09化反新課件第5章

1、第五章 化學(xué)反應(yīng)速率的數(shù)據(jù)收集與分析Collection and analysis of rate data Batch reactor data（間歇反應(yīng)器數(shù)據(jù)）Method of initial rates（初速率法）Method of half life（半衰期法）Differential reactors（微分反應(yīng)器）Least square analysis（最小二乘法）Experimental planning（實(shí)驗(yàn)安排）Evaluation of lab reactors（實(shí)驗(yàn)反應(yīng)器評價）圖5-1 微分法確定反應(yīng)級數(shù)例5-1 利用微分法分析壓力時間關(guān)系數(shù)據(jù)。 確定氣相叔丁酸叔丁酯

2、分解反應(yīng)的反應(yīng)級數(shù)。(CH3)3COOC(CH3)3 C2H6 + 2 CH3C=OCH3反應(yīng)在實(shí)驗(yàn)室恒溫間歇反應(yīng)器中進(jìn)行，反應(yīng)過程中記錄不同時刻體系的總壓力，見表E5-1.1，初始狀態(tài)的反應(yīng)物僅為純叔丁酸叔丁酯。 表E5-1.1壓力時間關(guān)系數(shù)據(jù)時間（min） 0 2.5 5.0 10.0 15.0 20.0壓力（mmHg）7.5 10.5 12.5 15.8 17.9 19.4圖E5-1.2 確定k和 Fig5-3 CAt of zero order reaction Fig5-3 CA一t of first order reactionFig5-3 CAt of second order

3、reaction Example 5-2 Kinetics using integral methodExample 5-3 method of initial rates in solid-liquid dissolution kineticsThe dissolution of dolomite, calcium magnesium carbonate, in hydrochloric acid is a reaction of particular importance in the acid simulation of dolomite oil reservoirs. The oil

4、is contained in pore space of the carbonate material and must flow through the small pores to reach the well bore. In matrix stimulation, HCl is injected into a well bore to dissolve the porous carbonate matrix. By dissolving the solid carbonate the pores will increase in size, and the oil and gas w

5、ill be able to flow out at faster rates, thereby increasing the productivity of the well. The dissolution reaction is4HCl + CaMg(CO3)2 Mg2+ + Ca2+ + 4Cl- + 2CO2 + 2H2O 4A (L) + B (S) products B is in excess (過量）The concentration of HCl at various times was determined from atomic absorption spectroph

6、otometer measurements of the calcium and magnesium ions. Determine the reaction order with respect to HCl from the data presented in Fig E5-3.1 for this batch reaction. Assume that the rate law is in the form given by equation (5-1) and that the combined rate law and mole balance for HCl can be give

7、n by equation (5-6).Solution At t=0 Taking the log 4N HCl溶液 1N HCl溶液 30 cm2 of solid per liter of solution Table 5-3 (除了1.0和4.0外，又補(bǔ)充了三個實(shí)驗(yàn)點(diǎn)) 初濃度 CHCl, 0（mol/dm3）1.04.02.00.10.5初速率1.22.01.360.360.74Example 5-4 Differential reactorThe formation of methane from carbon monoxide and hydrogen using a nicke

8、l catalyst was studied by Pursley. The reaction was carried out at 500 oF in a differential reactor where the effluent concentration of methane was measured.(a). Relate the rate of reaction to the exit methane concentration.(b) the reaction rate law is measured to be the product of a function of the

9、 partial pressure CO, f(CO), and a function of the partial pressure of H2, g(H2)3H2 + CO CH4 + 2H2ODetermine the reaction order with respect to carbon monoxide, using the data in table E5-4.1. Assume that the functional dependence of on PCO is of the form 實(shí)驗(yàn)編號Pco(atm)PH2(atm)CCH4(gmol/dm3)111.02.44x

10、10-421.81.04.40 x10-434.081.010.0 x10-44561.01.01.00.10.54.01.65x10-412.47x10-41.75x0-4實(shí)驗(yàn)編號PCO(atm)PH2(atm)CCH4(gmol/dm3)11.01.02.4410-47.3310-321.81.04.4010-413.210-334.081.010.010-430.010-341.00.11.6510-44.9510-351.00.52.4710-47.4210-361.04.01.7510-45.2510-3當(dāng)氫氣分壓為常數(shù)時 對前三次實(shí)驗(yàn)，以對作圖得，=1以氫氣為考察對象確定反應(yīng)速率方

11、程由表E5-4.2可以發(fā)現(xiàn)，PH2與的關(guān)系不能用冪指數(shù)形式表示。比較實(shí)驗(yàn)1，4，5，6發(fā)現(xiàn)，反應(yīng)速率先增大，然后減小，因此存在一個特定的值，使反應(yīng)速率達(dá)到最大值，根據(jù)這個發(fā)現(xiàn)可以給出反應(yīng)速率方程的表達(dá)式。低H2濃度時高H2濃度時需要找到一個合適的速率方程，使它同時適合高值和低Example 5-5 using least square analysis to determine rate law parametersCA0（mol/dm3）0.10.51.02.04.0（mol/m2h）1020.0730.701.844.8612.84電腦芯片生產(chǎn)過程中半導(dǎo)體的蝕刻也是一個較為重要的固-液溶解

12、反應(yīng)（見習(xí)題P5-12和12.10中的相關(guān)內(nèi)容），可以用不同的酸和鹽研究該反應(yīng)，反應(yīng)速率為液相中與半導(dǎo)體能帶相關(guān)的氧化還原電勢的函數(shù)。研究表明，僅通過改變酸的陰離子就可以使反應(yīng)速率提高105倍。利用下列數(shù)據(jù)，可以確定MnO2在HBr中溶解反應(yīng)的反應(yīng)級數(shù)和速率常數(shù)。RunCA0XiYiXiYiXi210.1-2.3020.00073-7.2216.615.2920.5-0.6930.007-4.963.420.4831.00.00.0184-4.00.00.042.00.6930.0486-3.02-2.090.4854.01.380.128-2.06-2.841.90b=1.4，=1.4a=-

13、3.99，k=1.8410-2（dm3/mol）0.4/m2h圖5-12 實(shí)驗(yàn)流程圖圖5-8 微分反應(yīng)器造價低、易操作、易控制、恒溫區(qū)保證。反應(yīng)程度淺，誤差大 圖5-14 積分反應(yīng)器成本造價低、容易操作、容易控制、恒溫區(qū)不好保證 圖5-15 攪拌間歇反應(yīng)器主要問題是如何保證全混流 圖5-16固相存在的攪拌反應(yīng)器Basket type reactor消除催化劑的內(nèi)外擴(kuò)散是關(guān)鍵 圖5-17 CSTR反應(yīng)器 圖5-18 提升管反應(yīng)器 反應(yīng)器類型取樣和分析等溫性能流固接觸催化劑失活加工難度微分P-FF-GFPG固定床GP-FFPG攪拌間歇FGGPGSCSRGGF-GPF-GCSTRFGF-GF-GP-F提升管F-GP-FF-GGF-G循環(huán)F-GGGF-GP-F脈沖GF-GPF-GGComparison of different reactorsG: good, F: fair, P: poorDetermine the reaction order and specific reaction rate using f