New Problems of Boiler Corrosion after Coupling Combustion of Coal and Biomass and Anti-Corrosion Technologies

This study explores the corrosion issues arising from the coupled combustion of coal and biomass and proposes potential solutions.Biomass,as a renewable energy source,offers advantages in energy-saving and carbon reduction.However,the corrosive effects of alkali metal compounds,sulfur(S)and chlorine(Cl)elements in the ash after combustion cannot be underestimated due to the high volatile content of biomass fuels.We investigate the corrosion mechanisms,as well as the transfer of Cl and alkali metal elements during this process.Comparative corrosion analyses are conducted among coal-fired boilers,pure biomass boilers and boilers with coupled combustion.Various biomass types in co-firing are studied to understand different corrosion outcomes.The main factors influencing corrosion include the physicochemical properties of biomass feedstock,furnace temperature and heating surface materials,with the chemical composition and ash content of biomass playing a dominant role.Currently,the methods used for anti-corrosion include water washing pretreatment of biomass feedstock,application of novel alloys and coatings and the development of additives to inhibit fouling,ash deposition and corrosion.Efficient inhibitors are economical and easy to produce.Additionally,biomass can be converted into biomass gasification gas,although challenges related to tar still need to be addressed.

Atomic-Scale Layer-by-Layer Deposition of Fe SiAl@ZnO@Al_(2)O_(3) Hybrid with Threshold Anti-Corrosion and Ultra-High Microwave Absorption Properties in Low-Frequency Bands

Developing highly efficient magnetic microwave absorb-ers(MAs)is crucial,and yet challenging for anti-corrosion properties in extremely humid and salt-induced foggy environments.Herein,a dual-oxide shell of ZnO/Al_(2)O_(3) as a robust barrier to FeSiAl core is introduced to mitigate corrosion resistance.The FeSiAl@ZnO@Al_(2)O_(3) layer by layer hybrid structure is realized with atomic-scale precision through the atomic layer deposition technique.Owing to the unique hybrid structure,the FeSiAl@ZnO@Al_(2)O_(3) exhibits record-high micro-wave absorbing performance in low-frequency bands covering L and S bands with a minimum reflection loss(RLmin)of-50.6 dB at 3.4 GHz.Compared with pure FeSiAl(RLmin of-13.5 dB,a bandwidth of 0.5 GHz),the RLmin value and effective bandwidth of this designed novel absorber increased up to~3.7 and~3 times,respectively.Fur-thermore,the inert ceramic dual-shells have improved 9.0 times the anti-corrosion property of FeSiAl core by multistage barriers towards corrosive medium and obstruction of the electric circuit.This is attributed to the large charge transfer resistance,increased impedance modulus|Z|0.01 Hz,and frequency time constant of FeSiAl@ZnO@Al_(2)O_(3).The research demonstrates a promising platform toward the design of next-generation MAs with improved anti-corrosion properties.

Preparation technology and anti-corrosion performances of black ceramic coatings formed by micro-arc oxidation on aluminum alloys

In order to prepare ornamental and anti-corrosive coating on aluminum alloys, preparation technology of black micro-arc ceramic coatings on Al alloys in silicate based electrolyte was studied. The influence of content of Na2WO4 and combination additive in solution on the performance of black ceramic coatings was studied; the anticorrosion performances of black ceramic coatings were evaluated through whole-immersion test and electrochemical method in 3.5% NaCl solution at different pH value; SEM and XRD were used to analyze the surface morphology and phase constitutes of the black ceramic coatings. Experimental results indicated that, without combination additives, with the increasing of Na2WO4 content in the electrolyte, ceramic coating became darker and thicker, but the color was not black; after adding combination additive, the coating turned to be black; the black ceramic coating was multi-hole form in surface. There was a small quantity of tungsten existing in the black ceramic coating beside α-Al2O3 phase and β-Al2O3 phase. And aluminum alloy with black ceramic coating exhibited excellent anti-corrosion property in acid, basic and neutral 3.5% NaCl solution.

In-situ formation characteristic, tribological characterization and anti-corrosion properties of quaternary composites films

Improvements of wear and corrosion properties are essential characteristic in engineering application. A study was made on the structure, electro-oxidation and properties of fabricated Zn-Al-SnO 2-Ti O2（Zn-Al-Sn-Ti） thin films using electrodeposition technique from chloride bath. The microstructural studies were performed by scanning electron microscopy with attached energy dispersive spectrometer（SEM-EDS）, optical microscopy（OPM） and X-ray diffractogram（XRD）. The electrochemical oxidation and erosion behavior in 3.65% Na Cl medium were studied by potentiodynamic polarization technique and characterized by atomic force microscopy（AFM）. The hardness and wear behavior of the electrodeposited film were performed by high diamond dura scan microhardness tester and CERT UMT-2 reciprocating sliding machine. It was found that a successful co-deposition of composite and particle were attained. Homogeneous imbedded grain structure distribution and fine refinement of crystal with improved micromechanical behavior was achieved. The corrosion resistance, hardness and wear stability resistance of the fabricated quaternary films improved significantly in all varied process parameter.

Investigation of anti-corrosion property of hybrid coatings fabricated by combining PEC with MAO on pure magnesium

Novel hybrid coatings on pure magnesium were prepared by combining plasma electrolytic carburizing(PEC)with micro-arc oxidation(MAO)to further enhance the anti-corrosion property in this paper.Scanning electron microscopy(SEM)was used to observe the microstructure of the coatings,meanwhile,energy dispersive spectrometry(EDS)and X-ray diffraction(XRD)were separately used to investigate the elemental as well as phase compositions of the coatings.The anti-corrosion property of the coatings was evaluated by potentiodynamic polarization curves as well as electrochemical impedance spectroscopy(EIS).The results show that PEC process is closely related with the effects of adsorption as well as diffusion of the activated carbon atoms,and it can provide a favorable pretreatment surface with predesigned chemical composition to obtain a new kind of phase,namely Si C with superior corrosion resistance and chemical stability,in the following PEC+MAO hybrid coatings.Meanwhile,PEC preprocessing also can afford an excellent micro-structure to increase the coating thickness as well as to improve the compactness of the PEC+MAO hybrid coatings.During the fabrication process of the PEC+MAO hybrid coatings,an overlapping phenomenon in regard to coating thickness can be observed instead of heaping up layer by layer.Compared with both single PEC surface modification layers as well as single MAO coatings,the PEC+MAO hybrid coatings exhibit more superior anti-corrosion property.Especially,the EIS data reveal that the PEC+MAO hybrid coatings can act as an effective protection system to provide relatively excellent long-range anti-corrosion protection.Note also that employing same MAO technique for both single MAO treatment as well as PEC+MAO combining procedure is the key to this research.

A Comparative Study on Several Anti-Corrosion Materials for Power FGD System

In the study organic-inorganic hybrid composite, epoxy modified silicone coating and vinyl ester flake mastic were comparatively used as several anti-corrosion materials that provided protection for flue gas desulfu-rization (FGD). The relationship between curing conversion rate of hybrid polymer and temperature was investigated by differential scanning calorimeter (DSC). The adhesion strength, coefficient of thermal expansion and flame retardant properties of three anti-corrosion materials were measured and analyzed. A corrosion test in 8% H2SO4 and 5% HCl at temperature cycle of 40°C~ 160°C was applied to study corrosion resistance of several anti-corrosion materials. Gravimetric measurement and morphological observation of three materials before and after corrosion test were comparatively analyzed in the paper. The small weight change and good morphological structure of hybrid composite during corrosion test demonstrate that hybrid composite has better anti-corrosion properties than epoxy modified silicone coating and vinyl ester flake mastic.

Influence of graphene on the anti-corrosion performance of epoxy-based coatings

In this work, graphene-modified epoxy-based anti-corrosion coatings were prepared and the influence of graphene on the anti-corrosion performance of the epoxy-based coatings was investigated with water contact angle test ,chemical solution immersion test, and electrochemical test. The water contact angle and chemical solution resistance of the epoxy-based coatings were improved with an increase in graphene content from 0 to 0.4%. These results prove that addition of graphene can significantly improve the hydrophobicity and impermeability of epoxy- based coatings. However, when the graphene content was increased to 0.5%, the performance of the epoxy-based coatings decreased because of graphene aggregation. Tafel polarization results show that graphene addition can significantly reduce the corrosion current density and corrosion potential of epoxy-based coatings, which enhance their anti-corrosion performance.

An electrochemical method for evaluating the resistance to cathodic disbondment of anti-corrosion coatings on buried pipelines

Methods for evaluating the resistance to cathodic disbondment （RCD） of anti-corrosion coatings on buried pipelines were reviewed. It is obvious that these traditional cathodic disbondment tests （CDT） have some disadvantages and the evaluated results are only simple figures and always rely on the subjective experience of the operator. A new electrochemical method for evaluating the RCD of coatings, that is, the potentiostatic evaluation method （PEM）, was developed and studied. During potentiostatic anodic polarization testing, the changes of stable polarization current of specimens before and after cathodic disbonding （CD） were measured, and the degree of cathodic disbondment of the coating was quantitatively evaluated, among which the equivalent cathodic disbonded distance AD was suggested as a parameter for evaluating the RCD. A series of testing parameters of the PEM were determined in these experiments.

Anti-Corrosion and Reconstruction of Surface Crystal Plane for Zn Anodes by an Advanced Metal Passivation Technique

For the aqueous Zn-ion battery,dendrite formation,corrosion,and interfacial parasitic reactions are major issues,which greatly inhibits their practical application.How to develop a method of Zn construction or treatment to solve these issues for Zn anodes are still great challenges.Herein,a simple and cheap metal passivation technique is proposed for Zn anodes from a corrosion science perspective.Similar to the metal anticorrosion engineering,the formed interfacial protective layer in a chemical way can sufficiently solve the corrosion issues.Furthermore,the proposed passivity approach can reconstruct Zn surface-preferred crystal planes,exposing more(002)planes and improving surface hydrophilicity,which inhibits the formation of Zn dendrites and hydrogen evolution effectively.As expected,the passivated Zn achieves outstanding cycling life(1914 h)with low voltage polarization(<40 mV).Even at 6 mA cm^(−2) and 3 mA h cm^(−2),it can achieve stable Zn deposition over 460 h.The treated Zn anode coupled with MnO_(2) cathode shows prominently reinforced full batteries service life,making it a potential Zn anode candidate for excellent performance aqueous Zn-ion batteries.The proposed passivation approach provides a guideline for other metal electrodes preparation in various batteries and establishes the connections between corrosion science and batteries.

The Effect of Cerium Dioxide (CeO_2) in an Anti-corrosion and Self-lubricating Coating

The effect of cerium dioxide(CeO_2)as an additive on the structure and properties of a melting type coating has been studied by means of microhardness measurement,scanning electron microscopy and thermal analysis. The results show that cerium dioxide can modify the microstructure and tribological properties of the coating. Model LIC-23 composite coating which contains CeO_2 performs well as a self-lubricating coating in hydrochloric acid solution.

An Abrasion Resistant TPU/SH-SiO_(2) Superhydrophobic Coating for Anti-Icing and Anti-Corrosion Applications

As a passive anti-icing strategy,properly designed superhydrophobic coatings can demonstrate outstanding performances.However,common preparation strategies for superhydrophobic coatings often lead to environmental pollution,high energy-consumption,high-cost and other undesirable issues.Besides,the durability of superhydrophobic coating also plagues its commercial application.In this paper,we introduced a facile and environment-friendly technique for fabricating abrasion-resistant superhydrophobic surfaces using thermoplastic polyurethane(TPU)and modified SiO_(2)particles(SH-SiO_(2)).Both materials are non-toxicity,low-cost,and commercial available.Our methodology has the following advantages:use of minimal amounts of formulation,take the most streamlined technical route,and no waste material.These advantages make it attractive for industrial applications,and its usage sustainability can be promised.In this study,the mechanical stability of the superhydrophobic surface was evaluated by linear wear test.It is found that the excellent wear resistance of the superhydrophobic coating benefits from the characteristics of raw materials,the preparation strategy,and the special structure.In anti-icing properties test,the TPU/SH-SiO_(2)coating exhibits the repellency to the cold droplets and the ability to extend the freezing time.The electrochemical corrosion measurement shows that the asprepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Q235 substrates.These results indicate that the TPU/SH-SiO_(2)coating possesses good abrasion resistance and has great potential in anti-corrosion and anti-icing applications.

A novel anti-corrosion coating for magnesium alloy

A novel enviromental protective water based metallic coating were prepared on the surface of AZ91D magnesium alloy. The properties and structure of the coating were investigated by adhension test, hardness test, heat resisting test, neutral salt spray test and scanning electron microscopy (SEM). The results show that the coating has a stepped structure which can achieve good adhesion of first-grade, heat resistance temperature of 400℃, hardness of HV_ 0.50/30210 and anti-corrosion time of 250h in salt spray test. Meanwhile, the film forming and corrosion mechanism of the coating were also put forward based on the results of the Fourier transform infrared spectroscopy (FTIR) test and electrochemical impedance spectroscopy (EIS) test.

Preparation of a TiO_(2)@o-Vanillin@TEOS-APTES Nanocontainer and Its Anti-Corrosion Performance on Steel

A TiO_(2)@o-vanillin@TEOS-APTES nanocontainer was prepared by an experimental process in which,firstly,2-hydroxy-3-methoxybenzaldehyde(o-vanillin)was loaded in a TiO_(2) container to obtain TiO_(2)@o-vanillin.Then,TiO_(2)@o-vanillin was encapsulated by tetraethyl orthosilicate(TEOS).Finally,3-aminopropyl triethoxysilane(APTES)was used to modify the obtained sample.The morphology,structural phase and thermal stability of the TiO_(2)@o-vanillin@TEOS-APTES nanocontainer were analyzed using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),X-ray diffractometry(XRD)and thermal gravimetric analysis(TG).The release rate of o-vanillin was investigated using an ultraviolet-visible(UV-vis)spectrometer.The anti-corrosion performances of the epoxy,epoxy@o-vanillin and epoxy@TiO_(2)@o-vanillin@TEOS-APTES coatings on steel sheets were evaluated using an electrochemical method and scarification experiments.The results showed that the impedance value of the epoxy@TiO_(2)@o-vanillin@TEOS-APTES coating was two orders of magnitude higher than that of the blank epoxy coating,and one order of magnitude higher than that of the epoxy@o-vanillin coating.The maximum inhibition rate of the epoxy@TiO_(2)@o-vanillin@TEOS-APTES coating on the steel can reach 97.3%.The scarification experiments confirmed that the epoxy@TiO_(2)@o-vanillin@TEOS-APTES coating had the best anti-corrosion performance.

Anti-Corrosion Test on Basal Slope Protection Materials

Through the introduction of the anti-corrosion test schemes, the test equipments and the test procedure for three kinds of basal slop protection materials including fence, mixed stump and geo-textile, this paper comes to a conclusion about the analysis of the anti-corrosion test, revealing that among all of the common basal slop protection materials, mixed stump and fence are with Class II anti-corrosion property, while the geo-textile is with the first-class anti-corrosion property.

Upcycling municipal solid waste to sustainable hydrogen via two-stage gasification-reforming

As global municipal solid waste(MSW)quantities continue to escalate,serious socio-environmental challenges arise,necessitating innovative solutions.Waste-to-hydrogen(WTH)via two-stage gasification-reforming(TSGR)presents an emergent technology for MSW upcycling,offering to ease waste management burdens and bolster the burgeoning hydrogen economy.Despite early initiatives to advance TSGR technology,a cohesive and critical analysis of cutting-edge knowledge and strategies to enhance hydrogen production remains lacking.This review aggregates literature on MSW upcycling to hydrogen via TSGR,with a focus on optimizing process control and catalytic efficiency.It underscores technological avenues to augment hydrogen output,curtail catalyst costs,and refine system performance.Particularly,the review illuminates the potential for integrating chemical and calcium looping into TSGR processes,identifying opportunities,and pinpointing challenges.The review concludes with a summary of the current state of techno-economic analysis for this technology,presenting outstanding challenges and future research directions,with the ultimate goal of transitioning WTH from theoretical to practical application.

Methanol steam reforming for hydrogen production driven by an atomically precise Cu catalyst

Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can be used as light-harvesting materials in solar energy utilization such as photocatalytic methanol steam reforming.In this work,we report an atomically precise Cu_(13)cluster protected by dual ligands of thiolate and phosphine that can be viewed as the assembly of one top Cu atom and three Cu_(4)tetrahedra.The Cu_(13)H_(10)(SR)_(3)(PR’_(3))_(7)(SR=2,4-dichlorobenzenethiol,PR’_(3)=P(4-FC_(6)H_(4))_(3))cluster can give rise to highly efficient light-driven activity for methanol steam reforming toward H_(2)production.

Chemical looping reforming of the micromolecular component from biomass pyrolysis via Fe_(2)O_(3)@SBA-16

To solve the problems of low gasification efficiency and high tar content caused by solid–solid contact between biomass and oxygen carrier in traditional biomass chemical looping gasification process.The decoupling strategy was adopted to decouple the biomass gasification process,and the composite oxygen carrier was prepared by embedding Fe_(2)O_(3) in molecular sieve SBA-16 for the chemical looping reforming process of pyrolysis micromolecular model compound methane,which was expected to realize the directional reforming of pyrolysis volatiles to prepare hydrogen-rich syngas.Thermodynamic analysis of the reaction system was carried out based on the Gibbs free energy minimization method,and the reforming performance was evaluated by a fixed bed reactor,and the kinetic parameters were solved based on the gas–solid reaction model.Thermodynamic analysis verified the feasibility of the reaction and provided theoretical guidance for experimental design.The experimental results showed that the reaction performance of Fe_(2)O_(3)@SBA-16 was compared with that of pure Fe_(2)O_(3) and Fe_(2)O_(3)@SBA-15,and the syngas yield was increased by 55.3%and 20.7%respectively,and it had good cycle stability.Kinetic analysis showed that the kinetic model changed from three-dimensional diffusion to first-order reaction with the increase of temperature.The activation energy was 192.79 kJ/mol by fitting.This paper provides basic data for the directional preparation of hydrogen-rich syngas from biomass and the design of oxygen carriers for pyrolysis of all-component chemical looping reforming.

Research on the Reform of the Process-Tracking Ideological and Political Assessment System in Applied Universities:Taking the Personal Finance Course as an Example

Using the Xi’an Mingde Institute of Technology students as the teaching object and the Personal Finance course as an example,we explore the reform of the ideological and political assessment system of process-tracking courses in applied universities.The article analyzes the feasibility of applying the curriculum ideological and political assessment system in college courses and compares the traditional assessment system.It also proposes that applying curriculum ideological and political assessment to the college curriculum assessment system will help improve students’understanding of the“value guidance”in curriculum ideological and political education and enhance the teaching effect.

Optimizing the sulfur-resistance and activity of perovskite oxygen carrier for chemical looping dry reforming of methane

Perovskite oxides has been attracted much attention as high-performance oxygen carriers for chemical looping reforming of methane,but they are easily inactivated by the presence of trace H_(2)S.Here,we propose to modulate both the activity and resistance to sulfur poisoning by dual substitution of Mo and Ni ions with the Fe-sites of LaFeO_(3)perovskite.It is found that partial substitution of Ni for Fe substantially improves the activity of LaFeO_(3)perovskite,while Ni particles prefer to grow and react with H_(2)S during the long-term successive redox process,resulting in the deactivation of oxygen carriers.With the presence of Mo in LaNi_(0.05)Fe_(0.95)O_(3−σ)perovskite,H_(2)S preferentially reacts with Mo to generate MoS_(2),and then the CO_(2)oxidation can regenerate Mo via removing sulfur.In addition,Mo can inhibit the accumulation and growth of Ni,which helps to improve the redox stability of oxygen carriers.The LaNi_(0.05)Mo_(0.07)Fe_(0.88)O_(3−σ)oxygen carrier exhibits stable and excellent performance,with the CH_(4)conversion higher than 90%during the 50 redox cycles in the presence of 50 ppm H_(2)S at 800℃.This work highlights a synergistic effect in the perovskite oxides induced by dual substitution of different cations for the development of high-performance oxygen carriers with excellent sulfur tolerance.

Using Aspen HYSYS to Develop a Custom Molecule-based Reformer Model

A new continuous catalytic reforming model was configured by using a molecule-based reactor module. Themodel was based on the Sinopec Research Institute of Petroleum Processing Co., Ltd. continuous catalytic reformer fullmodel, and was reduced to a size of 157 naphtha molecules (C1−C12) that underwent 764 reactions. The new model inheritedthe advantages of the original model, and had better solving performance and flexibility owing to support by the AspenHYSYS environment. Typical commercial plant data were selected for model validation, which showed advantages in theaccuracy of detailed predictions and the range of its application. In addition, the solving time was reduced from minutes toseconds. Therefore, the simplified model proved to be feasible for industrial application.