The Experts below are selected from a list of 2556 Experts worldwide ranked by ideXlab platform
Qin Qin - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic study for hydrogen production from bio oil via sorption enhanced Steam Reforming comparison with Conventional Steam Reforming
International Journal of Hydrogen Energy, 2017Co-Authors: Huaqing Xie, Yuanyuan Zhang, Jianrong Zhang, Qin QinAbstract:Abstract The thermodynamic analysis of the sorption-enhanced Steam Reforming (SESR) process of bio-oil for hydrogen production was investigated in terms of equilibrium compositions, energy consumption, with the comparison with the Conventional Steam Reforming (CSR) process. Compared to CSR process, the SESR process could obtain higher H2 yield and concentration at lower temperature and S/C ratio, with both of the yield and concentration reaching over 90%. For decreasing the energy consumption, the sensible heat of the hot output streams from the two processes was recovered, with the recovered heat calculated by pinch analysis. To produce the same amount H2, the total energy demand of the SESR process was obviously lower the CSR process, especially under low temperature zone. Finally, the parameters of the two processes were optimized with a matrix analysis method. For SESR process, the optimal SR conditions were the temperature of 500 °C–600 °C, the S/C ratio of 3.0, under which the consumptions of bio-oil and energy were about 20% and about 30% lower than those under the optimal conditions of CSR process, respectively.
Fausto Gallucci - One of the best experts on this subject based on the ideXlab platform.
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Resource scarcity in palladium membrane applications for carbon capture in integrated gasification combined cycle units
International Journal of Hydrogen Energy, 2014Co-Authors: Arash Helmi, Fausto Gallucci, Martin Van Sint AnnalandAbstract:Abstract Recently, many reviews on pre-combustion CO 2 capture (CCS) in an IGCC plant have been focused on the techno-economic performance of palladium-based membrane reactor modules downstream of Conventional Steam Reforming or shift reactors. Although the determination and minimisation of the amount of palladium necessary for a specific power production capacity has been the target of many research studies, surprisingly little attention has been paid in the open literature to the availability of this metal in the large quantities required for large scale applications. To fill this gap, the scope of this work was to compare the amount of palladium needed for pre-combustion CCS with Pd-membranes and the available production capacity of palladium. Two specific techno-economic studies with a different net IGCC power output were selected from the literature. In each case, the amount of palladium that is necessary for the plant to be in operation was compared with the world supply and demand for palladium. The results show that even for a power plant of “only” 1 GWe net electricity production utilizing membranes with the best reported performance, a relatively large (∼0.7%) amount of palladium is required compared to the total world supply. Considering the total worldwide electricity production from fossil fuels (14,455 TWh in 2010) a tremendous increase in the world supply of Palladium would be required to redirect from the traditional IGCC power plants without CO 2 capture units to the new membrane technology. We conclude that large scale pre-combustion capture of CO 2 using palladium membranes seems to be unfeasible and research on Pd-based membrane reactors should focus on small(er) scale applications.
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thermodynamic analysis of a membrane assisted chemical looping Reforming reactor concept for combined h2 production and co2 capture
International Journal of Hydrogen Energy, 2014Co-Authors: J A Medrano, Vincenzo Spallina, Martin Van Sint Annaland, Fausto GallucciAbstract:There is great consensus that hydrogen will become an important energy carrier in the future. Currently, hydrogen is mainly produced by Steam Reforming of natural gas/methane on large industrial scale or by electrolysis of water when high-purity hydrogen is needed for small-scale hydrogen plants. Although the Conventional Steam Reforming process is currently the most economical process for hydrogen production, the global energy and carbon efficiency of this process is still relatively low and an improvement of the process is key for further implementation of hydrogen as a fuel source. Different approaches for more efficient hydrogen production with integrated CO2 capture have been discussed in literature: Chemical Looping Combustion (CLC) or Chemical Looping Reforming (CLR) and membrane reactors have been proposed as more efficient alternative reactor concepts relative to the Conventional Steam Reforming process. However, these systems still present some drawbacks. In the present work a novel hybrid reactor concept that combines the CLR technology with a membrane reactor system is presented, discussed and compared with several other novel technologies. Thermodynamic studies for the new reactor concept, referred to as Membrane-Assisted Chemical Looping Reforming (MA-CLR), have been carried out to determine the hydrogen recovery, methane conversion as well as global efficiency under different operating conditions, which is shown to compare quite favorably to other novel technologies for H2 production with CO2 capture.
Mahmud T - One of the best experts on this subject based on the ideXlab platform.
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Steam Reforming of shale gas with nickel and calcium looping
'Elsevier BV', 2019Co-Authors: Adiya Zisg, Mahmud TAbstract:High purity H₂ production from shale gas using sorption enhanced chemical looping Steam Reforming (SE-CLSR) was investigated at 1 bar, GHSV 0.498 h⁻¹, feed molar Steam to carbon ratio of 3 and 650 °C for 20 reduction-oxidation-calcination cycles using CaO and 18 wt% NiO on Al₂O₃ as sorbent and catalyst/oxygen carrier (OC) respectively. The shale gas feedstock was able to cyclically reduce the oxygen carrier and subsequently reform with high H₂ yield and purity. For example H₂ yield of 31 wt% of fuel feed and purity of 92% were obtained in the 4th cycle during the pre-breakthrough period (prior to cycles with low sorbent capacity). This was equivalent to 80 and 43% enhancement compared to the Conventional Steam Reforming process respectively
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Hydrogen production from bio-oil: a thermodynamic analysis of sorption-enhanced chemical looping Steam Reforming
Elsevier, 2018Co-Authors: Spragg J, Mahmud TAbstract:The Steam Reforming of pyrolysis bio-oil is one proposed route to low carbon hydrogen production, which may be enhanced by combination with advanced Steam Reforming techniques. The advanced Reforming of bio-oil is investigated via a thermodynamic analysis based on the minimisation of Gibbs Energy. Conventional Steam Reforming (C-SR) is assessed alongside Sorption Enhanced Steam Reforming (SE-SR), Chemical Looping Steam Reforming (CLSR) and Sorption Enhanced Chemical Looping Steam Reforming (SE-CLSR). The selected CO2 sorbent is CaO(s) and oxygen transfer material (OTM) is Ni/NiO. PEFB bio-oil is modelled as a surrogate mixture and two common model compounds, acetic acid and furfural, are also considered. A process comparison highlights the advantages of sorption-enhancement and chemical looping, including improved purity and yield, and reductions in carbon deposition and process net energy balance. The operating regime of SE-CLSR is evaluated in order to assess the impact of S/C ratio, NiO/C ratio, CaO/C ratio and temperature. Autothermal operation can be achieved for S/C ratios between 1 and 3. In autothermal operation at 30 bar, S/C ratio of 2 gives a yield of 11.8wt%, and hydrogen purity of 96.9mol%. Alternatively, if autothermal operation is not a priority, the yield can be improved by reducing the quantity of OTM. The thermodynamic analysis highlights the role of advanced Reforming techniques in enhancing the potential of bio-oil as a source of hydrogen
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Steam Reforming of shale gas in a packed bed reactor with and without chemical looping using nickel based oxygen carrier
Elsevier, 2018Co-Authors: Adiya Zisg, Mahmud TAbstract:The catalytic Steam Reforming of shale gas was examined over NiO on Al₂O₃ and NiO on CaO/Al₂O₃ in the double role of catalysts and oxygen carrier (OC) when operating in chemical looping in a packed bed reactor at 1 bar pressure and S:C 3. The effects of gas hourly space velocity GHSV (h⁻¹), Reforming temperatures (600–750 °C) and catalyst type on Conventional Steam Reforming (C-SR) was first evaluated. The feasibility of chemical looping Steam Reforming (CL-SR) of shale gas at 750 °C with NiO on CaO/Al₂O₃ was then assessed and demonstrated a significant deterioration after about 9 successive reduction-oxidation cycles. But, fuel conversion was high over 80% approximately prior to deterioration of the catalyst/OC, that can be strongly attributed to the high operating temperature in favour of the Steam Reforming process
Xueyuan Bai - One of the best experts on this subject based on the ideXlab platform.
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comparative analysis on sorption enhanced Steam Reforming and Conventional Steam Reforming of hydroxyacetone for hydrogen production thermodynamic modeling
International Journal of Hydrogen Energy, 2013Co-Authors: Jing Wang, Xueyuan BaiAbstract:Abstract The chemical thermodynamics of sorption enhanced Steam Reforming (SESR) of hydroxyacetone for hydrogen production were investigated and contrasted with hydroxyacetone Steam Reforming (SR) by means of Gibbs free energy minimization principle and response reactions (RERs) method. Hydrogen is mainly derived methane Steam Reforming reaction from and water gas shift reaction. The former reaction contributes more than the latter one to hydrogen production below 550 °C and at higher temperature the latter one tends to dominate. The maximum hydrogen concentration is 70% in SR, which is far below hydrogen purities required by fuel cells. In SESR, hydrogen purities are over 99% in 525–550 °C with a WHMR greater than 8 and a CHMR of 6. The optimum temperature for SESR is approximately 125 °C lower than that for SR. In comparison with SR, SESR has the advantage of almost complete inhibition of coke formation in 200–1200 °C for WHMR ≥ 3.
Maria C Iliuta - One of the best experts on this subject based on the ideXlab platform.
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high temperature co2 sorbents and their application for hydrogen production by sorption enhanced Steam Reforming process
Chemical Engineering Journal, 2016Co-Authors: Marziehossadat Shokrollahi Yancheshmeh, Hamid R Radfarnia, Maria C IliutaAbstract:Abstract Among the available techniques for hydrogen production, the sorption enhanced Steam Reforming (SESR) is an emerging technology consisting in the integration of Reforming reaction (H2 production) and selective separation (CO2 sorption) in a single step, to shift thermodynamically the Reforming reaction and increase hydrogen production. It is a forefront technology to produce highly pure hydrogen that has several advantages against the Conventional Steam Reforming operation. The key element for a successful SESR process is the selection of suitable high-temperature CO2 sorbents. Due to the weakness of current CO2 sorbents (capacity decay and/or slow kinetics), the improvement of their performance is crucial to make the SESR process interesting for industrial applications. This review focuses on the main characteristics and preparation methods of CaO-based and alkaline-based sorbents, their advantages and drawbacks, the available techniques to improve their behavior in severe operating conditions, as well as the progress of their application in two important SESR processes, namely sorption enhanced Steam methane Reforming (SESMR) and sorption enhanced Steam glycerol Reforming (SESGR).