CO_2 Removal in SOFC Systems - CO_2 Capture in a Modified Process or Biological Fixation in Algae Production

摘要

The global climate change mainly caused by anthropogenic CO_2 forces the search for technologies to reduce the amount of CO_2 that is released to the atmosphere. One possibility is the fixation of CO_2 involving CO_2 sequestration, underground or in the ocean. Sequestration requires CO_2 liquefaction. It is shown that this is only feasible, if the CO_2 is concentrated to about 90%. In common SOFC plant design several % CO_2 are present in the exhaust gas depending on the air ratio in SOFC and afterburner. With modified tubular SOFC bundles including an electrochemical afterburner the high CO_2 concentrations can be reached. An SOFC power plant can be combined also with a biotechnological reactor for algae mass production. Mass and energy balances show that the advantages of the high temperature fuel cell match with the demands of the algae production unit. All products of the SOFC can be used: electric power for driving the pumps circulating around the culture medium, CO_2 and H_2O for the growth of the algae during daylight and high temperature heat of about 200°C for the drying apparatus.