Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical char...Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical characteristics of light hydrocarbons on the migration features,dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed,and the effect of migration on specific light hydrocarbon indexes is further discussed.The study indicates that,natural gas from the Lower Shihezi Formation(Pix)in the Dongsheng gas field displays higher iso-C5-7contents than n-C5-7contents,and the C6-7light hydrocarbons are composed of paraffins with extremely low aromatic contents(<0.4%),whereas the C7light hydrocarbons are dominated by methylcyclohexane,suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution.The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging,and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation.Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio,as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values.The dissolution causes the increase of isoheptane values of the light hydrocarbons,whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7contents compared to the iso-C5-7contents.展开更多
The field observation of 54 non-methane hydrocarbon compounds(NMHCs)was conducted from September 1 to October 20 in 2020 during autumn in Haidian District,Beijing.The mean concentration of total NMHCs was 29.81±1...The field observation of 54 non-methane hydrocarbon compounds(NMHCs)was conducted from September 1 to October 20 in 2020 during autumn in Haidian District,Beijing.The mean concentration of total NMHCs was 29.81±11.39 ppbv during this period,and alkanes were the major components.There were typical festival effects of NMHCs with lower concentration during the National Day.Alkenes and aromatics were the dominant groups in ozone formation potential(OFP)and OH radical loss rate(L_(OH)).The positive matrix factorization(PMF)running results revealed that vehicular exhaust became the biggest source in urban areas,followed by liquefied petroleum gas(LPG)usage,solvent usage,and fuel evaporation.The box model coupled with master chemical mechanism(MCM)was applied to study the impacts of different NMHCs sources on ozone(O_(3))formation in an O_(3)episode.The simulation results indicated that reducing NMHCs concentration could effectively suppress O_(3)formation.Moreover,reducing traffic-related emissions of NMHCs was an effective way to control O_(3)pollution at an urban site in Beijing.展开更多
The forming condition of coal and coaly organic matter is analyzed. The dynamics of hydrocarbon generation of coal and coaly organic matter is discussed. It has been pointed out that the temperature is the main predom...The forming condition of coal and coaly organic matter is analyzed. The dynamics of hydrocarbon generation of coal and coaly organic matter is discussed. It has been pointed out that the temperature is the main predominant factor for the hydrocarbon generation of coal; chemical effect of structural pressing and shearing force accelerates the evolution of hydrocarbon derived from coal, and is the prerequisite for the hydrocarbons to be expelled from coal. The existence of atoms of N, S, O etc. is the prerequisite for forming the hydrocarbons at early evolution stage. The importance of NSO compounds in the evolution of hydrocarbon generation has been emphasized.展开更多
基金Supported by the National Natural Science Foundation of China(42172149,U2244209)Sinopec Science and Technology Research Project(P23230,P22132)。
文摘Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical characteristics of light hydrocarbons on the migration features,dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed,and the effect of migration on specific light hydrocarbon indexes is further discussed.The study indicates that,natural gas from the Lower Shihezi Formation(Pix)in the Dongsheng gas field displays higher iso-C5-7contents than n-C5-7contents,and the C6-7light hydrocarbons are composed of paraffins with extremely low aromatic contents(<0.4%),whereas the C7light hydrocarbons are dominated by methylcyclohexane,suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution.The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging,and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation.Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio,as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values.The dissolution causes the increase of isoheptane values of the light hydrocarbons,whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7contents compared to the iso-C5-7contents.
基金supported by the National Key Research and Development Program of China(No.2017YFC0210001)National Natural Science Foundation of China(Nos.42022039,21671089)+2 种基金the Scientific Research Fund of Liaoning Provincial Education Department(No.L2020002)Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202011)the Youth Innovation Promotion Association CAS(No.2017042)
文摘The field observation of 54 non-methane hydrocarbon compounds(NMHCs)was conducted from September 1 to October 20 in 2020 during autumn in Haidian District,Beijing.The mean concentration of total NMHCs was 29.81±11.39 ppbv during this period,and alkanes were the major components.There were typical festival effects of NMHCs with lower concentration during the National Day.Alkenes and aromatics were the dominant groups in ozone formation potential(OFP)and OH radical loss rate(L_(OH)).The positive matrix factorization(PMF)running results revealed that vehicular exhaust became the biggest source in urban areas,followed by liquefied petroleum gas(LPG)usage,solvent usage,and fuel evaporation.The box model coupled with master chemical mechanism(MCM)was applied to study the impacts of different NMHCs sources on ozone(O_(3))formation in an O_(3)episode.The simulation results indicated that reducing NMHCs concentration could effectively suppress O_(3)formation.Moreover,reducing traffic-related emissions of NMHCs was an effective way to control O_(3)pollution at an urban site in Beijing.
文摘The forming condition of coal and coaly organic matter is analyzed. The dynamics of hydrocarbon generation of coal and coaly organic matter is discussed. It has been pointed out that the temperature is the main predominant factor for the hydrocarbon generation of coal; chemical effect of structural pressing and shearing force accelerates the evolution of hydrocarbon derived from coal, and is the prerequisite for the hydrocarbons to be expelled from coal. The existence of atoms of N, S, O etc. is the prerequisite for forming the hydrocarbons at early evolution stage. The importance of NSO compounds in the evolution of hydrocarbon generation has been emphasized.
