2. FAQs


  • Why was Tomakomai City in selected?
    There are several large-scale plants in Tomakomai City as sources of CO2. This area is characterized with an abundance of geological information obtained through the exploration activities of petroleum and natural gas. Several reservoirs which can store CO2 in a steady and safe state for a long term have been confirmed through the multiple serveys over many years. The utilization of aquifers found throughout Japan for CCS is expected will be realized by the results of the demonstration project in Tomakomai City.
  • What are the specific risks of CCS? What are the measures for them?
    A potential risk of the CCS project is a leakage of injected CO2 in the future. This demonstration project is designed to store CO2 in two layers, 2,400-3,000m and 1,100-1,200m below the seabed, respectively. There is a thick shielding layer right above these layers and they are considered to provide protection from leakage. An integrated monitoring system to monitor the state of CO2 reservoirs, should be operative at all times. We take all possible measures to maintain safety.
  • How to take measures against an unexpected CO2 seepage?
    Based on an experience that no precedent has been reported to date of seepage of petroleum and natural gas from reservoirs in deep underground, we think the potential for CO2 seepage from a reservoir located under the seabed at more than 1,000m in depth would be quite low. We have simulated several cases of seepage from the seabed. Furthermore, in case that facilities are damaged by a tsunami, an automatic emergency valve will be installed.
  • How much and over how many years will CO2 be injected?
    Over 100,000 tonnes of CO2 per annum for 3 years from 2016 to 2018 is scheduled to be injected. After the completion of injection, monitoring will be continued for two more years until 2020.
  • What should happen to the injected CO2?
    According to the IPCC* CCS Special Report (2005), when CO2 is injected, it remains trapped in the storage formation. After many years passed CO2 would increase the percentage of stable conditions, i.e., the CO2 would transform into immobile forms by dissolving in water or forming carbonate. *IPCC:Inter-governmental Panel on Climate Change