催化反應(yīng)工程（華東理工大學(xué)） 第五章2 環(huán)氧乙烷合成反應(yīng)器

二環(huán)氧乙烷合成反響器1環(huán)氧乙烷反響體系特性(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。反響〔1〕為選擇氧化反響，反響〔2〕為深度氧化反響。選反響〔1〕和反響〔2〕為獨(dú)立反響，C2H4和CO2為關(guān)鍵組分。管殼型反響器2.一維模型環(huán)氧乙烷反響器反響器模型物料衡算熱量衡算整理上式，得：床層的壓力降初值條件條件反響器內(nèi)徑8.034m反響管φ45×3.5mm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℃反響器入口氣量818845Nm3/h反響器入口氣體組成組分C2H4O2EOCO2H2OCH4ArN2C2H6摩爾分率0.300.080.00010.050.0050.50860.05270.00140.0022計(jì)算結(jié)果體積/m3140.0入口溫度/℃178熱點(diǎn)溫度/℃231.9出口溫度/℃230.2yout/%C2H427.90EO1.97CO25.91產(chǎn)量/t.d-1750.2選擇性/%82.03ΔP/MPa0.1893.二維模型環(huán)氧乙烷反響器氣相方程反響器模型－二維非均相固相方程反響器模型－二維非均相邊界條件其中，將上述數(shù)學(xué)模型無因次化，無因次準(zhǔn)數(shù)為反響器模型－二維非均相反響器模型－二維非均相氣相方程〔無因次化〕反響器模型－二維非均相固相方程〔無因次化〕反響器模型－二維非均相邊界條件〔無因次化〕模型參數(shù)的計(jì)算公式徑向彌散混合系數(shù)計(jì)算公式：流－固相傳質(zhì)系數(shù)計(jì)算公式：流－固相傳熱系數(shù)計(jì)算公式：管外沸騰水給熱系數(shù)計(jì)算方法模型參數(shù)的計(jì)算公式模型的數(shù)值求解〔1〕預(yù)測公式〔2〕校正公式1模型的數(shù)值求解〔2〕校正公式2模型的數(shù)值求解〔3〕固相方程采用一階中心差分模型的數(shù)值求解預(yù)測和校正方程消去的點(diǎn)。件，消去的點(diǎn)。那么可用代替，從而離散為新的預(yù)測和校正差分方程，代入用一階中心差別離散的邊界條〔4〕邊界條件的處理模型的數(shù)值求解原方程中項(xiàng)為不定項(xiàng)，根據(jù)L’Hospital法邊界條件用一階中心差別離散，再分別用上述計(jì)算框圖求解固相濃度和溫度方程操作條件：T0,T,Vsp,進(jìn)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(yù)測公式j(luò)>N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否是計(jì)算實(shí)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(shè)計(jì)生產(chǎn)能力為12萬噸/年核心設(shè)備反響器是立式列管固定床反響器，殼體走蒸汽，反響的原料氣走管內(nèi)。反響器特性和操作條件見下表表環(huán)氧乙烷合成反響器特性和操作條件催化劑填充高度7.00m反應(yīng)管內(nèi)徑31.3mm列管數(shù)8821催化劑外形尺寸6.5×2.5×6mm催化劑裝填量55.44ton空速4265.625h－1反應(yīng)壓力2.00MPa原料氣進(jìn)口溫度183.5℃飽和蒸汽壓力2.45MPa飽和蒸汽溫度225.6℃進(jìn)口原料氣組成（mol-%）ET25.06O27.8EO0.01H2O0.31CH462.1CO24.72空時(shí)產(chǎn)率188.85gEO·Lcat-1·h-1選擇率81.7%初期催化劑活性校正因子：0.8077

0.5685續(xù)表環(huán)氧乙烷合成反響器特性和操作條件模型預(yù)測值與工業(yè)實(shí)際值的比較出口氣體組成（mol-%）預(yù)測值實(shí)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(shí)產(chǎn)率gEO·Lcat-1·h-1188.851188.856選擇率（％）81.781.7模型預(yù)測值與工業(yè)實(shí)際值的比較由圖可以看出：模型預(yù)測值與工業(yè)實(shí)際值十分吻合。反響器模型能夠準(zhǔn)確描述反響器內(nèi)環(huán)氧乙烷合成過程，能夠全面反響操作條件對反響的影響。預(yù)測值實(shí)際值計(jì)算結(jié)果－氣相溫度分布ξz0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0183.50221.34228.60229.75229.77229.59229.40229.22229.06228.91228.78183.50221.34228.59229.74229.74229.58229.39229.21229.05228.90228.76183.50221.37228.55229.70229.72229.54229.35229.18229.01228.87228.73183.50221.41228.48229.61229.63229.46229.27229.10228.94228.80228.66183.50221.48228.40229.51229.52229.36229.18229.01228.85228.71228.58183.50221.57228.31229.38229.40229.24229.06228.90228.75228.61228.49183.50221.68228.23229.27229.29229.13228.96228.80228.65228.52228.40計(jì)算結(jié)果－固相外外表溫度分布ξz0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0206.00227.64232.81233.28233.11232.74232.37232.05231.75231.48231.23210.29227.19230.19231.33231.15230.89230.63230.40230.19230.00229.82207.68227.48232.13232.65232.41232.08231.75231.45231.19230.94230.72212.01227.04230.35230.72230.56230.34230.11229.91229.72229.55229.39212.30227.02230.33230.70230.54230.30230.07229.86229.67229.50229.34216.42226.59228.73228.98228.88228.74228.60228.47228.32228.24228.13219.92226.21227.54227.69227.64227.55227.46227.38227.30227.24227.17計(jì)算結(jié)果－氣相乙烯濃度分布ξz0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558.25060.24835.24539.24243.23961.23695.23444.23205.22979.22764.22558計(jì)算結(jié)果－固相外外表乙烯濃度分布ξz0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0.25030.24798.24493.24198.23919.23656.23407.23171.22947.22733.22529.25023.24799.24499.24204.23925.23661.23412.23175.22950.22736.25532.25027.24798.24495.24200.23921.23658.23409.23172.22948.22734.22530.25021.24799.24501.24206.23926.23662.23413.23176.22951.22737.22533.25020.24799.24501.24206.23927.23663.23413.23176.22951.22737.22533.25013.24801.24506.24211.23921.23667.23416.23179.22954.22740.22536.25006.24802.24509.24214.23934.23669.23419.23182.22956.22742.22537計(jì)算結(jié)果－氣相二氧化碳濃度分布ξz0.0000.1670.3330.5000.6670.8331.0000.00.10.20.30.40.50.60.70.80.91.0.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794.04720.04802.04922.05047.05167.05282.05392.05498.05600.05699.05794計(jì)算結(jié)果－固相外外表CO2濃度分布ξz0.0000.1670.33