共查询到19条相似文献,搜索用时 984 毫秒
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低温煤焦油与废旧塑料共熔油化的研究 总被引:5,自引:0,他引:5
用自制的反应装置研究了预处理后的低温煤焦油与废旧塑料共熔油化所得到的油品的性质,并分别与低温煤焦油和废旧塑料热裂解油品的性质进行了比较,考察了主要工艺条件对共熔油化过程的转化率和产品性质的影响。结果表明,在适当的添加煤焦油后,从废旧塑料热裂解和催化裂解得到的汽油的质量有所提高,但对柴油的质量影响不大。采用低温煤焦油与废旧塑料共熔油化的工艺不仅为“白色污染”的处理开辟了一条新途径,而且扩大了低温煤焦油的应用 相似文献
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本文详细综述了从30年代到现在国内外废旧塑料再生利用技术发展的过程及近几年废塑料回收最新技术,对未来肇旧塑料回收利用的发展趋势进行了预测。 相似文献
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制备特定无机阴、阳离子的选择性吸附材料有利于保障饮用水安全、控制外排污水生态风险、保障地表水环境质量,具有非常广泛的市场需求和应用前景。选择性离子吸附材料研发始于20世纪60年代,经过60年的高速发展,选择性离子吸附材料领域目前依旧保持了极高的研究热度和研究水平。本文概述了选择性离子吸附材料的研发历史、现状和主要研究方向,重点总结了四种选择性离子吸附原理(即分子印迹技术原理、软硬酸碱理论、非静电作用原理和竞争离子自我抑制原理)和它们的研究历史、选择性离子吸附材料制备与应用情况,展望了未来的研究方向,这些信息的整理归纳将为未来的选择性离子吸附材料研发、水中特定离子浓度控制提供重要的借鉴。 相似文献
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可降解塑料与环境保护 总被引:2,自引:0,他引:2
近年来可降解塑料解决生态环境的白色污染问题受到普遍关注。推广使用可降解塑料,具有绿色环保意义。本文阐述了可降解塑料的分类、降解原理及国内外可降解塑料技术发展的现状,拟对其在我国的应用做一综述。 相似文献
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Timmy Thiounn Rhett C. Smith 《Journal of polymer science. Part A, Polymer chemistry》2020,58(10):1347-1364
The global production and consumption of plastics has increased at an alarming rate over the last few decades. The accumulation of pervasive and persistent waste plastic has concomitantly increased in landfills and the environment. The societal, ecological, and economic problems of plastic waste/pollution demand immediate and decisive action. In 2015, only 9% of plastic waste was successfully recycled in the United States. The major current recycling processes focus on the mechanical recycling of plastic waste; however, even this process is limited by the sorting/pretreatment of plastic waste and degradation of plastics during the process. An alternative to mechanical processes is chemical recycling of plastic waste. Efficient chemical recycling would allow for the production of feedstocks for various uses including fuels and chemical feedstocks to replace petrochemicals. This review focuses on the most recent advances for the chemical recycling of three major polymers found in plastic waste: PET, PE, and PP. Commercial processes for recycling hydrolysable polymers like polyesters or polyamides, polyolefins, or mixed waste streams are also discussed. 相似文献
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“白色污染”已成为目前普遍关注的一个全球性环保课题。将光催化剂掺入到塑料中制备出环境友好的可光降解复合塑料,利用其光催化活性可以使废弃塑料在太阳光的照射下发生有效降解,是解决“白色污染”问题的有效途径之一。本文综述了近年来固相光催化降解废弃塑料的研究进展,介绍了光催化剂TiO2、ZnO、α-FeOOH和H3PW12O40对废弃塑料的固相光催化降解效率及各种复合塑料的光催化降解机理,阐述了对光催化剂进行表面改性可以改善其在聚合物中的分散性,以及对光催化剂进行修饰可以提高其对可见光的吸收,从而提高复合塑料的固相光催化降解活性及对太阳光的有效利用率。最后,展望了固相光催化技术在废弃塑料处理领域的应用前景。 相似文献
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利用焦化工艺处理废塑料技术研究 Ⅰ. 热天平与10 g固定床实验 总被引:3,自引:2,他引:3
利用热天平和10 g固定床反应器分别考察了北京市生活垃圾中的废塑料与首钢炼焦配煤的热失重特性及热解产物分布规律。实验研究表明,首钢炼焦配煤主要热分解温度区域为300 ℃~750 ℃,北京市废塑料主要热分解温度区域为300 ℃~550 ℃,二者在相互重叠的失重温度区间产生“协同效应”,且在一定配比范围内,共热解产物出现 “增油减水”现象。首次提出了协同效应强度的概念及其计算式: 和 ,并得出废塑料的添加量为1%时,协同效应强度最大。 相似文献
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利用焦化工艺处理废塑料技术研究 Ⅱ. 200 kg焦炉中试试验 总被引:5,自引:0,他引:5
利用200 kg焦炉考察两种废塑料(PS和WMP)与首钢炼焦配煤按不同比例均匀混合共焦化所得焦炭的质量变化规律,以期能为焦化工艺处理废塑料技术的工业应用提供基础数据。研究表明:废塑料与煤共焦化所得焦炭冶金焦率和焦炭质量降低明显,且随着废塑料添加比例增加,所得焦炭质量劣化程度整体加大;与添加同比例的PS相比,添加WMP虽得到较差的冶金焦率,但所得焦炭的转鼓强度(M40和M10)和反应后强度(CSR)均优于添加PS的情形;废塑料与炼焦配煤简单混合共焦化,严重影响焦炭质量,不能应用于工业实践。 相似文献
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Plastics are a major constituent of municipal solid waste that pose a growing disposal and environmental pollution problem due to their recalcitrant nature. To reduce their environmental impacts and allow them to be transformed during organic waste recycling processes, various materials have recently been introduced to improve the biodegradability of plastics. These include conventional plastics amended with additives that are meant to enhance their biodegradability, bio-based plastics and natural fiber composites. In this study, the rate and extent of mineralization of a wide range of commercially available plastic alternative materials were determined during composting, anaerobic digestion and soil incubation. The biodegradability was assessed by measuring the amount of carbon mineralized from these materials during incubation under conditions that simulate these three environments and by examination of the materials by scanning electron micrography (SEM). The results showed that during a 660 day soil incubation, substantial mineralization was observed for polyhydroxyalkanoate plastics, starch-based plastics and for materials made from compost. However, only a polyhydroxyalkanoate-based plastic biodegraded at a rate similar to the positive control (cellulose). No significant degradation was observed for polyethylene or polypropylene plastics or the same plastics amended with commercial additives meant to confer biodegradability. During anaerobic digestion for 50 days, 20–25% of the bio-based materials but less than 2% of the additive containing plastics were converted to biogas (CH4 + CO2). After 115 days of composting, 0.6% of an additive amended polypropylene, 50% of a plastarch material and 12% of a soy wax permeated paper pulp was converted to carbon dioxide. SEM analysis showed substantial disintegration of polyhydroxyalkanoate-based plastic, some surface changes for other bio-based plastics and coconut coir materials but no evidence of degradation of polypropylene or polypropylene containing additives. Although certain bio-based plastics and natural fibers biodegraded to an appreciable extent in the three environments, only a polyhydroxyalkanoate-based resin biodegraded to significant extents during the time scale of composting and anaerobic digestion processes used for solid waste management. 相似文献
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Xingchen Jiao Kai Zheng Qingxia Chen Xiaodong Li Yamin Li Weiwei Shao Jiaqi Xu Junfa Zhu Yang Pan Yongfu Sun Yi Xie 《Angewandte Chemie (International ed. in English)》2020,59(36):15497-15501
Reported here is the first highly selective conversion of various waste plastics into C2 fuels under simulated natural environment conditions by a sequential photoinduced C?C cleavage and coupling pathway, where single‐use bags, disposable food containers, food wrap films, and their main components of polyethylene, polypropylene, and polyvinyl chloride can be photocatalytically transformed into CH3COOH without using sacrificial agents. As an example, polyethylene is photodegraded 100 % into CO2 within 40 h by single‐unit‐cell thick Nb2O5 layers, while the produced CO2 is further photoreduced to CH3COOH. Various methods and experiments disclose that O2 and .OH radicals trigger the oxidative C?C cleavage of polyethylene to form CO2, while other investigations show that the yielded CH3COOH stems from CO2 photoreduction by C?C coupling of .COOH intermediates. This two‐step plastic‐to‐fuel conversion may help to simultaneously address the white pollution crisis and harvest highly valuable multicarbon fuels in natural environments. 相似文献
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