Professor from the University of Tokyo presented a CCS project in a saline aquifer in Japan; in his opinion, Brazil cam become a leader in the storage of CO2 in salt caverns

On Wednesday, October 17, the FAPESP Shell Research Centre for Gas Innovation (RCGI) was visited by the engineer and professor in the area of oceanic technology, policies, and the environment of the University of Tokyo, Toru Sato. He was in Brazil for an international conference, in Rio de Janeiro, and took advantage of the opportunity to come to the RCGI, in São Paulo, and speak about a pilot project for Carbon Capture and Storage (CCS) in the city of Tomakomai, which is the first of this type on the island of Hokkaido, located in northern Japan. Japan CCS Co. is responsible for the technology of the project, and Professor Sato is involved in the environmental assessment of the initiative.

“Tomakomai is a project being implemented by the Ministry of Economy, Commerce and Industry of Japan. Before the injection of CO2 began in 2016, there was a preparation period, with surveys and studies that took around seven years. It is the world’s first CCS initiative in an urban area,” Sato states. The reservoir is a deep saline aquifer and the CO2 comes from a plant that produces hydrogen. It is captured by chemical absorption and the recovery rate is 99.9%. Every day, 600 tons (200,000 per year) of CO2 are captured. And the purity of the stored CO2 is 99%.

“The Ministry of the Environment requires that the purity be 99%, because it fears leaks of toxic gases. In Japan, we have earthquakes and other extreme types of events the you do not have in Brazil,” he said.

Sato’s biggest concern is the leakage. “The probability is very low, but if CO2 leaks, maybe some of the marine organisms will be impacted. We have to monitor and know how marine life would react to a leak, if it should take place.” He says that there are two possible types of leakage: in the injector well and via geological faults. “Storage must be avoided where there are faults, because with the earthquakes, the faults grow.”

The Tomakomai project is rigidly monitored, including both onshore facilities (to measure the microseism caused by natural phenomena and offshore facilities, which, besides the two previous measurements, also come from parameters caused by the temperature and pressure of the reservoir. “This is the last year for CO2 to be injected into the reservoir. It will continue to be intensely monitored over the next five years.”

Social license – According to the Professor, the public acceptance of the projects of this type is very important, and this brings up the relevance of the environmental assessment. “It is also good to take note that there is a difference between local acceptance and global, or national, acceptance, in the case of a CCS project. Sometimes, the local population could even accept it, inspired by the fact that it is doing something about global warming. But, generally speaking, local acceptance is more complex, in terms of compensations in the case of offshore reservoirs, involving negotiations with organizations representing the interests of fishermen who fear that their fishing areas would be jeopardized by a leak, for example.”

Sato says that, in the case of the Tomakomai project, there was good local acceptance. “Paper industries are located there, as well as petroleum refineries. They are good taxpayers for the city, create jobs, and much more, and they need to capture and store CO2. So, the local population accepted the idea.”

The engineer believes that, regarding public acceptance of the practice of capturing and storing CO2, Brazil and Japan have distinctive profiles. And that, in his country, the function of the Ministries is to inform people regarding CCS – remembering that Japan also made commitments in Paris, and must fulfill them. “But there, we do not produce petroleum and natural gas, we only burn them. It is different in Brazil: CCS is becoming an integral part of the oil and gas industry. I imagine that Brazilians, in general, do not know the details of Petroleum and natural technologies. Therefore, they might not need to know the smallest details about CCS technologies.”

The RCGI’s Director of Human Resources, Karen Mascarenhas, says that the experiences reported by Sato are valuable for the group that is working at the Centre with the public perception of CCS. “It is a success story. The care that they have taken and the actions they developed for communicating with the community have a lot to teach us,” she says, after also having visited the pilot project in Tomakomai. The RCGI leads a group that is studying public perception and the social license for operating CCS initiatives in Brazil.

Salt caverns – Sato was enthusiastic after the presentation of the RCGI project that focuses on separating CO2 and CH4 gravitationally in salt caverns and storing CO2 in those reservoirs. “Storage in saline rock is an excellent solution and it is very safe. In the United States, in Russia, and in the Middle East, they use this type of reservoir to store fuels.”

According to the Japanese engineer, about 70% of the total cost of CCS operations has to do with the capture and separation of CO2 from other gases. “That is done chemically, today, and not physically. If Brazil is able to perform the separation of CO2 from other cases more cheaply and be successful with this technology, it can be the leader in CO2 storage in offshore salt caverns.