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Background. CKD-MBD is a mineral and bone metabolism syndrome caused by chronic kidney disease. FGF23 is an important factor regulating phosphorus and is the main influencer in the CKD-MBD process. In this study, we observed the correlation among serum FGF23 and calcium, phosphorus and parathyroid hormone, and the correlation between FGF23 levels and cardiac structural changes in MHD patients. Methods. We examined serum FGF23 concentrations in 107 cases of MHD patients using the ELISA method, recorded demographic information and biochemical data, and analyzed the correlation between serum FGF23 levels and blood calcium and blood phosphorus and PTH levels. All patients were evaluated by cardiac color ultrasound, and we finally analyzed the association between the FGF23 level and cardiac structural changes. Results. In 107 cases of MHD patients, serum FGF23 levels were linearly associated with serum calcium (r = 0.27 P < 0.01 ) and parathyroid hormone levels (r = 0.25, P < 0.05 ). FGF 23 was negatively correlated with age (r = −0.44, P < 0.01 ).Serum FGF23 levels were correlated with right atrial hypertrophy in HD patients ( P < 0.05 ). No correlation was found among FGF23, left ventricular hypertrophy/enlargement, and valve calcification stenosis ( P > 0.05 ). Conclusion. Serum FGF23 showed a positive correlation among blood calcium levels and PTH levels in hemodialysis patients, and FGF23 levels can affect the incidence of right atrial hypertrophy in MHD patients.

High-purity H2 could be obtained from biomass pyrolysis vapors via chemical looping with Fe–Al–Ni oxides as the oxygen carrier.

Enhanced hydrogen production performance was achieved via plasma-assisted CLHG with the highest hydrogen yield at 400 °C.

The doping of K improves C2+ selectivity in plasma-assisted chemical looping oxidation coupling of methane reaction at 400 °C.

A novel interconnected screw reactor was proposed to convert biomass to bio-oil and bio-char in this study. This reactor is expected to achieve direct heating of pyrolysis feedstocks and increase the reactor processing capacity through the recycling of biochar between the inner and outer screw. Here, we simulated the biomass particle flow and reaction process in this interconnected reactor by an extended discrete element method (DEM), the effect of char circulation on the reactor temperature distribution and the product yields are investigated. The results show that the char circulation increased the heating rate of biomass. At the inner and outer screw speed of 10 rpm and 1 rpm, the char circulation can reach 5.15 kg/h and the average temperature of biomass under the char circulation is about 30 °C higher than that without char circulation. The reaction simulation results show that at 500 °C, the yield of char, bio-oil and non-condensable gas are 18.9%, 40.6% and 40.5% respectively. The predicted product yields of char, bio-oil and non-condensable gas are also in good agreement with the experimental measurements.

Operating chemical looping process at mid-temperatures (550-750 oC) presents exciting potential for the stable production of hydrogen. However, the reactivity of oxygen carriers is compromised by the detrimental effect of the relatively low temperatures on the redox kinetics. Although the reactivity at mid-temperature can be improved by the addition of noble metals, the high cost of these noble metal containing materials significantly hindered their scalable application. In the current work, we propose to incorporate earth-abundant metals into the iron-based spinel for hydrogen production in a chemical looping scheme at mid-temperatures. Mn0.2Co0.4Fe2.4O4 shows a high hydrogen production rate at the average rate of ∼0.62 mmol.g-1.min-1 and a hydrogen yield of ∼9.29 mmol.g-1 with satisfactory stability over 20 cycles at 550 oC. The mechanism studies manifest that the enhanced hydrogen production performance is a result of the improved oxygen-ion conductivity to enhance reduction reaction and high reactivity of reduced samples with steam. The performance of the oxygen carriers in this work is comparable to those noble-metal containing materials, enabling their potential for industrial applications.

In this study, we examined and strengthened the motion and heat transfer characteristics of tire particles in a rotary kiln. To overcome the difficulty of controlling the residence time of tire pellets and poor heat transfer, a study was conducted on heat transfer enhancement owing to lifting flight in a rotary kiln with spiral grooves. We developed a particle mechanics model using the discrete element method, and then simulated tire particle motion and obtained results using the EDEM software platform. The obtained motion results were programmed on a MATLAB platform for performing a heat transfer simulation study on the improvement in heat transfer. The coupling model of motion and heat transfer of waste tire particles was established. Through the analysis of particle movement and heat transfer, the following conclusions are obtained: with the increase of the lifting flight, the particle swarm heats up faster and more uniformly; with the increase of the rotation speed, the temperature of the particles rises faster and more uniformly, which has only the same effect as the lifting flight; to a certain extent, the smaller particle size can also improve the heat transfer effect. The maximum error of the relatively accurate coupling model of tire particle motion and heat transfer in a rotary kiln was only 12%, which provides a certain guiding significance for the improved design of the reactor.

This study sought to investigate the protective effects of Astragaloside IV (AS-IV) on ischemia-reperfusion (I/R) renal injury based on the keap1-Nrf2/ARE signaling pathway.A total of 36 male Sprague-Dawley rats (aged: 8 weeks; weighing: 200-220 g) were randomly divided into the following 6 groups (n=6 per group): (I) the control group; (II) the sham operation group; (III) the kidney I/R injury group (the I/R group); (IV) the kidney I/R injury group treated with 2 mg/kg of AS-IV (the low-dose group); (V) the kidney I/R injury group treated with 5 mg/kg of AS-IV (the mid-dose group); and (VI) the kidney I/R injury group treated with 10 mg/kg of AS-IV (the high-dose group). Serum creatinine (CRE), serum urea, malondialdehyde (MDA), and superoxide dismutase (SOD) were examined using enzyme-linked immunoassay kits. Cell apoptosis and the pathological damage to the renal tissue were determined by terminal deoxynucleotidyl transferase dUTP nick end labeling, hematoxylin and eosin, and periodic acid-Schiff (PAS) staining. The immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR), and western blot methods were used to determine the expression of Nrf2, HO-1, Bcl-2 and Bax in the kidney tissue.In the I/R rat model, the serum CRE level was increased. In the acute kidney injury (AKI) and chronic kidney disease (CKD) models, AS-IV treatment significantly decreased serum CRE levels in a dose-dependent manner. AS-IV treatment also reduced the injury of renal tubular epithelial cells, increased the expression levels of Nrf2 and HO-1, decreased the rate of apoptosis, downregulated the level of MDA, and elevated the activity of SOD. In the CKD rat model, the AS-IV treatment groups had reduced renal tubular epithelial cell injury, increased expression levels of Nrf2 and HO-1, decreased MDA levels, and increased SOD activity compared to the I/R group.AS-IV induced the expression of Nrf2, enhanced the activity of antioxidant enzymes, reduced apoptosis, protected against renal I/R injury, and prevented AKI from transforming into CKD. These findings suggest that AS-IV is a promising drug for treating kidney injury.

Background: Previous studies have reported that serum magnesium (Mg) deficiency is involved in the development of heart failure, particularly in patients with end-stage kidney disease. The association between serum Mg levels and mortality risk in patients receiving hemodialysis is controversial. We aimed to estimate the prognostic value of serum Mg concentration on all-cause mortality and cardiovascular mortality in patients receiving hemodialysis. Methods: We did a systematic literature search in PubMed, EMBASE, Cochrane Library, and Web of Science to identify eligible studies that reported the prognostic value of serum Mg levels in mortality risk among patients on hemodialysis. We performed a meta-analysis by pooling and analyzing hazard ratios (HRs) and 95% confidence intervals (CIs). Results: We identified 13 observational studies with an overall sample of 42,967 hemodialysis patients. Higher all-cause mortality (adjusted HR 1.58 [95% CI: 1.31–1.91]) and higher cardiovascular mortality (adjusted HR 3.08 [95% CI: 1.27–7.50]) were found in patients with lower serum Mg levels after multivariable adjustment. There was marked heterogeneity (I2 = 79.6%, p < 0.001) that was partly explained by differences in age stratification and study area. In addition, subgroup analysis showed that a serum Mg concentration of ≤1.1 mmol/L might be the vigilant cutoff value. Conclusion: A lower serum Mg level was associated with higher all-cause mortality and cardiovascular mortality in patients receiving hemodialysis.

The chemical looping process is promising for CO2 conversion because of the much higher CO2 conversion efficiency than the photocatalytic and electrocatalytic processes. Conventional oxygen carrier...

Chemical looping technology holds great potential on efficient CO2 splitting with much higher CO production and CO2 splitting rate than photocatalytic processes. Conventional oxygen carrier requires high temperature (typically 850–1000 °C) to ensure sufficient redox activity, but the stable and high CO2 conversion is favored at a lower temperature, leading to the degrading on the reaction kinetics as well as the low CO production and CO2 splitting rate. In this paper, we prepared several ternary spinels and demonstrated their performance for chemical looping CO2 splitting at moderate temperatures. Using the promotion effect of Cu to cobalt ferrite reduction and reversible phase change of the reduced metals, Cu0.4Co0.6Fe2O4 exhibits high CO2 splitting rate (~144.6 µmol g–1 min–1) and total CO production (~9100 µmol g–1) at 650 °C. The high performance of this earth-abundant spinel material is also consistent in repeated redox cycles, enabling their potential in industrial use.

The reduction level for a metal oxides carrier determines the final hydrogen yield for a chemical looping hydrogen generation process. Nevertheless, when the oxygen carrier is reduced at a high level, the sintering of materials would be accelerated. In this paper, we prepare a Cu0·2Fe0·8(FeAl)Ox spinel material and investigate its hydrogen production performance. The results indicate that it exhibits a good redox stability even at reduction level of 0.75 during 20 cycles. In contrast, the deactivation of Fe2O3 oxygen carrier can be obviously observed in the first few cycles. This enable the material with stable hydrogen production at a high yield about 7 mmol/g, which is 3.5 times higher than that of Fe2O3. Upon SEM and XRD characterization techniques, we find that the reason of the both good stability and high hydrogen yield is that the ability of spinel support to inhibit sintering of Cu and Fe active compositions.

Reverse water gas shift on the basis of chemical looping technology provides a viable method for efficiently converting CO2 to CO for hydrocarbons at moderate temperature (

Tar measurement and calculation is crucial for understanding the in-situ tar elimination and hydrogen-rich syngas production during the biomass gasification process. In this study, the method of evaluating tar production was proposed and studied on a two-stage fixed-bed reactor. Two different groups of oxidized and reduced oxygen carriers were investigated for comparison. The collected tar was tested on a gas chromatography–mass spectrometry (GC-MS) system. The types of the tar were all belonged to aromatic hydrocarbons. The H2 composition in the syngas was over 34% in three reduced-OC conditions. The carbon percentage identified by the GC-MS was at the range of 93.75–95.05 wt%. The average carbon from the char combustion period was 2.85 mmol. The tar yield in the three oxidized-OC conditions was 43 ± 22 mg/g, 53 ± 11 mg/g, and 62 ± 8 mg/g, respectively. The result indicated that the reduced OC had a catalytic effect for increasing the H2 composition in syngas. On the other hand, the oxidized OC influenced the reactions by providing with lattice oxygen. The evaluation of the produced tar was beneficial for a further understanding of the mechanism for producing the H2-rich syngas.

Chemical looping hydrogen storage and the recovery of iron oxides by the redox cycles were recommended as an emerging approach for large-scale hydrogen storage with a high volumetric hydrogen storage density. However, iron oxides should be operated at a high temperature (>800 °C) for its sufficient redox activity, which would lead to a rapid deterioration of hydrogen storage performance over cycles. In this work, a series of ferrite-spinel materials A0.25Fe2.75O4 (A = Co, Cu, Ni, Zn or Mn) were prepared. Among all the additives to iron oxides, Co0.25Fe2.75O4 exhibits the highest volumetric hydrogen storage density (∼62.47 g L−1) and an average hydrogen production rate (∼132 μmol g−1 min−1) under 550 °C. Besides, the storage capacity was maintained over 10 cycles. The volumetric hydrogen storage density of this material was proportionate to the most advanced Rh–FeOx containing rare-earth metal; thus, it may have the potential for industrial application.

Chemical looping has been proposed as an emerging technology for large-scale hydrogen storage with the advantages of high volumetric hydrogen storage density, environmental compatibility, and safety. However, to ensure sufficient redox activity, conventional oxygen carrier materials must be operated at a temperature higher than 800 °C, leading to the rapid deterioration on the storage capacity over several cycles. In this work, we report a ternary ferrite-spinel material Cu0.5Co0.5Fe2O4 for chemical looping hydrogen storage and production. The material exhibits high volumetric hydrogen storage density (65.58 g·L−1) and average hydrogen production rate (142 μmol·g−1·min−1) at 550 °C. The performance is maintained with negligible deactivation over repetitive redox cycles. The high performance can be attributed to the ability of Cu and Co to improve the reduction and the reversible phase change during the oxidation stage at moderate temperatures. The performance of the Cu0.5Co0.5Fe2O4 is comparable to the state-of-the-art Rh-FeOx containing rare earth metals, which enables its potential in industry application.

Developing the oxygen carrier of high reduction degree and redox stability has key importance to the chemical looping hydrogen production. However, high reduction degree of oxygen carrier often leads to severe sintering and poor redox stability. Therefore, the trade-off between such two aspects of it must be considered. In this paper, a Co0·5Fe0·5(FeAl)Ox material was reported as an oxygen carrier and an investigation on the performance of its chemical looping hydrogen production was conducted. It exhibited a stable and high hydrogen yield of 8.53 mmol/g during 20 cycles even at the reduction degree of 0.75. Upon comparison, it was found that the obvious deactivation occurred in Fe2O3 material when its reduction degree was higher than 0.25. Upon various characterization techniques, we found that the high performance of such material was rightly because of the reversible exsolution and dissolution of its active compositions from and into the parent spinel support.

In this paper, a counter-flow rotary kiln incineration system with a processing capacity of 40 t/d of an environmental protection company in Jiangsu Province was used as the research object, and the mixed pyrolysis model and computational fluid dynamics（CFD）model of the counter-flow rotary kiln incineration system were established using Aspen plus and Fluent software. The influence of the operating temperature of the rotary kiln, the heating value of solid waste, the operating load of the rotary kiln, and the primary air volume and primary air speed on the operating effect of the rotary kiln were explored. Operating temperature, primary air volume and wind speed can all have a greater impact on the incineration performance of the counterflow rotary kiln. When the operating temperature of the counter-flow rotary kiln is greater than 800 o C, the hazardous waste heat value is not less than 1500 kcal/kg, and the primary wind speed is 1.5 m/s, the operating effect of the counter-flow rotary kiln incineration system is the best. The simulation results can provide theoretical guidance for the design and optimal operation of the counterflow rotary kiln incineration system.

Shifting chemical looping from high temperatures to intermediate temperatures could mitigate the materials from sintering and benefit for longer durability as well as process economy. However, oxygen carriers cannot perform sufficiently due to the degrading effect at lower temperatures, resulting in the decrease of hydrogen production ability. Although doping precious metals can improve the poor performance at intermediate temperatures, the high cost impeded their large-scale application. In this paper, a range of oxygen carrier materials consisted of earth abundant elements were prepared for chemical looping hydrogen production. The results indicated that CoFe2O4 exhibited the highest hydrogen yield of 11.9 mmol·g−1 and hydrogen production rate of 0.051 mmol g−1·s−1 at 650 °C, which was 1.7 times higher than that of Fe2O3. A combined experimental and DFT calculation method was used to understand the mechanism behind the performance. The results indicated that the synergistic effect between Co and Fe increased the reactivity of the ferrite materials. The enhanced hydrogen production performance was attributed to the high reduction degree and reversible phase change. This study can be also extended to develop more active oxygen carrier for chemical looping processes at intermediate temperatures.

The use of binary oxygen carrier allows for the materials of enhanced activity or stability during chemical looping process. However, the lack of mechanical understanding of the origin of the improvements hindered the rational design and control of the doping process in the oxygen carrier production. Here, we synthesized a series of M0.6Fe2.4Oy (M = Ni, Cu, Co, Mn) binary spinel materials and carried out various characterization techniques to study how the dopants influenced the material phase change, the oxygen transfer as well as the chemical looping performance. The results showed the chemical looping reactivity can be related to the oxygen transformation between lattice oxygen and oxygen vacancy, which was determined by the redox properties of both dopants and iron. The metal in tetrahedral site for Cu, Mn, Ni-doped sample were relatively stable, limiting oxygen transformation ability. In comparison, Co dopant promoted the reducibility of iron in tetrahedral site as well as metals in other sites, making almost all lattice oxygen rapidly transformed to oxygen vacancy during reduction. This was the main cause for the subsequent high hydrogen production rate (average ∼0.02 mmol. g−1.s−1) and yield (∼15.9 mmol.g−1). Upon cycling, the phase separation of single oxides from Co0.6Fe2.4Oy and Mn0.6Fe2.4Oy spinels led to the decreased ability of oxygen transformation. However, the performance was extremely stable for Cu0.6Fe2.4Oy with reversible phase change between spinel and (Fe, Cu) wusitite by the Cu-Fe interaction. Based on the current results, this work points to a promising Cu-Co co-doping material with both good reactivity and stability.

The biodegradability and clearance of metal-based nanomaterials have been questioned worldwide, which have greatly limited their clinical translation. Herein, ultrathin manganese dioxide (MnO2) nanosheets with broad near-infrared (NIR) absorption and pH-dependent degradation properties were prepared. After being modified with polyethylene glycol-cyclic arginine-glycineaspartic acid tripeptide (PEG-cRGD), the MnO2 nanosheets were then used as photothermal agent and nanocarrier to encapsulate chlorin e6 (Ce6) for targeted photothermal (PTT) and photodynamic (PDT) of cancer. As expected, the MnO2-PEG-cRGD nanosheets show high Ce6 loading capacity (351 mg/g), superb photothermal conversion performance (37.2%) and excellent colloidal stability. These nanosheets also exhibit pH-dependent and NIR-induced Ce6 release. Furthermore, the MnO2 nanosheets can be degraded by reacting with hydrogen peroxide in the acidic microenvironment, which are able to elevate the oxygen concentration in situ and thus reverses the tumor hypoxia. Thanks to these favorable properties and the cRGD-mediated tumor-targeted ability, the fabricated MnO2-PEG-cRGD/Ce6 nanocomposites can be effectively up taken by alpha-v beta-3 (αvβ3) integrin over-expressed prostatic carcinoma PC3 cells and achieve favorable therapeutic outcomes under a single 660 nm NIR laser, which is also verified by in vitro studies. The biodegradable MnO2-PEG-cRGD/Ce6 nanosheets developed in this work can be a promising nanoplatform for synergetic PTT/PDT cancer therapy.

Supporting materials are often employed to enhance the stability of iron oxides oxygen carriers, but the reactivity is compromised for the dilution of the active phase. Here, we report several iron oxides supported by ionic conducting gadolinium-doped cerium oxides (GDC) for efficient chemical looping hydrogen production. The results show that GDC support can simultaneously improve redox stability and activity. Specifically, the produced Fe2O3/Gd0.3Ce0.7O3−δ exhibits a high hydrogen production rate of ~0.71 mmol·g−1·min−1 and hydrogen yield of ~10 mmol·g−1 with negligible decay through 20 redox cycle. When using methane as the reducing agent, Fe2O3/Gd0.3Ce0.7O3−δ shows high methane conversion of 75.67% and much lower carbon deposition than Fe2O3. The high performance is attributed to the improved oxide ion-conductivity through the oxygen carrier, which is further verified as the ability of the GDC support to accelerate the oxygen diffusion in the bulk. The explored support effects in this work can be extended to design oxygen carrier materials with both high activity and stability.

The chemical looping process is promising for CO

A three-dimensional numerical simulation of the motion – heat-transfer coupling characteristics of waste tyre particles in a rotary kiln at 773–973 K was performed in this study. The particle dynamics and heat transfer characteristics were solved on a Lagrange grid. The motion model considered particle collisions using a nonslip collision model. Based on the particle motion results obtained, we considered three heat transfer mechanisms: particle–particle collision heat conduction, wall–particle radiation heat transfer, and wall–particle collision heat conduction. Subsequently, we established a mathematical model wherein the heat transfer associated with a particle is determined by its position in each time step, and implemented it on a JAVA platform to perform calculations. Finally, we obtained the temperature of each particle at each moment in the entire process. Further analysis of the simulation results shows that the average temperature and temperature standard deviation is governed by the wall temperature, rotation speed, and particle size.

Establishing a direct relationship between the mass change of iron-based oxygen carrier and gas production is crucial for the efficient operation and the control of the lattice oxygen release in biomass chemical looping gasification. In this study, a thermogravimetric fixed-bed reactor was designed to achieve the simultaneous measurement of the mass change and gas composition in the reduction of the oxygen carrier. Three oxygen carriers of pure iron (III) oxide, natural hematite, and red mud were used as candidates. The phase transfer of the oxygen carrier along with the biomass pyrolysis/gasification was studied. The mass loss rates and the gas composition were matched by three significant phase transition stages. The phase transitions from Fe2O3 to Fe3O4, Fe3O4 to FeO, and FeO to Fe occurred when CO appeared, CO/CO2 = 0.97, and CO/CO2 = 2.61, respectively. The extent of oxygen carrier reduction was 28.61% of pure iron (III) oxide, whereas the oxygen carrier reduction molar ratio was 74.50% of red mud. X-ray diffraction (XRD) spectrums showed the oxygen carrier was reduced to the metallic iron phase. Sintering and agglomeration were found in the reacted oxygen carriers of the scanning electron microscope (SEM) images.

The high reaction temperature required for chemical looping in water splitting presents challenges in terms of producing stable oxygen carrier materials (OCMs). The currently available materials are generally prepared by a deposition method through which iron oxides and refractory supports are spatially separated, thus having low activity and stability. Here, we report CoFeAlOx as an OCM, in which the active phase of the CoFe alloy and the parent spinel support are homogeneously mixed into a solid solution. Using a variety of characterization techniques, we studied the exsolution and dissolution effects of the CoFe alloy on the spinel support in a chemical looping redox cycle and found that the exsolution process can be tailored by the reduction level, which determines the interface structure. When reduced by CO, the exsolved particles were similar to the deposited analogues, showing obvious sintering. However, for the sample reduced by CO and CO2, the exsolved CoFe alloy can be embedded into the support, with it re-emerging fresh and confined at each reduction period. After 20 cycles, it showed a high hydrogen production rate and outstanding stability, demonstrating that the controllable exsolution could significantly improve the high temperature redox performance. Based on these results, this study also provides a new dimension for designing improved redox materials for chemical looping, calcium looping, or solar-driven thermochemical applications.

Chemical Looping Pyrolysis-Gasification (CLPG) of biomass is established as a novel concept for high quality syngas production. The process divides the main chemical reactions in different zones for biomass pyrolysis and gasification, then achieves residual char combustion and Oxygen Carrier (OC) regeneration consistently. The understanding of the process is first determined by calculation of possible chemical reactions using Gibbs Free Energy (ΔG). Experimental work for different effects of the fuel reactor (FR) temperature and the Steam-to-Biomass Mass Ratio (S/B) are then investigated in terms of syngas components, Hydrogen to Carbon Monoxide Molar Ratio (H2/CO), and Cold Gas Efficiency (CGE). Results show that at the FR temperature of 820 °C and S/B of 1.00 kg kg− 1, the optimized condition of H2/CO and CGE are obtained at 2.45 mol mol− 1 and 61.87%, respectively. With S/B increasing from 1.25 kg kg− 1 to 2.00 kg kg− 1, the H2/CO increases to 2.99 kg kg− 1, while the CGE decreases to 51.64%. The water-gas shift (WGS) reaction and the steam-iron reaction are approaching 0 kJ mol− 1 over the FR temperature of 820 °C in calculation, which confirms the contribution of these two reactions comparing with experimental tests. The research proposes an approach for efficient gasification of high volatile-content solid fuel using the advanced chemical looping technology.

In this work, catalytic and noncatalytic fast pyrolysis of waste tires were studied in an analytical pyrolyzer coupled with gas chromatography-time-of-flight mass spectrometry to obtain valuable monocyclic aromatic hydrocarbons (MAHs), especially benzene, toluene, ethylbenzene, xylene etc. (BTEX). The various influencing factors such as the heating rate (10−20000 °C/s), atmosphere (He, H2, N2, CH4, O2), temperature (500−800 °C), and time (5−30 s) were explored. The heating rate and temperature had the greatest influence on the distribution of pyrolysis products, where 40.91 % MAHs were obtained at 500 °C/s and 750 °C in helium atmosphere. In the process of catalytic fast pyrolysis, the nine zeolite catalysts were investigated. The Hβ catalyst is conducive to the formation of MAHs (up to 53.09 %), while the content of BTEX was only 9.05 %. The MCM-41Q catalyst is beneficial to the formation of BTEX (22.35 %), as the content of MAHs was 46.09 %.

Fresh biomass self-moisture gasification (BSMG) is a promising route for biomass utilization. Unlike conventional biomass steam gasification (BSG), BSMG used the moisture content in biomass as the gasifying agent. In this work, the performance of biomass self-moisture chemical looping gasification (BSM-CLG) was compared with dry biomass chemical looping gasification (DB-CLG) and biomass steam chemical looping (BS-CLG) gasification. The data analyzed was the gas cumulative compositions, the hydrogen-to-carbon monoxide ratio (H 2 /CO), the lower heating value (LHV) and the gas yield. Results showed that the moisture content increased the gas yield from 0.9927 Nm 3 kg −1 to 1.1646 Nm 3 kg −1 , while the steam increased the H 2 /CO ratio from 0.6398 mol mol −1 to 0.7436 mol mol −1 in the process. The interaction between OC and biomass moisture increased the biomass reactivity. The differing gasification reactivity was due to different water diffusion between the methods of biomass gasification. The diffusion of moisture content and steam had opposite directions, and the different diffusion led to the moisture content impacted the initial gasification stage, but the steam influenced the biomass molecular structure rearrangement.

Chemical looping is a novel process in clean energy conversion with inherent CO2 sequestration. For successfully operating the chemical looping, the cyclic material must meet a variety of criteria, such as high dispersion of the cyclic phase on the support, large external surface area, and small crystallite size, etc. in attempt to better activity and stability. In this paper, we applied a colloidal crystal templated sol–gel synthesis route to produce materials for chemical looping with hydrogen storage. To understand the role of template in the sol–gel process, two samples prepared with or without template were investigated by various characterization techniques. The results showed the template could not only promote the homogeneity of the metallic precursors, but also efficiently control the material morphology. The resulting high dispersion and confinement effects endowed this material better activity and stability in chemical looping multicycles. Our current experiments demonstrated this strategy can be used as a platform for convenient incorporation of a variety of structural features, and we anticipated it can be extended to synthesis more chemical looping materials.

Operating chemical looping at moderate temperatures circumvents the issue that the sintering of oxygen carrier materials is serious at typical operating conditions, 800-950 °C. However, lower temperatures can lead to deterioration on the reaction kinetics and thereby the low H

Pyrolysis of waste tires can not only solve environmental problems but also recycle waste materials. However, the poor thermal conductivity and the significant energy consumption of the conventional thermal decomposition method severely hinders the implementation of this technology. Microwave pyrolysis is an appealing approach to recycling waste tires since the waste tires contain a high amount of metal oxides additives and carbon black, which can quickly absorb microwave radiation and convert it into heat. During the pyrolysis process, the generated gaseous, liquid, and solid products were all collected separately and characterized. The major components of the pyrolysis gases were H2, CH4, and C2H4. The liquid products were complex mixtures of organic compounds with large proportions of aromatics (BTX) and limonene. The solid residues have high contents of amorphous carbon and inorganic compounds (SiO2, SO3 and ZnO) formed from additives employed in tire formulation. It is worth noting that the use of microwave pyrolysis to decompose waste tires can greatly shorten the pyrolysis time, inducing the pyrolysis reaction completed within 20 min.

Chemical looping redox cycle of oxygen storage materials offers a versatile platform to convert methane to value-added products in a clean and efficient manner. However, the highly dynamic nature of the oxygen diffusion process restrains the selective formation of the target products over a long reaction period. In this work, we show the oxygen storage materials-comprising of iron oxides and zirconium oxide support, with the nickel catalyst controllably deposited—that significantly enhanced the syngas selectivity. Mechanistic study indicated the oxygen releasing rate can be well controlled within a long reaction period by the specific spatial structure, demonstrating a new strategy to tune the oxygen diffusion in chemical looping process. Through the observed spatial effects, this work can be also extended to develop more oxygen storage materials for the other chemical looping applications, e.g. methane reforming, methane oxidative coupling, ethane oxidative dehydrogenation, etc.