Kellogg合成氨工艺进展

综述了以先进合成氨工艺和转化换热系统技术为代表的Ｋｅｌｌｏｇｇ第二代合成氨工艺，较详细介绍了钌基催化剂和转化换热器。     

论合成氨尿素装置减排CO2节能创新工艺发展前景

随着国家资源税和排碳税的开征,节能减排成为合成氨尿素生产企业生存发展的重要出路。介绍了轻烃多气流纯氧自热转化的节气、增产、减排CO2创新工艺的工艺原理、技术特征以及天然气合成氨装置的扩改方案;阐述了天然气三一段换热转化制合成氨的工艺流程设计以及蒸汽转化炉、换热转化炉、二段自热转化炉等主要设备的专有技术特点;以300 t/d合成氨装置为例,论述了天然气一段转化等压一次变换联尿装置的设计规模、单元组成、工艺流程和生产开车原则。结果表明,该创新工艺比传统法工艺增产20%~100%,节气20%~30%,减排CO220%~80%,老厂改造或新建装置皆可采用。     

合成氨装置扩能改造总结

合成氨厂分2期对2套合成氨装置进行配套扩能改造,以新老系统转化工序实施“并联换热式转化”工艺为重点,在不改变原外加热式箱式一段炉转化工艺的前提下,采用并联换热式转化工艺,使转化工序的生产能力达到160kt／a,为合成氨生产装置能力由96．5kt／a扩能改造到160kt／a奠定了坚实基础,并为联碱厂由285kt／a扩能改造到450kt／a提供了强有力的支撑。     

小型合成氨厂节气节能工艺评价 (Ⅰ)外热式蒸汽转化工艺

作者从工程开发设计的观点出发,对世界上主要8种天然气蒸汽转化工艺用于小型合成氨厂的节气节能改造进行评价。本刊将分8个专题向读者介绍。本文对“外热式蒸汽转化工艺”用于改造以间歇蒸汽转化工艺生产合成氨小厂时的工艺流程、主要原料消耗、技术经济指标进行了研究计算、分析和比较,为国内105家以天然气为原料的小型合成氨厂节气节能改造的方案选择提供依据。     

焦炉煤气净化及合成氨工艺的改进

在焦炉煤气净化及合成氨工艺中,采用了一系列新技术,对合成氨煤气进行脱硫、脱碳和甲烷转化.新工艺流程短,能耗低,合成氨产量高,经济效益好,实现了废水零排放.     

小型合成氨厂节气节能工艺评价 (Ⅶ)换热式并联蒸汽转化工艺

作者对“换热式并联蒸汽转化工艺”用于改造以间歇蒸汽转化工艺生产合成氨小厂的工艺流程、主要原料消耗、技术经济指标和风险性进行了研究、计算、分析和比较。为国内105家以天然气为原料的小型合成氨厂节气节能改造的方案选择提供依据。     

小型合成氨厂节气节能工艺评价 (Ⅷ)换热式转化深冷净化工艺

作者对“换热式转化深冷净化工艺”用于改造以间歇蒸汽转化工艺生产合成氨小厂的工艺流程、主要原料消耗、技术经济指标和风险性进行了研究、计算、分析和比较,为国内105家以天然气为原料的小型合成氨厂节气节能改造的方案选择提供依据。     

合成氨转化燃料气系统自控系统设计

分析了合成氨装置转化燃料气部分的工艺过程,重点讨论了燃料气系统中的部分控制方案和联锁设计.结果表明:合成氨装置转化燃料气系统工艺过程设计合理,仪表联锁与控制方案设计合理,既能够满足正常的工业生产,又有效合理的从安全角度起到了保护设备的作用.     

合成氨转化燃料气系统自控系统设计

分析了合成氨装置转化燃料气部分的工艺过程,重点讨论了燃料气系统中的部分控制方案和联锁设计。结果表明:合成氨装置转化燃料气系统工艺过程设计合理,仪表联锁与控制方案设计合理,既能够满足正常的工业生产,又有效合理的从安全角度起到了保护设备的作用。     

降低蒸汽转化法合成氨装置生产成本的有效途径

根据蒸汽转化法制氨过程的工艺特点，从降低合成气中CH4含量的角度出发，对降低合成氨生产能耗与成本的途途进行深入分析。在此基础上，提出了PSA与化学法的组合净化工艺，对应用组合净化工艺进行合成氨装置扩能改造的可能性和新型合成氨工艺的技术经济效果进行了初步探讨。     

民用工业中复合材料桁架的应用和发展

本文叙述了复合材料桁架的构造、分类和计算方法,突出了复合材料桁架的优越性能和在民用工业中的应用前景;在分析大量文献资料的基础上阐述复合材料桁架杆件的多种加工工艺,并比较不同截面形式对杆件性能的影响;探讨复合材料杆件的破坏机理和分析方法,介绍节点的类型和各自的特点,提出节点及连接部位存在的关键问题;根据国内外复合材料桁架的研究和应用现状,阐述了复合材料桁架的性能和不同的设计方法,总结归纳影响复合材料桁架性能的关键因素和设计中存在的一些问题,并提出改进杆件设计、节点设计和优化复合材料桁架的建议。     

Enzymes-Assisted Extraction of Plants for Sustainable and Functional Applications

The scientific community and industrial companies have discovered significant enzyme applications to plant material. This rise imparts to changing consumers’ demands while searching for ‘clean label’ food products, boosting the immune system, uprising resistance to bacterial and fungal diseases, and climate change challenges. First, enzymes were used for enhancing production yield with mild and not hazardous applications. However, enzyme specificity, activity, plant origin and characteristics, ratio, and extraction conditions differ depending on the goal. As a result, researchers have gained interest in enzymes’ ability to cleave specific bonds of macroelements and release bioactive compounds by enhancing value and creating novel derivatives in plant extracts. The extract is enriched with reducing sugars, phenolic content, and peptides by disrupting lignocellulose and releasing compounds from the cell wall and cytosolic. Nonetheless, depolymerizing carbohydrates and using specific enzymes form and release various saccharides lengths. The latest studies show that oligosaccharides released and formed by enzymes have a high potential to be slowly digestible starches (SDS) and possibly be labeled as prebiotics. Additionally, they excel in new technological, organoleptic, and physicochemical properties. Released novel derivatives and phenolic compounds have a significant role in human and animal health and gut-microbiota interactions, affecting many metabolic pathways. The latest studies have contributed to enzyme-modified extracts and products used for functional, fermented products development and sustainable processes: in particular, nanocellulose, nanocrystals, nanoparticles green synthesis with drug delivery, wound healing, and antimicrobial properties. Even so, enzymes’ incorporation into processes has limitations and is regulated by national and international levels.     

Preparation and surface-active properties of the sodium soaps,mono- and diethanolamides and diol and triol sulfates of cycloaliphatic C21 Di- and C22 Tricarboxylic acids

Cycloaliphatic C₂₁ di- and C₂₂ tricarboxylic acids were prepared by the Diels-Alder reaction of dehydrated castor oil (DCO) fatty acids (containing 48% conjugated and 42% nonconjugated dienes) with acrylic and fumaric acids, respectively. The reaction temperature, time, catalyst concentration, and mole ratio of reactants were varied to get maximum yields of the di- and tricarboxylic acids. The unreacted DCO fatty acids were removed from the products by partition between aqueous methanol and n-hexane. The products were converted to methyl esters and characterized as the substituted cyclohexene derivatives before and after dehydrogenation with Pd/C in xylene, hydrogenation with Pd/C in decalin and oxidation with periodate-permanganate reagent and by mass and proton nuclear magnetic resonance spectrometry. The acids were converted to sodium soaps, mono- and diethanolamides and the corresponding diol and triol sulfates, and the resulting products were evaluated for their surface-active properties. The sodium soaps showed better calcium tolerance and poorer foaming power than sodium oleate. The diethanolamides were inferior to lauroyl diethanolamide in wetting and emulsifying power. The monoethanolamides were better than the respective diethanolamides and lauroyl diethanolamide in wetting property. The diol and triol sulfates were poorer in wetting and emulsifying ability and better in calcium tolerance than sodium lauryl sulfate.     

COMBINED INNOVATIVE HEAT PUMP DRYING TECHNOLOGIES AND NEW COLD EXTRUSION TECHNIQUES FOR PRODUCTION OF INSTANT FOODS

There is an increased demand for convenient foods including ready-to-eat and instant products. These products are desired with minimum concentration of synthetic chemicals. This creates challenges for the food industry and dryers manufactures to develop new technologies to process difficult-sensitive materials and to supply final products with high quality and improved properties. Fruits and vegetables are mainly composed of water, carbohydrates, proteins and lipids. Due to modification of chemical and physical bonds the compounds the material becomes viscous and sticky during processing. Conventional dryers have limitations in handling such sensitive materials. Heat pump dryers have been applied in the production of a diversity of ready-to-eat foods and dried instant products for the last five years at SINTEF-NTNU. Besides being energetically efficient and environmentally friendly, the heat pump drying technology provides a wide range of drying conditions as required to produce powders with improved characteristics. This work describes the new technologies and processing line for the production of instant foods as well as the measurements on the properties and quality attributes for raw, intermediate and final instant products.     

Effects of Extraction Temperature and Preservation Method on Functionality of Soy Protein

The effects of extraction temperature and preservation method on the functional properties of soy protein isolate (SPI) were determined. Four extraction temperatures (25, 40, 60, and 80 °C) were used to produce SPI and yields of solids and protein contents were determined. Three preservation methods were also tested (spray-drying, freeze-drying, and freezing–thawing) and compared to fresh (undried) samples for each extraction temperature. No differences in yields of solids and protein were observed among SPIs extracted at 25, 40, and 60 °C; however, SPI extracted at 80 °C yielded significantly less solids and protein. Extraction temperature significantly affected SPI functionality. As extraction temperature increased, solubility and emulsification capacity decreased; surface hydrophobicities, emulsification activities and stabilities, and dynamic viscosities increased; and foaming properties improved. Preservation method also significantly affected SPI functionality. Drying method did not affect the denaturation enthalpies of SPIs, but spray-dried SPIs had higher solubilities, surface hydrophobicities, and emulsification stabilities, and lower viscosities, emulsification activities and rates of foaming than freeze-dried SPI exhibited. Emulsification and foaming capacities and foaming stabilities were similar for both methods of drying. There was significant interaction between extraction temperature and preservation method for all functional properties except emulsification capacity.     

COMBINED INNOVATIVE HEAT PUMP DRYING TECHNOLOGIES AND NEW COLD EXTRUSION TECHNIQUES FOR PRODUCTION OF INSTANT FOODS

ABSTRACT

There is an increased demand for convenient foods including ready-to-eat and instant products. These products are desired with minimum concentration of synthetic chemicals. This creates challenges for the food industry and dryers manufactures to develop new technologies to process difficult-sensitive materials and to supply final products with high quality and improved properties. Fruits and vegetables are mainly composed of water, carbohydrates, proteins and lipids. Due to modification of chemical and physical bonds the compounds the material becomes viscous and sticky during processing. Conventional dryers have limitations in handling such sensitive materials. Heat pump dryers have been applied in the production of a diversity of ready-to-eat foods and dried instant products for the last five years at SINTEF-NTNU. Besides being energetically efficient and environmentally friendly, the heat pump drying technology provides a wide range of drying conditions as required to produce powders with improved characteristics. This work describes the new technologies and processing line for the production of instant foods as well as the measurements on the properties and quality attributes for raw, intermediate and final instant products.     

Environment and colour: The technological interface

Technology and colour are viewed as interfaces between the environment, humans and human activity. Examples are provided of ways of facilitating and improving access to and use of colours by commercial users of colour coatings through improvements in the accuracy of measuring and displaying colour. By analogy, the task of providing effective interfaces within the coatings industry, between the coatings industry and the environment and between the coatings industry and the public and political domain are discussed. Examples of information shortfalls are cited to illustrate how distortions arise. Examples of more effective, integrated technological, organisational and political interfacing are culled from the author's experiences.     

Role of Douglas fir (Pseudotsuga menziesii) carbohydrates in resistance to budworm (Choristoneura occidentalis)

The current year's growth of Douglas fir contains galactose, unusual in that this carbohydrate makes up 78.7% of the total carbohydrate fraction. An agar diet study was undertaken to determine the effects of galactose, other carbohydrates, and terpenes on western spruce budworm larval mortality, growth rate, and adult biomas production. All concentrations of the carbohydrates and terpenes tested, as well as other mineral elements not tested, were typical of the current year's foliage of Douglas fir. In experiment I, the diet containing 5.61% total carbohydrate did not significantly affect larval mortality when compared to the control diet. However, diets containing 9.45% and 15% total carbohydrate concentrations significantly increased larval mortality 64% and 96.1%, respectively, when compared to the control. Also in experiment I, terpenes alone (78.9% morality) and terpenes in combination with 9.45% and 15% total carbohydrates significantly increased larval mortality (97.2% and 100%, respectively) when compared to mortality on the control diet (44%). To determine which carbohydrate was causing the adverse effect, 6% glucose, 6% fructose, and 6% galactose were placed individually and in combination with terpenes in diets in experiment II. The 6% galactose diet significantly increased larval mortality and reduced growth rate when compared to the control, glucose, and fructose diets. Glucose resulted in 16% less larval mortality, significantly enhanced female larval growth rate and pupal weight, but did not affect male larval growth rate and pupal weight, when compared to the control. Fructose resulted in a significant decrease in larval mortality and a general trend of enhanced female and male larval growth rate and pupal weight. Larval mortality on terpenes alone was not significantly different from the control, but terpenes with 6% galactose increased larval mortality and decreased female and male growth rate and pupal weight significantly when compared to glucose-terpene and fructose-terpene diets. No significant interactions were found between carbohydrates and terpenes in either experiment.     

聚苯胺及其衍生物在杀菌防污领域的应用进展

抗菌剂在涂料、膜、生物智能材料等材料表面的防污领域有着极其重要的应用价值。随着环保意识的增强，长效、环境友好型的抗菌剂成为当前研究的主流。其中，聚苯胺由于其良好的生物相容性和物理化学性能，是一种极具潜力的抗菌剂。聚苯胺的抗菌机理可由自身的氧化还原活性、阳离子吸附效应及电化学活性3方面分析。概括了聚苯胺及其衍生物的结构及制备方法；进一步从杀菌防污机理出发，综述了聚苯胺及其衍生复合材料在不同防污材料中应用的研究进展，包括在接触杀菌型表面、释放杀菌型表面、抗黏附型表面3种类型的材料中的应用。此外，提出了聚苯胺在防污应用中需进一步解决的问题及发展方向。     

离子液体和低共熔溶剂绿色回收废旧锂离子电池的研究进展

温和条件下废旧锂离子电池的绿色高效回收具有重大意义，目前利用离子液体和低共熔溶剂回废旧收锂离子电池的综述报道较少。本综述回顾近年离子液体和低共熔溶剂回收废旧锂离子电池，分析离子液体和低共熔溶剂对不同锂离子电池正极材料回收的差异性，介绍绿色溶剂结构、酸碱性、电池组成、温度、时间、质量比等因素对回收的影响，归纳绿色溶剂回收废旧锂离子电池的热力学和动力学规律及其溶解机制，并指出利用离子液体和低共熔溶剂回收废旧锂离子电池目前存在的一些问题及其提出可能的应对策略。