Page 52 - Plastics News February 2019

teChnoLogy

Carbon gas storage cavern is the best way to obtain clean energy from

a fossil fuel

set of technologies that is expected to have its first According to Meneghini, Brazil will be the first place in
A results four years from now is designed to resolve one the world to use this concept, and the model could be
of the world's greatest oil and gas exploration challenges exported to other countries. In addition to storing CO2,
today: carbon dioxide (CO2) and methane (CH4) emission the cavern can also store methane and separate the two
in the atmosphere.The innovation, the result of a patent gases using gravity. Since CH4, also referred to as natural
deposited in 2018, consists of injecting the CO2 and CH4 gas, has a lower density, it will remain in the top part of
that comes from wells during oil extraction into salt the cavern for possible later use. The carbon dioxide will
caverns as a way to reduce the amount of carbon gas in remain in the lower part. The researcher expects that at
the emissions. The first "pilot cavern" may be ready by 2022 least the initial cavern construction tests will take place
and is the result of studies carried out at the Research by 2022. The most optimistic scenario provides that 2022
Center for Gas Innovation (RCGI), established by FAPESP will be the year the cavern begins operations.
and Shell, headquartered at the Polytechnic School of Carbon gas capture- "What is new is not just the cavern,
the University of São Paulo (Poli-USP). The RCGI is one but the various innovations that go along with it, such
as supersonic gas separators, compressors designed
optimizing topology, and graphene nanotube membranes
used to separate the gases," said the researcher. The
new CO2 compressors are vital to the functioning of the
project, given the extreme pressure conditions found
there. From the water line itself, the distance from the
surface to the sea floor is 2,000 to 3,000 meters in depth.
That and other variables leave gas in what is known as the
supercritical state."It has the density of a liquid and the
viscosity of a gas. Therefore, a compressor designed for
that specific condition is necessary. We have developed
a new methodology that consists of optimizing the
compressor precisely to the conditions of the supercritical
fluid," Meneghini told. Another technology related to
of the Engineering Research Centers (ERC) funded by São the carbon dioxide caverns are the gas separators.
Paulo Research Foundation -- FAPESP in partnership with Also because of the pre-salt conditions, what is known
companies. "This is a concept known as Carbon Capture as variable geometry supersonic separators are being
Storage (CCS). In this case, the CO2 is stored in large developed for each composition of the mixture of CO2 and
caverns in the salt layer itself. This is perhaps one of the methane. Besides that, graphene nanotube membranes
best ways to obtain clean energy from a fossil fuel during are also being developed to separate the gases with the
the production process," said Julio Meneghini, a professor least possible energy loss.Carbon gas capture can also
at Poli-USP and RCGI coordinator. Meneghini was one of occur during ethanol generation. "The captured gas may
the speakers on the first day of sessions held during FAPESP be stored or used in the food industry, in the production
Week London, taking place in London February 11-12, of carbonated drinks like soda. By doing this, negative
2019. The site of the cavern in which the initial tests will emission values can be obtained," said Meneghini, who
be run has not yet been determined, but is expected to be explained that the experiments are still being carried
in one of the areas that hold pre-salt oil fields. During this out on a small scale. The technologies are emerging
initial phase, it will likely be half the size of the caverns within a context of increasing per capita energy demand
that will be used when the technology is operating at full throughout the world and the need to mitigate emissions
capacity: 450 meters in height by 150 meters in width. in light of global climate change.

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