Steam methane reforming reaction enhanced by a novel K2CO3-Doped Li4SiO4 sorbent: Investigations on the sorbent and catalyst coupling behaviors and sorbent regeneration strategy

Zhang, Qi; Shen, Chen; Zhang, Sai; Wu, Yuping

doi:10.1016/j.ijhydene.2015.12.116

Cited by 57 publications

(27 citation statements)

References 49 publications

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“…Suitable characteristics of a raw material or solid phases, to be susceptible to pyrolysis, should include two conditions: a minimum E a of the pyrolytic process and a high amount of H 2 in the gas produced. The collection of hydrogen to energy production has also been carried in other researches by biomass pyrolysis [20,49,50]. In our case, the highest concentrations of H 2 produced and minimum E a are related to samples obtained at medium-high temperatures.…”

Section: Hydrogen Production By Pyrolysismentioning

confidence: 68%

Effect of autohydrolysis on hemicellulose extraction and pyrolytic hydrogen production from Eucalyptus urograndis

Loaiza

Palma

Díaz

et al. 2020

Biomass Conv. Bioref.

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Ensuring environmental and social-economic sustainability in the use of materials from lignocellulosic biomass requires their fractionation and valorization of their main components. In this work, we used Eucalyptus urograndis wood to obtain chemicals and energy. The raw material was characterized in chemical terms and then subjected to autohydrolysis under variable operating conditions to optimize the extraction of hemicellulose derivatives relative to cellulose. The kinetics of the pyrolysis process was modeled in terms of activation energy and hydrogen production. Using temperatures in the range of 180-190°C and treatment times in the range of 15-30 min allowed more than 74.5% of all hemicellulosic components in the raw material to be selectively extracted into the liquid post-hydrolysis phase, more than 90% of all glucan to remain in the solid phase and up to 27.8% of lignin to be removed. The thermal behavior of solid fraction was examined by thermogravimetric analysis, using variable heating rates under a nitrogen atmosphere, and the activation energy can be estimated by using the Flynn-Wall-Ozawa method. Based on the results, the pyrolysis of E. urograndis can be modeled as a first-order reaction. The activation energy (E a) at a fractional conversion α between 0.3 and 0.7 was 183 to 199 KJ mol −1 for the raw material, whereas that for the solid residue from autohydrolysis ranged from 179 to 186 kJ mol −1 at same fractional conversion when operational temperature in autohydrolysis was upper 185°C. Based on the results, using temperatures above 180°C and times of 15 min or longer [i.e., operating at the (0,0) experimental point for the autohydrolysis process] in combination with degrees of conversion from 0.3 to 0.8 reduced the activation energy of the pyrolysis process in relation to the raw material by up to 12% and removed hemicellulose by more 74.5% from it. In parallel, the comparative analysis of the E a values and the composition of the pyrolysis gas obtained showed a negative relationship between E a and the amount of hydrogen produced.

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Section: Hydrogen Production By Pyrolysismentioning

confidence: 68%

Effect of autohydrolysis on hemicellulose extraction and pyrolytic hydrogen production from Eucalyptus urograndis

Loaiza

Palma

Díaz

et al. 2020

Biomass Conv. Bioref.

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“…The doping of alkali metals, such as Na and K, could produce a layer of molten salts with low eutectic temperature, which reduced diffusion resistance effectively, thus the limiting step of Li 4 SiO 4 material for CO 2 absorption could be resolved. The CO 2 absorption performance of various alkali metal-doped Li 4 SiO 4 materials is summarized in Table 2 [39,40,41,42,43,44,45,46].…”

Section: Synthesis Of Li4sio4 Materials With Superior Cyclic Absormentioning

confidence: 99%

“…Olivares-Marín [47] et al synthesized K 2 CO 3 -doped Li 4 SiO 4 material with fly ash as the silicon precursor, and they reported that the CO 2 absorption capacity of the prepared Li 4 SiO 4 material increased with the increase of the dopant amount. It is also worth noting that Zhang et al [42] reported that the K 2 CO 3 doped Li 4 SiO 4 material cooperated well with the Ni/γ-Al 2 O 3 catalyst in the sorption-enhanced steam methane reforming (SE-SMR) system, and high-purity hydrogen (>95%) could be obtained at lower temperatures ranging from 500 to 550 °C, and the presence of steam in the regeneration atmosphere could improve the reaction rate obviously. Mejía-Trejo et al [48] prepared Na-doped Li 4 SiO 4 material by doping Na 2 CO 3 into the starting materials of TEOS and Li 2 CO 3 through the co-precipitation route, and they noted that the addition of Na 2 CO 3 increased the activity and reduced the equilibrium temperature of Li 4 SiO 4 material for CO 2 absorption, and Li 3.85 Na 0.15 SiO 4 had the highest CO 2 absorption capacity among various Na-doped Li 4 SiO 4 materials.…”

Section: Synthesis Of Li4sio4 Materials With Superior Cyclic Absormentioning

confidence: 99%

Performance of Li4SiO4 Material for CO2 Capture: A Review

Yan

et al. 2019

IJMS

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Lithium silicate (Li4SiO4) material can be applied for CO2 capture in energy production processes, such as hydrogen plants, based on sorption-enhanced reforming and fossil fuel-fired power plants, which has attracted research interests of many researchers. However, CO2 absorption performance of Li4SiO4 material prepared by the traditional solid-state reaction method is unsatisfactory during the absorption/regeneration cycles. Improving CO2 absorption capacity and cyclic stability of Li4SiO4 material is a research highlight during the energy production processes. The state-of-the-art kinetic and quantum mechanical studies on the preparation and CO2 absorption process of Li4SiO4 material are summarized, and the recent studies on the effects of preparation methods, dopants, and operating conditions on CO2 absorption performance of Li4SiO4 material are reviewed. Additionally, potential research thoughts and trends are also suggested.

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“…To further improve the kinetics under low CO2 partial pressure conditions, doping of foreign materials [31,32], especially alkali carbonates [33,34], into Li4SiO4 particles has been studied. Zhang et al [35] and Seggiani et al [36] prepared K2CO3-or Na2CO3doped Li4SiO4 particles by means of a solid-state reaction. Yang et al [37] designed alkali carbonate-doped sorbents with micron-sized pores using an impregnated suspension method.…”

Section: Introductionmentioning

confidence: 99%

Sorption of CO2 on NaBr co-doped Li4SiO4 ceramics: Structural and kinetic analysis

Wang

Zhao

Clough

et al. 2019

Fuel Processing Technology

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Structurally modified and improved NaBr co-doped Li4SiO4 ceramics were developed for CO2 absorption in low-CO2-concentration atmospheres. Pure and NaCldoped Li4SiO4 ceramics were also prepared for comparison. The samples were analyzed by X-ray diffraction, Scanning Electron Microscopy, N2 adsorption, X-ray photoelectron spectroscopy, differential scanning calorimetry, and thermogravimetric analyses (dynamic and isothermal). The sorption kinetics were obtained using a double exponential model. The results showed that both Na and Br can be introduced into the Li4SiO4 structure and doped on Li and oxygen sites, respectively. The doped sample presented a Li2O-enriched surface, guaranteeing abundant Li-O sites and our significantly different from previous anionic (CO3, F and Cl) doping of Li4SiO4, Br doping also generated macroporous features with small particle size. These favorable characteristics promoted the surface chemisorption kinetics. Moreover, DSC analysis confirmed the formation of the molten phases during CO2 absorption, which helps improve the lithium diffusion kinetics. Here, 0.1 mol NaBr doping was used to reach a maximum absorption capacity (>30.0 wt.%) in 15 vol.% CO2, suggesting that NaBrdoped Li4SiO4 ceramics have great potential for CO2 capture at high temperature.

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Steam methane reforming reaction enhanced by a novel K2CO3-Doped Li4SiO4 sorbent: Investigations on the sorbent and catalyst coupling behaviors and sorbent regeneration strategy

Cited by 57 publications

References 49 publications

Effect of autohydrolysis on hemicellulose extraction and pyrolytic hydrogen production from Eucalyptus urograndis

Effect of autohydrolysis on hemicellulose extraction and pyrolytic hydrogen production from Eucalyptus urograndis

Performance of Li4SiO4 Material for CO2 Capture: A Review

Sorption of CO2 on NaBr co-doped Li4SiO4 ceramics: Structural and kinetic analysis

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