Modelling isotope fractionation during primary cracking of natural gas: a reaction kinetic approach

摘要: Abstract A numerical model has been developed to compute stable carbon isotope variations in natural gas (methane) by calculating 13 CH 4 and 12 generation as a set of parallel first-order reactions primary cracking. The goal this work was combine the description fractionation with established kinetic models for generation. Stable ratios methane from sedimentary organic matter are characterized initial ratio precursors within constant difference activation energy between C - C-methane corresponding precursor sites. Methane is calculated separately . automatically implies temperature dependence processes which not taken into consideration previous works. This new offers theoretical explanation mathematical observed variability δ -values during open-system pyrolysis experiments. Carbon isotopes thermogenic origin can be simulated any geological history. application method two coaly rock samples Pokur formation northern West Siberia results values very similar those reservoirs (δ 1 =−42‰ −54‰). finding supports at an early stage maturation.