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Hydrocarbons cracking is important industrial process for olefins large-scale production. Ethane, liquefied petroleum gas (LPG) and gasoline represents usual feedstock of the process, however heavy refinery streams such as atmospheric gas oil or hydrocracked vacuum distillates are also important feedstock of steam crackers. Ethane is commonly considered to be the best type of feedstock providing high yield of ethylene and minimal yield of undesirable pyrolysis oil. Moreover, forming of coke during the ethane cracking is slower, therefore longer operational period of reactor is possible for this feedstock.

But the cracking of light feedstock generally requires very sharp cracking condition, and specifically, in the case of ethane. The best cracking results are possible only under modified cracking coil operational parameters: high temperature, minimal pressure-drop, specific spent time. These settings are very energy-intensive and on the edge of industrial coil construction limits. In addition, ethane conversion reaches at most 65 %.

The conversion of cracking reaction under constant conditions is directed by the hydrogen-abstraction reaction. Rate of this reaction is driven by the concentration of active radicals in the reaction mixture. Activity of these radicals is often lower in the cases of light types of feedstock, such as ethane, because the energy of C-C bond in the ethane molecule is higher (in comparison to heavy types of feedstock) hence initiation is slow. If the cause of low conversion of ethane is kinetic (and not thermodynamic), it is possible to shift the conversion under the same reaction conditions by stimulating of radical activity using a source of radicals. In the scale of ethane cracking there is no possibility to initiate the reaction by dosing of usual initiators, such as hydroperoxides. But preliminary searching indicates that methanol is a good candidate for this purpose specifically for easiness of its cracking and low cost. Moreover, there are another reasons to understand alcohol-hydrocarbon mixture cracking and its mechanism, but to the best our knowledge there no similar study has been published to date.

In this paper a mathematical model of copyrolysis will be presented. First step of modeling includes the verifying of ethane cracking thermodynamic limits. In the next step, a consistent kinetic model of ethane-methanol copyrolysis is created using previously developed models of pure components. Interfering of those two reaction mechanism and fusion of models will be demonstrated. This kinetic model will be extended by a model of laboratory reactor (for future experimental verification). Dependence of ethane cracking conversion on the methanol dosing will be investigated and the influence of methanol to cracking products distribution will be presented.