煤焦催化氣化中非均相反應動力學的研究

李偉偉 張榮 畢繼誠 鄭巖

摘 要：以神木煤焦為研究對象，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）、催化劑負載量、水蒸氣分壓、氫氣分壓和一氧化碳分壓對碳轉化率和氣化反應速率的影響。結果表明，對于非均相的催化氣化反應來說，反應速率順序為C-H2O >C-CO2>C-H2。H2和CO不同程度地抑制煤焦水蒸氣氣化反應，CO的抑制作用明顯大于H2。在700℃，當添加5%的CO，碳轉化率降低約50%。基于Langmuir-Hinshelwood（L-H）方程，結合隨機孔模型，同時考慮催化劑負載量及氣化產物分壓的影響，建立了煤焦催化水蒸氣氣化動力學模型，模型預測反應速率常數與實驗值誤差在10%以內，說明建立的動力學模型可以較好地模擬煤焦的催化水蒸氣氣化反應過程。

關鍵詞：催化氣化 加壓固定床 動力學 隨機孔模型

Study of Heterogeneous Reaction Kinetics in Catalytic Coal Gasification

Li Weiwei1 Zhang Rong1 Bi Jicheng1 Zheng Yan2

（1.Institute of Coal Chemistry，Chinese Academy of Sciences； 2.State Key Laboratory of Coal-based Low-carbon Energy，ENN）

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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