The second phase of Japanese R&D program for CO2 ocean sequestration

The "Moving-ship" scheme technically offers the maximum dilution of injected liquid CO2. Captured and liquefied at the plant on land, CO2 is delivered by ship and injected into ocean depths of 1000 to 2500 in with a suspended and towed pipe by a slowly moving ship. For a realistic scale, the CO2 discharge rate is 100kg/sec, towing speed is 3m/sec, the width of the wake of the pipe is 2m; the initial dilution ratio becomes about 1/60,000 prior to full droplet dissolution at 1,000m. The 5-year R&D program (Phase-2) includes the verification of the dilution scheme of the above-mentioned concept by the ocean experiment. At the same time, based on the actual biological survey in the same site, the assessment of environmental impact for the hypothetical full-scale implementation will be conducted; the lethal CO2 concentration limit value will be identified for the mid-depth plankton of the site by the method developed in the first phase (from 1997 to 2002) of the NEDO R&D program, and will then used in the food-web based assessment model of the site. The opportunity of the ocean experiment is open to the international partners, and the verified dilution factor attainable by moving-ship concept coupled with the established assessment methodology will be submitted to the international forum in order to obtain the legal acceptance of this technology as a measure of CO2 emission reduction. The Phase 2 was started in April this year, however, the experimental plan of the CO2 injection into the ocean will be revised because the permission for the experiment in Norway was withdrawn by the ministry of the environment last August.