Review: Recycling of nylon from carpet waste

Large amounts of post‐consumer carpet are discarded every year. Most of this waste is currently landfilled, while a small percentage is incinerated. The face carpet fibers, consisting primarily of nylon 6 and nylon 6,6, represent the majority component in the carpet waste. Recent financial incentives and environmental constraints have motivated the industrial sector to develop recycling strategies for these fibers. Depolymerization into their constituent monomers is the most complex recycling route, but at the same time it produces the most valuable product. A second alternative involves the use of solvents for the extraction of carpet fiber components in their polymeric form. Finally, a third recycling option yields thermoplastic mixtures by melt blending the carpet waste. The recent literature on the recycling of nylon from carpet waste is reviewed in this paper. The paper also includes a section focusing on the current state of carpet recycling at the Industrial level.     

合成纤维的回收再利用技术

综述了废旧服装纺织品、废旧地毯、纤维增强复合材料、车用纺织品中合成纤维的各种回收再利用方法:详述了废旧涤纶及锦纶的化学回收及物理回收再利用技术;指出了我国合成纤维回收再利用的技术瓶颈,并建议我国应集中科研力量开展合成纤维回收再利用关键技术和设备的研究,建立合成纤维回收再利用示范基地。     

Recycling Nylon 6 Carpet to Caprolactam

The recycling of nylon 6 carpet via depolymerization provides the potential for an environmentally benign new process to produce world-class caprolactam. This article describes the depolymerization of nylon 6 carpet in the presence of steam under medium pressure (800-1500 kPa, 100-200 psig). A small laboratory apparatus was set up to demonstrate the feasibility of the scheme. A total of eight runs were carried out using ～180 g of pellitized carpet and 2-6 g/min steam (at 101-1500 kPa, 0-200 psig, and 300-340°C). In our best run at 340°C, 6 g/min of steam, and 1500 kPa (200 psig) for 3 h, we obtained a 95% yield of crude caprolactam. The lactam purity was 94.4%, resulting in an overall 89.7% yield of caprolactam. The laboratory data were used to construct a computer model of the process for both batch and continuous-flow stirred reactors.     

动态循环提取雷公藤总生物碱的过程研究

雷公藤是一种重要的中药材,其有效成分萜类、生物碱可用于治疗类风湿性关节炎等多种疾病.动态循环提取雷公藤生物碱是雷公藤中药生产中的一个重要工段.今用紫外分光光度法分析总生物碱的含量,测定了雷公藤动态循环提取过程中总生物碱浓度和提取时间的关系.并分析了动态循环提取过程的机理,建立了相应的数学模型,该模型仅含一个参数.模型拟合结果与工业操作数据符合良好,可用于工业动态循环提取过程的模拟和优化.     

废旧尼龙制品的循环利用

文章简要总结了尼龙生产和消费概况,归纳出大宗可回收循环利用的尼龙制品主要为地毯和汽车使用的尼龙6和尼龙66材料,针对大宗尼龙消费品介绍了相应的回收工艺和技术,并对其它尼龙品种的回收再生和一些新的处理工艺作了部分介绍。     

满足不同需求的水热电联产系统的模型和设计简

In order to improve the energy efficiency, reduce the CO2 emission and decrease the cost, a cogenera- tion system for desalination water, heat and power production was studied in this paper. The superstructure of the cogeneration system consisted of a coal-based thermal power plant （TPP）, a multi-stage flash desalination （MSF） module and reverse osmosis desalination （RO） module. For different demands of water, heat and power production, the corresponding optimal production structure was different. After reasonable simplification, the process model ot each unit was built. The economical model, including the unit investment, and operation and maintenance cost, was presented. By solving this non-linear programming （NLP） model, whose objective is to minimize the annual cost, an optimal cogeneration system can be obtained. Compared to separate production systems, the optimal system can reduce 16.1%-21.7% of the total annual cost. showing this design method was effective.     

废旧塑料回收利用的现状及发展

随着塑料使用量的大增,废旧塑料己造成了严重的环境污染,同时又蕴含着重要的再生资源。石油和煤不可再生,资源紧缺,从节约地球资源和保护地球环境的角度考虑,目前各国对废旧塑料回收都非常重视,投入大量人力、物力乃至立法,开发各种废旧塑料回收利用的关键技术.废旧塑料回收方法主要有熔融再生,热裂解,能量回收,回收化工原料及其它。主要用途以及技术研究方向有制造燃油、生产防水抗冻胶、制取芳香族化合物、制备多功能树脂胶、防火装饰板、再生颗粒、生产克漏王、制备环保漆、沥青改性材料、流化床气化。相应的设备研制还未跟上。     

液化天然气深冷-膜蒸馏海水淡化系统集成与分析

提出了一种PRICO天然气液化-膜蒸馏（MD）海水淡化系统集成方法,利用PRICO过程压缩机出口的余热驱动MD海水淡化。采用Aspen Plus和GAMS建立了集成系统的数学模型,综合考虑系统的结构、物流物性、设备规模、操作参数等系统设计问题,分析不同设计下系统的投资、能耗、运行费用以及MD单位产水成本。模型应用于一个处理量为1 kmol/s的PRICO天然气液化系统与MD集成的案例研究。计算结果表明,单位产水成本最小时,系统产水成本为1.98 USD/m³,淡水产量为5.78 m³/h,与反渗透等海水淡化技术相比,MD在经济性方面具有较强的竞争力。     

复合材料蜂窝夹芯楔形结构件修补工艺研究

复合材料因其优越性,越来越广泛的应用于航空领域。随着应用的增加,并为了有效的降低成本,复合材料修补技术成为一项急需解决的关键技术。热补仪是目前复合材料修补的主要设备,因具有易携带、易操作、成本低等优点而在复合材料修补中应用最为广泛。本文通过试验和修补实例对热补仪修补的复合材料楔形结构的热补仪的热均匀性进行了系统研究,得出了最佳的修补方法。     

浅析玻璃纤维湿法薄毡生产线粘结剂循环系统

介绍了玻璃纤维湿法薄毡作为现在复合材料行业发展最快的材料之一,广泛应用于屋面防水基材、电路板基材、地毯基材、蓄电池隔板毡的情况,并着重介绍了玻璃纤维湿法薄毡生产工艺中的粘结剂循环系统,分析了粘结剂泵的选型,粘结剂循环罐的液位控制,粘结剂的pH值控制系统及粘结剂的抽吸分离系统。     

无渣皂化生产环氧丙烷新技术的开发

针对环氧丙烷生产中产生的皂化废液的回用进行了一系列实验,包括皂化废液用于氯醇化反应的小试、工业化模拟实验,用电解液作皂化剂的工业化模拟实验,皂化废液的淡化与浓缩实验,浓缩的皂化废液电解模拟实验等,提出了无渣皂化生产环氧丙烷的工业化设计方案：采用氯化钠电解液代替石灰乳液进行无渣皂化生产环氧丙烷,部分皂化废液直接返回氯醇化工序,另一部分皂化废液经过多效减压蒸发分离成浓盐水和淡水;浓盐水经重饱和后送到隔膜电解装置进行电解,产生含NaOH的电解液、Cl2和H2,Cl2返回氯醇化工序作为氯醇化反应原料;淡水返回氯醇化工序代替工业水。由此,环氧丙烷生产装置和隔膜法烧碱生产装置形成一个完整的闭路循环体系,解决了传统的氯醇法环氧丙烷生产中废渣及废水污染的问题。     

Woodlike Properties from Carpet and Textile Fibrous Waste: Mitigating the Coming Landfill Crisis

Large-volume usage of textile and carpet fibrous waste may be achieved with a low-cost material that has woodlike properties. Formulations and properties of composites, laminates, and honeycomb sandwich constructions made from carpet and textile fibrous waste in a high-modulus phenol formaldehyde matrix are described. Using design parameters based on the mechanics of bending beams and the moduli of the fibrous component materials, one can achieve apparent bending moduli of 1 million psi (6.9 GPa) and bending strengths of 10, 000 psi (69 MPa). To achieve these woodlike properties, it is best to use waste carpet material in the core and higher-modulus textile materials such as cotton and polyester in the outer layers. About 20 wt.% phenolic resin is suggested for the matrix component.     

基于智能控制系统的陶瓷球磨机神经网络控制方法的开发

介绍了球磨机负荷智能监控系统的整体结构设计。采用声发射波传感器提取信号，用分布式的微型控制器控制球磨机的运行状态，保证了球磨机的良好运行。同时，笔者基于神经网络的概念具体分析了智能控制系统的控制方法的开发步骤，引入神经网络对球磨机模型进行辨识，通过对物理特性跟踪实现对产量的控制，使其以最小方差保持在最佳值附近，以便实现高产、稳产。     

基于机器学习的塑料分类回收预测系统

塑料分类回收预测系统主要由垃圾接收装置、垃圾预测分类装置、垃圾压缩装置和垃圾回收储存装置4部分组成,其中垃圾预测分类装置凭借提出的塑料预测分类模型执行塑料分类工作。塑料预测分类模型应用深层次的Inception卷积神经网络,提取高度抽象的关键塑料特征。实验结果表明:塑料分类回收预测系统的预测分类准确率高于传统的预测分类模型约2%。     

低碳经济背景下塑料包装的逆向物流回收体系研究

随着低碳经济理念的提出和发展,塑料包装废弃物的回收处理问题逐渐成为人们讨论的热点话题.为解决塑料包装回收问题,垃圾回收站、包装生产商和快递企业等分别作为主导建立了符合低碳经济发展理念的逆向物流回收体系.但目前塑料包装的逆向物流回收体系仍旧存在诸多问题,需要政府、企业、消费者多方合作,不断完善塑料包装逆向物流回收体系,提...     

High-Pressure Reverse Osmosis for Industrial Water Recycling: Permeate-Sided Pressure Drop as Performance-Limiting Factor

In the chemical industry large amounts of saline wastewater occur. Its disposal into rivers is a considerable burden to the ecosystem. To strive for a circular economy and enable a viable raw material recycling, energy-efficient concentration processes are requisite. High-pressure reverse osmosis meets this criterion, but its industrial application demands suitable membrane elements that withstand the exceptional operation conditions and provide sufficient performance. Hence, new requirements regarding the design of spiral-wound elements arise. To identify those, specific performance-limiting effects need a better understanding.     

废旧反渗透膜循环再利用研究现状与进展

随着反渗透（RO）技术在水处理领域的广泛应用,全球每年有数百万计的废旧RO膜组件作为垃圾被处理处置,由此造成了环境污染与资源浪费。本文首先综述了废旧RO膜可能的循环再利用方案和相关的应用案例,为了比较不同循环方式对环境的影响,概述了通过全生命周期分析（LCA）的方法评价不同循环利用方式的环境效益和物质投入的研究进展。文章指出研究结果表明：回收利用废旧RO膜是研究RO膜末端处理的方法之一,其中包括通过使用清洗后的RO膜作为新生RO膜直接再利用、通过化学转化为其他多孔膜材料再循环使用、通过清洗RO膜拆解回收RO膜。另外,LCA在膜工艺中的分析仍以评估使用过程为主,而缺少在膜设计、膜改造和膜回收等关键过程的分析研究。     

反渗透技术在废水处理中应用的研究进展

反渗透技术是一种高效、易操作的液体分离技术,同传统的废水处理方法相比具有处理效果好,可实现废水的循环利用和对有用物质回收等优点。文章简要介绍了反渗透技术的基本原理,重点介绍了反渗透技术在垃圾渗滤液、矿区污水、钢铁工业废水、电厂废水处理中的应用研究进展状况。并讨论了反渗透膜技术的预处理、反渗透膜污染及清洗和反渗透技术的发展前景。     

Measurement of 2-ethyl-1-hexanol emitted from flooring materials and adhesives

It has been reported that 2-ethyl-1-hexanol (2E1H) was emitted through hydrolysis between di-2-ethylhexyl phthalate used as plasticizer in flooring material and moisture generated from a strongly alkaline material such as concrete slab. The purpose of this study was to clarify the relationship between diffusion of 2E1H in flooring material and 2E1H emission rate from floor surface. In this study, we measured 2E1H emitted from floor paper, poly(vinyl chloride) (PVC) tile, cushion floor and carpet for 200,?days and effective diffusion coefficients for 2E1H in various flooring materials were measured. Effective diffusion coefficients of 2E1H for cushion floor and PVC tile were 115?×?10^?9 and 7.8?×?10^?9 m²/s, respectively. Emission rate of 2E1H emitted from flooring material significantly depends on the kind and shape of flooring materials and was influenced by the effective diffusion coefficient for 2E1H of flooring material. Emission rates of 2E1H from floor surface varied with the amount of 2E1H and resin present in the adhesive. When carpet was attached to the flooring material with high water content using adhesive, emission of 2E1H significantly increased. The results show that primary and secondary emissions of 2E1H from the adhesive influence the emission rate of 2E1H for flooring material.     

基于加工中心在机逆向测量的研究

零件数字化是逆向工程中的一项关键技术,它是指采用某种测量方法和设备测出实物各表面的若干组点的几何坐标。本文利用加工中心作为逆向工程中的零件数字化工具,建立了系统的功能模型,介绍了测头与数控系统的连接方法、数据的传输和格式转换,实现在机测量与计算机辅助设计系统的集成。在机测量的核心是数控设备与测头系统的通讯以及测点坐标的传输。该系统集自动测量和加工功能于一体,既能降低数控设备的闲置率,又可减少投资,为中小企业实施逆向上程提供了有效的解决方案。