废旧塑料回收与利用进展

本文根据国内期刊发表的２４篇有关塑料回收利用文献，介绍了１９９３年以来，国内废旧塑料回收与利用进展情况．     

废旧塑料回收利用的经济价值

本文着重分析了废旧塑料回收利用的经济价值,介绍了世界各主要国家回收利用废塑料的现状,并结合我国国情提出了改进意见和建议。     

废旧塑料回收利用的途径

文中简要介绍了废旧塑料的几种处理和再利用方法,从长远看,废塑料的再资源化及新型塑料制品的开发是当前塑料处理的总方向。     

废旧塑料回收利用的途径

介绍了废旧塑料的几种处理和再利用的方法，从长远看，废塑料的再资源化及新型塑料制品的开发是当前废塑料处理的总方向。     

废旧塑料回收利用及技术进展

本文重点评述了PVC、聚酯、PS、聚烯烃、聚氨酯、聚碳酸酯等各种塑料的回收利用和综合利用技术进展。     

废旧塑料分选技术

废旧塑料的回收包括 3个阶段 :收集、分选、加工或再生等步骤。只有清洁的废旧塑料才能生产高质量的产品 ,这需要有效的塑料分选方法。评述了光选、电选、风力分选、密度分选、浮选等废旧塑料分选技术 ,指出浮选在废旧塑料分选方面具备独特优势     

Production of liquid fuels from waste plastics

Exploratory work was carried out to develop a process for conversion of mixed plastic wastes into liquid transportation fuels or petrochemicals. The concept used is based on thermal depolymerization of the polymers in a suitable solvent followed by catalytic conversion of the resulting polymeric fragments into hydrocarbons with boiling points below 525°C. The process is carried out batch-wise over a zeolite catalyst at temperatures from 350°C to 450°C and at atmospheric pressure. No hydrogen is used and volatile products formed are continuously removed from the reactor. Tests were carried out on polyethylene and polypropylene alone, and on mixtures of the two. Finally, a synthetic mixture of four different plastics was tested. From 90% to 98% of the plastic was converted to gases or distillable hydrocarbons. Of this yield, from 20% to 55% was gas, primarily propylenes and butylenes, and from 32% to 70% was a light hydrocarbon oil. Very little non-distillable coke or residue was formed. The use of mixtures did not affect the high conversions obtained, but the results could only be approximately predicted based on a pro-rating of results for the individual components.     

废弃塑料化学回收及升级再造研究进展

塑料对人类社会进步和经济发展发挥着重要作用,但其大规模生产和不恰当的处置已造成了严重的生态灾难。通过化学回收和化学升级再造的方法将废弃塑料转化为高附加值的产品是实现塑料资源可持续发展的关键技术之一。本综述总结了近年来废弃塑料的回收现状和化学升级再造的途径,包括催化热解、化学解聚、催化氢解、光催化、化学氧化等,着重探讨了反应条件对于产物分布和产率的影响、催化剂的构效关系及反应机理等。针对目前存在的反应条件严苛、催化剂成本高且重复利用性差等问题,提出未来研究方向包括优化工艺条件、弄清催化剂失活机理和开发价格低廉的高效催化剂,有望进一步实现废塑料资源化利用的工业化发展。     

溴系阻燃塑料的回收再利用

介绍了回收利用溴系阻燃塑料的3种方法:①机械回收;②焚烧以回收能量;③焚烧或裂解以回收溴或氢溴酸。分析回收过程的环保问题。评述了机械法和焚烧法在技术上、生态上和经济上都是可行和安全的,但应采用合理的焚烧工艺,并严格控制和监测二口恶英的产生和释出。     

Recycling of commingled plastics waste containing polypropylene,polyethylene, and paper

Polymer waste recycling is a major technical problem, because large amounts of synthetic polymers are produced every day and polymeric wastes are gathered from municipal solid wastes. There are a few polyolefins, such as polyethylene (PE) and polypropylene (PP) with huge amounts of paper in the waste materials. In order to recycle the commingled plastics waste that contains paper, hydrolytic treatment is needed prior to conventional processing. In this project, the optimum conditions of hydrolytic treatment of paper and the mechanical properties and morphological state of different compositions of PP high‐density PE (HDPE) blends with paper were studied. Ethylene‐propylene‐diene copolymer (EPDM) was added to improve the mechanical properties of blends. The results show that the hydrolytic treatment of paper improves the mechanical properties, such as the tensile strength and modulus of the PP/HDPE/paper composites relative to the untreated samples, and up to 30% paper can be added to commingled PP and HDPE blends. The EPDM was used as an impact modifier. The plastics waste containing paper can be used in applications such as artificial wood. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2573–2577, 2001     

利用废杂塑料制备燃料油

为使废杂塑料的产物回归石油产品，介绍了废杂塑料制备燃料油工艺中原料的分离、原料的预处理、催化剂的使用以及热分解、裂解工艺条件。     

车用废旧塑料的再生处理技术

随着塑料工业的迅速发展,塑料制品的应用渗透到国民经济的各个领域及人们的日常生活中。随着车用塑料应用的日益广泛,塑料制品已成为现代汽车的重要组成部分。由于车用废旧塑料再生利用迫在眉睫,介绍了车用废旧塑料的分类,研究了车用废旧塑料的常见处理方法,同时指出车用废旧塑料再生利用有利于环境保护。     

废弃玻璃钢的资源化研究进展

介绍了废弃玻璃钢的种类和来源,综述了国内外各种废弃玻璃钢的资源化研究进展,其中包括热解、水解、醇解、常压解聚,粉碎回收、能量回收、以及作为水泥原料、高炉炼铁还原剂使用等,探讨了我国在废弃玻璃钢资源化研究中存在的问题及对策,提出了今后我国废弃玻璃钢资源化研究的方向。     

塑料包装废弃物回收处理及进展

塑料包装废弃物的处理方法基本上可分为填埋、焚烧及回收再生利用。填埋是把垃圾作为废物处理,对垃圾资源的利用率低,不符合国家可持续发展战略。焚烧法可将不能再次利用的混杂塑料在焚烧炉中焚化,由其产生的大量热量可再次充分利用。但焚烧的过程中会产生大量的有害气体,对环境及人体造成危害。回收再生利用包括机械再生利用和化学再生利用。机械再生利用包括直接再生利用及改性再生利用;化学再生利用主要有热分解和化学分解两类。塑料再生利用是国家解决资源短缺的一个重大战略问题,我国废塑料回收利用前景看好。     

Thermoplastic elastomers from reclaimed rubber and waste plastics

Thermoplastic elastomeric compositions from reclaimed rubber and scrap plastics were prepared. The physical properties, dynamic mechanical properties, rheological behavior, and phase morphology of the blends were studied. A 50:50 rubber/plastic ratio was found to be the best for processability, ultimate elongation, and set properties. A sulfur‐accelerator system was found to be better than a peroxide system for dynamic crosslinking. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2035–2042, 2002