塑料衍生碳材料用于超级电容器的研究现状

塑料制品的过度使用,导致了严重的环境问题。将废旧塑料回收并转化为高附加值的碳材料并用于超级电容器等储能装置有着重要的意义,能够有效地降低环境污染并节约能源。本文首先对超级电容器的应用情况和塑料的使用以及回收处理现状进行了简单叙述,介绍了常见的废弃塑料处理方法、超级电容器的储能特点以及利用废弃塑料制备超级电容器碳材料的潜在价值;接着介绍了多孔碳电极材料的制备方法,对不同的制备方法的具体要求及其优缺点进行了简单分析;随后介绍了几种生活中常见的塑料,按照这些塑料的种类,分别对这些常见塑料回收用作超级电容器碳材料的研究现状进行了详细概述;最后对目前的研究现状进行总结,并对未来的研究方向进行展望。将废弃塑料回收并转化为超级电容器用活性碳材料,是一种新型的废弃塑料回收再利用的有效手段,能够有效地解决白色污染问题。     

碳中和背景下国内外废塑料裂解法回收进展

人类生产生活对塑料制品日益增长的需求使得塑料废弃物迅速增加,由此引起的环境问题和社会问题亟待解决。本文综述了碳中和背景下国内外废塑料裂解法回收进展,从废塑料裂解催化剂、废塑料裂解反应器、废塑料与其他固废共裂解三个方面对废塑料裂解技术进展进行总结,归纳了国内外塑料回收企业和石油石化企业在废塑料裂解回收方面的进展,分为裂解法制油和裂解法制化学品两个方面。阐明了废塑料回收在节约能源、碳减排和经济性方面的意义,指出国内废塑料裂解法回收存在法规缺失、废塑料分类不清晰、产业链条不完善、相关学术研究不深入等问题,提出国内石油石化企业应从全生命周期角度出发对废塑料进行裂解法回收处理,结合上下游产业链,分阶段实施废塑料裂解产油品路线和产化学品路线。     

固体废弃物微波技术处理及其资源化

随着国民经济的快速发展,废旧橡胶轮胎、废旧塑料、废旧纤维素以及污泥等固体废弃物的量迅猛增加,固体废弃物的处理和资源化已迫在眉睫。在固体废弃物的处理及资源化过程中,微波技术具有加热速率快、加热均匀和固体废弃物有价值资源的选择性好等优点。采用微波技术处理废旧橡胶轮胎时,产物中的液体有机物选择性比较高,对炭黑和钢丝等物料的回收也比较简单,国外已有日均处理(6 000~7 000)条废旧轮胎的工业化生产线,可以实现废旧轮胎100%资源化再利用;在废旧塑料聚丙烯中添加石墨等微波吸收物质,然后进行微波技术处理,烯烃类组分的液体产物可以达到48.16%;废旧纤维素及其制品可以在较低温度下进行微波处理,废纸在200℃进行微波裂解可以获得15%的裂解气、42%的裂解油和43%的炭黑;含油污泥进行微波技术处理不但可获得液体有机物,还能够实现污泥的油水分离。因此,采用微波技术处理固体废弃物是一个废物的减量化、无害化和资源化过程,具有很好的应用前景。对近年来采用微波技术处理这些固体废弃物及其资源化的研究进展进行总结和评述,以期对我国固体废弃物处理和资源化的发展提供参考。     

废旧轮胎裂解炭黑的改性及其应用进展

废旧轮胎作为对环境有害的固体废弃物，其组成包括炭黑、白炭黑和胶粉等多种有价值的资源。在现有回收技术中，废轮胎热裂解技术可有效回收裂解油、炭黑和钢丝等，在国内获得了广泛应用。相对于已经普遍利用的热解油和钢丝来说，热解炭黑含有质量分数14-21%的灰分和胶质层，它的高价值利用是实现废旧轮胎循环回用的关键。很多研究者开展了热解炭黑不同的改性处理工艺研究，改性后的热解炭黑可被应用于多个领域。该文主要概括了热解改性炭黑在橡胶生产中的补强作用、改性活性炭吸附剂、电池材料、以及沥青和油墨填料等方面的应用，综述了上述应用领域内热解炭黑的处理和改性方法，并指出今后热解炭黑高价值回用的方向和改性方法。     

废弃聚苯乙烯塑料在环境与能源中的高值化应用进展

聚苯乙烯是塑料材料家族中的重要组成部分,它具有质轻、隔热、防水、廉价等一系列优点。由于它的化学稳定性优异,自然界很难将其直接降解,通常采用填埋或焚烧进行处理,不仅对环境造成了严重的污染,同时也是资源的严重浪费。近年来,由于化学及材料科学快速发展,针对废弃聚苯乙烯回收及高值化研究已经得到广泛关注。本文从环境和能源角度详细综述了近年来废弃聚苯乙烯高值化应用的研究进展,从废弃聚苯乙烯的高值化方式和产物出发分为以下三个主要部分:通过物理或化学手段将废弃聚苯乙烯塑料转化为高分子功能材料;作为模板剂或碳源制备多孔碳材料;将废弃聚苯乙烯塑料裂解为小分子有机物。     

废旧塑料资源再生循环利用管理和发展现状

随着塑料制品使用量的增加,难以自然降解的废旧塑料对生态环境造成严重污染.废旧塑料资源再生循环利用为废旧塑料无害化、减量化、资源化处理开辟了新途径.国内外对废旧塑料的资源再生循环利用投入大量的人力、物力,并针对废旧塑料资源再生循环利用发布了相关政策,相关部门研究开发了各类废旧塑料回收利用技术,不仅有利于提升废旧塑料的经济...     

烟用二醋酸纤维素滤棒回收工艺探索及应用

介绍了烟用二醋酸纤维素滤棒的回收工艺流程,采用这种工艺回收的二醋酸纤维素材料,可以做为烟用丝束生产原料的掺配料,实现了资源的循环利用和环保目的,解决了烟草废弃物的处理难题。     

Controlled release of 2‐methyl‐4‐chlorophenoxy acetic acid herbicide from waste gelatin–based blends and composites

The volume of plastic waste is becoming a serious problem for waste management. Waste management is based on four hierarchical approaches: reduction, reuse, recycling, and energy recovery. We now report on recycling of gelatin scraps that are derived during the production of pharmaceutical capsules, by using the gelatin scraps in the production of controlled‐release systems. This may help to minimize the side effects that often accompany the conventional application of pesticides. More important, the gelatins themselves, when degraded, might be useful to soil solarization and crop growth. Using and recycling these waste materials in the proposed application would save natural resources and consequently would be economically useful. The synthesis of gelatin films, and composites incorporating 2‐methyl‐4‐chlorophenoxy acetic acid (MCPA) as herbicide, will be described. Morphology and mechanical properties of the films were investigated by scanning electron microscopy and tensile tests, respectively. The release of the MCPA herbicide from the prepared blends and composites was investigated. The prepared formulation proved to be useful for agricultural applications. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1420–1427, 2004     

废旧塑料摩擦荷电机理及摩擦电选技术研究进展

塑料由于材质轻、化学性质稳定、成本低、耐磨性及耐腐蚀性好等优点被广泛应用于工程建设、食品安全、交通运输以及医疗等领域,如果处理不当会对环境造成严重的污染,废塑料污染防治已成为全球关注的环境问题。目前处理废旧塑料的常用方法有风选法、浮选法、静电分离法和光选法等,摩擦电选作为一种新型干式分选方法越来越受到研究者们的重视,其具有工艺简单、污染小、投资少、成本低等优点。本工作针对废旧塑料的分选回收利用,详细介绍了摩擦电选的荷电机理、影响因素、荷电装置和分选设备的研究现状,指出了目前通过摩擦电选回收废旧塑料的技术问题,并对摩擦电选技术未来的发展趋势和应用进行了展望。     

电子废弃物机械–物理协同强化资源化利用的研究进展

电子废弃物组成复杂,含有金属相、有机物、氧化物材料等;其结合方式复杂,有黏结、螺丝连接、焊锡固定和卡扣连接等。在这些复杂的成分之中不仅含有多种稀贵金属而且还包含像铅、镉等多种有毒的重金属和各种溴化阻燃剂等有毒的有机物。这些电子废弃物如果不能进行有效回收,将会对环境造成巨大的危害,同时电子废弃物中稀贵金属的含量远高于自然矿物,因此回收电子废弃物中稀贵金属将能有效地缓解自然资源日益紧张的局面。与传统的化学回收方法相比,机械物理的回收方法具有操作简单、经济效益好、环境污染小等优点,被广泛应用于电子废弃物的回收过程。本工作概述了近年来电子废弃物机械物理资源化利用的研究进展,对机械物理回收的各个过程进行了系统地总结,包括前期的拆解和破碎过程以及最重要的物理分选技术,通过对不同分选技术优缺点的比较,指出对破碎产物进行形态调控将极大地提高机械物理处理的回收效率。     

PET废弃物水解及醇解化学回收技术研究

聚对苯二甲酸乙二醇酯(PET)具有良好的透明性、气体阻隔性和力学性能、且无毒无味,广泛应用饮料瓶、纤维、工程塑料和薄膜等领域。我国是世界PET生产、消费第一大国,废弃PET排入自然界造成白色污染。PET化学回收方法,将PET解聚成单体或低聚体,是实现PET废弃物循环利用最为有效的途径。本文重点对PET废弃物的水解、醇解等化学回收方法的技术研究及工业化进展进行了综述。     

环境对改性塑料表面亲/疏水转变的作用机制

塑料制品因其质量轻、性质稳定等优点而得到广泛使用,但大部分废旧塑料未被合理回收而成为污染物,对环境造成了危害。因此,废旧塑料回收、再加工成为保护环境和资源利用的有效途径。而分离是废旧塑料能进行再加工的重要环节,目前已经发展了丰富的分离方法,其中塑料浮选法因具有工艺简单、污染少的特点而受到人们的青睐。但在塑料浮选中,其表面亲疏水性受环境的影响,该过程进一步恶化分离效果。为了避免分离过程的波动性,急需探究环境因素对亲疏水性的作用。基于此,本文选取了ABS、PC、PS三种废旧塑料,探究环境对浮选分离及表面亲疏水性基团重构的影响。结果表明：氧化改性后的ABS、PC、PS处于极性环境时,塑料可浮性基本未发生改变,接触角发生轻微浮动,表面仍保持亲水性。处于乙醇环境中,塑料可浮性上升,其接触角上升至75°左右,表面疏水性恢复速度大于极性环境。而在非极性环境中,塑料可浮性上升速度较快,表面完全恢复为未改性前的疏水性。在极性环境中,亲水基团更容易停留在表面,随着极性的减小,亲水基团逐渐迁移至本体,塑料表面恢复为疏水。因此,极性环境更有利于塑料表面保持亲水性。     

Immobilization of Borate Waste Simulate in Cement-Water Extended Polyester Composite Based on Polyethylene Terephthalate Waste 1-Mechanical Properties of the Final Waste Forms

ABSTRACT

This paper discusses the suitability of Ordinary Portland Cement (OPC), water-extended polyester (WEP), based on recycled polyethylene terephthalate (PET), composite for stabilization/solidification (S/S) of borate waste solution originating from the primary coolant circuit of pressurized water reactors (PWRs).

This treatment is a new and attractive economical process that aims at keeping man and his environment healthy through controlling the dispersion of radioactive wastes (i.e., borate waste solution) and the solid plastic waste materials (i.e., PET).

Mechanical integrity of the WEP as well as its polymer composite (PC) with OPC was studied under different experimental conditions. Compressive strength measurements for the final waste forms of PC containing borate waste simulate were also evaluated using various compositions of the PC (e.g., water of hydration, polymer:cement ratio, borate content, etc.)

Based on the data obtained so far, it could be concluded that the candidate PC with the formulation of polymer:cement ratio 3%, water:cement ratio 40%, polymer:water of emulsion 80/20, and containing up to 3% by weight borate waste simulate shows compressive strength values acceptable for different transportation, storage, and disposal processes.     

Catalytic conversion of waste plastics: focus on waste PVC

Effective waste management must address waste reduction, reuse, recovery/recycling and, as the least progressive option, waste treatment. The increase in plastic waste production is a serious environmental issue. Plastics consumption continues to grow and while plastic recycling has seen a significant increase since the early 1990s, consumption still far exceeds recycling. Waste plastic can, however, serve as a potential resource and, with the correct treatment, can be reused or serve as hydrocarbon raw material or as a fuel. PVC, highly versatile with many applications, is non‐biodegradable and has a high Cl content (56% of the total weight). Waste PVC incineration is highly energy demanding and can result in the formation of toxic chloro‐emissions with adverse ecological, environmental and public health impacts. The Cl component must be removed from any waste PVC derived gas or oil before it can be used. An overview of the existing waste plastic treatment technologies is provided with an analysis of the available literature on thermal and catalytic PVC degradation. Thermal degradation results in random scissioning of the polymer chains generating products with varying molecular weights and uncontrolled Cl content. There is a dearth of literature dealing with the catalytic dechlorination of PVC. A case study is presented to illustrate the role heterogeneous catalysis can play in PVC waste treatment. The efficacy of Pd/Al₂O₃ to promote PVC dechlorination is demonstrated, where a significant decrease (by up to a factor of 560) in the liquid fraction Cl content is recorded in addition to differences (relative to thermal degradation) in the gas phase product, i.e. higher C₁? C₄ content with preferential alkane formation. Copyright © 2007 Society of Chemical Industry     

固废基无机高分子混凝剂研究进展及改进途径

无机高分子复合型混凝剂具有优越的絮凝能力,但目前于基于固废资源化利用制备无机高分子复合混凝剂的相关研究缺乏系统性。本文介绍了三类固废基无机高分子复合混凝剂的制备工艺、性质特点,简述了其在水处理领域的应用、作用机理及存在的问题,并结合新型无机高分子复合混凝剂的研究进展,分析了固废基无机高分子复合混凝剂的发展方向。根据已有结果,文中指出需要从固废原料的化学组成,建立全面的固废资源,优化不同来源固废基无机高分子复合混凝剂的制备工艺;其次指出应进行混凝剂的物耗、能耗等技术经济分析,促进其规模化生产使用;并提出对污泥固废应进行循环资源化利用,关注制备过程中产生的无机盐,避免对水质的不良影响;最后表明,应加强混凝剂功能化研究,开发具有协同效应的固废基无机高分子复合混凝剂。     

废旧塑料的回收与利用

综述了利用区块链技术进行废旧塑料的回收.使用区块链技术建立的塑料银行可以激励人们自发地回收废旧塑料.废旧塑料的回收流程大多是线下的,监管困难,使用区块链技术可以使用户在区块链上查询全流程的回收数据,便于监管.在废旧塑料的分选和利用方面,介绍了聚乙烯和聚丙烯的分选,聚对苯二甲酸乙二酯与聚氯乙烯混合固体塑料的分选.废旧塑料...     

Recycling of polymers from plastic packaging materials using the dissolution–reprecipitation technique

In this work, results are presented on the application of the dissolution/reprecipitation technique in the recycling of polymers from waste plastic packaging materials used in food, pharmaceuticals and detergents. Initially, the type of polymer in each packaging was identified using FT-IR. Furthermore, experimental conditions of the recycling process (including type of solvent/non-solvent, initial polymer concentration and dissolution temperature) were optimized using model polymers. The dissolution/reprecipitation technique was applied in the recycling of a number of plastic materials based on polyethylene (LDPE and HDPE), polypropylene, polystyrene, poly(ethylene terephthalate) and poly(vinyl chloride). The recovery of the polymer was measured and possible structural changes during the recycling procedure were assessed by FT-IR spectroscopy. Potential recycling-based degradation of the polymer was further investigated by measuring the thermal properties (melting point, crystallinity and glass transition temperature), of the polymer before and after recycling, using DSC, their molecular properties (average molecular weight) using viscosimetry, as well as their mechanical tensile properties. High recoveries were recorded in most samples with the properties of the recycled grades not substantially different from the original materials. However, a slight degradation was observed in a few samples. It seems that this method could be beneficial in waste packaging recycling program.     

废塑料基复合材料粉体法综合回收技术

介绍了国内外对废塑料基复合材料回收技术的相关现状,根据废塑料基复合材料的特点采用机械粉碎、解离(大型破碎、中碎、粉碎解离)、高压静电分选的方法回收废塑料复合材料,回收金属(铝等)的纯度达99%以上;金属(铝等)回收率达99%以上;回收塑料的纯度达96%以上,接近甚至超过国外同类技术的水平。在回收过程中不使用任何化工原料,不使用水,不排放任何污染物。     

轻油裂解法生产氰化钠工艺中裂解余热利用

轻油裂解法生产液体氰化钠过程中,存在大量的余热,一部分热量将原料预热,其余热量通过循环冷却水带出系统后经凉水塔排至环境中,浪费了大量热能。介绍了一种化工生产中的余热回收利用方法。通过对氰化钠车间的工艺、设备及管道进行改造,将氰化钠生产余热替代蒸汽引入厂区供暖及加热设备中,对裂解余热加以利用,并对余热能效进行计算。结果表明,氰化钠余热利用后每年可回收大量热能,节省了煤的用量,减少了环境污染。