Abstract:

Based on the statistical data of coal chemistry and coal petrology of 154samples of coal, graphite and vitrinite collected in China, this paper proposesa model of structural formula, thermal evolution process and hydrocarbon pro-ductivity of humic coal, and comes to following conclusions: 1.The typical molecular formuia of Chinese lignite with a vitrinite reflec-tance of 0.359% is C₁₀₂H₉₆O₂₆. 2.Coalification can be divided into five stages. In the second stage, thebreakaway of methoxyl groups raises the curtain on the formation of hydrocarbon. 3.Under geological condition, the hydrocarbon productivity P₂ of residualcoal (water- and ash-free basis) conforms to following equation: p₂=402e^{-2.75(R_o-0.10)}, (0.30≤R_o<4.80) Where vitrinite reflectance R_o is expressed as percentage, and P₂ is m³t^-1. Under the condition of simulation test, the hydrocarbon potential P₃ con-forms to following equation: P₃=598(R_o-0.20)^0.55e^{-1.154(R_o-0.20)}, (R_o≥0.359).