首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
在10g固定床反应器中对PVC在惰性气氛下的热解脱氯特性及有关工艺参数进行考察,并研究了热解终温(FPT)对PVC热解产物产率的影响。实验结果表明,在温度为300℃,反应时间为3h,升温速率为5℃/min条件下,PVC中大部分的氯可脱除,脱氯率可达90%,另有约10%的氯残留在液体产物及固态残渣中,且升温速率越慢,分解程度越大,反应的起始分解温度也越低。随着热解终温的提高,可燃气体率增大,焦油和残渣产率则减少。  相似文献   

2.
以内蒙古锡林郭勒盟褐煤为原料,借助于煤热解制备出民用洁净低硫褐煤半焦,考察了热解温度、升温速率、恒温时间及煤粒粒径等工艺条件对所制备的褐煤半焦中总硫、有机硫及无机硫含量的影响。实验结果表明:在500~800℃热解温度范围内,褐煤半焦中总硫含量随着热解温度的增加呈现先减小后增加的趋势,热解温度为700℃时褐煤半焦中总硫质量分数达到最低值(0.98%);热解升温速率越慢,越有利于褐煤中硫的释放,升温速率为10℃/min时褐煤中硫释放程度最大(脱硫率为67%);热解恒温时间过短或过长都会影响煤中硫的脱除,最佳热解恒温时间为60 min;随着煤粒粒径的增大,热解过程中传质阻力增加,不利于煤中硫的脱除,粒径≤0.2 mm时褐煤半焦中硫含量最低。  相似文献   

3.
几种典型城市生活垃圾的热解特性和动力学分析   总被引:1,自引:0,他引:1  
针对四种不同的城市生活垃圾原料:木屑、稻草、橡胶和塑料在不同升温速率(10、20、30、40℃/min)下进行的热重分析试验,探讨生物质热解的影响因素。通过热重曲线分析城市生活垃圾的热解规律,并使用阿伦尼乌斯公式和Coats-Redfern积分法计算热解反应动力学参数。研究结果表明:几种典型的城市生活垃圾热解过程分三个阶段:干燥预热、快速失重和缓慢失重阶段。随着升温速率的增加,热解曲线向高温区移动,升温速率升高对热解过程总失重量影响不大;但是提高升温速率会加快热解反应过程。塑料相对于其他三种物质热解失重峰值温度高出120℃以上,塑料的活化能远大于其他三种物质,是四种城市生活垃圾最难热解的物质。  相似文献   

4.
研究了混合废塑料与煤共热解过程中氯的迁移规律,并通过对实验数据进行处理和分析,采用分布率研究了氯在焦炭、焦油、煤气三相中的分布规律,并建立了数学模型.结果表明,在高温热解(1000℃)条件下,氯在三相中的分布比例与废塑料(WP)的加入量、恒温时间、加热速率有关.随恒温时间、升温速率的增加,焦炭中氯的分布率逐渐减小,而焦油和煤气中氯的分布率逐渐增加.但当恒温时间、升温速率达到一定值时(如100min、16℃/min),三种产物中氯的分布率变化不再明显.控制WP加入量、恒温时间、升温速率,可以控制氯在焦炭中的残留量,实验数据分析证明,在废塑料加入量不大于4%时,只要提高恒温时间和升温速率,就可以使焦炭中的氯含量降到比较低的水平.  相似文献   

5.
在小型干馏装置中进行油页岩热解破碎特性实验,考察升温速率、热解终温、恒温时间对油页岩热破碎的影响。结果表明:提高升温速率、热解终温和延长恒温时间,均在不同程度上促进油页岩的热破碎。升温速率的影响主要体现在10℃/min之下,热解终温的影响主要体现在520℃以上,而恒温时间的影响主要是在2 h之前。经灰色关联计算,结果表明:热解终温对油页岩破碎产生的影响最大,升温速率次之,恒温时间最小。  相似文献   

6.
研究了煤与PVC共热解过程中氯的释放机理,实验蛄果表明,氯的释放率与热解温度、加热速率、恒温时间、PVC的加入量有关.在PVC加入量不大于3%时,如果热解工艺条件达到要求,焦碳中氯的残留量可以接近配煤焦的氯含量.根据实验数据对煤与PVC共热解过程中氯的释放表观动力学进行了分析,发现用一级反应方程处理结果与实验数据非常接近,并通过作图计算出了表观活化能.  相似文献   

7.
针对松木在不同条件下热解的失重规律,用热重分析法对松木的热解失重过程进行了系统研究。分析了松木样品在不同升温速率(5、10、20、30℃/min)和不同温度(200、250、300、350、400℃)条件下恒温4h热解的实验结果,发现松木样品的非等温失重过程由脱水、保持、剧烈失重和缓慢失重4个阶段组成,并且在相同条件下样品的质量对松木的热解过程有一定的影响。在恒温热解过程中,不同的恒温温度条件其失重曲线形态基本相似,但在200、250、400℃条件下恒温热解的热重曲线与300、350℃条件下恒温热解的热重曲线相比较较为平缓。研究结果,为研究松木的热解反应动力学模型及对其合理利用提供了一定的理论基础。  相似文献   

8.
城市生活垃圾筛上物的热解研究及实验   总被引:5,自引:0,他引:5  
对城市生活垃圾场筛上物垃圾进行热解实验,研究特定垃圾的热解过程及其规律.实验采用热解终温为550℃和700℃,热解物料为原始筛上物垃圾和加入热解残炭的筛上物垃圾,实验设备为间歇运行的固定床式热解炉.实验结果表明:热解终温700℃与550℃相比,热解产物中固体和液体的产率降低,瞬时产气速率和气体产率均升高;瞬时产气速率曲线与瞬时耗电量曲线形状一致,迟滞时间为5~10min;物料底部热解产物焦炭存在与否对热解得到的固液气产率、产气特性和能量消耗等方面几乎没有影响.  相似文献   

9.
将油页岩通过酸处理和低温灰化,获得高纯度的有机质和矿物质,利用程序升温装置与二氧化硫在线分析仪.在升温速率为5℃/min的条件下,分别研究了在燃烧过程中茂名油页岩及其有机质与矿物质释放二氧化硫的本征动力学.结果表明,有机硫释放二氧化硫的温度范围为210~470℃,并按两段处理得到了其动力学参数.黄铁矿硫释放二氧化硫的温度范围为290~510℃.文中对油页岩中硫的燃烧转化机理进行了初步的探讨.  相似文献   

10.
文章以白竹和烟煤为原料,在不同共炭化温度、不同掺混比条件下制备共炭化产物,采用热重分析法研究产物在不同升温速率条件下的燃烧特性,并采用Kissinger-Akahira-Sunose(KAS)法和Flynn-Wall-Ozawa(FWO)法计算动力学。结果表明,共炭化产物在燃烧过程中只出现1个峰,与煤单独燃烧基本一致,但综合燃烧特性优于煤;随着共炭化温度升高(350~550℃),灰分增多,燃烧效果下降;随着升温速率提高,样品微商热重(derivative thermogravimetric, DTG)曲线向高温段偏移,但样品的失重量不变;随着白竹掺混比增加,共炭化产物燃烧的失重量随之减少,着火、燃烧性能逐渐提升;白竹与煤共炭化产物燃烧时会出现协同效应;采用FWO法、KAS法活化能结果相近,FWO法模型较优,其线性相关系数高于0.95;白竹与烟煤按质量比7∶3掺混,在350℃条件下共炭化,升温速率为20℃/min时共炭化产物综合燃烧特性指数最好(3.98×10-7 min-2·℃-3),最小着火能量最低(85.85 kJ/...  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号