High temperature fuel cells to reduce CO2 emission in the maritime sector

Recently the interest in the sustainability of the maritime sector has increased exponentially. The International Maritime Organization (IMO) set as objective the reduction of CO2 emissions by 2030 by a margin of 40% compared to 2008. Recent studies showed that, according to the ships and the emission mitigation method applied, only 15–25% of CO2 reduction is de facto needed. Fuel cells represent an answer to meet this regulation. We propose two different solutions: (i) produce with SOFCs instead of engines the minimum power necessary to cut 20% of the emissions, or (ii) reduce the engine power of about 10% balancing the power requirement using MCFCs with CO2 capture. Using Aspen Plus each solution was investigated. The analysis contemplated LNG steam reforming to produce the H2 necessary for cell operation and the separation and liquefaction of CO2. Two case studies were considered comparing existing passenger ships with engines working on HFO and on LNG respectively. Although both solutions showed potential for the reduction of CO2 emissions respecting the IMO regulations, the SOFC solution requires a major change in the design of the ship, while MCFCs are proposed as an urgent solution allowing ship retrofitting without demanding update.