Experimental study on co-pyrolysis characteristics of typical medical waste compositions

Thermal decomposition of 21 kinds of binary mixtures between typical medical compositions was investigated under nitrogen conditions by dynamic thermogravimetric analysis（TGA） at 25–800 °C. The weighed sum method（WSM） coupled with thermal analysis was applied to study the interaction between components. Then, co-pyrolysis kinetic model of the binary mixtures（tube for transfusion（TFT） and gauze） was established to verify the reliability of conclusions. The results show the follows. 1） Strong or weak interactions are shown between binary mixtures containing polyvinyl chloride（PVC）, the main ingredient of TFT. The addition of other medical waste could enhance first stage decomposition of TFT. While, the secondary stage pyrolysis may be suppressed or enhanced or not affected by the addition. 2） There exists no interaction between catheter and other component, the DTG peak temperature representing Ca CO3 decomposition in catheter fraction is obviously lower than that of pure catheter; while,the shape of DTG peak keeps unchanged. 3） No evident reaction occurs between the other mix-samples, it is considered that their co-pyrolysis characteristics are linear superposition of mono-component pyrolysis characteristics.     

Thermogravimetric characteristics and different kinetic models for medical waste composition containing polyvinyl chloride-transfusion tube简

Thermogravimetric study of medical transfusion tube （MTT） waste containing polyvinyl chloride （PVC） was carried out using the thermogravimetric analyser （TGA） with N2, at different heating rates of 5, 10, 20, 30, 50 ℃/min. The purpose is to obtain pyrolysis characteristics and kinetic parameters of medical waste. The experimental results indicate that the pyrolysis behavior of the MTT sample is in agreement with its main ingredient of PVC, appearing two stair stepping stages. The influence of the additives in MTT on pyrolysis behavior was also revealed, which could improve MTT pyrolysis at lower temperature in the first stage, and cause obvious unsmoothness and asymmetry of the second DTG peak. Four n-order kinetic models of Coats-Redfern, Ozawa, Kissinger and Freeman-carroll were used to get the kinetic parameters. Furthermore, a novel ＂two-step four-reaction model＂ was established to simulate the whole continuous process. The different methods and the kinetic parameters thus obtained were discussed and compared with each other in literatures. The reasons of deviation among kinetic values were tried to be elucidated. The new established model could more satisfactorily describe the pyrolysis process of MTT, being more mechanistic and conveniently serving for the engineering.     

废旧橡胶的催化裂解工艺

介绍了催化裂解技术对废旧橡胶回收再利用的处理工艺。废旧橡胶细块与催化剂A在400℃发生催化裂解反应,生成合成橡胶原始状态的产物,经分离得裂解气、石油馏分及炭黑产品。其生产过程能耗低,产品质量好,无污染物排放,产品具有综合利用价值。     

废旧橡胶粉对混合骨料混凝土力学特征的影响

为拓展废旧轮胎、再生骨料及天然浮石的应用范围,研究了在1∶1(再生骨料和天然浮石体积比为1∶1)混合骨料中外掺不同粒径(粒径20目、60目、80目、100目、120目)和不同掺量(掺量3%、6%、9%)的废旧橡胶粉,分析混合骨料混凝土的早期力学性能和微观结构。试验结果表明:在粒径相同的条件下,废旧橡胶粉使混合骨料混凝土的抗压强度降低率增大;掺量相同时,80目抗压强度下降率最大;从环境扫描电镜中得出,橡胶粉、再生骨料、浮石与水泥界面是薄弱区域,是造成混合骨料混凝土强度降低的主要原因。     

Pyrolysis kinetics and TG-FTIR analysis of waste epoxy printed circuit boards

Thermal decomposition of waste epoxy PCBs was performed in different atmospheres (nitrogen,argon,air and vacuum) at a heating rate of 10 °C/min by DSC-TGA,and the pyrolysis characteristic was analyzed. The gases volatilized from the experiment were qualitatively analyzed by TG-FTIR. Kinetics study shows that pyrolysis reaction takes place between 300 and 400 °C,and the activation energies are 256,212 and 186.2 kJ/mol in nitrogen,argon and vacuum,respectively. There are two mass-loss processes in the decompo...     

医疗废物焚烧过程中无机溴的迁移特性研究

为了研究焚烧温度、组分和停留时间对医疗废物焚烧过程中无机溴迁移行为的影响,利用管式炉焚烧系统,选择医疗废物中典型有机组分脱脂棉和聚丙烯,通过加入适量的NaBr进行焚烧平衡实验.实验表明:管式炉焚烧系统可以满足溴的迁移行为研究.焚烧温度对无机溴的迁移有重要影响,与聚丙烯相比,脱脂棉焚烧过程中Br的析出明显降低;聚丙烯焚烧中无机溴的析出过程可以分为2个阶段;脱脂棉焚烧时,无机溴的析出分为3个阶段;无机溴在焚烧过程中转化为HBr的比率并不高,在含溴医疗废物焚烧过程中,绝大部分溴都会释放出来,但最终只有少量排入大气．     

硫化温度对HDPE改性杜仲医用胶性能的影响

通过硫化特性曲线测定、形状记忆性能测定以及力学性能测定研究了不同硫化温度对HDPE共混改性杜仲医用橡胶性能的影响．结果表明：共混体系的最佳硫化温度为165℃,此温度下硫化胶的断裂伸长率、拉伸强度和弯曲强度分别可达到465．24％、21．28Mpa和1．024Mpa,所得改性胶回复率可达98．0％,软化点在55℃左右,达到了作为医用橡胶的使用要求．     

医疗废物焚烧中Cd/Cu/Pb/Zn的分布研究

以医疗垃圾中主要组分为研究对象,利用热力学平衡方法,研究在不同温度和气氛下Cd、Cu、Pb、Zn重金属元素的转化和迁移规律.研究结果表明,Cd、Pb较易挥发而Zn、Cu较难挥发,这主要与各元素的蒸汽压相关.随着温度的升高,在氧化性气氛下,各元素对应产物生成呈现从硫酸盐到氧化物再到气态单质(含氯时为硫酸盐到氧化物和氯化物)的趋势;在还原性气氛下,各元素对应产物呈现从硫化物到气态单质(含氯时为硫化物到单质和氯化物)的趋势;在相同温度下,还原性气氛更利于元素的挥发.从而根据在不同的焚烧温度下不同的产物形态进行重金属的污染控制.     

煤的热解动力特性研究

本文对不同煤种进行了挥发份析出的热重分析实验，得到了不同煤种和不同升温过程的实验结果及热解动力学参数Ｋ和Ｅ。本文还建立了热解过程的数学模型，模型简单实用，其计算结果与实验数据符合较好。     

中孔分子筛催化废聚烯烃裂解反应研究进展

对近年来中孔分子筛催化废聚烯烃裂解反应的研究进展进行了综述,并对中孔分子筛与传统的小孔分子筛在催化废聚烯烃裂解反应中的结果进行了比较。指出中孔分子筛作为处理废聚烯烃的催化剂,具有很好的应用前景。建议今后应在提高中孔分子筛催化剂的酸强度、活性以及稳定性等方面做进一步研究。     

呼伦贝尔褐煤负压热解特性研究

利用改进的格金低温干馏仪考察了呼伦贝尔褐煤的负压热解特性.研究表明,随着热解压力的降低(101.32kPa降到20.32kPa),半焦产率减少0.83%,焦油产率增加1.27%.通过对热解产物组成的分析发现:随着热解压力的降低,半焦中碳元素含量减少,氧元素含量增加,半焦整体结构变得松散;热解焦油中中性化合物的含量随热解压力降低呈下降趋势,酸性化合物的含量呈升高趋势;焦油中轻质组分含量随热解压力的降低逐渐减少,可能是轻质烷烃和烯烃发生裂解反应生成了气态烃类物质进入热解气中;重质组分逐渐增多,可能是煤中本应留在常压热解半焦中的组分随热解压力的减小挥发逸出进入焦油组分.     

无机灰分对餐厨沼渣中有机质热解特性的影响

针对餐厨垃圾厌氧处理所产生的沼渣具有产量大、灰分质量分数高的特点,研究沼渣中无机灰分对其热解过程的影响. 通过热重分析和热裂解?气相色谱质谱联用技术（Py-GC/MS）分析沼渣热解动力学特性及其产物. 动力学分析结果表明,沼渣除灰后,失重速率显著提高,热解起始温度由180 ℃降至160 ℃. 除灰沼渣的总表观活化能比沼渣的略高,原因可能是除灰使沼渣内部孔隙增加,在促进挥发分析出的同时,削弱了部分组分在热解过程中的催化裂解作用. 产物分析结果表明,NaCl能够促进油相产物中烃类向酮类的转化,ZnCl₂通过促进酸类的脱羧作用,使烃类质量分数提高至66.8%;Fe₂O₃和Al₂O₃使烃类物质的质量分数分别提高至66.8%和72.7%,CaO和MgO可以促进酸类脱羧生成酮,使产物中酮类的质量分数高达46.5%和39.4%.     

废轮胎流化床热解过程典型污染气体的排放特性

在小型流化床试验台上进行废轮胎的热解试验,研究不同工况条件下H2S、HCN、NH3气体的排放特性.研究结果表明:废轮胎热解中S生成H2S的转化率为0.5%～26.0%.不同工况条件下热解时H2S的排放量随热解温度的变化规律相似,都有峰值出现.但是在CO2气氛下热解时,峰值温度降低,H2S的排放量略高于在N2气氛下热解.废轮胎热解时燃料氮的排放以NH3为主,其转化率为10%～55%,远大于生成HCN的转化率(<0.5%).热解温度是影响N生成NH3的主要因素,流化速度和床料粒径对其影响不大.随着温度的升高,N生成NH3的转化率提高.在CO 2气氛下热解时,N生成NH3的转化率随热解温度升高而下降,这正好与N2气氛下热解时的趋势相反.在试验范围内,N在向NH3和HCN转化之间没有必然联系.     

FR4型废弃印刷线路板热解的实验研究

废弃电子印刷线路板含有大量的金属及非金属成分,合理的回收方法不仅可以减少对环境的污染,还能回收大部分金属成分。本文针对FR4型废弃印刷线路板进行了热解处理的实验研究,对其热失重规律、吸热规律、热解残余物等进行了分析,获得了FR4型印刷线路板热解处理的基本规律,对印刷线路板资源化具有重要意义。     

Low Temperature Dechlorination of Densified Refuse Derived Fuel in Pyrolysis

Study on behavior of chlorine contained in oval-shaped densified refuse derived fuel (d-RDF) prepared from municipal solid waste in pyrolysis was carried out by means of temperature-programmed electrical furnace, and the gas evolving from pyrolysis was investigated by FFIR. De-HC1 rate was calculated by determining the emission fraction of HC1 in the flue gas and the fraction of C1 left in the pyrolysis residue. The results show that C1 in the d-RDF releases primarily in the form of HC1 during the pyrolysis, and the initial releasing temperature of HC1 enhances with the increase of heating rate. Meanwhile, the higher the end temperature of pyrolysis, the more the C1 released. De-HCl rate is about 70% when the end temperature of pyrolysis is around 600℃. Besides, mechanism of C1 release is discussed.     

废弃印刷线路板催化热解的试验研究

在固定床反应器惰性气氛条件下,分别在无催化剂、铜粉和ZSM-5型分子筛存在时对FR-4型溴化环氧树脂基板进行热解试验,计算了不同条件下的产物产率和结焦率,并对热解油350℃以下馏分进行了GC-MS分析。结果表明,不同反应条件下气体和液体产率有所差异,使用分子筛与不使用催化剂所制热解油的产物组成比较相似,而在铜粉催化条件下,液体产物与其他两种催化条件下液体产物差别较大。     

一种具有优良特性橡胶的研究

以丙烯酸乙酯（EA）为主单体,采用乳液聚合方法,利用丙烯酸甲酯（MA）,丙烯腈（ACN）及少量交联单体,制备扯断强度高,扯断伸长率较好,耐油性好,抗紫外线优良,综合性能优异的丙烯酸酯橡胶。研究了单体的配方及聚合方法。结果表明：当三者的配比为90：8：2时,采用本研究所描述的聚合方’法．可得到物理及机械性能优良的丙烯酸酯橡胶。     

The dynamic characteristics of silicone rubber isolator

The dynamic stiffness and the specific damping energy, as well as the vibration response characteristics of a silicone rubber isolator were researched. The results of the vibration test showed that the silicone rubber isolator was excellent in the performance of vibration control. The dynamic stiffness and the damping characteristics were non-linear. From the comparison between experimental results and simulation analysis, the displacement transmissibility characteristics of the isolator were obtained. As a result, the dynamic characteristics of the isolator could be accurately described by the quadratic type non-linear terms at small amplitude.     

城市生活垃圾燃烧和热解特性的研究

利用红外一热重联用技术研究了模化城市生活垃圾(model—municipal solid waste，MMSW)的热解和燃烧特性。结果表明，MMSW在低于300℃时热解和燃烧的失重特性基本一致，升温速率对热解固体残渣的产率有影响。利用分峰拟合处理技术对：MMSW热处理过程的DSC曲线进行分析，发现MMSW燃烧和热解基本上是所含物质失重特性的叠加。对MMSW热处理过程进行动力学分析计算，得出MMSW热解、燃烧的反应级数在1～2之间，平均活化能在30～50kJ／mol。同时还对热解和燃烧过程逸出气体的红外图谱进行了分析和对比。     

废弃液晶面板中液晶材料的热解特性

作为废弃液晶面板的重要组成部分,液晶材料中含有芳环、氰基、氟、氯、溴等基团,若随意丢弃或采用不当的处置方式将严重污染环境。本研究拟利用热解处理技术实现对液晶材料的无害化处理,探究了废旧薄膜晶体管液晶显示器中液晶材料的热解特性。液晶材料的热重分析结果表明,液晶材料的主要热解温度为300～500?C;热解实验表明,热解温度对液晶材料热解产物的影响较大,其中300?C和500?C条件下主要生成了双环己烷类、联苯类等化合物,而在800?C条件下主要生成多环芳烃;此外,考察了热解温度、氮气流量及固相停留时间对液晶去除率的影响,在优化条件下液晶的去除率可达94.2%。本研究为废旧液晶面板中液晶材料的无害化处理提供了技术参数和理论参考。