No abstract

No abstract

No abstract

No abstract

Based on published data, a mathematical model of paraffin hydrocarbon hydrocracking process has been built, and its adequacy has been tested.A need for partial replacement of crude by alternative sources of feedstock (by natural and associated gases, coal, biomass, etc.) has become the impetus for development of alternative fuels: methanol, dimethanol ether (DME), and synthetic liquid hydrocarbons (SLH). Methanol and DME have a high octane number (ON) and cetane rating (CR), but the design of the engine and fuel system must be altered for their use. Fuels produced by Fischer-Tropsch (FT) synthesis do not differ from traditional fuels with respect to physico-chemical characteristics, but possess low operational characteristics: gasolines -low ON, diesel fuels -unsatisfactory low-temperature properties. Chemical transformation of the structure of the hydrocarbons, which leads to enhancement of the operational characteristics of fuel is therefore required for use of products of FT synthesis as motor fuels.Reforming and hydrocracking make it possible to improve the operational characteristics of the products of FT synthesis [1]. Homologs of benzene, which elevate the ON of gasoline are formed during reforming. During hydrocracking, the ON and low-temperature characteristics are improved owing to manifestation of methyl substituents in the chain of paraffin hydrocarbons. Reforming loses its significance in view of the more stringent requirements regarding the content of aromatic hydrocarbons. Hydrocracking and hydroisomerization therefore emerge first and foremost as methods of improving the operational characteristics of both traditional fuels, and also products of FT synthesis.Despite the fact that hydrocarbons produced by FT synthesis are identical to the paraffin hydrocarbons of crude, they have a number of peculiarities: a homogeneous group composition (predominantly paraffins), absence of sulfur, and the possibility of producing lube-oil components from the paraffins, the separation of which is difficult from a reaction mixture with petroleum products. In this connection, it is irrational to mix synthetic