膜分离技术在造纸工业废水回用中的应用

造纸工业是我国水资源消耗大户,造纸废水水量大、有机物含量高、造成的环境污染影响大,对造纸废水治理在全世界范围内都在关注废水回用,提高水循环利用率,减少水资源消耗和废水排放污染。膜分离技术是在一定压力下进行混合液分离的技术,近年来膜分离技术快速发展,在海水淡化、化工、食晶、医药、电子等工业废水处理中应用较多,本文对膜分离技术在国内外造纸工业废水回用中的应用研究进行了介绍,并对膜分离技术在造纸工业废水回用的研究方向进行了论述。     

中国化肥产业现状与近期走势

2007年是我国化肥产业重要的转折时期,分析表明我国化肥产业面临的机遇很多,挑战也很大。目前国际市场需求迫切,国内资源产业蒸蒸日上、技术装备日臻成熟、龙头企业竞争力增强,但是也存在着产业优惠政策取消、产品结构调整、产业投资过热、市场体系建设不完善、化肥需求不明等挑战。预计今后几年中国化肥产业的基本走势将呈现氮肥、磷肥产业分别“硬着陆”和“软着陆”、钾肥产业维持现状、市场体系迟缓建设、农业需求拉动力减弱的基本态势。     

Membrane Technology in Bioprocess Science

Membrane technology plays more and more a crucial role in the purification of biotechnological products. Integration of membrane based unit operations becomes a trend for ongoing process designs. By this, in addition to the well‐established membrane unit operations like microfiltration, ultrafiltration, nanofiltration and reverse osmosis, new membranes, modules and systems were developed in the last years. Herein, the efforts in the area of membrane chromatography should be mentioned as a major research topic. This paper focuses on the state of the art in membrane technology, especially in the field of biotechnology, and on innovative developments in the field of membrane chromatography as well as on process design methods, which are necessary to fulfill the challenges for competitive technologies for the future. To minimize the risk that is inherent in the design of any new process, it is essential to use unit operation models that describe the process behavior accurately. Modeling efforts, which were originally developed for other membrane unit operations, show a great potential for the adaption to new developed membrane technologies.     

Some considerations about bioethanol combustion in oil-fired boilers

The combustion of bioethanol in boilers has been analyzed and compared with conventional liquid fuels. The study includes an experimental evaluation of combustion performance as well as the estimation of the impact of replacing gasoil by ethanol on the thermal efficiency of an industrial boiler.Several works have been dedicated to the study of fuel substitution in internal combustion engines, being the use of gasoil-bioethanol blends in engines a common practice. However, very few studies have addressed the characterization of switching of conventional liquid fuels by bioethanol in boilers.Combustion tests demonstrate significant differences between bioethanol and gasoil flames. Soot, NO_x and SO₂ emissions are significantly lower with ethanol, whereas this fuel can produce higher amounts of CO than gasoil if the burner is not properly adapted. The experimental tests have demonstrated that both the burner and boiler operation should be readjusted or modified as a result of the change of fuel in industrial boilers. If thermal input is to be kept constant, nozzles of larger capacities must be used and the air feeding rate needs to be significantly modified. Also, the flame detector may have to be replaced and the fuel feeding system should be revised due to the enhanced tendency of ethanol to cavitation. Using the same thermal input may not guarantee keeping the same steam production, but some parameters of boiler operation should be modified in order to avoid reductions in the capacity of the boiler when switching from gasoil to bioethanol, such as gas recirculation fraction, steam cooling systems and percentage of oxygen in the exhaust gases.The feasibility of burning bioethanol in gasoil boilers has been analyzed, and the results confirm that fuel switching is technically possible and offers some advantages in terms of pollutants reduction.     

中国微藻生物柴油产业的发展机遇和挑战

介绍了国内外研发微藻生物柴油的动态,预见用工业装置生产微藻生物柴油的技术近几年内将取得重大突破,微藻生物柴油产业将成为一个新兴的替代能源产业.我国微藻生物柴油产业化研究和国际水平基本同步,是一个全新的自主创新领域,提出应抓住微藻生物柴油产业的发展机遇.对工业化生产微藻生物柴油的光生物反应器设计技术、微藻培养控制系统、配...     

膜分离技术在石油化工领域的应用

膜分离技术是通过扩散系数不同达到气体分离的新兴分离技术,在近十几年得到了快速度发展。因其装置结构简单、维护费用低、能耗小等特点逐步在石油化工行业推广应用。综述了膜分离技术在油气回收、石油产品生产加工等领域的实际情况,分析了膜分离技术的应用现状,并对膜分离技术的应用前景进行了展望。     

Membrane‐Based Hybrid Processes: A Review

Abstract

It has been widely recognized that membrane separation processes can offer many advantages over conventional mass transfer processes. A large number of membrane separation processes are currently being practiced in various sectors of industries. Despite the advantages, membrane processes often suffer from shortcomings when used individually. To overcome such limitations, membrane‐based hybrid processes have been developed to maximize the productivity of the target separation processes. In this review, the membrane hybrid processes reported in the literature are classified into several categories and chosen examples of the processes are presented to show the general trends in the development of membrane‐based hybrid processes.     

制造产业面临的新挑战(上)

介绍由美国国家研究委员会编写,由美国科学院出版社出版的报告《２０２０ 年想像中的制造产业面临挑战》。制造产业企业要在 ２０２０ 年的竞争环境下取得成功,就必须在能力上有很大的改进以迎接挑战,该报告提出六大挑战和相应的技术措施,它们是：同时并行制造、人力和技术资源集成、信息转变为知识、环境兼容性,可再行构筑的企业和创新工艺     

Wind-Aided Intensified eVaporation (WAIV) and Membrane Crystallizer (MCr) integrated brackish water desalination process: Advantages and drawbacks

Due to the increasing of water shortage problems, the need for inland brackish water RO will continue to increase in future. However, the primary limitations to further application of RO inland are the cost and technical feasibility of concentrate disposal. In this work, Membrane Crystallizer (MCr) and Wind-Aided Intensified eVaporation (WAIV) technologies have been applied in order to mitigate the impact of concentrates on the environment. In particular, the research activity has been carried out on a desalination system in which brackish water was first pre-treated, then desalinated through reverse osmosis (RO) operation. Finally, RO concentrates were further treated in WAIV and MCr units. The effect of the presence of organic contaminants and antiscalants were studied by analysing RO operations working at different recovery factors and with different pre-treatments. In the absence of an antiscalant, RO operates at 75% recovery factor and at a pH low enough to ensure no calcium carbonate precipitation. In the presence of an antiscalant, RO process might work until a recovery factor of 88%. The analysed integrated RO + WAIV + MCr system allowed to reach recovery factors as high as 76.6–88.9% and limit brine discharge to less than 0.75–0.27% of the raw water fed to the system.     

膜生物反应器中膜的清洗研究

对膜生物反应器处理柠檬酸酸洗废水中膜的清洗进行了研究，通过不同的清洗方法对膜通量的恢复程度进行评价。确定了反冲洗时间及反冲洗周期，经过试验研究与分析，在反冲洗的同时结合正洗的清洗方法，效果好于单纯的反冲洗方法；确定了化学清洗剂种类、清洗剂的用量以及化学清洗周期。采用物理清洗与化学清洗相结合的方法，清洗效果很好。保证了MBR的稳定运行。     

过程系统工程的发展和面临的挑战

过程系统工程是一门蓬勃发展中的重要学科。对这门学科的发展沿革做了简略回顾,然后对这门学科所做出的贡献和差距、存在的问题进行了探讨,最后指出过程系统工程在21世纪所面临的挑战及发展机遇。     

Protein Shift – How Membrane Technology Can Contribute

Proteins are not only important for our daily diet but also one of the most important food ingredients worldwide. Since the 1970ies membrane processes have established themselves as a key unit operation in protein processing, e.g., in the dairy industry. The recent trend of the protein shift moving consumption of animal-based to plant-based proteins provides new applications for membrane processes. Thus, in this work, the opportunities to transfer the membrane processing experiences from animal-based proteins to plant-based protein products will be the focus.     

The promise of a technology revolution in cassava bioethanol: From Thai practice to the world practice

The abundance of low-cost feedstock and the cost-effective technology are of great importance for reinforcing industrialization of bioethanol for fuel use as sustainably-sourced and eco-friendly energy. This paper describes improved techniques that increase the root productivity of cassava (Manihot esculenta Crantz) and its conversion to bioethanol by the energy-saving technology being developed in Thailand. The productivity of cassava roots can be significantly increased from 22 to 60 tons/ha simply by applying yield improved varieties and good cultivation practices; important ones are soil plowing, high stake quality, weed control, good planting and harvesting period, land conservation with organic fertilizers and water irrigation. Currently, the world production of cassava is around 220 million tons per annum with the average yield of 12 tons/ha and the total acreage of 18.5 million ha. If the root productivity increases, for instance, by 5 tons/ha, around 90 million tons of roots are produced which can be converted to 15,000 ML of ethanol by Simultaneous Saccharification and Fermentation (SSF) process, a current production process of which cooked and enzymatically-liquefied cassava materials are subjected to saccharifying enzymes and yeasts in concert. The promising energy-saving technology for converting cassava chips to ethanol has also been introduced at a pilot scale by using a granular starch hydrolyzing enzyme in an uncooked process.     

Advances of macroalgae biomass for the third generation of bioethanol production

In recent years, utilization of renewable sources for biofuel production is gaining popularity due to growing greenhouse gas (GHG) emissions which causes global warming. There has been a great effort in exploring alternative feedstock for bioethanol production. In this context, the production of third-generation bioethanol from macroalgae has emerged as an alternative feedstock to food crop-based starch and lignocellulosic biomass. This is mainly due to the fast growth rate of macroalgae, no competition with agricultural land, high carbohydrate content and relatively simple processing steps compared to lignocellulosic biomass. This review paper provides an insight of recent innovative approaches for macroalgae bioethanol production, including conventional and advanced hydrolysis process to produce fermentable sugar, various fermentation technologies, economic analysis and life cycle assessment. With the current technology maturity, efficient utilization of macroalgae as sustainable source for bioethanol and other value-added chemicals production could be achieved in the near future.     

Pervaporative separation of bioethanol produced from the fermentation of waste newspaper

In this study, a hydrophobic polymeric polydimethylsiloxane (PDMS) membrane was used for the pervaporative separation of bioethanol produced from fermentation of lignocellulosic biomass (waste newspaper) and glucose. As a preliminary study, the pervaporation permeation performance showed strong dependence on feed concentration and temperature. The pervaporation of bioethanol produced by the fermentation of waste newspaper by Saccharomyces cerevisiae decreased process performance. However, the process performance was restored reversibly by water cleaning. The pervaporative separation of bioethanol from the fermentation of waste newspaper was carried out without any significant decreasing process performance in the study.     

膜生物反应器膜污染的研究进展

从膜的结构性质、反应器操作条件、处理液微生物性质三个方面介绍了膜生物反应器膜污染机理研究的进展,总结了优化膜生物反应器设计、调节膜生物反应器操作条件、在线超声控制、化学方法等膜污染控制的常用方法,对未来膜污染研究进行了展望。     

膜分离节能技术的国内外应用进展

详述了近年来国内外膜分离技术的进展,尤其是膜分离技术的应用在节能、环保领域和石油、化工行业所取得的成效。     

An investigation of the catalytic abatement of emissions from the combustion of diesel/bioethanol blends

In this study, we investigated the activity of pre-sulfated 1%Pt–2%Sn/γ–Al₂O₃ on the catalytic abatement of the combustion emissions of three fuels: pure diesel E(0), pure bioethanol E(100) and bioethanol blended diesel containing 10% bioethanol E(10). The emissions generated, by each blend combustion, were conducted continuously to the catalyst sample. The catalytic activity was determined by following the evolution of the outflow emissions concentrations by FTIR gas spectroscopy as a function of the catalyst temperature. Results showed that the addition of bioethanol to diesel may be necessary to enhance the catalytic oxidation of diesel unburned hydrocarbons and particulate matter on pre-sulfated 1%Pt–2%Sn/γ–Al₂O₃.