Conceptual design and analysis of ITM oxy-combustion power cycles

Abstract

Ion transport membrane (ITM)-based oxy-combustion systems could potentially provide zero-emissions power generation with a significantly reduced thermodynamic penalty compared to conventional carbon capture applications. This article investigates ITM-based oxy-combustion power cycles using an intermediate-fidelity model that captures the complex physical coupling between the two systems and accurately accounts for operational constraints. Coupled ITM-cycle simulation reveals hidden design challenges, facilitates the development of novel cycle concepts, and enables accurate assessment of new and existing power cycles. Simulations of various ITM-based zero and partial-emissions power cycles are performed using an intermediate-fidelity ITM model coupled to power cycle models created in ASPEN Plus®. The objectives herein are to analyze the prevalent ITM-based power cycle designs, develop novel design modifications, and evaluate the implementation of reactive ITMs. An assessment of the potential for these ITM power cycles to reduce both the thermodynamic penalty and reactor size associated with ITM air separation technology is conducted. The power cycle simulation and analysis demonstrate the various challenges associated with implementing reactive ITMs; hybridization (the use of both reactive and separation-only ITMs) is necessary in order to effectively utilize the advantages of reactive ITMs. The novel hybrid cycle developed herein displays the potential to reduce the size of the ITM compared to the best separation-only concept while maintaining a comparable First Law efficiency. Next, the merit of implementing partial-emissions cycles is explored based on a proposed linear-combination metric. The results indicate that the tradeoff between the main thermodynamic performance metrics efficiency and CO(2) emissions does not appear to justify the use of partial-emissions cycles.

Combined investigation of bulk diffusion and surface exchange parameters of silver catalyst coated yttrium-doped BSCF membranes

“…where J O 2 is the oxygen flux, x is the molar fraction of oxygen or nitrogen, F is the volumetric flow rate of the permeate stream and A is the membrane area. In eqn (5), molecular oxygen transport associated with bulk air leaks were deducted from the total measured oxygen concentration, so that only the oxygen related to the ionic transport was reported. The leak ratio of oxygen was typically less than 2% at 900 1C.…”

“…Two key coal-fired processes in this area are oxyfuel firing (the combustion of coal with oxygen) and coal gasification (the treatment of coal with oxygen and steam to produce syngas). [3][4][5] A central requirement of these processes is the large-scale supply of oxygen, which in commercial processes is primarily restricted to cryogenic distillation, an energy-intensive technology which imposes substantial costs on power generation.…”

Optimal Applications and Combinations of Renewable Fuel Production from Biomass and Electricity

“…Here, the total production volume can be either covered by several identical hybrid plants or by a combination of nonhybrid plants (the so-called “linear combination”). So far, the linear combination metric has been applied in the context of power generation only − but not for bio-, e-, and bio-e-hybrid plants.…”

“…To compare hybrid plants with a combination of nonhybrid plants on a global fleet level, Mancini and Mitsos 48 as well as Sheu et al 49 , 50 have proposed a linear combination metric. Here, the total production volume can be either covered by several identical hybrid plants or by a combination of nonhybrid plants (the so-called "linear combination").…”

Correction: Conceptual design and analysis of ITM oxy-combustion power cycles

“…In ref. 1 Mancini and Mitsos simulated a variety of ion transport membrane (ITM) power cycles. The authors discussed the benefits of partial emissions cycles over a combination of zero-emissions cycles and conventional combined cycles using a linear combination metric.…”