对燃料乙醇的生产过程能量效率的估算

介绍了美国国家可再生实验室对木质纤维素生物质生产燃料乙醇的能量效率的模拟结果,并应用该模拟结果,估算了不同的原料、不同的生产工艺(如糖化发酵时间和精馏方式),各个生产单元的过程能耗。这些估算结果有助于选择较为合适的原料和生产工艺。     

生物质原料供应链技术经济研究进展

生物质原料供应链是生物质资源转化的基础保障，是未来实现大规模生物质能源开发利用的关键所在。本文对生物质供应链相关技术问题进行了分析，分别介绍了生物质原料收获与收集、储存与预处理、运输等技术现状与存在的问题。同时，对供应链的技术经济性进行了综述，对比阐述了国内外采用的研究方法，通过建立定量化的数学模型来优化供应链的技术经济指标是当前研究的主要方式。国内外研究结果显示，生物质原料的收购价格、收集半径和收购模式是影响生物质供应链成本的关键因素。我国由于户均耕地占有面积小，生物质原料分散，生物质供应链是一个复杂的系统工程。在此基础上，进一步对生物质供应链的发展提出了展望，为生物质资源供应链的研究与发展提供参考和借鉴。     

Implications of biodiesel production and utilisation on global climate – A literature review

Over the last few years, the favourable political environment has led to an increasing use of biofuels in the worldwide transportation sector. This development is mainly driven by concerns about the security of energy supplies and the intention to mitigate anthropogenic greenhouse gases (GHG). However, recently, the sustainability of a broad biofuel production and use has, in particular, been strongly questioned. Against this background, in this study a literature review on available and recently published life cycle assessment (LCA) studies for biodiesel has been carried out and the potential GHG emission savings from biodiesel production and use compared to fossil diesel have been analysed. The results of the reviewed studies underline the significant influence of the effects of land use change and the importance of avoiding the conversion of natural land into agricultural areas. If no land use change takes place, the results show moderate to good GHG savings for biodiesel (depending on the type of converted raw materials as well as on the chosen biomass conversion technology). In particular, the biodiesel feedstock production and the source of energy for the production process strongly influence the overall result of the GHG balance of biodiesel.     

Potential and assessment of lactic acid production and isolation – a review

The majority of commodity plastics is made from petroleum‐based chemicals. Lactic acid serves as a monomer for the production of the biodegradable polymer polylactic acid (PLA). This paper provides a review on the state of the art production and isolation process for lactic acid. Problems in production and isolation have been identified, the relevant results in optimized production are presented in the first part of the paper. In the second part, a decision matrix is used as a guideline for the discussion on the state of research in the isolation and purification of lactic acid. Mechanical unit operations, mass transfer unit operations, reactive separation techniques, and process combinations are reported in the literature. At the end, an economic evaluation of isolation processes such as conventional precipitation, reactive membrane separation, and reactive distillation are presented. © 2017 Society of Chemical Industry     

Applications of biofiltration in drinking water treatment – a review

Biofiltration is a process in which an otherwise conventional granular filter is designed to remove not only fine particulates but also dissolved organic compounds through microbial degradation. Biofiltration can reduce the need for chemicals in drinking water treatment and thus improved applications of biofiltration in drinking water treatment can be viewed as green or sustainable engineering technology. Recent trends in biofiltration technology for drinking water treatment have or have attempted to extend the performance of biofilters through gaining a better understanding of operational constraints. This review articles summarizes important operational parameters influencing biofiltration performance such as hydraulic loading, empty bed contact time (EBCT), temperature, media type, and backwashing conditions. In addition, recent advancements in biofiltration operations including, ozonation, ammonia removal and the influence of nutrient (nitrogen, phosphorous) supplementation to facilitate carbon removal are explored. ? 2015 Society of Chemical Industry     

生物质能产业现状及发展前景

生物质能的开发利用是发展新型能源的重要选择,是国际可再生能源领域的焦点.本文总结了我国生物质能资源现状及发展潜力,介绍了国外生物质能发展概况并综合评价了我国生物质产业,主要包括沼气产业、生物质液体燃料、生物质发电以及固体成型燃料产业的发展现状,阐述了我国推动生物质能发展的政策环境,展望和预测了我国物质能源的发展前景,并对生物质产业发展提出建议.     

Filtration of biomass with laboratory‐scale submerged hollow fibre modules – effect of operating conditions and module configuration

The filtration behaviour of submerged hollow fibres, the effect of gas flow rate, feed concentration, module configuration and fibre diameter have been assessed by filtration of yeast suspensions. The fouling behaviour of the submerged hollow fibre was affected by the average imposed flux, flux distribution, and local critical flux. The results suggest that stable performance is obtained when the averaged imposed flux (J_mi) is lower than the critical flux (J_cr) although an initial deposition may occur due to the high local initial flux. In addition, the module configuration had a critical influence on filtration performance. Comparison between tight and loose modules indicated that the loose module [1.0 > (fixed ends distance/fibre length) > 0.95] was significantly better than the tight bundle at high feed concentration or low gas flow rates due to reduced inter‐fibre clogging. The study also showed that the smaller fibre was better than the larger fibre for filtration with bubbling with the submerged hollow fibre system. © 2002 Society of Chemical Industry     

Steam‐air blown bubbling fluidized bed biomass gasification (BFBBG): Multi‐scale models and experimental validation

During fluidized bed biomass gasification, complex gas‐solid mixing patterns and numerous chemical and physical phenomena make identification of optimal operating conditions challenging. In this work, a parametric experimental campaign was carried out alongside the development of a coupled reactor network model which successfully integrates the individually validated sub‐models to predict steady‐state reactor performance metrics and outputs. The experiments utilized an integrated gasification system consisting of an externally‐heated, bench‐scale, 4‐in., 5 kWth, fluidized bed steam/air blown gasifier fed with woody biomass equipped with a molecular beam mass spectrometer to directly measure tar species. The operating temperature (750–850°C) and air/fuel equivalence ratio (ER = 0–0.157) were independently varied to isolate their effects. Elevating temperature is shown to improve the char gasification rate and reduce tar concentrations. Air strongly impacts the composition of tar, accelerating the conversion of lighter polycyclic‐aromatic hydrocarbons into soot precursors, while also improving the overall carbon conversion. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1543–1565, 2017     

生物质热解和气化制取富氢气体的研究现状

随着世界能源和环境问题的发展,洁净的氢能源成为备受关注的新能源。目前,生物质热化学法作为制取富氢气体的有效方法而被广泛研究。本文系统地介绍了国内外通过生物质热解和气化制取富氢气体的研究现状,包括热解气化工艺、物料特性、热源类型、反应条件、气化剂及催化剂等对制取富氢气体的影响。重点介绍了不同类型催化剂在生物质热解和气化反应中的应用,以及催化剂在制取富氢气体方面的优势及其作用机理。提出生物质热解和气化制取富氢气体所面临的主要问题是寻求既高效又寿命长的新型或混合型催化剂,或者从工艺、反应器的改进入手,改善催化剂的催化环境,从而解决其失效问题。     

One‐step production of CO‐ and CO2‐free hydrogen from biomass

The reaction between a biomass (cellulose, sucrose, glucose, starch, cotton, or Japanese paper) and NaOH in the presence of water vapor produced pure hydrogen without CO and CO₂ at temperatures in the range 473–623K. The addition of Ni/Al₂O₃ or Rh/Al₂O₃ catalyst to cellulose enhanced the production of hydrogen at <573 K. The reaction between cellulose and NaOH can be written as: C₆H₁₀O₅ + 12NaOH + H₂O = 6Na₂CO₃ + 12H₂. The reactivities of alkali metal hydroxides were: KOH > NaOH ? LiOH. Copyright © 2004 Society of Chemical Industry     

Distillation technology – still young and full of breakthrough opportunities

Throughout history, distillation has been the most widespread separation method. However, despite its simplicity and flexibility, distillation still remains very energy inefficient. Novel distillation concepts based on process intensification, can deliver major benefits, not just in terms of significantly lower energy use, but also in reducing capital investment and improving eco‐efficiency. While very likely to remain the separation technology of choice for the next decades, there is no doubt that distillation technology needs to make radical changes in order to meet the demands of the energy‐conscious modern society. This article aims to show that in spite of its long age, distillation technology is still young and full of breakthrough opportunities. Moreover, it provides a broad overview of the recent developments in distillation based on process intensification principles, for example heat pump assisted distillation (e.g. vapor compression or compression–resorption), heat‐integrated distillation column, membrane distillation, HiGee distillation, cyclic distillation, thermally coupled distillation systems (Petlyuk), dividing‐wall column, and reactive distillation. These developments as well as the future perspectives of distillation are discussed in the context of changes towards a more energy efficient and sustainable chemical process industry. Several key examples are also included to illustrate the astonishing potential of these new distillation concepts to significantly reduce the capital and operating cost at industrial scale. © 2013 Society of Chemical Industry     

国内外生物质能源政策对比研究

介绍了国内外发展生物质能源的政策状况和特点,并对其进行了比较与分析。指出相对于生物质能源发展较快的国家,我国相关政策还不够健全和完善。最后对我国生物质能源政策提出了建议。     

Co‐gasification of woody biomass and sewage sludge in a fixed‐bed downdraft gasifier

Experimental and numerical studies of cogasification of woody biomass and sewage sludge have been carried out. The gasification experiments were performed in a fixed‐bed downdraft gasifier and the experimental results show that 20 wt % dried sewage sludge in the feedstock was effectively gasified to generate producer gas comprising over 30 vol % of syngas with an average lower heating value of 4.5 MJ/Nm³. Further increasing sewage sludge content to 33 wt % leads to the blockage of gasifier, which is resulted from the formation of agglomerated ash. The numerical models were then developed to simulate the reactions taking place in four different zones of the gasifier (i.e., drying, pyrolysis, combustion, and reduction zones) and to predict the producer gas composition and cold gas efficiency. The deviation between the numerical and experimental results obtained was lower than 10%. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2508–2521, 2015     

北京地区生物质能利用工程现状及政策建议

介绍了北京地区可利用的生物质资源量,生物质能利用工程的发展现状,从整体和个体角度阐述了北京地区生物质能利用存在的问题,最后从管理、技术、产业发展等方面对北京市扩大生物质能利用提出了针对性的对策和建议。     

Electrochemical deposition of poly[N,N′‐ethylene–bis(salicylideneiminato)–nickel(II)] nanobelts as electrode materials for supercapacitors

N,N′‐ethylene–bis(salicylideneiminato)]–nickel(II) [Ni(salen)] was synthesized in situ onto the surface of multiwalled carbon nanotubes via a one‐step potentiostatic electrodeposition as one‐dimensional nanobelts. The synthetic process was free of any templates or additives. Potential played a key role in the formation of the poly[N,N′‐ethylene–bis(salicylideneiminato)]–nickel(II)] {poly[Ni(salen)]} nanobelts, and the electrical conductivities of the poly[Ni(salen)] decreased with increasing deposition time. The capacitance values of poly[Ni(salen)] were 272, 195, and 146 F/g at 0.05 mA/cm² for deposition times of 10, 20, and 30 min, respectively. The capacitance of the sample with a particle structure was much lower than that of poly[Ni(salen)] with a nanobelt structure. The poly[Ni(salen)] nanobelts exhibited a better capacitive behavior than the poly[Ni(salen)] particles because the nanobelt structure made access for the charge and ion to the inner part of the electrode easier. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39561.     

Enhanced Multiferroic and Magnetocapacitive Properties of (1 − x)Ba0.7Ca0.3TiO3–xBiFeO3 Ceramics

The structures, Curie temperature, dielectric relaxor behaviors, ferroelectricity, ferromagnetism, and magnetocapacitance of the (1?x)Ba_0.70Ca_0.30TiO₃–xBiFeO₃ [(1?x)BCT–xBF, x = 0–0.90] solid solutions have been systematically investigated. The ceramics have coexisted tetragonal (T) and orthorhombic (O) phases when x ≤ 0.06, coexisted pseudocubic (PC) and O phases when x = 0.065, coexisted cubic and O phases when 0.07 ≤ x ≤ 0.12, PC phase when 0.21 ≤ x ≤ 0.42, coexisted T and rhombohedral (R) phases when 0.52 ≤ x ≤ 0.70, and R phase when x ≥ 0.75. Significantly, composition‐dependent microstructures and Curie temperature are observed, the average grain size increases from 1.9 μm for x = 0, reaches 12.0 μm for x = 0.67, and then decreases to 1.3 μm for x = 0.90. At room temperature, the ceramics with x = 0.42–0.70 show piezoelectric properties and multiferroic behaviors, characterized by the polarization‐electric field, polarization current intensity–electric field, and magnetization–magnetic field curves, the composition with x = 0.67 has maximum polarization, remnant polarization, maximum magnetization, and remnant magnetization of 15.0 μC/cm², 9.1 μC/cm², 0.33 emu/g, and 0.14 emu/g, respectively. In addition, the magnetocapacitance is evidenced by the increased relative dielectric constant with increasing the applied magnetic field (H). With ΔH = 8 kOe, the composition with x = 0.67 shows the largest values of (ε_r(H) ? ε_r(0))/ε_r(0) = 2.96% at room temperature. The structure–property relationship is discussed intensively.