The hydrogen economy, fuel cells, and electric cars

Hopes have again been raised about developing a “hydrogen economy”, in which hydrogen could be expected to replace oil and natural gas for most uses, including transportation and heating. It is again being claimed that hydrogen will be a widely available, clean, safe fuel. This article argues that such expectations are almost certainly illusory. Hydrogen, like electricity, is not an energy resource but an energy carrier. It takes more energy to extract hydrogen from water than burning the hydrogen can ever provide. There are also inevitable losses in storage, transmission, and final mechanical or heating applications. The question then turns on the efficiency—and safety—of the entire chain of conversion, from the energy source (fossil, solar, or other) to the final use. Moreover, energy sources (preferably renewable, for the long term) can be used for the direct creation of electricity, which can be introduced into the existing grid without requiring a vast investment in a new hydrogen distribution system. In addition, a hydrogen-based system would be unacceptably dangerous. This report will present a detailed technical and economic analysis of the problems with the proposed hydrogen economy and the advantages of some alternatives, principally electricity-based. A hypothetical case of what would be required for a hydrogen filling station serving the general public is closely examined.     

水泥工业碳减排路径分析

介绍了目前国内的碳中和背景及发展现状,并基于水泥产业碳排放的相关数据,对该行业碳减排的方法和途径进行分析。水泥工业90%的二氧化碳排放来自熟料生产(碳酸钙分解、燃料燃烧),其余的10%来自原材料的准备和水泥制品的生成。指出发展创新减排燃烧、节能降耗技术、提高替代燃料掺烧量以及二氧化碳的捕集、封存与利用（CCUS）,是实现水泥产业碳中和的主要手段。     

合成气制烃的催化过程和催化剂发展动态

4 合成气直接制烃催化剂提高合成过程竞争力的总趋势是控制选择性,开发定向合成催化过程和催化剂。目的产品是液体燃料汽油、柴油,化工原料乙烯、丙烯、异丁烯等低碳烯烃以及裂解原料低碳烷烃。4.1 合成低碳烯烃     

Interaction of Two Diffusion Flames Spreading Along a Metal Substrate Wetted with Different Fuels

The paper reports an experimental and theoretical study of the interaction of two diffusion flames propagating over the surface of two different liquid fuels applied to both sides of a thin metal substrate. It is shown that in this system, there may be formation of a unified complex — a doublesided flame which has the properties of a steadystate flame with a peculiar structures. Some velocity and structural dependences for doublesided flames are determined. A mathematical model for a doublesided flame is proposed that adequately describes experimental relations. A physical model for a doublesided flame with a pulsating flame of the heavier fuel is formulated.     

陶瓷烧成中SOx的排放及降低SOx的方法

本文分析了陶瓷烧成过程中S0x的主要来源以及降低SOx排放的方法。同时，还简要介绍了目前主要的几种SOx排放处理方法．并对减少我国陶瓷窑炉燃烧带来的污染提出几点建议。     

A review of nanofluid heat transfer and critical heat flux enhancement—Research gap to engineering application

As a novel strategy to improve heat transfer characteristics of fluids by the addition of solid particles with diameters below 100 nm, nanofluids exhibit unprecedented heat transfer properties and are being considered as potential working fluids to be used in high heat flux systems such as electronic cooling systems, solar collectors, heat pipes, and nuclear reactors. The present paper reviews the state-of-the-art nanofluid studies on such topics as thermo-physical properties, convective heat transfer performance, boiling heat transfer performance, and critical heat flux (CHF) enhancement. It is indicated that the current experimental data of nanofluids thermal properties are neither sufficient nor reliable for engineering applications. Some inconsistent or contradictory results related to thermo-physical properties, convective heat transfer performance, boiling heat transfer performance, and CHF enhancement of nanofluids are found in data published in the literature. No comprehensive theory explains the energy transfer processes in nanofluids. To bridge the research gaps for nanofluids' engineering application, the urgent work are suggested as follows. (1) Nanofluid stability under both quiescent and flow conditions should be evaluated carefully; (2) A nanofluid database of thermo-physical properties, including detailed characterization of nanoparticle sizes, distribution, and additives or stabilizers (if used), should be established, in a worldwide cooperation of researchers; (3) More experimental and numerical studies on the interaction of suspended nanoparticles and boundary layers should be performed to uncover the mechanism behind convective heat transfer enhancement by nanofluids; (4) Bubble dynamics of boiling nanofluids should be investigated experimentally and numerically, together with surface tension effects, by considering the influences of nanoparticles and additives if used, to identify the exact contributions of solid surface modifications and suspended nanoparticles to CHF enhancement in boiling heat transfer. Once we acquire such details about the above key issues, we will gain more confidence in conducting application studies of nanofluids in different areas with more efficiency.     

Ion Exchange Technology in Spent Fuel Reprocessing

Solvent extraction is the major unit operation employed in spent nuclear fuel reprocessing. The operation yields three streams; fission product waste, uranium product and plutonium product. Ion exchange is primarily used in reprocessing as a tail-end method to concentrate and isolate the plutonium product stream. This review will describe the details of plutonium recovery and purification by both cation- and anion-exchange processing. A brief overview of miscellaneous uses of ion-exchange employed in reprocessing will also be given.     

Development of Computer Code SAFFRON for Evaluating Breached Pin Performance in FBR's

In order to evaluate the breached pin behavior in FBR, the breached pin performance analysis code SAFFRON was developed. Based on the results of run-beyond-cladding-breach test in EBR-II as a collaborative program between PNC and U.S. DOE, the following behaviors were taken into cosideration; fuel sodium reaction product (FSRP) formation, resultant fuel expansion, breach extension of cladding and release of delayed neutron precursors into the coolant. Using 3-dimensional elastic analyses by finite element method, breached pin diameter increase is adequately predicted with the reduced Young's modulus of the breached fuel. The delayed neutron signal response in on-line diagnosis was evaluated in relation to the growth of FSRP and breached area enlargement.     

Optical Trappings of ThO2 and UO2 Particles Using Radiation Pressure of a Visible Laser Light

Optical trappings of ThO₂ and UO₂ particles have been first demonstrated in water using the radiation pressure of a TEM₀₀-mode He-Ne laser beam of λ=633 nm. It was observed that a ThO₂ particle was successfully trapped three-dimensionally in the focus region and transferred by moving the focus. On the other hand, for a UO₂ particle of which a refractive index and an extinction coefficient are relatively large in the visible region, only two-dimensional trapping was observed when the beam focus was located near the bottom of the particle. One of the main difficulties in the optical trapping of nuclear fuel particles is attributed to their relatively large absorption coefficients in the visible region. Computational studies on three-dimensional optical trapping performances of absorbing particles were, therefore, perfomed with a simulation code based on geometrical optics. The present calculation can well predict the experimental results on the optical trapping characteristics for ThO₂ and UO₂ particles.