Effect of Succinonitrile on Electrical,Structural and Thermal Properties of PVA-Based Polymer Electrolyte for Magnesium Battery

This paper report the synthesis and properties of a series of composite polymer electrolytes formed by dispersion of a non-ionic organic plastic material SN （succinonitrile） into poly（vinyl alcohol） complexed with magnesium acid salt. SEM （scanning electron microscope） images of different SN concentrations of films revealed that large open pore structure were also frequently present, when SN content increase up to 7.5 wt%. The addition of SN greatly enhances ionic conductivities of the electrolytes which is due to the high polarity and diffusivity of SN. The Mg2~ （magnesium ion） ion conduction is confirmed from impedance spectroscopy and transport number measurements. The highest conducting sample in the plasticized system was used to fabricate Mg （magnesium） battery with configuration Mg/SPE/TiO2. The discharge capacity of the fabricated battery was 17.5 mAh/gm.     

Study on Adsorption of Water in MCM41 Containing Metal Ions by Molecular Dynamic Simulations

To clarify whether the adsorption of water in MCM41 can be promoted by introducing some metal ions onto its surface, molecular dynamics simulations were carried out to investigate the behavior of some water molecules confined in mesoporous MCM41 whose pore size was tailored to 2.5 nm. Pure silica MCM41 as well as those containing some metal ions such as Al3 , Cu2 , and La3 was simulated, and by observing the local average density distribution of particles, we found that both the MCM41 containing Al3 and that of La3 performed higher adsorption and lower desorption temperature. It is concluded that the adsorption is improved mainly owing to the diversities of polarity, active sites, and structure imported by these metal ions.     

Carbon Dioxide Mineralisation and Integration with Flue Gas Desulphurisation Applied to a Modern Coal-Fired Power Plant

For Finland, carbon dioxide mineralisation was identified as the only option for CCS （carbon capture and storage） application. Unfortunately it has not been embraced by the power sector. One interesting source-sink combination, however, is formed by magnesium silicate resources at Vammala, located -85 km east of the 565 MWe coal-fired Meri-Pori Power Plant on the country＇s southwest coast. This paper assesses mineral sequestration of Meri-Pori power plant CO2, using Vammala mineral resources and the mineralisation process under development at Abo Akademi University. That process implies Mg（OH）E production from magnesium silicate-based rock, followed by gas/solid carbonation of the Mg（OH）2 in a pressurised fluidised bed. Reported are results on experimental work, i.e., Mg（OH）2 production, with rock from locations close to Meri-Pori. Results suggest a total CO2 fixation capacity -50 Mt CO2 for the Vammala site, although production of Mg（OH）2 from rock from the site is challenging. Finally, as mineralisation could be directly applied to flue gases without CO2 pre-capture, we report from experimental work on carbonation of Mg（OH）2 with CO2 and CO2-SO2-O2 gas mixtures. Results show that SO2 readily reacts with Mg（OH）2, providing an opportunity to simultaneously capture SO2 and CO2, which could make separate flue gas desulphurisation redundant.     

Theoretical energy consumption analytical method for metal separation process

<正>The theoretical energy consumption(TEC)analytical methods and the calculated models for the electrolytic and thermal reduction metal separation processes have been put forward based on thermodynamics and physical chemistry principles,providing theoretical foundation for choosing the optimum metal separation methods.Based on the models,the TECs of the Mg separation processes are taken as an example,and have been calculated and analyzed contrastively,including the MgCl_2 electrolytic method,the MgO electrolytic method with inert electrode and with carbon anode,and the silicothermic method.It is shown that the thermal method is more reasonable than the electrolytic methods to separate Mg under low efficiency of coal power generation.     

Experimentation of a Membrane-based Concentration Gradient Energy Storage of Liquid Desiccant Solutions Driven by Solar Energy

Solar energy storage is an indispensable and sustainable utilization mode of renewable energy; environment friendly, large-capacity, low heat loss, and long-term storage are critical to improving the integration of solar energy supply. Traditional thermal energy storage mode cannot achieve long-term storage due to the heat loss even under the excellent thermal insulation measures. In this work, a solar-powered membrane-based concentration gradient energy storage of liquid desiccant solutions is presented. In the membrane distillation process driven by solar energy under the right solar radiation conditions, the liquid desiccant solution is concentrated gradually and long-term stored as the concentration gradient energy. To this end, the measured temperature of solar hot water is in the range of 40°C to 90°C from May to September, 2018, in Xi'an, China. And then, the Li Br solution(50 wt%), the Li Cl solution(35 wt%), and the Ca Cl2 solution(40 wt%) were membrane-based concentrated in the temperature range of 42°C to 63°C, separately. The results showed that the water vapor pressure difference decides the water vapor transferred across the membrane pores from the liquid desiccant side to the air side. The energy storage density of liquid desiccant solutions increases along with the increases in temperature and the membrane area. Consequently, when the Li Br, Li Cl, and Ca Cl_2 solutions are concentrated from 50% to 55%, from 35% to 40%, and from 40% to 45%, separately, the concentration energy storage density is 245 k J/kg, 350 k J/kg, and 306 k J/kg, which is equivalent to or even higher than ice storage capacity. Due to the two independent closed cycle of the liquid desiccant solution and air, the liquid desiccant solution's concentration gradient energy storage can be long-term stored environment-friendly without any insulation measures.     

SI Engine Fueled with Gasoline,CNG and CNG-HHO Blend: Comparative Evaluation of Performance,Emission and Lubrication Oil Deterioration

Hydroxy gas (HHO) is one of the potential alternative fuels for spark ignition (SI) engine,notably due to simultaneous increase in engine performance and reduction in exhaust emissions.However,impact of HHO gas on lubrication oil for longer periods of engine operation has not yet been studied.Current study focuses on investigation of the effect of gasoline,CNG and CNG-HHO blend on lubrication oil deterioration along with engine performance and emissions in SI engine.HHO unit produces HHO gas at 4.72 L/min by using 6 g/L of KOH in the aqueous solution.CNG was supplied to the test engine at a pressure of 0.11 MPa using an electronically controlled solenoid valve.Engine tests were carried out at different speeds at 80%open throttle condition and various performance parameters such as brake power (BP),brake specific fuel consumption(BSFC),brake thermal efficiency (BTE),exhaust gas temperature and exhaust emissions (HC,CO_2,CO and NO_x)were investigated.In addition,various lubrication oil samples were extracted over 120 h of engine running while topping for drain out volume and samples were analyzed as per ASTM standards.CNG-HHO blend exhibited better performance i.e.,15.4%increase in average BP in comparison to CNG,however,15.1%decrease was observed when compared to gasoline.CNG-HHO outperformed gasoline and CNG in the case of HC,CO_2,CO and brake specific fuel consumption (31.1%decrease in comparison to gasoline).On the other hand,CNG-HHO produced higher average NO_x (12.9%) when compared to CNG only.Furthermore,lubrication oil condition(kinematic viscosity,water contents,flash point and total base number (TBN)),wear debris (Iron (Fe),Aluminum(Al),Copper (Cu),Chromium (Cr)) and additives depletion (Zinc (Zn),Calcium (Ca)) presented a significant degradation in the case of CNG-HHO blend as compared to gasoline and CNG.Lubrication oil analyses illustrated 19.6%,12.8%and 14.2%decrease in average viscosity,flash point and TBN for CNG-HHO blend respectively.However,average water contents,Fe,Al and Cu mass concentration appeared 2.7%,25×10~(-6),19×10~(-6),and 22×10~(-6) in lubrication oil for CNG-HHO respectively.     

Experimental Study on Pore Distribution Characters and Convert Rate of CaO

During the reaction between calcium sorbents and SO2, calcium sorbents are first calcined and converted into CaO. CaO can be obtained by calcining Ca(OH)2or CaCO3. The porosity of the sorbent is increased because of calcination and is decreased because of sulfurization. In the calcination process H2O or CO2 is escaped from the particles and pores are formed in particles. The reaction or convert rate of CaO is influenced strongly by the pore structure characters. From Ca(OH)2 to CaO the escape velocity of H2O or its mass transfer is one of the key factors influencing the pore forming. During calcination process different healing velocity, different heating time and temperature were suggested. The temperature rising rate and calcining temperature play important role to the pore structure. The convert rates of CaO obtained through different calcining conditions were investigated experimentally. Some interesting results were showed that the calcium utilization of CaO particles is determined not only by the special surface area and total pore volume, but also by pore-size distribution. The main factor influencing the sulfation is the pore diameter distribution at lower sulfation temperature. For higher reaction temperature specific volume is the important reason. But pore-size distribution is strongly influenced by heat flux and temperature in the calcining process.     

HCl Dry Removal with Modified Ca-Based Sorbents at Moderate to High Temperatures

Modified Ca-based sorbents were obtained by adding sodium alkali into Ca(OH)2 and CaCO3. Reactive properties of modified Ca-based sorbents with acidic gases were investigated through reacting with gaseous HC1 at 450-760℃, and SEM and XRD technologies were adopted to get information on the reaction mechanism. Experimental data showed that HC1 dry removal efficiencies increased with temperature before 700℃ for all of the investigated sorbents, and there existed improved sorbents that corresponded to the highest removal efficiencies under the similar conditions. SEM photographs exhibited morphology difference between original and improved sorbents both before and after the reaction; and displayed that improved sorbents formed more porous product layers than original sorbents especially at higher temperature when product sintering became heavier, which is favorable to HC1 dry removal. XRD analysis showed that (1) improved Ca(OH)2 and CaCO3 were less crystalline than original lime and limestone; (2) the re     

Effect of Nanoparticle Type and Surfactant on Heat Transfer Enhancement in Spray Cooling

In this study,the heat transfer characteristics of nanofluids used in spray cooling systems were examined.Three nanofluids,i.e.,Cu,CuO,and Al2 O3,respectively,with volume fractions ranging from 0.1%to0.5%,as well as different volume fractions of a surfactant Tween 20,were used.In addition,their contact angles were measured to examine the heat-transfer characteristics.Under the same experimental conditions,with the increase in the volume fraction of the Cu nanoparticles from 0.1%to 0.5%,the maximum heat flux qmax increased from 3.36 MW/m2 to 3.48 MW/m2 from the impinging central point to r=30 mm(r is the distance from the impingement point),and the corresponding temperature of qmax increased from 400℃to 420℃.Results revealed that with increasing Tween 20 concentrations,the contact angle decreased because of the decrease in the surface tension of nanofluids and improvement of the wetting ability,and the corresponding qmax increased from 3.48 MW/m2 to 3.94 MW/m2 at the impact central point.     

Design and Sizing Electric Micro Generator Using Thermoelectric Modules

This paper presents the development of a methodology for calculating sizing electric micro sources of power generation using TEG （thermoelectric modules） to capture energy industrial process waste. Since the thermoelectric modules are able to convert a temperature gradient directly into electricity and still occupy a small space, and have no vibration or noise during operation. Furthermore, the cogeneration using thermoelectric modules is totally clean and reuses part of the residual thermal energy to generate power, or improve the overall yield of the process and avoid the emission of gases to the environment. Therefore, this research contributes to the development of a green energy to numerical modeling for the design and dimensioning of micro-sources of electric power generation from performance curves and predetermined temperature gradients industrial processes. The result is an effective methodology for the design and conditioning the voltage level and power of micro allowing the size of the electrical quickly and securely for many industrial applications, varying the types of modules used area, voltage and power generated.     

Ammonia decomposition over nickel catalysts supported on alkaline earth metal aluminate for H2 production

The Ni catalysts supported on alkaline earth metal aluminate compounds, Ni/AM-Al-O (AM = Mg, Ca, Sr, Ba) were synthesized to investigate the influence of their basic property on NH₃ decomposition activity. The basic strength of the catalysts was confirmed to correspond to that of added alkaline earth metal in the support materials (Ni/Mg–Al–O < Ni/Ca–Al–O < Ni/Sr–Al–O < Ni/Ba–Al–O) from CO₂-TPD measurement. This basic strength of the catalysts could influence the catalytic activity for NH₃ decomposition, which increased in order of the Ni/Mg–Al–O < Ni/Ca–Al–O < Ni/Sr–Al–O < Ni/Ba–Al–O catalysts. NH₃-TPSR showed that the strong basic property weakened H₂ adsorption but slightly strengthened N₂ adsorption for the catalysts except for the Ni/Mg–Al–O catalyst. From the kinetic analysis, the absolute value of the H₂ reaction order decreased with increasing basic strength of the catalysts, indicating that the strong basic property of the catalysts could alleviate the H₂ inhibition in ammonia decomposition.     

Enhanced photoelectrochemical performance of anatase TiO2 by metal-assisted S–O coupling for water splitting

In this study, hybrid density functional theory calculations have been used to investigate the electronic structures of (Mg, S), (2Al, S), (Ca, S), and (2Ga, S) codoped anatase TiO₂, aiming at improving their photoelectochemical performance for water splitting. It is found that the acceptor metals (Mg, Al, Ca, and Ga), assisting the coupling of the incorporated S with the neighboring O in TiO₂, lead to the fully occupied energy levels in the forbidden band of TiO₂, which is driven by the antibonding state π* of the S–O bond. It is also found that the metal-assisted S–O coupling can prevent the recombination of the photo-generated electron–hole pairs and effectively reduce the band gap of TiO₂. Among these systems, the (Mg, S) codoped anatase TiO₂ has the narrowest band gap of 2.206 eV, and its band edges match well with the redox potentials of water. We propose that this metal-assisted S–O coupling could improve the visible light photoelectrochemical activity of anatase TiO₂.     

Effects of transition metal Ti and its compounds on hydrogen adsorption performance of Mg17Al12

Catalytic effects of Ti, Ti_n (n = 2–4), TiC, and TiO₂ clusters on hydrogenation of the Mg17Al12(110) surface were investigated by using density functional theory. The geometry structure, adsorption energy, dissociation barrier, density of state, electron density, and electron density difference were calculated. As a result, the adsorption energy and dissociation barrier of hydrogen on the Ti-containing Mg17Al12(110) surfaces were effectively improved as compared with the clean Mg17Al12(110) surface. Such as the adsorption energy of H(H2) on the Mg17Al12(110) surface was ?0.18 (?0.13) eV, while the related energy of H(H2) on the Mg17Al12(110)/TiO2 system was ?1.50 (?1.22) eV. In addition, H2 molecules could be spontaneously dissociated to H atoms on the Mg15Ti2Al12(110), Mg17Al12(110)/Ti3, and Mg17Al12(110)/TiO2 surfaces. The results of electronic structures indicated that the H s states principally hybridized with the Ti s and d states. The mechanism of Ti, Ti_n (n = 2–4), TiC, and TiO2 clusters on the promoted hydrogenation of Mg17Al12 was explained.     

Interface mixing and hydrogen absorption in Pd/Mg and Pd/Al/Mg thin films

Pd/Mg bilayers and Pd/Al/Mg trilayers were prepared onto glass substrates at room temperature (RT) by UHV magnetron sputtering. Mixing effects at the Pd–Mg and Al–Mg interfaces were studied in-situ, immediately after deposition, by X-ray Photoelectron Spectroscopy (XPS). Additionally, the interfaces of the Pd/Al/Mg trilayer for the Al thickness equal to 1 nm were examined. Hydrogen absorption was monitored in-situ at RT by simultaneous resistivity and optical transmittance measurements. Formation of MgH₂ phase was confirmed by ex-situ X-ray diffraction measurements. The XPS studies revealed rather sharp interface between Al and Mg layers. On the other hand, a significant interface mixing for the Pd/Mg bilayers and Pd/1 nm – Al/Mg trilayers was observed. Further studies showed that an additional layer of Al, deposited between magnesium and palladium layers, can significantly improve the hydrogen absorption kinetics at RT. The optimal thickness of the Al layer was found to be 0.5 nm.     

Pre-reforming of liquefied petroleum gas over nickel catalysts supported on magnesium aluminum mixed oxides

A series of Ni/Mg_xAl catalysts with different Mg/Al molar ratios were prepared by impregnating Mg-Al mixed oxides with nickel nitrate aqueous solution and used for the pre-reforming of LPG in the temperature range of 400-500 °C. XRD and H₂-TPR results showed that the Ni/Mg_xAl catalysts calcined at 800 °C mainly consisted of γ-Al₂O₃, Mg(Ni)Al₂O₄ and Mg(Ni)O phases varying with Mg/Al molar ratio without free NiO species observed. The effects of Mg/Al molar ratio, S/C molar ratio and reaction temperature on the catalytic behavior of the Ni/Mg_xAl catalysts were investigated in detail. The results revealed that the catalyst with Mg/Al molar ratio of 1.25 had the highest catalytic activity and stability. The increase in S/C molar ratio promoted both the steam reforming of LPG and the methanation of carbon oxides and hydrogen. The stability tests of 15%Ni/Mg_1.25Al catalyst showed that the catalyst was stable for the pre-reforming of LPG, and the stability decreased with elevating the reaction temperature due to more coke deposition.     

Effects of Mg and Al doping on the electronic structure and dehydrogenation of LiBH4·NH3

The electronic structures and bonding characters, the occupation energies of dopants, as well as the formation energies of Frenkel defects in pure LiBH₄·NH₃ and in Mg- and Al-substituted LiBH₄·NH₃ were investigated by using first-principles calculations. The occupation energies show that the substitutions with Mg and Al destabilize LiBH₄·NH₃ and that Mg substitution is easier than Al substitution. Substitution with Mg or Al partly reduced interactions between B–H and N–H atoms, thus improving the dehydrogenation property of LiBH₄·NH₃. At the same time, substitution with Mg or Al increases the interactions between metal and N atoms, which stabilize the NH₃ group and inhibit the release of NH₃ during dehydrogenation. The formation energy of Frenkel defects indicates that Mg or Al doping facilitates the formation of Frenkel defects. Our theoretical studies show that Mg and Al are good candidates but Al is better than Mg for improving the dehydrogenation property of LiBH₄·NH₃.     

Synergistic effect of TiF3@ graphene on the hydrogen storage properties of Mg–Al alloy

Mg–Al alloy was prepared by sintering and mechanical alloying, and the effects of graphene (Gp), TiF₃ and Gp/titanium (III) fluoride (TiF₃) on the hydrogen storage properties of the Mg–Al alloy were studied. The results show that Gp and TiF₃ could improve the hydrogen storage properties of Mg–Al alloy. In particular, Gp and TiF₃ showed good synergistic effect for enhancing the hydrogen storage properties of Mg–Al alloy. For example, when 1.0 wt% of H₂ was absorbed/desorbed, the hydrogen adsorption/desorption temperature of the Mg–Al alloy and Mg–Al-M (M = Gp, TiF₃, and TiF₃@Gp) composites were 241/343 °C, 185/310 °C, 229/292 °C and 159/280 °C, respectively. For the Mg–Al alloy, the apparent activation energy was 176.5 kJ mol^?1, and it decreased to 139.8 kJ mol^?1, 171.6 kJ mol^?1, and 94.3 kJ mol^?1, with the addition of Gp, TiF₃ and TiF₃@Gp composites, respectively. Evidently, the comprehensive hydrogen storage properties of Mg–Al alloy were improved remarkably under the synergistic effect of Gp and TiF₃.     

Ab initio study of effects of Al and Y co-doping on destabilizing of MgH2

First-principles calculations based on density functional theory (DFT) were performed to study the destabilizing mechanism of co-doped MgH₂ with Al and Y. From the minimization of total electronic energy, the preferential positions of dopants are determined. The calculated formation enthalpy and substitution enthalpy show that incorporation of Al combined with Y atoms into MgH₂ is energetically favorable relative to Al doping alone. Due to strong interaction of the dopant Y with Mg and Al, the hydrogen dissociation energy and the dehydrogenation enthalpy are both reduced, indicating that the synergetic effect of Al and Y on destabilizing the MgH₂ is superior to that of Al doping. The electronic structures show that the breakage of Mg–H bond is much easier in co-doped case, because of the conduction band shift below the Fermi level and the hybridization of dopants with Mg atoms, which effectively decrease the hybridization between Mg and H.     

Improving the hydrogen storage properties of MgH2 by reversibly forming Mg–Al solid solution alloys

Supersaturated Mg(Al) solid solutions with reduced lattice constants were successfully prepared by ball milling Mg and Al powder mixtures. The microstructure and phase transition were investigated by XRD. The results indicated that disproportionation of supersaturated Mg(Al) solid solution to MgH₂ and Al was caused by hydrogenation, then equilibrium Mg(Al) solid solution formed after dehydrogenation, while the intermetallic compound Mg₁₇Al₁₂ reversibly decomposed to MgH₂ and intermediate phase Al₃Mg₂ which could further decompose to MgH₂ and Al by hydriding. These reversible phase transitions make Mg–Al alloys show an observably lowered de/hydriding enthalpy and activation energy in comparison with pure Mg.     

Characteristics of hydrogen production with carbon storage by CO2-rich hydrothermal alteration of olivine in the presence of Mg–Al spinel

Artificial control of olivine alteration has potential applications for both H₂ production and CO₂ reduction (by mineralization and hydrogenation). To explore methods to overcome the still-constrained olivine alteration problem, olivine + spinel alteration experiments were performed with the addition of Mg–Al spinel in CO₂-rich (0.5 M NaHCO₃) solution under hydrothermal conditions (300 °C and 10 MPa). Mg–Al spinel enhanced olivine serpentinization significantly (more than 2 times), and generation of both H₂ and CO₂ hydrogenation products was accelerated (up to 3 times) with ≥10 wt% Mg–Al spinel especially at the latter stage of the 72 h reaction.Mineral measurements revealed that more Al released from Mg–Al spinel was incorporated into Al-serpentine by the replacement of Fe with higher Mg–Al spinel content. Both Al and Fe incorporated into Al-serpentine were released as the reaction proceeded. Thus, H₂ production was elevated with the presence of a large amount Mg–Al spinel at the latter stage of the reaction. HCO₃⁻ played an important role in the promotion of Mg–Al spinel dissolution with the release of Al, which was stored in magnesite after being utilized. This study also suggests that the presence of Mg–Al spinel (5–20 wt%) in the starting mineral does not have significant influence on the total H₂ yield from olivine alteration over the entire operation period.