoirs can cause to the environment, not to mention the risk of leaks. According to the professor, the bacteria that were awakened feed off CO2, and “they love it!” So in the future the idea is to inject these resuscitated microorganisms into the sea caves and wait for the supercritical carbon to mutate. “This process can also give rise to other products like alcohol or hydrocarbon. We’re studying the scientific and economic viability of this idea.”
Sea: Clean energy generation
But the sea has more to offer than just carbon-storing caves. “The sea is an ally in reducing CO2 emissions as it can provide clean energy and supply raw materials for renewable fuels,” says oceanographer Frederico Brandini, who sees the tides, currents, algae, and ocean winds as solutions to mitigate the greenhouse effect. “In the coastal area, there’s a series of alternatives to address the energy crisis and reduce our reliance on non-renewable fuels. The most widely used now is wind power. Shifting our energy mix towards alternative power is possible. Stopping drinking water or producing food isn’t.”
He explains that the oceans have historically played a role to absorb the excess of carbon dioxide from the atmosphere, but there is a saturation point. “If this trend continues, the oceans will hit their maximum capacity of absorbing CO2 and start releasing it back into the atmosphere.”
The Schurmann family, who has lived in a sailboat for almost 40 years, is on their fourth round-the-world expedition, the Voice of the Oceans, whose mission is to produce content on the consequences of the human actions in the seas. The first leg of the trip will be concluded in November, when they reach New Zealand. The sailors point out that the oceans are the lungs of the Earth, as most of the planet’s oxygen comes from the sea. Besides contributing to the world’s oxygen production, the phytoplankton stores at least 25% of the CO2 emitted by fossil fuels that are burned by our species.
According to professor Brandini, the wind power is the one that has been explored the most in coastal areas, with parks scattered across the coast and off shore. “But daily tidal circulation is the most steady and predictable ocean process with potential to generate power.”
There are basically two possibilities of drawing power from tides: power station dams and underwater turbines. “The first power station dam was built in 1966 and is still in operation in the estuary of the Rance River in France, with a production capacity of 240 MW.”
Brandini admits that, although good, this idea presents problems. “The biggest one is the environmental impact from building dams in estuarine regions. In Brazil, this would be an environmental and socioeconomic catastrophe.” He believes that most appropriate technology for drawing energy from tides would be installing underwater turbines. “They operate as windmills but are underwater and capture the energy from the currents created by the tidal cycles. Each unit generates 750-1500 KW depending on the local current,” the professor said. He added that “projects that draw energy from the surface wave motion or underwater pressure variations resulting from ocean wave motion have been investigated in Scotland, Canada, Australia, South Africa, and the United States.”
Marine microalgae for production of biofuels: Cheap and renewable
Other studies indicate the advantages of producing biofuels from microalgae. “They are single-cell plant-like organisms that don’s use fresh water, can be cultivated in floating tanks in the sea with no agriculture conflict and use ocean nutrient sources, provided that nutrient-rich deep waters are pumped to the surface. Nothing that a little bit of technology and political willingness can solve,” says Brandini.
Microalgae have a much higher photosynthetic efficiency than land plants, with rapid growth and plant biomass accumulation. That’s to say they grow more per acre in less time. “They are also efficient in carbon fixation. It’s estimated that each ton of algae biomass consumes 2 tons of CO2 through photosynthesis. This is ten to twenty times more that what’s absorbed by oilseed crops.”
Plastic planet
The Schurmann Family warns of the recent years’ increase in the amount of plastic found in the oceans across the world. “According to a report from the UN, From Pollution to Solution: A Global Assessment of Marine Litter and Plastic Pollution, by 2040 it’s estimated that the seas receive 23-37 million tonnes of plastic per year. “It’s a ridiculous amount of waste. It’s very important to understand that there’s no such thing as ‘throwing out’”, the Shurmann family told ANBA.
“When we come across such alarming data and witness what’s behind them, it takes our breath away. But with Voice of the Oceans, we’re looking for solutions.” Two years into the journey, the Schurmann Family has been accompanied by “hundreds of people, non-profits and initiatives that operate across various work fronts in order to minimize the impact of the plastic invasion in the oceans and its consequences for the health of the planet.”
“The sea is a future hope for clean energy production,” says Brandini. For professor Oller, who keeps researching alternatives to give a different destination for carbon other than the atmosphere, we are already using the most efficient technology now, that has been tested and approved: ethanol. “It’s the only economically viable fuel,” he assures.
Report by Paula Pisani, especially for ANBA
Translated by Guilherme Miranda
