Advancements in biomass gasification research utilizing iron-based oxygen carriers in chemical looping:A review

Biomass,recognized as renewable green coal,is pivotal for energy conservation,emission reduction,and dualcarbon objectives.Chemical looping gasification,an innovative technology,aims to enhance biomass utilization efficiency.Using metal oxides as oxygen carriers regulates the oxygen-to-fuel ratio to optimize synthesis product yields.This review examines various oxygen carriers and their roles in chemical looping biomass gasification,including natural iron ore types,industrial by-products,cerium oxide-based carriers,and core-shell structures.The catalytic,kinetic,and phase transfer properties of iron-based oxygen carriers are analyzed,and their catalytic cracking capabilities are explored.Molecular interactions are elucidated and system performance is optimized by providing insights into chemical looping reaction mechanisms and strategies to improve carrier efficiency,along with discussing advanced techniques such as density functional theory(DFT)and reactive force field(ReaxFF)molecular dynamics(MD).This paper serves as a roadmap for advancing chemical looping gasification towards sustainable energy goals.

Iron-based catalysts encapsulated by nitrogen-doped graphitic carbon for selective synthesis of liquid fuels through the Fischer-Tropsch process

Fischer‐Tropsch synthesis(FTS)has the potential to be a powerful strategy for producing liquid fuels from syngas if highly selective catalysts can be developed.Herein,a series of iron nanoparticle catalysts encapsulated by nitrogen‐doped graphitic carbon were prepared by a one‐step pyrolysis of a ferric L‐glutamic acid complex.The FeC‐800 catalyst pyrolyzed at 800°C showed excellent catalytic activity(239.4μmolCO gFe–1 s–1),high C5–C11 selectivity(49%),and good stability in FTS.The high dispersion of ferric species combined with a well‐encapsulated structure can effectively inhibit the migration of iron nanoparticles during the reaction process,which is beneficial for high activity and good stability.The nitrogen‐doped graphitic carbon shell can act as an electron donor to the iron particles,thus promoting CO activation and expediting the formation of Fe5C2,which is the key factor for obtaining high C5–C11 selectivity.

Recent advances in application of iron‐based catalysts for CO_(x) hydrogenation to value‐added hydrocarbons

The widespread utilization of fossil fuels has caused an associated increase in CO_(2) emissions over the past few decades,which has resulted in global warming and ocean acidification.CO hydrogenation(Fischer‐Tropsch synthesis,FTS)is considered a significant route for the production of liquid fuels and chemicals from nonpetroleum sources to meet worldwide demand.Conversion of CO_(2) with renewable H_(2) into valuable hydrocarbons is beneficial for reducing dependence on fossil fuels and mitigating the negative effects of high CO_(2) concentrations in the atmosphere.Iron‐based catalysts exhibit superior catalytic performance in both FTS and CO_(2) hydrogenation to value‐added hydrocarbons.The abundance and low cost of iron‐based catalysts also promote their wide application in CO_(x) hydrogenation.This paper provides a comprehensive overview of the significant developments in the application of iron‐based catalysts in these two fields.The active phases,promoter effect,and support of iron‐based catalysts are discussed in the present paper.Based on understanding of these three essential aspects,we also cover recent advances in the design and preparation of novel iron‐based catalysts for FTS and CO_(2) hydrogenation.Current challenges and future catalytic applications are also outlined.

Analysis of the Intrinsic Uncertainties in the Laser-Driven Iron Hugoniot Experiment Based on the Measurement of Velocities

One of the most challenging tasks in the laser-driven Hugoniot experiment is how to increase the reproducibility and precision of the experimental data to meet the stringent requirement in validating equation of state models. In such cases, the contribution of intrinsic uncertainty becomes important and cannot be ignored. A detailed analysis of the intrinsic uncertainty of the aluminum-iron impedance-match experiment based on the measurement of velocities is presented. The influence of mirror-reflection approximation on the shocked pressure of Fe and intrinsic uncertainties from the equation of state uncertainty of standard material are quantified, Furthermore, the comparison of intrinsic uncertainties of four different experimental approaches is presented. It is shown that, compared with other approaches including the most widely used approach which relies on the measurements of the shock velocities of AI and Fe, the approach which relies on the measurement of the particle velocity of Al and the shock velocity of Fe has the smallest intrinsic uncertainty, which would promote such work to significantly improve the diagnostics precision in such an approach.

Highly Sensitive Fiber-Optic Faraday-Effect Magnetic Field Sensor Based on Yttrium Iron Garnet

The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization-maintaining optical fiber links the sensor head to the source and detection system, in which the technique of phase shift cancellation is used to cancel the phase shift that accumulatein the optical fiber. Flux concentrators were exploited to enhance the YIG crystal magneto-optic sensitivity .The sensor system exhibited a noise-equivalent field of 8 pT/√Hz and a 3 dB bandwidth of ～10 MHz.

The relationship between the microstructures and catalytic behaviors of iron–oxygen precursors during direct coal liquefaction

A series of both unsupported and coal‐supported iron–oxygen compounds with gradual changes in microstructure were synthesized by a precipitation‐oxidation process at 20 to 70°C.The relationship between the microstructures and catalytic activities of these precursors during direct coal liquefaction was studied.The results show that the microstructure could be controlled through adjusting the synthesis temperature during the precipitation‐oxidation procedure,and that compounds synthesized at lower temperatures exhibit higher catalytic activity.As a result of their higher proportions ofγ‐FeOOH orα‐FeOOH crystalline phases,the unsupported iron–oxygen compounds synthesized at 20–30°C,which also had high specific surface areas and moisture levels,generate oil yields 4.5%–4.6%higher than those obtained with precursors synthesized at 70°C.It was also determined that higher oil yields were obtained when the catalytically‐active phase formed by the precursors during liquefaction(pyrrhotite,Fe1-xS)had smaller crystallites.Feed coal added as a carrier was found to efficiently disperse the active precursors,which in turn significantly improved the catalytic activity during coal liquefaction.

Electromagnetic Environment Impact of Mobile Communication Iron Tower on Adjacent Building and Its Countermeasures

For several lightning-strike disasters related to base station iron tower of mobile communication carrier operator, disaster-inducing factors were analyzed. The reason was as below： after lightning receptor of base station iron tower of mobile communication carder operator was struck by lightning, electromagnetic radiation was generated in the process lightning current leaking into the ground. In addition, it was lightning scattered- strike phenomenon induced by overhead lightning rod, that is, ground lightning falling density around overhead lightning rod was larger than mean at the site. Finally, some improvement measures were put forward.

Review of Directly Producing Light Olefins via CO Hydrogenation

Directly making light olefins via CO hydrogenation is a promising process toobtain a non-petroleum based supply of alkenes. Limited by the ASF distribution function ofFischer-Tropsch synthesis, the yield of light olefins (C_2-C_4) can not reach the desired levels,which is a great challenge to overcome. Beginning with a brief introduction of F-T synthesis, thispaper provides a review of current research, including thermodynamic analysis, the ASF distributionfunction, the reaction performance of CO hydrogenation and slurry reactor studies. The problemscurrently faced by this research area are presented at the end of the article.

Tribological behaviour of sintered iron based self-lubricating composites

This work is a review of previous works,presenting and discussing the most important results obtained by an ongoing research program towards the development of innovative,low-cost,self-lubricating composites with a low friction coefficient and high mechanical strength and wear resistance.Special emphasis is given to uniaxial die pressing of solid lubricant particles mixed with matrix powders and to metal injection moulding associated with in situ generation of solid lubricant particles.Initially,a microstructural model/processing route (powder injection moulding followed by plasma-assisted debinding and sintering) produced a homogeneous dispersion of in situ generated solid lubricant particles.Micrometric nodules of graphite with diameter smaller than 20 μm were formed,constituting a nanostructured stacking of graphite foils with nanometric thickness.Micro Raman analysis indicated that the graphite nodules were composed of turbostratic 2D graphite having highly misaligned graphene planes separated by large interlamellae distance.Large interplanar distance between the graphene foils and misalignment of these foils were confirmed by transmission electron microscopy and were,probably,the origin of the outstandingly low dry friction coefficient (0.04).The effect of sintering temperature,precursor content,metallic matrix composition and surface finish is also reported.Furthermore,the influence of a double-pressing/double-sintering (DPDS) technique on the tribological performance of self-lubricating uniaxially die-pressed hBN + graphite-Fe-Si-C-Mo composite is also investigated.Moreover,the tribological behaviour of die-pressed Fe-Si-C matrix composites containing 5,7.5 and 10 wt％ solid lubricants (hBN and graphite) added during the mixing step is analysed in terms of mechanical properties and wear mechanisms.Finally,the synergy between solid lubricant particles dispersed in a metallic matrix and fluid lubricants in a cooperative mixed lubrication regime is presented.

THE RANGE OF AMORPHOUSFORM FOR Fe- Mo SYSTEM BY MECHANICAL ALLOYING

Mechanicalalloyingof Fex Mo1 x( x = 0 2 0 9) with blend elements Fe and Mo powders havebeen performedina highenergyplantball. Theresultsindicatedthatthesolubilityof Fein Moor Moin Feis morethen 20at.% andthecomposition x ofamorphousofthissystem is in therangeof0 4 0 7 . Accordingtothethermodynamicpropertiesfortheamorphousformofalloys,thecomposition range of amorphous form for Fe Mosystem hasbeen investigatedwith Miedematheory. Thetheoreticalresults arein reasonable with experimental data.

Cu/Ta sheaths for iron-based superconductors:First experimental findings in Ca/K-1144 wires

Iron based superconducting wires(IBSCs)produced by the Powder in Tube(PIT)method rely on the use of silver sheaths as chemical buffer between the outer metal and the superconducting core.The adoption of silver entails however some limitations,such as the viable temperature range when coupled with copper,and the incompatibility with calcium-based IBSCs already at 600℃,driving the research towards other wires architecture.Taking inspiration from the low temperature superconductors field,we decided to evaluate the adoption of tantalum as diffusion barrier in a layered Cu/Ta architecture,choosing a Ca/K-1144 IBSC as case study considering the high reactivity issues already reported in the case of silver sheaths for this compound.Squared wires were produced through a groove rolling lamination process coupled with a thermal treatment at 800℃.The microstructural analyses show the absence of interdiffusion between the different parts of the wire,and the magnetic characterization shows performance in line with similar polycrystalline manufacts,with margin of enhancement to be pursued via the optimization of the mechanical process and other experimental variables.The reported results suggest thus the effectiveness of tantalum as diffusion barrier for Ca/K-1144 PIT wires.

Specific heat in superconductors

Specific heat is a powerful tool to investigate the physical properties of condensed materials.Superconducting state is achieved through the condensation of paired electrons,namely,the Cooper pairs.The condensed Cooper pairs have lower entropy compared with that of electrons in normal metal,thus specific heat is very useful in detecting the low lying quasiparticle excitations of the superconducting condensate and the pairing symmetry of the superconducting gap.In this brief overview,we will give an introduction to the specific heat investigation of the physical properties of superconductors.We show the data obtained in cuprate and iron based superconductors to reveal the pairing symmetry of the order parameter.

Physical properties and phase diagram of NaFe_(1-x)V_(x)As

We grew a series of NaFe_(1-x)V_(x) As(0 ≤ x ≤ 0.03) single crystals and performed the measurements of resistance,magnetic susceptibility, and specific heat to study the superconducting phase diagram by doping V into Na Fe As. Both the structural and the spin-density-wave(SDW) transitions are slightly suppressed by V-doping. While superconducting transition temperature is enhanced to the maximum value of 15 K when the optimal doping level x = 0.007 and then is suppressed rapidly with further V-doping, displaying a small superconducting dome. Our results suggest that V-impurities should act as strong magnetic scattering centers which cause the sharp suppression of superconductivity in NaFe_(1-x)V_(x) As.

Green fuel from coal via Fischer-Tropsch process： scenario of optimal condition of process and modelling

Extracting, transportation and the using from fossil fuels can damage to the hydrosphere, the biosphere and the Earth＇s atmosphere. But humans always need to this valuable substance. The production of oil derivatives by means of forest waste and coal through the Fischer-Tropsch process is an appropriate solution for the cleanliness of all parts of the environment. For the production of favorite products by the synthesis of Fischer-Tropsch, the performance of the catalyst under different operating conditions should be predictable. For this reason, in this paper, eight mathematical models were determined for the selectivity of five products of methane, light hydrocarbons, gasoline, diesel and wax based on three factors of reduction temperature, time on stream, and He/CO ratio inlet gas on iron-based catalyst. The results showed that the reduction temperature factor had the most effective on the selectivity of hydrocarbon products, exception diesel, so that the increase of the reduction temperature led to increase of the selectivity of methane, light hydrocarbons, gasoline and reduce of the degree of selectivity of the wax and vice versa. For the diesel selectivity, factor of the He/CO ratio inlet gas was the most effective than other factors.

Superconducting anisotropy and vortex pinning in CaKFe_(4)As_(4) and KCa_(2)Fe_(4)As4F_(2)

The vortex pinning determining the current carrying capacity of a superconductor is an important property to the applications of superconducting materials.For layered superconductors,the vortex pinning can be enhanced by a strong interlayer interaction in accompany with a suppression of superconducting anisotropy,which remains to be investigated in iron based superconductors(FeSCs)with the layered structure.Here,based on the transport and magnetic torque measurements,we experimentally investigate the vortex pinning in two bilayer FeSCs,CaKFe_(4)As_(4)(Fe1144)and KCa_(2)Fe_(4)As4F_(2)(Fe12442),and compare their superconducting anisotropyγ.While the anisotropyγ≈3 for Fe1144 is much smaller thanγ≈15 in Fe12442 around Tc,a higher flux pinning energy as evidenced by a higher critical current density is found in Fe1144,as compared with the case of Fe12442.In combination with the literature data of Ba_(0.72)K_(0.28)Fe2As_(2) and Nd Fe As_(O0.82)F_(0.18),we reveal an anti-correlation between the pinning energy and the superconducting anisotropy in these Fe SCs.Our results thus suggest that the interlayer interaction can not be neglected when considering the vortex pinning in Fe SCs.

Oxidation in Ca/K-1144 iron-based superconductors polycrystalline compounds

Iron‐based superconductors(IBSCs)are a class of material under investigation for the development of superconducting wires in the low‐temperature‐high magnetic fields power application.Among the various families of IBSCs,the 1144 CaKFe_(4)As_(4) compound is a promising material able to achieve outstanding superconducting properties with a cheap and simple chemical composition.Oxidation,in these compounds,is considered an obstacle for high intergranular critical current density,J_(c,GB).A study devoted to the evaluation of oxidation phenomena and their effects on the superconducting properties is thus needed in order to fully understand the involved mechanisms.From the evaluation of polycrystalline samples obtained by a mechanochemically assisted synthesis route,a degradation of the critical temperature and critical currents has been observed concurrently with oxygen accumulation at grain boundaries in open porosities.However,the crystalline structure at an atomic level seems not affected,as well as intragranular superconducting properties assessed by means of calorimetric methods.These results suggest that loss of superconducting properties in Ca/K‐1144 compounds following oxidation is significantly associated with the worsening of grain connectivity.

Novel magnetic silk fibroin scaffolds with delayed degradation for potential long-distance vascular repair

Although with the good biological properties,silk fibroin(SF)is immensely restrained in long-distance vascular defect repair due to its relatively fast degradation and inferior mechanical properties.It is necessary to construct a multifunctional composite scaffold based on SF.In this study,a novel magnetic SF scaffold(MSFCs)was prepared by an improved infiltration method.Compared with SF scaffold(SFC),MSFCs were found to have better crystallinity,magnetocaloric properties,and mechanical strength,which was ascribed to the rational introduction of iron-based magnetic nanoparticles(MNPs).Moreover,in vivo and in vitro experiments demonstrated that the degradation of MSFCs was significantly extended.The mechanism of delayed degradation was correlated with the dual effect that was the newly formed hydrogen bonds between SFC and MNPs and the complexing to tyrosine(Try)to inhibit hydrolase by internal iron atoms.Besides,theβ-crystallization of protein in MSFCs was increased with the rise of iron concentration,proving the beneficial effect after MNPS doped.Furthermore,although macrophages could phagocytose the released MNPs,it did not affect their function,and even a reasonable level might cause some cytokines to be upregulated.Finally,in vitro and in vivo studies demonstrated that MSFCs showed excellent biocompatibility and the growth promotion effect on CD34-labeled vascular endothelial cells(VECs).In conclusion,we confirm that the doping of MNPs can significantly reduce the degradation of SFC and thus provide an innovative perspective of multifunctional biocomposites for tissue engineering.

Simultaneous CO2 capture and H2 generation using Fe2O3/Al2O3 and Fe2O3/CuO/Al2O3 as oxygen carriers in single packed bed reactor via chemical looping process

The chemical looping concept provided a novel way to achieve carbon separation during the production of energy or substances. In this work, hydrogen generation with inherent CO2 capture in single packed bed reactor via this concept was discussed. Two oxygen carriers, Fe203 60 wt.% and Fe2O3 55 wt.%/CuO 5 wt.% supported by Al2O3, were made by ball milling method. First, according to the characteristics of the reduction breakthrough curve, a strict fuel supply strategy was selected to achieve simultaneous CO2 capture and HE production. Then, in the long term tests using CO as fuel, it was proved that CuO addition improved hydrogen generation with the maximum intensity of 3700 μmol H2·g^-1 Fe2O3 compared with Fe-Al of 2300 μmol HE.g^-1 Fe2O3. The overall CO2 capture efficiency remained 98%- 98.8% over 100 cycles. Moreover, the reactivity of deactivated materials was recovered nearly like that of fresh ones by sintering treatment. Finally, two kinds of complex gases consist of CO, HE, CH4 and CO2 were utilized as fuels to test the feasibility. The results showed all components could be completely converted by Fe-Cu- Al in the reduction stage. The intensity of hydrogen production and the overall CO2 capture efficiency were in the range of 2000-2400 μnol H2^g^-1 Fe2O3 and 89%, 95%, respectively.