Nippon Steel and Sumitomo Metal developed a plant to recover carbon dioxide and recycle the recovered carbon dioxide for a material of industrial gases with 40% smaller amount of energy than the existing plant. The new plant uses special liquid for efficient absorption of CO2 that Nippon Steel and Sumitomo Metal developed in collaboration with Research Institute of Innovative Technology for the Earth. The special absorption liquid is sprayed inside the tank filled with exhaust fumes, and subsequently the special absorption liquid that contains CO2 is transferred to another tank and heated to discharge CO2. The discharged CO2 is used for industrial gases, carbonated drinks, and a raw material of dry ice. Unlike the existing plant that needs to heat the absorption liquid containing CO2 to 120 degrees centigrade, the new plant has to heat only to 95 degrees centigrade. In addition, heat generated in the process to absorb CO2 contained in the exhaust fumes can also be recycled. Accordingly, the required heat energy can be reduced by 43%.
Nippon Steel and Sumikin Engineering will market the new technology to industrial gas companies both at home and abroad. Enhanced oil recovery, the technology to infuse unproductive oil fields with CO2 to increase oil production, attracts attention worldwide especially from Asia and Africa. The plant to recover 50,000 tons of CO2 is priced at 2 billion yen and that to recover 1 million tons of CO2 is priced at 9 billion yen. There are two kinds of technologies to recover CO2 from exhaust fumes. The chemical absorption method uses alkali solution that absorbs CO2 with the help of a chemical reaction, while the physical absorption method uses methanol and takes in CO2 applying high pressure.
Enhanced Oil Recovery