Coupling an oxygen generation cycle with an oxy-fuel combustion spark ignition engine for zero NOx emissions and carbon capture: A feasibility study

An oxycombustion spark-ignition engine coupled to an O2 production cycle based on a mixed electronic-ionic ceramic-type membrane is studied in this paper. The exhaust gases drive oxygen production through a heat exchanger network and a set of turbochargers. Initially, a study at medium speed is carried out to determine the influence of the oxygen concentration and the engine compression ratio on the system performance. A 16.3 % of fuel consumption reduction is reached when 30% of O2 mass fraction and an engine compression ratio of 20 are implemented when compared with conventional engine operation. Then, a full load study in a wide range of engine speeds is performed, where a maximum fuel consumption reduction of 21 % is obtained at high speed (5000 rpm) comparing with conventional engine operation. The study shows the whole cycle has demonstrated promising performance parameters at different working conditions (O2 mass fraction, compression ratio, engine load and speed).