Molten Carbonate Fuel Cells for Carbon Capture From a Cogeneration System: A Comparative Analysis of Performance to Other Separation Technologies

2017 ◽  
Author(s):  
Marco Badami ◽  
Marco Cipriano ◽  
Gregory Kowalski ◽  
Armando Portoraro ◽  
Mansour Zenouzi

This paper develops a mathematical model for the performance assessment and optimization of a small-scale molten carbonate fuel cell (MCFC) stack for the CO2 capture and liquefaction from the exhausts coming from an Internal Combustion Engine (ICE) cogenerator. An internal heat exchangers network has been developed for enhancing heat recovery, optimizing the efficiency of the global system. The model is innovative because, even though similar studies are reported in literature, they have never focused on a small-scale applications of a cogeneration system or compared the global performance to other means of carbon capture and storage (CCS). The energetic performance of the system has been compared to that of a monoethanolamine (MEA) adsorption system, which today is the most common technology for the carbon capture in large scale power plants. The results of the simulation show a carbon capture percent of about 81.3%, while the electrical output of the MCFC is around 280 kW with a conversion efficiency of 54%. The overall efficiency of the cogenerator and CCS system is about 37%. In the investigated MCFC technology the CCS system has a high carbon capture efficiency and produces a net power output unlike competing technologies.

Author(s):  
Luca Mastropasqua ◽  
Stefano Campanari ◽  
Jack Brouwer

High temperature fuel cells have been studied as a suitable solution for Carbon Capture and Storage (CCS) purposes at a large scale (>100 MW). However, their modularity and high efficiency at small-scale make them an interesting solution for Carbon Capture and Utilisation at the distributed generation scale when coupled to appropriate use of CO2 (i.e., for industrial uses, local production of chemicals etc.). These systems could be used within low carbon micro-grids to power small communities in which multiple power generating units of diverse nature supply multiple products such as electricity, cooling, heating and chemicals (i.e., hydrogen and CO2). The present work explores fully electrochemical power systems capable of producing a highly pure CO2 stream and hydrogen. In particular, the proposed system is based upon integrating a Solid Oxide Fuel Cell (SOFC) with a Molten Carbonate Fuel Cell (MCFC). The use of these high temperature fuel cells has already been separately applied in the past for CCS applications. However, their combined use is yet unexplored. Moreover, both industry and US national laboratories have expressed their interest in this solution. The reference configuration proposed envisions the direct supply of the SOFC anode outlet to a burner which, using the cathode depleted air outlet, completes the oxidation of the unconverted species. The outlet of the burner is then fed to the MCFC cathode inlet which separates the CO2 from the stream. Both the SOFC and MCFC anode inlets are supplied with pre-reformed and desulfurized natural gas. The MCFC anode outlet, which is characterised by a high concentration of CO2, is fed to a CO2 separation line in which a two-stage Water Gas Shift (WGS) reactor and a PSA/membrane system respectively convert the remaining CO into H2 and remove the H2 from the exhaust stream. This has the significant advantage of achieving the required CO2 purity for liquefaction and long-range transportation without requiring the need of cryogenic or distillation plants. Moreover, the highly pure H2 stream can either be sold as transportation fuel or a valuable chemical. Furthermore, different configurations are considered with the final aim of increasing the Carbon Capture Ratio (CCR) and maximising the electrical efficiency. Moreover, the optimal power ratio between SOFC and MCFC stacks is also explored. Complete simulation results are presented, discussing the proposed plant mass and energy balances and showing the most attractive configurations from the point of view of total efficiency and CCR.


Author(s):  
Luca Mastropasqua ◽  
Stefano Campanari ◽  
Jack Brouwer

The modularity and high efficiency at small-scale make high temperature (HT) fuel cells an interesting solution for carbon capture and utilization at the distributed generation (DG) scale when coupled to appropriate use of CO2 (i.e., for industrial uses, local production of chemicals, etc.). The present work explores fully electrochemical power systems capable of producing a highly pure CO2 stream and hydrogen. In particular, the proposed system is based upon integrating a solid oxide fuel cell (SOFC) with a molten carbonate fuel cell (MCFC). The use of these HT fuel cells has already been separately applied in the past for carbon capture and storage (CCS) applications. However, their combined use is yet unexplored. The reference configuration proposed envisions the direct supply of the SOFC anode outlet to a burner which, using the cathode depleted air outlet, completes the oxidation of the unconverted species. The outlet of the burner is then fed to the MCFC cathode inlet, which separates the CO2 from the stream. This layout has the significant advantage of achieving the required CO2 purity for liquefaction and long-range transportation without requiring the need of cryogenic or distillation plants. Furthermore, different configurations are considered with the final aim of increasing the carbon capture ratio (CCR) and maximizing the electrical efficiency. Moreover, the optimal power ratio between SOFC and MCFC stacks is also explored. Complete simulation results are presented, discussing the proposed plant mass and energy balances and showing the most attractive configurations from the point of view of total efficiency and CCR.


Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1452 ◽  
Author(s):  
Collings ◽  
Mckeown ◽  
Wang ◽  
Yu

While large-scale ORC power plants are a relatively mature technology, their application to small-scale power plants (i.e., below 10 kW) still encounters some technical challenges. Positive displacement expanders are mostly used for such small-scale applications. However, their built-in expansion ratios are often smaller than the expansion ratio required for the maximum utilisation of heat sources, leading to under expansion and consequently higher enthalpy at the outlet of the expander, and ultimately resulting in a lower thermal efficiency. In order to overcome this issue, one possible solution is to introduce an internal heat exchanger (i.e., the so-called regenerator) to recover the enthalpy exiting the expander and use it to pre-heat the liquid working fluid before it enters the evaporator. In this paper, a small-scale experimental rig (with 1-kW rated power) was designed and built that is capable of switching between regenerative and non-regenerative modes, using R245fa as the working fluid. It has been tested under various operating conditions, and the results reveal that the regenerative heat exchanger can recover a considerable amount of heat when under expansion occurs, increasing the cycle efficiency.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 387
Author(s):  
Salvatore F. Cannone ◽  
Andrea Lanzini ◽  
Massimo Santarelli

Natural gas is considered a helpful transition fuel in order to reduce the greenhouse gas emissions of other conventional power plants burning coal or liquid fossil fuels. Natural Gas Hydrates (NGHs) constitute the largest reservoir of natural gas in the world. Methane contained within the crystalline structure can be replaced by carbon dioxide to enhance gas recovery from hydrates. This technical review presents a techno-economic analysis of the full pathway, which begins with the capture of CO2 from power and process industries and ends with its transportation to a geological sequestration site consisting of clathrate hydrates. Since extracted methane is still rich in CO2, on-site separation is required. Focus is thus placed on membrane-based gas separation technologies widely used for gas purification and CO2 removal from raw natural gas and exhaust gas. Nevertheless, the other carbon capture processes (i.e., oxy-fuel combustion, pre-combustion and post-combustion) are briefly discussed and their carbon capture costs are compared with membrane separation technology. Since a large-scale Carbon Capture and Storage (CCS) facility requires CO2 transportation and storage infrastructure, a technical, cost and safety assessment of CO2 transportation over long distances is carried out. Finally, this paper provides an overview of the storage solutions developed around the world, principally studying the geological NGH formation for CO2 sinks.


2020 ◽  
Vol 10 (5) ◽  
pp. 20190065 ◽  
Author(s):  
William J. Schmelz ◽  
Gal Hochman ◽  
Kenneth G. Miller

We model the costs of carbon capture and storage (CCS) in subsurface geological formations for emissions from 138 northeastern and midwestern electricity-generating power plants. The analysis suggests coal-sourced CO 2 emissions can be stored in this region at a cost of $52–$60 ton −1 , whereas the cost to store emission from natural-gas-fired plants ranges from approximately $80 to $90. Storing emissions offshore increases the lowest total costs of CCS to over $60 per ton of CO 2 for coal. Because there apparently is sufficient onshore storage in the northeastern and midwestern United States, offshore storage is not necessary or economical unless there are additional costs or suitability issues associated with the onshore reservoirs. For example, if formation pressures are prohibitive in a large-scale deployment of onshore CCS, or if there is opposition to onshore storage, offshore storage space could probably store emissions at an additional cost of less than $10 ton −1 . Finally, it is likely that more than 8 Gt of total CO 2 emissions from this region can be stored for less $60 ton −1 , slightly more than the $50 ton −1 Section 45Q tax credits incentivizing CCS.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2319 ◽  
Author(s):  
Peter Viebahn ◽  
Emile Chappin

For many years, carbon capture and storage (CCS) has been discussed as a technology that may make a significant contribution to achieving major reductions in greenhouse gas emissions. At present, however, only two large-scale power plants capture a total of 2.4 Mt CO2/a. Several reasons are identified for this mismatch between expectations and realised deployment. Applying bibliographic coupling, the research front of CCS, understood to be published peer-reviewed papers, is explored to scrutinise whether the current research is sufficient to meet these problems. The analysis reveals that research is dominated by technical research (69%). Only 31% of papers address non-technical issues, particularly exploring public perception, policy, and regulation, providing a broader view on CCS implementation on the regional or national level, or using assessment frameworks. This shows that the research is advancing and attempting to meet the outlined problems, which are mainly non-technology related. In addition to strengthening this research, the proportion of papers that adopt a holistic approach may be increased in a bid to meet the challenges involved in transforming a complex energy system. It may also be useful to include a broad variety of stakeholders in research so as to provide a more resilient development of CCS deployment strategies.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1538-C1538
Author(s):  
Matthew Dunstan ◽  
Wen Liu ◽  
Shyue Ping Ong ◽  
Anubhav Jain ◽  
Kristin Persson ◽  
...  

Carbon capture and storage (CCS) applications offer a plausible solution to the urgent need for a carbon neutral energy source from stationary sources, including power plants and industrial processes. The most mature technology for post-combustion capture currently uses a liquid sorbent, amine scrubbing. However, with the existing technology, a large amount of heat is required for the regeneration of the liquid sorbent, which introduces a substantial energy penalty. Operation at higher temperatures could reduce this energy penalty by allowing the integration of waste heat back into the power cycle. New solid absorbents for use at intermediate to high temperatures, such as CaO, have shown promise in pilot plant studies, but are still far from ideal due to their poor capacity retention upon successive cycling. This presentation will describe our studies aimed at rationally selecting and designing materials for carbon capture and storage applications. We use ab initio calculations of oxide materials from the Materials Project database1 in an effort to screen for novel materials with optimal thermodynamic and kinetic properties for CO2 looping applications. From the determination of a material's optimised structure and ground state energy we have then constructed a screening routine for materials within the database based on simulating their carbonation equilibria and phase stability under differing atmospheric concentrations of CO2. A number of promising materials were identified from the screening, and we are currently investigating their properties experimentally, by using a combination of methods (including thermogravimetric analysis, in situ x-ray diffraction and microscopy). In this way we are able to assess the validity of the screening methodology, and use the insights afforded by experimental studies to iteratively improve the entire process.


2021 ◽  
Vol 7 (3) ◽  
pp. 58
Author(s):  
Carolina Font-Palma ◽  
David Cann ◽  
Chinonyelum Udemu

Our ever-increasing interest in economic growth is leading the way to the decline of natural resources, the detriment of air quality, and is fostering climate change. One potential solution to reduce carbon dioxide emissions from industrial emitters is the exploitation of carbon capture and storage (CCS). Among the various CO2 separation technologies, cryogenic carbon capture (CCC) could emerge by offering high CO2 recovery rates and purity levels. This review covers the different CCC methods that are being developed, their benefits, and the current challenges deterring their commercialisation. It also offers an appraisal for selected feasible small- and large-scale CCC applications, including blue hydrogen production and direct air capture. This work considers their technological readiness for CCC deployment and acknowledges competing technologies and ends by providing some insights into future directions related to the R&D for CCC systems.


Sign in / Sign up

Export Citation Format

Share Document