废轮胎热解行为的研究进展

介绍废轮胎热解行为的研究进展状况,包括废轮胎热解的技术分类、热解过程和动力学模型、影响因素以及热解产物。温度、升温速率、催化剂、载气与粒径等均会对废轮胎热解过程产生影响,其中温度是最关键的因素,在不同的温度阶段,轮胎的不同组分发生热解,表现为其各自独特的热解现象和特征,可以根据所需目标产物的不同,选择相应的热解技术及工艺条件。指出未来废轮胎热解的研究方向为开发性能更加优异的反应器、寻找更加廉价高效的催化剂、对反应机理及动力学进行进一步研究、开发热解产物的应用途径及加工技术等。     

废轮胎水媒高温高压热解试验研究

在管式热解反应器内对废轮胎进行水蒸气气氛下的热解试验研究。结果表明,高压水蒸气气氛下,废轮胎在高于200℃时开始发生热解,500～650℃时发生剧烈反应,随着热解温度的升高,热解气的产率明显增大,热解炭产率相对稳定。元素分析和孔隙度分析表明,热解炭是一种高含碳率的多孔状物质,碳元素质量分数高达0.70左右,孔隙率高达60%左右。主要由中孔结构组成、微孔结构极不发达的热解炭经进一步处理后在大分子物质吸附方面具有较大的应用前景。     

废轮胎热解制取液化油的实验研究

以废轮胎胶粉为原料,在体积为500 m L的间歇反应器中开展了胶粉液化制取液化油的实验研究。重点考察了胶粉粒径和反应温度对产物分布的影响,通过密度、元素分析、高温模拟蒸馏和GC-MS分析,对最佳条件下获得的液化油的物性和组成进行详细分析。结果表明,在胶粉粒径0.70 mm和反应温度500℃的条件下,液化油收率高达55.50%。液化油的性质复杂,含有一定量的硫氮,轻质油馏分达到57%,主要成分为带烷基侧链的芳烃和环烯烃以及少量的杂原子化合物。     

废轮胎热解技术的现状及发展趋势

概述国内外废轮胎热解技术的研究现状及发展趋势,国外废轮胎热解采用移动床,固定床、流化床、烧蚀床、悬浮炉和回转窑等反应器,有代表性的热解工艺包括真空移动床,两段移动床、流化床、连续烧蚀床和回转窑热解工艺等;通常热解炭被粉碎处理作为炭黑使用,热解油作为燃料油使用,废钢丝网收再利用.国内对废轮胎热解技术的研究大多局限于微型和小型试验台研究,产业化应用研究水平相对于国外较低,尚末开发出技术成熟的中试规模以上的热解工艺.开发经济性更佳、资源利用更彻底的热解工艺将是今后废轮胎热解技术研究的重点.     

废轮胎热解油的化学组成分布

以工业试验装置生产的废轮胎热解油为研究对象,对废轮胎热解油中的烃类和非烃类化合物的分布进行研究。结果表明,热解油中的芳烃、烯烃含量高,饱和烃含量低,属于高硫高氮高酸油。热解油中硫主要以噻吩形式存在,总硫含量及噻吩硫含量随着馏分沸点的升高而增大;硫醇硫主要集中于小于300 ℃的馏分中;硫醚硫主要集中于小于150 ℃和大于500 ℃的馏分中。热解油中的总氮含量随着馏分沸点的升高而增大,碱性氮含量占1/3,非碱性氮占2/3。热解油中酸性组分主要集中于200～400 ℃的馏分中。     

废轮胎热解制油技术及油品应用前景

综述了国内外废轮胎热解制油技术的研究进展,对比了真空移动床热解、外热式批量进料固定床热解、内热式火焰固定床热解、回转窑热解和流化床快速热解等各种废轮胎热解技术的工艺及其特点;总结了热解产物中热解油的理化特性;并针对热解油高热值、高芳烃含量等特点,提出废轮胎热解油的可能应用前景,包括热解油整体作为燃料油燃烧或提取苯、甲苯、二甲苯及苧烯等具有较高经济价值的化工产品。     

生物质与废轮胎共热解及催化对热解油的影响

生物质稻壳与废轮胎以不同比例组成的均匀混合物在管式固定床内共热解,MCM-41和SBA-15作为催化剂,对产生的热解油性质进行了研究。结果表明,随着废轮胎在混合物中比例增加,热解油产率和热值在增加,而黏度和密度在降低。当稻壳占到60%（质量）时,热解液体产率为44.5%（质量）,热解油热值为40 MJ·kg-1,热值与柴油接近;温度对热解油的产率和组分柠檬精油的生成影响较大。对组成一定的混合物,在热解温度500℃时二者均达到最大。通过对热解油主要组分柠檬精油和氧含量的分析说明,共热解过程中组分间可以产生一定的相互作用,并具有协同效果,体现在柠檬精油组分的含量低于加权后的浓度,氧含量大于加权后的数值;与没有催化剂存在情况相比,MCM-41和SBA-15的存在能显著降低热解液体的黏度和密度,其中,SBA-15的降低效果更为明显。     

废轮胎橡胶热解技术研究进展

热解技术为废轮胎的回收问题带来了新的解决方案,其能耗低、污染小、产物利用率高,逐渐成为回收利用废轮胎的主要方法。本文综述了近年来国内外关于废轮胎橡胶热解技术的研究进展,包括废轮胎热解的机理、热解的新技术和新工艺、热解过程的影响因素、热解产物及其应用等。总结了国内外近年来废轮胎热解技术的发展状况,指出未来的研究趋势。     

废轮胎热解炭黑的研究进展

热解发黑作为废轮胎热解的关键产物,其品质较差,达不到使用要求,而且会对环境造成二次污染.主要介绍了废轮胎热解炭黑常用的分析表征方法,对热解炭黑的活化改性及再利用途径进行综述,旨在提高其利用价值.     

废轮胎热解资源化研究新进展

用热解法处理废旧轮胎能够实现能源的最大回收有价值产品的充分再利用,代表了当今废旧轮胎处理的发展方向。本文重点介绍了废轮胎的热解机理,热解动力学,热解过程控制及其产品特性的研究进展,并对今后废轮胎热解资源化研究发展方向提出了建议。     

废旧轮胎催化热解油品分析

采用ZSM-5和超稳Y(USY)分子筛催化剂,利用两段法固定床研究废旧轮胎的催化热解.通过对轮胎的催化热解后的轻质油品(＜160 ℃)分析,发现热解后油品中单环芳香烃含量增加.如在热解温度500 ℃、催化温度400 ℃和催化剂与轮胎比例0.5的情况下,对没有催化剂以及含ZSM-5催化剂及USY催化剂的轮胎热解,得到的轻质馏分中苯的含量分别是0.15%、0.99%和1.89%,甲苯的含量分别是3.04%、5.68%和17.70%.这对从废旧轮胎热解油中提取化学化工物质的工艺研究有着重要的指导意义.     

垃圾裂解动力学研究现状

本文中介绍了垃圾裂解动力学的研究现状,并较为详细的介绍了垃圾热裂解和微波裂解动力学的发展状况。比较了两者各自的特点。     

Porosity and surface characteristics of activated carbons produced from waste tyre rubber

Waste tyre rubber has proven to be a suitable precursor for the production of high quality activated carbons. The performance of these carbons in commercial applications such as water treatment or gas purification is highly dependent on their surface characteristics. This paper presents an in‐depth investigation on how production conditions may affect the yield and characteristics of activated carbons produced from tyre rubber. For this purpose, three tyre rubbers of different particle sizes were consecutively pyrolysed and then activated in a steam atmosphere at 925 °C using a laboratory‐scale rotary furnace. Activation was conducted at different intervals over 80–640 min to achieve different degrees of carbon burn‐off. The resulting carbons were analysed for their elemental composition, ash content and nitrogen gas adsorption characteristics. The BET and t‐plot models were used to investigate various aspects of their porosity and surface area characteristics. SEM analyses were also conducted for visual examination of the carbon surface. Results show that pyrolytic chars, essentially mesoporous materials, developed a very narrow microporosity during the initial stages of the activation process (up to 15–25 wt% burn‐off). Further activation resulted in the progressive enlargement of the average micropore width and a gradual development of the mesoporous structure. Total micropore volumes and BET surface areas increased continuously with the degree of activation to reach values up to 0.498 cm³g^?1 and 1070 m²g^?1 respectively, while external surface areas developed more rapidly at degrees of activation above 45 wt% burn‐off. Results presented in this work also illustrate that carbons produced from powdered rubber developed a narrower and more extensive porosity, both in the micropore and mesopore range, than those produced from rubber of a larger particle size. © 2001 Society of Chemical Industry     

A comparative study on the performance, emission and combustion studies of a DI diesel engine using distilled tyre pyrolysis oil–diesel blends

Alternate fuels like ethanol, biodiesel, LPG, CNG, etc., have been already commercialised in the transport sector. In this context, pyrolysis of solid waste is currently receiving renewed interest. The disposal of waste tyres can be simplified to a certain extent by pyrolysis. In the present work, the crude tyre pyrolyisis oil (TPO) was desulphurised and then distilled through vacuum distillation. Also, two distilled tyre pyrolysis oil (DTPO)–diesel fuel (DF) blends at lower and higher concentrations were used as fuels in a four stroke single cylinder air cooled diesel engine without any engine modification. The results were compared with diesel fuel (DF) operation. Results indicate that the engine can run with 90% DTPO and 10% diesel fuel.     

The pyrolysis of scrap automotive tyres: The influence of temperature and heating rate on product composition

Shredded automotive tyre waste was pyrolysed in a 200 cm³ static batch reactor in a N₂ atmosphere. The compositions and properties of the derived gases, pyrolytic oils and solid char were determined in relation to pyrolysis temperatures up to 720 °C and at heating rates between 5 and 80 °C min⁻¹. As the pyrolysis temperature was increased the percentage mass of solid char decreased, while gas and oil products increased until 600 °C after which there was a minimal change to product yield, the scrap tyres producing approximately 55% oil, 10% gas and 35% char. There was a small effect of heating rate on the product yield. The gases were identified as H₂, CO, CO₂, C₄H₆, CH₄ and C₂H₆, with lower concentrations of other hydrocarbon gases. Chemical class composition analysis by liquid chromatography showed that an increase in temperature produced a decrease in the proportion of aliphatic fractions and an increase in aromatic fractions for each heating rate. The molecular mass range of the oils, as determined by size exclusion chromatography, was up to 1600 mass units with a peak in the 300–400 range. There was an increase in molecular mass range as the pyrolysis temperature was increased. FT-i.r. analysis of the oils indicated the presence of alkanes, alkenes, ketones or aldehydes, aromatic, polyaromatic and substituted aromatic groups. Surface area determination of the solid chars showed a significant increase with increasing pyrolysis temperature and heating rate.     

典型杂质掺混对废塑料热解油特性的影响

以从4个典型的废弃物处理场取得的与废塑料掺混的杂质样品作为纯塑料热解过程中的添加剂,研究不可回收废塑料中掺混的杂质组分对塑料热解油品质的影响。研究内容包括4种杂质（I₁～I₄）对聚乙烯、聚丙烯、聚苯乙烯及混合塑料热解的影响以及杂质中的无机和有机组分在热解中分别起到的作用。结果表明,杂质的添加将塑料热解油中主要组分的富集度由65.5%提升到79.2%～90.3%;其中来源于废旧自行车拆解厂的杂质I₄对热解油组成的影响最为显著。I₄使得聚乙烯及聚丙烯热解油中的烯烃含量分别提高了25.0%及21.1%,但对聚苯乙烯的热解没有显著影响。I₄对塑料热解的影响可分为三个方面：无机灰分作为热载体起到的作用、特定活性灰分组分的催化作用以及杂质中有机组分参与热解的影响。灰分作为热载体促进了聚合物分子链的裂解;活性灰分组分能够催化加氢及氢转移等反应;而I₄中有机组分热解提高了油相产物中芳烃和烯烃的含量。该研究将为废塑料规模化热解过程中原料的预处理及热解油品质调控提供指导。     

城市生活垃圾热解气化技术研究进展

从城市生活垃圾热转化方式的比较入手,简要阐明了热解气化过程,讨论了各类热解气化反应器的优缺点,概述了城市生活垃圾热解、气化实验研究进展以及热解气化技术中试及应用情况。通过比较各类实验研究,明确了热解温度、加热速率对热解产物产量及产物分布的影响,气化温度、氧气当量比(RO)对含氧气化反应的影响,气化温度、水蒸气与城市生活垃圾质量比(S/M)对水蒸气气化反应的影响。指出了城市生活垃圾热解气化实验研究热点在于优化控制参数,提高反应速率,促进目标产物高值化,抑制其它产物及污染物的生成,以及城市生活垃圾热解气化技术的发展方向。     

城市垃圾热裂解制取合成气的研究

以树叶为原料,利用热裂解装置进行试验,并对其裂解产物的组成进行了分析。结果表明：树叶热裂解产物为生物油、合成气和炭。而其合成气成分主要由CO、CH4、H2和水蒸气组成。     

Value-added products from waste: Slow pyrolysis of used polyethylene-lined paper coffee cup waste

The objectives of this study were to examine how to recycle cup waste efficiently and effectively and to determine if cup waste can be converted into liquid, solid, and gas value-added products by slow pyrolysis. The characteristics and potential utilizations of the pyrolysis products were investigated. The study included the effects of temperature, heating rate, and different feedstocks. The yield of pyrolysis oil derived from cup waste increased from 42% at 400°C to 47% at 600°C, while the yield of char decreased from 26% at 400°C to approximately 20% at 600°C. Acetic acid and levoglucosan were identified as the main components of the pyrolysis oil. The char obtained at 500°C was physically activated at 900°C for 3 h with CO₂. The adsorption capacity of the activated char was investigated with model compounds, such as methyl orange, methylene blue, ibuprofen, and acetaminophen. The results showed that the adsorption capacity of the activated char was similar to that of commercial activated carbon produced from peat. The higher heating value of the produced gas stream calculated at 400°C was 19.59 MJ/Nm³. Also, conventional slow pyrolysis (CSP) and microwave-assisted pyrolysis (MAP) technologies were compared to determine the differences in terms of products yields, composition and characteristics of the pyrolysis oil, and their potential applications. The CSP yields higher liquid products than MAP. Also, the pyrolysis oil obtained from the CSP had significantly more levoglucosan and acetic acid compared to that of the MAP.