Sorption enhanced hydrocarbons reforming for fuel cell powered generators

International Journal of Greenhouse Gas Control

Abanades

Murillo

et al. 2012

122

165

a b s t r a c tThis work presents a conceptual design of a novel method to obtain hydrogen and/or electricity from natural gas and a concentrated stream of CO 2 suitable for permanent geological storage. The method is based on the well known Sorption Enhanced Reforming (SER) principles for H 2 production using a CaO/CaCO 3 chemical loop. A second chemical loop of Cu/CuO is employed to solve the problem of endothermic CaCO 3 calcination in order to regenerate the sorbent and release the concentrated CO 2 . The reduction reaction of CuO with natural gas, CO or H 2 is shown to be feasible for providing the necessary heat for calcination. A preliminary design of the process has been carried out based on the principles of fixed bed operation and high temperature PSA, making use of the information offered by the literature to define the operating best conditions for the key gas-solid reaction steps and assuming ideal plug flow behaviour in all the reactors during the chemical reactions and gas-solid heat transfer. This makes it possible to define the precise operating windows for the process, so that the reactors can operate close to neutrally thermal conditions. Special material properties (particularly the Ca/inert and Cu/inert ratios) are required, but these are shown to be within the limits of what have been reported in the literature for other gas/solid reaction processes using the same reactions. The conclusion is that there is a great potential for achieving a high degree of energy efficiency with the proposed process by means of a sequence of reactions under the conditions described in this work.

Section: Introductionmentioning

confidence: 80%

Conceptual design of a hydrogen production process from natural gas with CO2 capture using a Ca–Cu chemical loop

International Journal of Greenhouse Gas Control

Abanades

Murillo

et al. 2012

122

165

“…Among different solid sorbents, CaO is considered to be one of the most suitable catalyst for the process of CO2 absorption/desorption, because of its availability, low price, high durability and absorption capacity [18][19][20][21][22][23]. The reaction of CO2 with CaO is stoichiometric and exothermic with the maximum theoretical absorption capacity of 79 wt.% [24]:…”

Section: Carbon Capture and Storage Technologiesmentioning

confidence: 99%

A radiofrequency heated reactor system for post-combustion carbon capture

Chemical Engineering and Processing: Process Intensification

Sotenko

Derevschikov

et al. 2016

Several problems with stabilization of electricity grid system are related to the time lag between the electricity supply and demand of the end users. Many power plants run for a limited period of time to compensate for increased electricity demand during peak hours. The amount of CO2 generated by these power installations can be substantially reduced via the development of new demand side management strategies utilizing CO2 absorption units with a short start-up time.The sorbent can be discharged using radiofrequency (RF) heating to fill the night-time valley in electricity demand helping in the stabilization of electricity grid. Herein a concept of RF heated fixed bed reactor has been demonstrated to remove CO2 from a flue gas using a CaCO3 sorbent. A very stable and reproducible operation has been observed over twenty absorptiondesorption cycles. The application of RF heating significantly reduced the transition time required for temperature excursions between the absorption and desorption cycles. The effect of flow reversal during desorption on desorption time has been investigated. The desorption time was reduced by 1.5 times in the revered flow mode and the total duration of a single absorption-desorption cycle was reduced by 20%. A reactor model describing the reduced desorption time has been developed. 2 Highlights• An RF reactor system has been demonstrated for post-combustion carbon capture.• The transition time between the absorption and desorption cycles was reduced by 2 times as compared to conventional heating• The reverse CO2 desorption flow mode reduced the desorption time by 1.5 times.• The energy efficiency of RF heated and conventionally heated bench reactors was compared

“…CaO as a solid sorbent for CO2 has been well studied in the calcium looping cycle and offers some benefits, such as cheap precursors and simplicity of the preparation procedure, high stability and absorption capacity [14][15][16][17][18][19]. The theoretical absorption capacity of CaO is 79 wt.…”

Section: Introductionmentioning

confidence: 99%

Performance of novel CaO-based sorbents in high temperature CO 2 capture under RF heating

Sotenko

Chemical Engineering and Processing: Process Intensification

et al. 2017

ReuseThis article is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) licence. This licence only allows you to download this work and share it with others as long as you credit the authors, but you can't change the article in any way or use it commercially. More information and the full terms of the licence here: https://creativecommons.org/licenses/ Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. AbstractThe problem of CO2 mitigation on a small and medium scale can be resolved by developing a combined system of CO2 capture and its consecutive conversion into valuable products. The first stage of CO2 looping, however, should be reliable, effective and easy to control and radiofrequency heating, as a new advanced technology, can be used to improve the process.CO2 absorption and desorption RF units can be installed within power plants and powered during the periods of low energy demand thus stabilizing the electrical grid. In this work, aCaO sorbent produced by template synthesis was studied as a sorbent for a CO2 looping system under RF heating which offers short start-up times, highly controlled operation, high degree of robustness and low price. The sorbent reached its stable CO2 capacity of 15.4 wt.% already after 10 temperature cycles (650/850 o C) under RF heating. Higher CO2 desorption rate and lower degree of the sorbent sintering was observed under RF heating as compared to conventional heating.2