The objective of this review is to analyze potential technologies and their baseline performance of producing hydrogen from catalytic steam reforming of biodiesel byproduct glycerol. High oxygen ...content and high impurity level of biodiesel byproduct glycerol, as well as the complex intermediates and high coking potential in its thermal degradation, make the modeling, design, and operation of glycerol steam reforming a challenge. Thermal decomposition characterization of biodiesel byproduct glycerol was covered, and the recent developments and methods for high-purity hydrogen production from glycerol steam reforming were illustrated. The thermodynamics constraint of water gas shift reaction can be overcome by the sorption-enhanced steam reforming process, which integrated catalytic steam reforming, water gas shift reaction and in-situ CO2 removal at high temperatures in a single stage reactor. The effectiveness of both the enhanced H2 production and the use of CO2 sorbents have been demonstrated and discussed. The technical challenges to achieve a stable high-purity hydrogen production by the sorption-enhanced steam reforming process included extending operation time, selecting suitable sorbents, finding a way for continuous reaction-regeneration of catalyst and sorbent mixture and improving process efficiencies. The continuous sorption-enhanced steam reforming of glycerol was designed by a simultaneous flow concept of catalyst and sorbent for continuous reaction-regeneration using two slow moving-bed reactors for high-purity hydrogen production and CO2 capture, and in this process, catalyst and sorbent were run in nearly fresh state for H2 production. The sorption-enhanced chemical-looping reforming was also demonstrated. The paper discusses some issues and challenges, along with the possible solutions in order to help in efficient production of hydrogen from catalytic steam reforming of biodiesel byproduct glycerol.
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In regions where the development of formal finance is relatively lagging behind, commercial credit has partially replaced the role of formal finance and facilitated the development of the private ...economy and even the country, thus making commercial credit an important entry point for understanding and promoting sustainable economic development. Taking the Hangzhou Bay Greater Bay Area as a case study, based on the City Business Credit Environment Index (CEI) from 2015 to 2019, we examine the characteristics of business credit networks using social network analysis and discuss the impact of business credit on urban green economy efficiency heterogeneity by drawing on spatial econometrics. The study confirms that the structure of business credit networks in the Hangzhou Bay Greater Bay Area tends to be dense, the network density and number of connections show growth, the spatial network structure is taking shape, and the strength of spatial connections among cities has increased. Hangzhou, Shaoxing, Jiaxing and Shanghai are at the centre of the network and play a radiation-driven role. The business credit network in the Hangzhou Bay Greater Bay Area is characterised by self-stability and has evolved from a multi-centre to a single centre. Business credit is negatively correlated with the efficiency of the green economy in the Hangzhou Bay Area, which is a departure from the Chinese "financial development paradox". In terms of heterogeneity, the relationship remains consistent for port cities and open coastal cities in general, while the effect is less pronounced for cities above sub-provincial level. The study concludes that, with the high-quality economic development of the Hangzhou Bay Greater Bay Area, the Chinese "financial development paradox" does not exist in the region at this stage, which also highlights the need to accelerate the construction of a Chinese-style modernisation theory and practice system.
Based on the China City Commercial Credit Environment Index (CEI), a more scientific spatial DID model was used to examine the long-term impact of the opening of ports and trading in the late Qing ...Dynasty on the urban commercial credit environment, taking cities above the prefecture level in the Yangtze River Delta as a sample. The study confirms that: (1) the opening of ports and commerce in the late Qing Dynasty had a significant contribution to the urban commercial credit environment, which was conducive to the transformation of production methods and interpersonal relationships from traditional to modern, and to the improvement of the urban commercial credit environment. (2) Before the signing of the Treaty of Shimonoseki, the local forces of the late Qing Dynasty were resistant to the economic aggression of the Great Powers, and the positive impact of the opening of ports and trading on the commercial credit environment of port cities was more significant, but the impact was not obvious after the signing of the Treaty of Shimonoseki. (3) From the history of the opening of ports for trade in the late Qing Dynasty, the economic aggression of the Western powers against the non-patronage areas by means of the buying class objectively strengthened the concept of rule of law and credit awareness in the local market and exerted a long-term influence on the commercial credit environment of the cities, but the impact of the opening of ports for trade on the commercial credit environment of the patronage areas was not prominent. (4) Cities located in the sphere of influence of the common law powers had a more pronounced impact on the commercial credit environment as their institutions and concepts were more easily transplanted, while the impact of the opening of ports and trading on the commercial credit environment of cities in the sphere of influence of the civil law powers was not significant. Policy Insights: (1) Enhance the ability to negotiate with foreign countries on economic and trade matters from a level-headed world perspective, and be bold and adept at fighting unreasonable rules, standards and requirements in order to better optimise the business credit environment; (2) Regulate the use of administrative resources and avoid undue administrative intervention, which is an important prerequisite for improving the basic system of the market economy to enhance the business credit environment; (3) Emphasise both connotative development to follow a Chinese style modernisation path, and (3) emphasising selective cooperation to promote outward development, promoting the interaction, convergence and matching of domestic and foreign regulations, and continuously improving the regional commercial credit environment.
Single‐crystal tin selenide (SnSe), a record holder of high‐performance thermoelectric materials, enables high‐efficient interconversion between heat and electricity for power generation or ...refrigeration. However, the rigid bulky SnSe cannot satisfy the applications for flexible and wearable devices. Here, a method is demonstrated to achieve ultralong single‐crystal SnSe wire with rock‐salt structure and high thermoelectric performance with diameters from micro‐ to nanoscale. This method starts from thermally drawing SnSe into a flexible fiber‐like substrate, which is polycrystalline, highly flexible, ultralong, and mechanically stable. Then a CO2 laser is employed to recrystallize the SnSe core to single‐crystal over the entire fiber. Both theoretical and experimental studies demonstrate that the single‐crystal rock‐salt SnSe fibers possess high thermoelectric properties, significantly enhancing the ZT value to 2 at 862 K. This simple and low‐cost approach offers a promising path to engage the fiber‐shaped single‐crystal materials in applications from 1D fiber devices to multidimensional wearable fabrics.
Single‐crystal SnSe fibers are achieved using thermal drawing and laser‐induced recrystallization. The resulting single‐crystal rock‐salt SnSe fibers possess high thermoelectric properties, enhancing the ZT value close to 2 at 860 K, while being highly flexible, ultralong, and mechanically stable. This simple and low‐cost approach engages the fiber‐shaped high‐performance single‐crystal materials in applications from 1D fiber devices to multidimensional wearable fabrics.
Sorption-enhanced chemical-looping steam reforming in an alternating fixed-bed reactor.
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•Efficient SE-CLSR was experimentally demonstrated in alternating fixed-bed reactor.•Sorbent to ...catalyst ratio dependencies during SE-CLSR were determined.•The superior molar ratio of Ca/Ni in OC and sorbent was to be 2.0–3.0 in SE-CLSR.•Alternating multiple cycles’ SE-CLSR demonstrated remarkable stability with 90% H2.
In this study, the effects of sorbent addition for in-situ CO2 removal on hydrogen production by sorption-enhanced chemical looping steam reforming (SE-CLSR) of ethanol have been evaluated in an alternating fixed-bed reactor using a mixture of NiO/Al2O3 oxygen carrier catalyst (OC) and CaO based sorbent at moderate operating conditions (T: 600 °C, P: 1.0 atm and S:C: 3.0). The experimental data were compared with chemical equilibrium analysis based on the minimization of Gibbs free energy. The results demonstrated that NiO component in the OC was first reduced by ethanol and the reduced OC was responsible of catalytic steam reforming and water gas shift (WGS) for hydrogen production. The CO2 produced was efficiently removed by CaO based sorbent, also resulting in the process intensification considerably. It appears that the superior molar ratio of sorbent to OC (Ca/Ni) is to be 2.0–3.0 and the highest hydrogen selectivity and feeding conversion were obtained at 3.0 of Ca/Ni ratio. Hydrogen production was inhibited using further high Ca/Ni ratio due to the OC particles were surrounded and diluted by sorbent. The exothermic reactions also provided the heat to raise the temperature of the reactor. In-situ CO2 removal by solid sorbent promotes ethanol dehydration and CC carbon bonds cleavage, and thus, the hydrogen production route of conventional CLSR is changed. Continuous high-purity hydrogen production was achieved by integrating the oxidization, steam reforming, WGS, and in situ CO2 capture in an alternating fixed-bed reactor.
•A concise analytical solution for SC-CAES system was presented for the first time.•The analytical solution is universal for SC-CAES and other similar CAES systems.•A method of sectional treatment ...and Taylor expansion was carried out.•Exergy analysis for SC-CAES system with its analytical model was conducted.
An analytical solution for a novel Compressed Air Energy Storage (CAES) system, Supercritical Compressed Air Energy Storage (SC-CAES) system, was conducted in this paper. The analytical solution can explore the evolution and its reason of roundtrip efficiency varying with system key parameters in depth, while it can also reveal the coupling mechanism of different sections of the system. On that basis, the model of exergy destruction for each part was obtained, and the exergy destruction can be easily calculated. Furthermore, the analytical solution has the character of universality due to the deduced method of sectional treatment, hence it can be extended to other similar CAES systems. Lastly, a sensitivity analysis and an exergy analysis were conducted for SC-CAES system. It is found and proved that the system efficiency varies linearly with isentropic efficiencies of compressor and expander, temperature difference of intercooler and reheater, pressure loss of intercooler and reheater. Meanwhile, the main factors of the varying tendency of total exergy destruction with different parameters are revealed.
Stable aqueous TiO2 nanofluids with different particle (agglomerate) sizes and concentrations are formulated and measured for their static thermal conductivity and rheological behaviour. The ...nanofluids are then measured for their heat transfer and flow behaviour upon flowing upward through a vertical pipe in both the laminar and turbulent flow regimes. Addition of nanoparticles into the base liquid enhances the thermal conduction and the enhancement increases with increasing particle concentration and decreasing particle (agglomerate) size. Rheological measurements show that the shear viscosity of nanofluids decreases first with increasing shear rate (the shear thinning behaviour), and then approaches a constant at a shear rate greater than 100s-1. The constant viscosity increases with increasing particle (agglomerate) size and particle concentration. Given the flow Reynolds number and particle size, the convective heat transfer coefficient increases with nanoparticle concentration in both the laminar and turbulent flow regimes and the effect of particle concentration seems to be more considerable in the turbulent flow regime. Given the particle concentration and flow Reynolds number, the convective heat transfer coefficient does not seem to be sensitive to the average particle size under the conditions of this work. The results also show that the pressure drop of the nanofluid flows is very close to that of the base liquid flows for a given Reynolds number.
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection-induced inflammatory responses are largely responsible for the death of novel coronavirus disease 2019 (COVID-19) patients. ...However, the mechanism by which SARS-CoV-2 triggers inflammatory responses remains unclear. Here, we aimed to explore the regulatory role of SARS-CoV-2 spike protein in infected cells and attempted to elucidate the molecular mechanism of SARS-CoV-2-induced inflammation.
SARS-CoV-2 spike pseudovirions (SCV-2-S) were generated using the spike-expressing virus packaging system. Western blot, mCherry-GFP-LC3 labeling, immunofluorescence, and RNA-seq were performed to examine the regulatory mechanism of SCV-2-S in autophagic response. The effects of SCV-2-S on apoptosis were evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), Western blot, and flow cytometry analysis. Enzyme-linked immunosorbent assay (ELISA) was carried out to examine the mechanism of SCV-2-S in inflammatory responses.
Angiotensin-converting enzyme 2 (ACE2)-mediated SCV-2-S infection induced autophagy and apoptosis in human bronchial epithelial and microvascular endothelial cells. Mechanistically, SCV-2-S inhibited the PI3K/AKT/mTOR pathway by upregulating intracellular reactive oxygen species (ROS) levels, thus promoting the autophagic response. Ultimately, SCV-2-S-induced autophagy triggered inflammatory responses and apoptosis in infected cells. These findings not only improve our understanding of the mechanism underlying SARS-CoV-2 infection-induced pathogenic inflammation but also have important implications for developing anti-inflammatory therapies, such as ROS and autophagy inhibitors, for COVID-19 patients.
•SARS-CoV-2 spike triggers autophagy and apoptosis in ACE2-expressing cells.•SARS-CoV-2 spike induces autophagy through ROS-suppressed PI3K/AKT/mTOR pathway.•SARS-CoV-2 spike-induced autophagy promotes inflammatory responses and apoptosis.
Hydrogen production from thermochemical conversion has been considered the most promising technology for the use of biomass, and some novel methods are also being developed for low cost and high ...efficiency. This review presents the recent progress in the studies on hydrogen production from different kinds of biomass by pyrolysis, gasification and steam reforming without and/or with chemical-looping technologies. Considering potential applications, the Ni-based catalysts made of cheap and earth-abundant elements are especially important for the economically viable hydrogen production from biomass by thermochemical conversion, and can also effectively be compensated for and modified, to some extent, by using extremely low noble metal loading for retaining high catalytic activity, high coke resistance and long-term stability. The catalyst modification strategies of adding other metals, minimizing Ni particle sizes and improving the supports are highlighted. The sorption-enhanced steam reforming (SESR) and chemical looping steam reforming (SE-CLSR) processes with in situ CO 2 removal using different reactors have been considered to change the normal equilibrium limits of the water–gas shift (WGS) reaction, and thus increase feedstock conversion and process performances. The auto-thermal operating conditions and CO 2 capture during hydrogen production can be achieved by chemical looping processes with cyclic oxidation–reduction of oxygen carriers (OCs). This paper discusses the related issues, challenges and prospects, along with the possible solutions in order to help in the development of efficient hydrogen production from the thermochemical conversion of biomass.
Electrical energy storage technologies for stationary applications are reviewed. Particular attention is paid to pumped hydroelectric storage, compressed air energy storage, battery, flow battery, ...fuel cell, solar fuel, superconducting magnetic energy storage, flywheel, capacitor/supercapacitor, and thermal energy storage. Comparison is made among these technologies in terms of technical characteristics, applications and deployment status.
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