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1.
甲醇合成催化剂XNC-98的本征动力学   总被引:1,自引:3,他引:1  
在等温积分反应器中研究了四川西南化工研究院研制的新型甲醇合成催化剂XNC-98的本征动力学。实验采用的催化剂为60~80目的细颗粒催化剂,实验压力为4~5MPa,反应温度为210~260℃,空速为8000~12000h^-1。采用了Langmuir—Hinshelwood本征动力学模型。用改进的高斯-牛顿法确定动力学模型参数。残差分析和统计检验结果表明,所得到的本征动力学模型与实验数据吻合良好,为采用细颗粒催化剂的三相淤浆床甲醇合成反应器的设计提供了理论依据。  相似文献   

2.
在等温积分反应器中,压力2.5~5.6MPa,温度210~255℃,空速6000~20000h^-1的实验条件下,对西南化工研究院研制的新型低温低压甲醇合成催化剂C302—2的CO、CO2加氢合成甲醇的本征动力学进行了研究。用改进的单纯形法和改进的高斯-牛顿法相结合对所采用的Langmuir—Hinshelwood型动力学模型进行参数估值,得到本征动力学方程。残差分析和统计检验结果表明,得到的本征动力学模型是适定的,可良好地适合于反应条件。实验结果可以为采用细颗粒催化剂的三相淤浆床甲醇合成反应器设计提供本征动力学数据。  相似文献   

3.
采用一种内循环折流式生物反应器进行脱氮实验.分别用硝酸盐、亚硝酸盐和氨作为氮源配制模拟废水进行研究.结果表明:该反应器具有良好的除氮功能.当以硝酸盐或亚硝酸盐为氮源时,总氮与硝酸盐、亚硝酸盐的去除速率几乎相同,其降解规律可以用分数级动力学进行很好地拟合,其反应级数为0.88.当以氨作为氮源时,可以实现同步硝化和反硝化.此时氨氮的去除仍可以0.88级动力学进行描述.而总氮的去除规律符合3级反应动力学.在相同的碳氮比(C/N)情况下,硝酸盐和亚硝酸盐的去除速率远大于氨氮的去除速率,且总氮的去除速率随C/N的增加而增加.  相似文献   

4.
丙醛与氨气固相环合催化反应机理的研究   总被引:3,自引:0,他引:3  
在固定床反应器中,研究了丙醛与氨环合的反应动力学特性,研究结果表明,当催化剂粒度小于0.8mm时,内扩散影响可以排除,当气体流速W/FA0<3.6时,外扩散影响可以排除,提出了简化的丙醛气相环合动力学模型,实验值和计算值基本相符,反应级数为一级,反应速率表达式为(-γA)W=83.45exp(-14.55/RT)CA.提出了3种机理模型假设,根据实验数据拟合的结果,认为模型2的假设可以合理地解释实验现象,研究了固定床催化反应模型,假定为拟一维模型,研究了丙醛转化率与床层高度之间的关系,可供工业固定床反应器设计参考。  相似文献   

5.
由于在反应器中进行反应情况比较复杂,微观动力学得出的反应速率式一般不适用。本文针对反应器中各种情况讨论化学反应速率。  相似文献   

6.
为了掌握烟气脱硝用尿素水解制氨工艺的放大规律,通过建立中试装置来模拟工业反应器的传递过程,对尿素水解工艺开展了中试及工业化放大试验研究。结果表明,尿素溶液在一定温度、压力下发生水解反应生成氨气、二氧化碳和水蒸气的混合气,气液相平衡可采用修正的LewisRandall方程和Herry方程分别描述。当操作温度为150℃时,反应-扩散准则数M为0.036,表明尿素水解制氨为液相慢反应,本征反应速率远小于氨气扩散速率,反应器的产氨速率由动力学控制,可简化为温度和反应平衡常数的函数;水解反应器内加热蒸汽发生冷凝换热,液相区则产生泡核沸腾;根据中试试验数据建立的表观动力学模型,可用于指导工业反应器的结构设计。该研究将为烟气脱硝用尿素水解制氨工艺开发及反应器放大设计提供重要参考。  相似文献   

7.
本书是理解光催化技术原理及应用的指南,其内容包括基本原理、文献综述及理论应用等方面。其重点在于多相光催化作用的化学反应工程方面,尤其是反应动力学模型、反应器辐照及反应器设计。对水和大气中污染物转换的实际应用也进行了评述。本书共有9章,各章内容分别如下:1.建立光催化动力学反应速率方程:基本原理和参数;  相似文献   

8.
La0.5Sr0.5Ni0.5Cu0.5O3催化剂上的CO氧化反应动力学   总被引:2,自引:0,他引:2  
利用内循环无梯度反应器对钙钛矿型催化剂 La0 .5 Sr0 .5 Ni0 .5 Cu0 .5 O3上 CO氧化反应的动力学进行了研究 ,实验中通过分别测定 CO和 O2 的分压对氧化反应速率的影响 ,得出了相应的曲线关系 ,通过对所有动力学数据用计算机进行多元线性回归 ,得出动力学方程 r =2 .2 6× 1 0 8e-1 0 3 0 0 0 /8.3 1 4 T Pco0 .5 ,根据动力学实验结果初步提出了 CO在该催化剂上氧化机理模型 .  相似文献   

9.
C302催化剂上甲醇合成反应宏观动力学   总被引:10,自引:4,他引:6  
在内循环无梯度反应器中测定了低压甲醇合成反应宏观动力学。实验采用5m m ×5m m 圆柱状颗粒催化剂,实验压力5MPa,反应温度215~260 °C。以双曲型动力学方程建立了以各组分逸度表示的CO、CO2 加氢合成甲醇的双速率宏观动力学模型,并用改进高斯-牛顿法根据实验数据获得了动力学模型中的参数。残差分析和统计检验表明,动力学模型是适定的。宏观反应动力学方程成功应用于上海焦化总厂年产20 万吨大型甲醇合成反应器的模拟放大。  相似文献   

10.
甲基叔丁基醚(MTBE)裂解是一条比较理想的生产高纯度异丁烯的工艺路线.采用管式反应器,在170~230℃、0.2~0.6 MPa、液相空速0.5~2 h-1的条件下,对SPC-01型固体杂多酸催化剂上甲基叔丁基醚裂解制异丁烯的工艺进行了研究,考察了操作条件对裂解过程的影响.当反应压力为0.4 MPa、反应温度为210~230℃、液相空速为0.5~1.0 h-1时,MTBE转化率高于92.2%,异丁烯和甲醇选择性均大于99.9%.采用一维平推流积分反应器模型建立幂函数裂解动力学方程,利用最小二乘法对动力学实验数据进行参数拟舍,获得了裂解动力学方程,并对模型进行了检验.  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.
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