Abstract: The kinetics of carbon deposition and its subsequent gasification by steam in the heptane-steam reforming process on a Chinese nickel catalyst has been studied in the temperature range of 460-550℃ and at a pressure of 1.01 ×105 Pa. The constant coking rates are represented as without steam ro = 1.99 ×107exp(-16100/RT)PHep0.97., with steam re=4.71 × 106exp( -18600/RT)PHep0.94.PH2O-0.98, and the constant decoking rates as carbon deposited without steam carbon deposition with steam The reaction order, energy of activation, pre-exponential factor and the role of steam are discussed. It is concluded that the function of steam during carbon deposition is not only to gasify the deposited carbon, but also, more significantly to suppress the formation and growth of carbon fibre nuclei.

摘要： 本文研究了460—550℃,一个大气压下,正庚烷在国产RKN催化剂上,水蒸汽转化过程中的积碳和随即的水蒸汽消碳动力学.得到了无水蒸汽下恒速积碳速率γ_0=1.99×10~7exp[-16100/RT]P_(Hep)~(0.97)kg(C)/kg(cat.)h,有水蒸汽下的恒速积碳速率γ_c=4.71×10~6exp[-18600/RT]P_(Hep)~(0.94)P_(H_2O)~(-0.96)kg(C)/kg(cat.)h;以及无水蒸汽下积碳累积量约40mg后,用水蒸汽消碳的恒速消碳速率γ_0~’=3.75×10~8exp[-30000/RT]kg(C)/kg(cat)h,和有水蒸汽时积碳约40mg后,即用水蒸汽消碳的恒速消碳速率γ_c~’=4.52×10~8exp[-29600/RT]×[1十0.27×ln(P_(Hep)/P_(H_2O))]kg(C)/kg(cat)h的动力学方程式.讨论了反应级数、反应活化能和指前因子以及水蒸汽的作用.提出了水蒸汽的作用不单是气化已生成的积碳,其更本质的作用是抑制和消除碳须核(Carbon fibre nuclei)的形成和生长的观点.