催化反應工程華東理工大學第五章2環(huán)氧乙烷合成反應器

1、二 環(huán)氧乙烷合成反應器 11 環(huán)氧乙烷反應體系特性 (1) (2) (3)在銀催化劑上，乙烯（簡稱ET）氧化除得到產(chǎn)物環(huán)氧乙烷（簡稱EO）外，主要副產(chǎn)物是二氧化碳和水。反應（1）為選擇氧化反應，反應（2）為深度氧化反應。選反應（1）和反應（2）為獨立反應，C2H4和CO2為關(guān)鍵組分。2管殼型反應器32. 一維模型環(huán)氧乙烷反應器 反應器模型 物料衡算熱量衡算4整理上式，得：床層的壓力降初值條件5已知條件反應器內(nèi)徑 8.034m 反應管 453.5mm 高度 8m 管數(shù) 15431根入口壓力 1.89MPa 入口溫度 178 沸騰水壓力 2.4252MPa 溫度 223 反應器入口氣量 81884

2、5Nm3/h反應器入口氣體組成組 分C2H4O2EOCO2H2OCH4ArN2C2H6摩爾分率0.300.080.00010.050.0050.50860.05270.00140.00226計算結(jié)果體積/m3 140.0入口溫度/ 178熱點溫度/ 231.9 出口溫度/ 230.2yout /%C2H4 27.90 EO 1.97 CO2 5.91產(chǎn)量/t.d-1 750.2選擇性/% 82.03P/MPa 0.18973. 二維模型環(huán)氧乙烷反應器氣相方程8反應器模型二維非均相固相方程9反應器模型二維非均相邊界條件其中，10將上述數(shù)學模型無因次化，無因次準數(shù)為反應器模型二維非均相11反應器模

3、型二維非均相氣相方程（無因次化）12反應器模型二維非均相固相方程（無因次化）13反應器模型二維非均相邊界條件（無因次化）14模型參數(shù)的計算公式 徑向彌散混合系數(shù)計算公式： 流固相傳質(zhì)系數(shù)計算公式：15流固相傳熱系數(shù)計算公式：管外沸騰水給熱系數(shù)計算方法模型參數(shù)的計算公式 16模型的數(shù)值求解 （1）預測公式17（2）校正公式1模型的數(shù)值求解 18（2）校正公式2模型的數(shù)值求解 19（3）固相方程采用一階中心差分模型的數(shù)值求解 20預測和校正方程消去 的點。件，消去 的點。則可用 代替，從而離散為新的預測和校正差分方程，代入用一階中心差分離散的邊界條（4）邊界條件的處理模型的數(shù)值求解 原方程中項為不

4、定項，根據(jù)L Hospital法邊界條件用一階中心差分離散，再分別用上述21計算框圖求解固相濃度和溫度方程操作條件：T0,T,Vsp,進口氣體組成。軸徑向分段數(shù)N,M求解氣相濃度和溫度校正公式求解氣相濃度和溫度預測公式jN結(jié)束打印該截面氣固相濃度和溫度分布k=0j=0k=0k=1j=j+0.5k=1j=j+0.5k=0否是22計算實例 上海石化總廠化工廠采用的氧氣法環(huán)氧乙烷合成路線，屬于美國SD公司技術(shù)。環(huán)氧乙烷設計生產(chǎn)能力為 12萬噸/年核心設備反應器是立式列管固定床反應器，殼體走蒸汽，反應的原料氣走管內(nèi)。反應器特性和操作條件見下表23表 環(huán)氧乙烷合成反應器特性和操作條件催化劑填充高度7.0

5、0m反應管內(nèi)徑31.3mm列管數(shù)8821催化劑外形尺寸6.52.56mm催化劑裝填量55.44ton空速4265.625h1反應壓力2.00MPa原料氣進口溫度183.5飽和蒸汽壓力2.45MPa飽和蒸汽溫度225.624續(xù)表 環(huán)氧乙烷合成反應器特性和操作條件25模型預測值與工業(yè)實際值的比較出口氣體組成（mol-%）預測值實際值ET22.5622.65O25.225.32EO2.292.21H2O1.331.45CH462.8162.60CO25.795.77出口氣體溫度（）228.5228.6空時產(chǎn)率gEOLcat-1h-1188.851188.856選擇率（）81.781.726模型預測值

6、與工業(yè)實際值的比較由圖可以看出：模型預測值與工業(yè)實際值十分吻合。反應器模型能夠準確描述反應器內(nèi)環(huán)氧乙烷合成過程，能夠全面反應操作條件對反應的影響。 預測值實際值27計算結(jié)果氣相溫度分布 z0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0183.50221.34228.60229.75229.77229.59229.40229.22229.06228.91228.78183.50221.34228.59229.74229.74229.58229.39229.21229.05228.90228.76183.50

7、221.37228.55229.70229.72229.54229.35229.18229.01228.87228.73183.50221.41228.48229.61229.63229.46229.27229.10228.94228.80228.66183.50221.48228.40229.51229.52229.36229.18229.01228.85228.71228.58183.50221.57228.31229.38229.40229.24229.06228.90228.75228.61228.49183.50221.68228.23229.27229.29229.13228.96

8、228.80228.65228.52228.4028計算結(jié)果固相外表面溫度分布 z0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0206.00227.64232.81233.28233.11232.74232.37232.05231.75231.48231.23210.29227.19230.19231.33231.15230.89230.63230.40230.19230.00229.82207.68227.48232.13232.65232.41232.08231.75231.45231.19230.9

9、4230.72212.01227.04230.35230.72230.56230.34230.11229.91229.72229.55229.39212.30227.02230.33230.70230.54230.30230.07229.86229.67229.50229.34216.42226.59228.73228.98228.88228.74228.60228.47228.32228.24228.13219.92226.21227.54227.69227.64227.55227.46227.38227.30227.24227.1729計算結(jié)果氣相乙烯濃度分布 z0.0000.1670.3

10、330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.2320

11、5.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.2255830計算結(jié)果固相外表面乙烯濃度分布 z0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.

12、91.0.25030.24798.24493.24198.23919.23656.23407.23171.22947.22733.22529.25023.24799.24499.24204.23925.23661.23412.23175.22950.22736.25532.25027.24798.24495.24200.23921.23658.23409.23172.22948.22734.22530.25021.24799.24501.24206.23926.23662.23413.23176.22951.22737.22533.25020.24799.24501.24206.23927.2

13、3663.23413.23176.22951.22737.22533.25013.24801.24506.24211.23921.23667.23416.23179.22954.22740.22536.25006.24802.24509.24214.23934.23669.23419.23182.22956.22742.2253731計算結(jié)果氣相二氧化碳濃度分布 z0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0.04720.04802.04922.05047.05167.05282.05392.05498

14、.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922

15、.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.0579432計算結(jié)果固相外表面CO2濃度分布 z0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0.04729.04816.04942.05066.05185.05299.05409.05514.05615.05713.05807.04731.04816.04938.05063.05182.05296.05406.05511.05613.05711.05806.04729.04816.04940.05065.05184.05298.05408.05513.05614.05712.05807.04732.04815.04937.0506