煤焦催化氣化中非均相反應(yīng)動(dòng)力學(xué)的研究

李偉偉 張榮 畢繼誠(chéng) 鄭巖

摘 要：以神木煤焦為研究對(duì)象，在小型加壓固定床上考察了不同氣化劑（水蒸氣、二氧化碳、氫氣）、催化劑負(fù)載量、水蒸氣分壓、氫氣分壓和一氧化碳分壓對(duì)碳轉(zhuǎn)化率和氣化反應(yīng)速率的影響。結(jié)果表明，對(duì)于非均相的催化氣化反應(yīng)來(lái)說(shuō)，反應(yīng)速率順序?yàn)镃-H2O>C-CO2>C-H2。H2和CO不同程度地抑制煤焦水蒸氣氣化反應(yīng)，CO的抑制作用明顯大于H2。在700 ℃，當(dāng)添加5%的CO，碳轉(zhuǎn)化率降低約50%?；贚angmuir-Hinshelwood（L-H）方程，結(jié)合隨機(jī)孔模型，同時(shí)考慮催化劑負(fù)載量及氣化產(chǎn)物分壓的影響，建立了煤焦催化水蒸氣氣化動(dòng)力學(xué)模型，模型預(yù)測(cè)反應(yīng)速率常數(shù)與實(shí)驗(yàn)值誤差在10%以內(nèi)，說(shuō)明建立的動(dòng)力學(xué)模型可以較好地模擬煤焦的催化水蒸氣氣化反應(yīng)過(guò)程。

關(guān)鍵詞：催化氣化 加壓固定床 動(dòng)力學(xué) 隨機(jī)孔模型

Abstract：Gasification of Shenmu coal char have been carried out in a pressured fixed bed reactor to investigate the effect of gasification agents （H2O， CO2， H2）， catalyst loading， and partial pressure of hydrogen and carbon monoxide on the carbon conversion and reaction rate. Results show that the order of rate for heterogeneous reactions is： C-H2O >C-CO2>C-H2. H2 and CO inhibit the steam gasification to some extent. The inhibition by CO is much greater than that of H2.Carbon conversion decreases by about 50% with the addition of only 5%CO at 700 ℃.A kinetic model is developed combined Langmuir-Hinshelwood （L-H） with the random pore model， considering the effect of catalyst loading and the partial pressure of gasification product. The deviation between predication and experiment vale is less than 10%， indicating that the derived kinetic model is appropriate for describing catalytic steam coal gasification.

Key Words：Catalytic coal gasification；Pressured fixed bed；Kinetics；Random pore model

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