Photovoltaic project investment based on the real options method: An analysis of the East China power grid region

Distributed photovoltaics (PV) play a key role in the energy transition. We construct an investment value and timing assessment model based on the real options method to improve scientific decision-making in distributed PV investing in an uncertain environment. The model is applied to analyze projects in the East China Power Grid region under multiple self-consumption ratio scenarios. The results show that investing in distributed PV projects is beneficial, but there are differences in the optimal investment timing under different self-consumption ratios. Investors can defer investment for as early as one year to obtain optimal investment value.     

Effects of ellipsoidal and regular hexahedral particles on the performance of the waste heat recovery equipment in a methanol reforming hydrogen production system

Hydrogen production from methanol has attracted attention due to its wide range of raw material sources and mature technology. Using waste heat of industrial high temperature solid particles like blast slag and steel slag etc. To provide vaporization heat and reaction heat for the reaction between methanol and water is an emerging technology for hydrogen production from methanol, which can save additional thermal energy resources. Herein, the performances of equipment that uses the waste heat of ellipsoidal and regular hexahedral particles to provide a heat source for methanol to hydrogen were explored by the DEM-CFD method. Compared with spherical particles of the same equivalent diameter, ellipsoidal and regular hexahedral particles have poor fluidity in the stagnant area, and the empty area is enlarged and irregular in shape. The average velocity peaks of the ellipsoidal and regular hexahedron particles are larger than those of spherical particles, and the overall mean velocity fluctuation of ellipsoidal particles is similar to that of spherical particles while the regular hexahedron particles' is larger. The average temperature drop rate of the ellipsoidal and regular hexahedral particles is slower than that of spherical particles, the uniformity of temperature distribution is worse than that of spherical particles. The ellipsoidal and regular hexahedral particles’ average effective heat transfer coefficient is smaller than that of spherical particles, and the heat transfer effect is weaker than that of spherical particles. The effective heat transfer coefficient of ellipsoidal particles is 2.95 W/(m⁻²∙K⁻¹) lower than that of spherical particles and the effective heat transfer coefficient of hexahedral particles is 6.09 W/(m⁻²∙K⁻¹) lower than that of spherical particles. Therefore, compared with the spherical particles of the same equivalent diameter, ellipsoidal and regular hexahedral particles produce less hydrogen.     

Highly homogeneous multicomponent mesoporous catalysts: Defective amorphous vs. nanocrystalline CeO2 structure towards CO-PROX reaction

Mesoporous multicomponent materials with uniform pore sizes and well-defined network geometries are viewed as highly attractive candidates in the catalysis field. However, their synthesis at a high homogeneity level is considered quite challenging. Herein, alumina based mixed oxides (Al/Ce/Cu or Fe) are produced through a facile evaporation-induced-self-assembly route and tested towards preferential oxidation of CO in H₂-rich gas. The effect of several synthetic parameters is investigated, with citric acid addition identified as a key factor in view of obtaining high mesoscopic order and notable homogeneity, particularly at high dopant amounts. Following thermal aging at 900 °C, metal oxides distribution and nanoporous nature are well-preserved with a parallel nucleation of ceria nanoparticles into the semi-crystalline inorganic framework. CO-PROX assessment of the aged samples reveals a drastic enhancement in catalytic activity, especially for the ternary Cu–Ce–Al system, associated with material's structural reconstruction strongly affecting metal–support interaction.     

Wettability and wettability modification methods of porous transport layer in polymer electrolyte membrane electrolysis cells (PEMEC): A review

As a key component of polymer electrolyte membrane electrolysis cells (PEMEC), the wettability of anode porous transport layer (APTL) plays an important role on the transport of gas and liquid water in the anode. This paper reviews the research progress on the materials, structural parameters and wettability of APTL, and discusses qualitatively the effect of wettability on the detachment characteristics of oxygen bubbles which are on the surface or in the internal pore channels of APTL by establishing force models of an oxygen bubble. For the surface wettability modification of titanium (Ti) fiber-based APTL, the feasibility of four surface chemical modification methods, namely silane coupling agent modification, dopamine (DA) modification, grafting modification based on Ultraviolet (UV) irradiation or supercritical fluid technology are analyzed, which makes up for the blank of review articles in this field. Finally, the above-mentioned chemical modification methods are possible research opportunities for the wettability transformation of APTL.     

Electrostatics of granules and granular flows: A review

In past decades, the electrostatics of granules and granular flows has obtained more and more attention due to many industrial problems and the associated development of new technologies. Granule-wall collision causes electrification, where charge transfer can be characterized by work function, electron transfer, ion transfer, and material transfer. Electrification is affected by many factors and increases with granule processing, and the charge amount can reach a saturated state where electrification no longer increases, which has been confirmed by single granule and granule conveying systems. In addition, the presence of electrostatic charges has profound influences in relevant areas, including chemistry, chemical engineering, energy, pharmaceuticals, and so on. The measurement technology of electrostatics used in granule conveying systems has been improved with the continuous progress of industry. Furthermore, electrostatics of granules and granular flows will be developed into a more accurate area together with other subjects as an interdisciplinary problem to be concerned. In addition, in the pneumatic conveying system, granule-wall and granule-granule collision or friction can cause material transfer due to material breakage. The working mechanism of the material transfer due to collision or friction has never been fully understood. Such problems will be solved gradually in the future.     

亚甲基蓝对直流电镀纳米孪晶铜组织及力学性能的影响

纳米孪晶铜具有高强高导高韧的优异性能,使其成为近年来电子封装领域的研究热点.众所周知,添加剂在直流电镀过程中对镀层质量起着至关重要的作用.亚甲基蓝作为一种常用的染料型添加剂,在电镀铜行业中被广泛使用.该研究在直流电镀过程中,将不同浓度的亚甲基蓝添加到纳米孪晶铜电解液中,并进一步研究纳米孪晶铜的微观组织和力学性能与亚甲基...     

Surface Density of Cobalt Single Atoms Manipulating Hydroxyl Radical Generation Via Dual Pathways: Electrons Supply and Active sites

Photocatalytic generation of ^•OH from O₃ is an intriguing avenue for aqueous organics degradation due to the high utilization of photogenerated electrons, but ambiguous information about charge transfer and surface-active sites hinders the optimization of photocatalysts. In this work, a series of cobalt single-atom catalysts (SACs) anchored on graphitic carbon nitride to improve ^•OH generation from O₃ via electron reduction and catalytic activation dual pathway is synthesized. Various characterization and density functional theory calculations reveal that cobalt single atoms can introduce trap states for holes, which improve the light-harvesting ability and accelerate the transfer of electrons and holes. Meanwhile, Co single atoms can also act as active sites to accelerate ozone decomposition and produce ^•OH directly. Particularly, the influence of different surface densities of Co single atoms on photogenerated electron supply and surface reaction is disclosed. A higher density of Co provided more active sites for O₃ catalytic activation, but the narrowed distance between oxidation and reduction centers reduces the supply of available electrons by worsening the charge recombination. This work offers an atomic-level correlation of the isolated metal density and photocatalytic properties, and can scientifically guide the design of high-performance photocatalysts for organic synthesis and water purification.     

Co-Combustion of Oil Sludge Char and Brown Coal in a Continuous Fluidized-Bed Combustor

For developing technologies for innocent disposal of/energy recovery from high-ash oil sludge char (OSC), it was continuously combusted in a 10 kg h⁻¹ fluidized-bed combustor. Addition of brown coal (BC) improved its combustion, but excessive BC was prone to cause slagging. Fine coke particles in OSC and volatiles in BC led to staged temperatures along the fluidized bed through air-staging co-combustion, enabling excellent combustion performance as well as efficient NO_x reduction, especially when coupled with selective non-catalytic reduction. Thus, there is a potential to cleanly recover energy from OSC by its co-combustion with BC.     

Combustion synthesis of lanthanum oxide supported Cu,Ni, and CuNi nanoparticles for CO2 conversion reaction

The reverse water gas shift (RWGS) process is considered a feasible method for lowering greenhouse gas emissions by utilizing CO₂ and converting it to CO. Herein, we evaluated the catalytic conversion of CO₂ through the RWGS reaction over transition metal nanoparticles supported on lanthanum. Catalysts of selected active metals (Cu, Ni, and CuNi) on lanthanum oxide support were investigated in a packed bed tubular reactor within a temperature range of 100–600 °C to assess their catalytic activity and selectivity towards CO. The results of the catalyst's activity and stability experiments showed maximum CO₂ conversions of 57%, 68% and 74% for Cu–La₂O₃, Ni–La₂O₃, and CuNi–La₂O₃, respectively, at 600 °C and excellent stability over a 1440-min time on stream (TOS) with a carbon deposition rate of less than 3 wt%. However, among all investigated catalysts, only the 1 wt% Cu–La₂O₃ catalyst displayed a CO selectivity of 100% at all the studied temperatures, whereas the nickel-containing catalysts showed selectivity for methane along with carbon monoxide. Furthermore, the morphological properties of the support and catalysts, as well as the effect of the reaction conditions on the catalysts surface, were studied using a variety of techniques, including XRD, TEM, SEM-EDX and TPR. The results showed promising potential for the application of transition metal catalysts on lanthanum oxide support for RWGS that could be extended to other hydrogenation reactions.