Study on a novel solid oxide fuel cell/gas turbine hybrid cycle system with CO2 capture

Abstract

SUMMARYA novel solid oxide fuel cell (SOFC)/gas turbine (GT) hybrid cycle system with CO 2 capture is proposed based on a typical topping cycle SOFC/GT hybrid system. The H 2 gas is separated from the outlet mixture gas of SOFC1 anode by employing the advanced ceramic proton membrane technology, and then, it is injected into SOFC2 to continue a new electrochemical reaction. The outlet gas of SOFC1 cathode and the exhaust gas from SOFC2 burn in the afterburner 1. The combustion gas production of the afterburner1 expands in the turbine 1. The outlet gas of SOFC1 anode employs the oxy-fuel combustion mode in the afterburner 2 after H 2 gas is separated. Then, the combustion gas production expands in the turbine 2. To ensure that the flue gas temperature does not exceed the maximum allowed turbine inlet temperature, steam is injected into the afterburner 2. The outlet gas of the afterburner 2 contains all the CO 2 gas of the system. When the steam is removed by condensation, the CO 2 gas can be captured. The steam generated by the waste heat boiler is used to drive a refrigerator and make CO 2 gas liquefied at a lower temperature. The performance of the novel quasi-zero CO 2 emission SOFC/GT hybrid cycle system is analyzed with a case study. The effects of key parameters, such as CO 2 liquefaction temperature, hydrogen separation rate, and the unit oxygen production energy consumption on the new system performance, are investigated. Compared with the other quasi-zero CO 2 emission power systems, the new system has the highest efficiency of around 64.13%. The research achievements will provide the valuable reference for further study of quasi-zero CO 2 emission power system with high efficiency.

Energy and exergy-based working fluid selection for organic Rankine cycle recovering waste heat from high temperature solid oxide fuel cell and gas turbine hybrid systems

“…Thus, the effects of waste heat source temperature on the bottoming ORC subsystems and fluid selection are of importance to further be investigated. The exhaust temperature is chosen in the range of 500 K to 600 K based on the typical exhaust temperatures found in literature .…”

“…Thus, the effects of waste heat source temperature on the bottoming ORC subsystems and fluid selection are of importance to further be investigated. The exhaust temperature is chosen in the range of 500 K to 600 K based on the typical exhaust temperatures found in literature [2,6,9,11,14,[30][31][32][33]. Figure 10 shows the actual thermal efficiency of ORC system with different working fluids when exhaust temperature varies from 500 K to 600 K. It is evident that the effect of the exhaust temperature on the cycle performance strongly depends on the critical point temperature of the working fluids.…”

Coupling effects of fuel reforming process and fuel utilization on the system performance of a natural gas solid oxide fuel cell/gas turbine hybrid system

“…Preheated reformate (B) and air (5) participated in the electrochemical reactions in SOFC to generate DC power. Unutilized fuel (C) from SOFC stack was mixed with cathode exhaust air (6), and burned in the post-combustor to further increase the temperature before entering the turbine to generate AC power. The total system's net electrical power was the combination of DC and AC power.…”

“…5 Carbon capture could be adopted easily in the SOFC-GT hybrid due to the exhaust gas from SOFC anode is not diluted with nitrogen. 6,7 Recent research demonstrated that this hybrid could maintain high efficiencies during load following and part load operation, which makes it a good fit for distributed energy generation systems and micro-grids. 8,9 Recently, hybrid SOFC/GT systems fueled with natural gas (NG) are gaining increasing attentions all over the world due to the competitive pricing and increasing availability of NG.…”

Optimierungskonzepte für Deckensysteme – von Halbfertigteilen bis zur Fertigteilbauweise

“…In this work, the first two reactions are assumed to reach chemical equilibrium since completion is reached very quickly at high temperatures > 600 °C 17, while the electrochemical reaction has a fixed extent to match the given fuel utilization. The equilibrium constants K shift corresponding to the water‐gas shift reaction are calculated as proposed by 19, 20: …”