An experimental investigation into the pre-treatment of synthetic membranes using sodium hydroxide solutions

In this paper the effect of two pre-treatment methods are compared experimentally for the filtration of (i) a spent sulphite liquor (17.8 wt.% dry solids) using a 20 kg mol⁻¹ molar mass cut off (MMCO) fluoropolymer membrane and (ii) a molasses solution (45° Brix) using a polysulphone (Psf) membrane (1.5 μm pore size). Both feeds are industrially relevant, and subject to severe fouling issues when membranes are used in their subsequent processing. The pre-treatment methods evaluated were: (i) conditioning with water at 60 °C only [Protocol 1], and (ii) conditioning with water at 60 °C followed by cleaning with 0.5 wt.% NaOH [Protocol 2]. Results are presented that confirm the benefits of sodium hydroxide preconditioning upon performance, supporting the suggestion by some membrane manufacturers that this step be included as part of the pre-treatment protocol.     

Advanced exergoenvironmental analysis of a near-zero emission power plant with chemical looping combustion

Carbon capture and storage (CCS) from power plants can be used to mitigate CO(2) emissions from the combustion of fossil fuels. However, CCS technologies are energy intensive, decreasing the operating efficiency of a plant and increasing its costs. Recently developed advanced exergy-based analyses can uncover the potential for improvement of complex energy conversion systems, as well as qualify and quantify plant component interactions. In this paper, an advanced exergoenvironmental analysis is used for the first time as means to evaluate an oxy-fuel power plant with CO(2) capture. The environmental impacts of each component are split into avoidable/unavoidable and endogenous/exogenous parts. In an effort to minimize the environmental impact of the plant operation, we focus on the avoidable part of the impact (which is also split into endogenous and exogenous parts) and we seek ways to decrease it. The results of the advanced exergoenvironmental analysis show that the majority of the environmental impact related to the exergy destruction of individual components is unavoidable and endogenous. Thus, the improvement potential is rather limited, and the interactions of the components are of lower importance. The environmental impact of construction of the components is found to be significantly lower than that associated with their operation; therefore, our suggestions for improvement focus on measures concerning the reduction of exergy destruction and pollutant formation.     

Integration of calcium and chemical looping combustion using composite CaO/CuO-based materials

Calcium looping cycles (CaL) and chemical looping combustion (CLC) are two new, developing technologies for reduction of CO(2) emissions from plants using fossil fuels for energy production, which are being intensively examined. Calcium looping is a two-stage process, which includes oxy-fuel combustion for sorbent regeneration, i.e., generation of a concentrated CO(2) stream. This paper discuss the development of composite materials which can use copper(II)-oxide (CuO) as an oxygen carrier to provide oxygen for the sorbent regeneration stage of calcium looping. In other words, the work presented here involves integration of calcium looping and chemical looping into a new class of postcombustion CO(2) capture processes designated as integrated CaL and CLC (CaL-CLC or Ca-Cu looping cycles) using composite pellets containing lime (CaO) and CuO together with the addition of calcium aluminate cement as a binder. Their activity was tested in a thermogravimetric analyzer (TGA) during calcination/reduction/oxidation/carbonation cycles. The calcination/reduction typically was performed in methane (CH(4)), and the oxidation/carbonation stage was carried out using a gas mixture containing both CO(2) and O(2). It was confirmed that the material synthesized is suitable for the proposed cycles; with the very favorable finding that reduction/oxidation of the oxygen carrier is complete. Various schemes for the Ca-Cu looping process have been explored here that would be compatible with these new composite materials, along with some different possibilities for flow directions among carbonator, calciner, and air reactor.     

废纸脱墨浆生产线中胶黏物的分布调查

在脱墨浆生产线典型部位取样分离的纤维组分和细小组分,通过采用四氢呋喃（THF）进行抽提分析,对废纸脱墨浆生产线典型部位浆料的水相中的黏性物质进行了分布调查。结果表明：从卸料塔到流浆箱,浆料中纤维组分和细小组分的THF抽出物分别降低了约74%和35%;溶解与胶体物质（DCS）的含量降低了约57%。     

酶在合成纤维化学加工中的应用

酶在纺织加工中的应用始于1857，当时人们利用麦芽的提取物在织物印花前去除它上面的淀粉浆。1912年以前，只有淀粉酶这一种商品化的酶。德国慕尼黑的Diaman公司于1900年推出名为Diastator的酶，并证实了这种酶对淀粉退浆更有效，而且避免了原来用硫酸处理时所引起的损     

全球合成纤维生产停滞

据日本化学纤维协会估计,2005年世界化学纤维产量(不包括聚烯烃)达3 410万t( 0.8%),比2004年多25万t.2005年全球纺织纤维产量为6 050万t(-1.4%),3年中首次减少(表1).2004年产量增幅高达16%,2005年产量下降的部分原因是对这种高增幅的反作用.     

Biodiesel fuel production by transesterification of oils

Biodiesel (fatty acid methyl esters), which is derived from triglycerides by transesterification with methanol, has attracted considerable attention during the past decade as a renewable, biodegradable, and nontoxic fuel. Several processes for biodiesel fuel production have been developed, among which transesterification using alkali-catalysis gives high levels of conversion of triglycerides to their corresponding methyl esters in short reaction times. This process has therefore been widely utilized for biodiesel fuel production in a number of countries. Recently, enzymatic transesterification using lipase has become more attractive for biodiesel fuel production, since the glycerol produced as a by-product can easily be recovered and the purification of fatty methyl esters is simple to accomplish. The main hurdle to the commercialization of this system is the cost of lipase production. As a means of reducing the cost, the use of whole cell biocatalysts immobilized within biomass support particles is significantly advantageous since immobilization can be achieved spontaneously during batch cultivation, and in addition, no purification is necessary. The lipase production cost can be further lowered using genetic engineering technology, such as by developing lipases with high levels of expression and/or stability towards methanol. Hence, whole cell biocatalysts appear to have great potential for industrial application.     

浅谈燃料乙醇生产技术进展

简述了燃料乙醇－作为一种可再生能源，它可减少环境的污染，被称为“清洁燃料”及它在国外的使用情况；并重点介绍了燃料乙醇的几种生产技术方法。     

经编机成圈机构的运动学分析

采用UG软件建立高速经编机传动及成圈机构的CAD模型,通过UG/Motion模块对其进行运动学仿真,并分别分析了槽针、针芯、梳栉这3个主要成圈部件的相对运动关系,得出了能够正确实现成圈运动的配合关系曲线。在此基础上,指出了梳栉最佳横移时间以及成圈机构的运动特性对经编机运行的影响。     

Physicochemical aspects of synthetic food production]

The authors discuss the general approach to the problem of the protein architecture and the working of proteins to synthetic foods. They present the main results from relevant studies on the compatibility and interactions of proteins and polysaccharides in aqueous media and deal with possibilities of influencing the structure formation and the physical properties of gels of given composition.     

An investigation of sources of Campylobacter in a poultry production and packing operation in Barbados

Chicken meat is frequently contaminated with Campylobacter jejuni and is thought to be the major source of organisms causing human Campylobacter enteritis. Genotypic similarities between Campylobacter isolates from chicken meat at retail outlets and patients with gastroenteritis in Barbados suggested that it is a vehicle for infection of humans on the island and prompted this investigation of transmission of Campylobacter in a local poultry operation. Campylobacter testing was conducted at the hatchery, on the broiler farm and in the processing plant for two consecutive production cycles. The genetic relatedness of Campylobacter isolates was determined by RAPD typing with primer OPA 11. Hatchery samples and week-old chicks were negative for Campylobacter. Flocks became colonized as early as three weeks after introduction to the farm. Ten distinct RAPD genotypes were identified among isolates. Some genotypes were similar and may be of clonal origin. There was no evidence of vertical transmission of Campylobacter. The results suggest that the broiler flock was infected from more than one source in the farm environment.     

生物柴油微波裂解脱羧制备烃类燃料的研究

本文以生物柴油为原料制备生物柴油钠皂,在不同微波反应条件下,研究了空气和氩气中对生物柴油钠皂裂解脱羧的影响。对液体烃类裂解产物进行GC–MS分析,不加入催化剂,空气中裂解主产物为长链烯烃,氩气中为短链烯烃;加入催化剂,空气和氩气条件下主产物均为短链烯烃。研究结果表明,微波优先裂解极性羧基端,然后裂解C=C双键附近的C–C单键;氧气能够加快脱羧反应的速率;催化剂促进C=C双键附近C–C单键的断裂并促进芳香烃的生成。     

薯类原料生物转化燃料乙醇研究进展

对我国红薯、木薯和马铃薯转化燃料乙醇的发展现状及存在的问题进行了综述.论述了3种原料的生物学特性、种植情况及其燃料乙醇的生产工艺进展,比较了3种原料生产燃料乙醇的经济参数,对当前我国燃料乙醇产业发展提出了建议并展望了薯类乙醇发展的未来.对我国燃料乙醇产业的发展有一定指导意义.     

化学法生物柴油生产工艺改进研究

以棉籽油为原料,探讨了化学法制取生物柴油过程中以吸附剂处理替代水洗干燥的精制工艺.通过正交试验研究了吸附剂处理对生物柴油质量的影响.结果表明:在吸附剂用量、混合时间和吸附温度3个因素中,吸附剂用量影响最大,其次为混合时间,吸附温度的影响最小.用1.5%和2%吸附剂在70 ℃下搅拌处理20～25 min后的产品质量明显强于吸附剂其他处理方式得到的生物柴油产品质量,主要指标能达到中国生物柴油国家标准<柴油机燃料调合用生物柴油(BD100)>的相关要求.     

2009年全球化学纤维产量结构

<正>据日本化学纤维协会(JFCA)预计,2009年世界化学纤维(不含聚烯烃和醋酯卷烟过滤嘴丝束)产量增长了7%(增加270万t),达4140万t(表1)。中国化学纤维产量增长了14.7%(增加226万t),     

食品蛋白质的化学改性研究进展

综述了酰化作用、去酰胺作用、磷酸化作用、糖基化作用、共价交联作用等食品蛋白质的化学改性技术及方法。     

Morphological investigation of chemical peel on photodamaged facial skin

Chemical peeling involves the topical application of a wounding agent with the goal of effecting an organized regeneration of the skin. The histological and ultrastructural features of actinic- and age-related damage include structural abnormalities that disrupt normal epidermal and dermal architecture. In the present study, five patients with actinically damaged skin underwent an enhanced medium depth peel using 70% glycolic acid and 35% trichloroacetic acid. Biopsy specimens were taken before the peel, and 3 months after the peel for histological and electron microscopic examination. Clinical resolution of actinic damage corresponded with restoration of epidermal polarity. Characteristic histological and ultrastructural features of the skin after peeling include markedly decreased epidermal intracytoplasmic vacuoles, decreased elastic fibres, increased activated fibroblasts and organized parallel arrays of collagen fibrils. We conclude that electron microscopic studies after a medium depth peel of photodamaged skin reveal more profound changes than those seen histologically.     

生物柴油工业化生产的现状及其经济可行性评估

介绍了化学法生产生物柴油的两种主要工艺,对国内外生物柴油生产的经济可行性评估现状进行了综述,分析了影响生物柴油生产成本的4个主要因素,即原料费用、生产工艺、甘油价值和生产规模,并提出了我国发展生物柴油产业的可行办法.还讨论了农场合作型生物柴油厂的运行模式及其经济可行性.