Oil refining — the large-capacity manufacture based on transformations of oil, its fractions and oil gases in commodity mineral oil and raw material for petrochemistry, the basic organic synthesis and microbiological synthesis. This manufacture represents set of physical carried out on oil refining factories physical and chemical-technological processes and the operations including preparation of raw material, its initial and secondary processing. Before processing oil subject to special preparation all over again on oil producing regions, and then it is direct on oil refining factories where it release from stratum waters, mineral salts and mechanical impurity and stabilize, driving away mainly propan-butanic, and sometimes in part pentane hydrocarbonic fractions. Initial oil refining consists in its division into the fractions differing by limits of boiling away, with the help initial or secondary atmospheric and vacuum distillation. Such processing allows to allocate from oil only initially present substances. The assortment, completely define an output and quality of developed products a chemical compound of raw material.
For increase of an output of so-called light mineral oil (the fractions boiling up to 350°С, — gasolines, kerosene, gas turbine, diesel and jet fuel) and improvements of quality of fractions and the products received at distillation, secondary oil refining is widely used. It includes the following processes:
• destructive processing of heavy and residual raw material;
• the processes providing improvement of quality of the basic types of mineral oil fuel and oils;
• processing of oil gases, manufactures of oils, paraffins, additives, bitumens and other special types of mineral oil, and also petrochemical and chemical raw material.
To the basic modern lines of oil refining carry:
• integration of individual capacities of technological installations;
• a combination of processes and their reduction of energy capacity due to increase of activity and selectivity of catalysts, recycling of departing thermal energy, optimization of heat exchange and factor of surplus of air submitted in technological furnaces, etc.;
• a deepening of oil refining; improvements of quality of commodity mineral oil at deterioration processed oils;
• wide introduction of automation and a computerization etc.
To number of the primary factors determining a choice of the circuit of oil refining, the output of light mineral oil and the maintenance(contents) of sulfur in oil concern. Processing sulphurous and with high content of sulfur oils, containing sulfur in amount accordingly 0,5-2,5 % and more than 2,5 % on weight, demands inclusion in structure oil refining factories of installations of hydro-clearing and sulfur hydro-removing of mineral oil. To destination oil refinery plant (ORP) share on the enterprises of fuel and fuel — oil structures, and also a fuel — oil structure with release of petrochemical production (while abroad they are called «ORP a chemical structure», in the USSR they referred to as petrochemical combines). Most important characteristic ORP — depth of oil refining which is defined by an output (in calculation on oil, % on weight) all light mineral oil either only motor fuel or, on the contrary, an output of residual boiler fuel — black oil in comparison with its natural contents in raw material, can be achieved with the help various destructive processes. Their densities (the relation of total capacity of installations to capacity of installations of initial oil refining) defines opportunities ORP and a oil-refining industry as a whole on maintenance of the certain depth of processing.
In Russia today there is actual a problem of increase of depth of oil refining. Average depth of oil refining on Russia is submitted in table 4 and in figure 1. For comparison the Central European parameter makes 80 %. However, in Russia still there are enterprises with depth of the oil refining which are not exceeding 30 %.
For the decision of a question on increase of depth of oil refining up to a global level in Russia until recently it was impossible to do without expensive western technologies. However recently began to appear and the Russian technologies of processing of the heavy oil rests (tar, black oil), allowing to finish depth of oil refining in Russia from 60 % accessible for today, up to 87-90 % (for example, the technology developed by experts of Joint-Stock Company "Pandsher-holding").
It is necessary to note, that Depth of oil refining in joint-stock company "Bashneftechem" in 2001 has made 73,5 % and has deduced (removed) this enterprise in number of the best in Russia. In the following, 2002, the tendency of reduction of use of capacities of the enterprises for initial oil refining at "Bashneftechem" up to 56,6 % was observed.
Before receipt of crude oil from oil fields on ORP from it separate stratum water and mineral salts. Besides for decrease (reduction) of losses of valuable hydrocarbons at transportation and storage, and also maintenance of constant pressure of gas to oil at submission on ORP it subject stabilization, i.e. drive away propane-butane, and sometimes in part and pentane fraction of hydrocarbons.
Initial oil refining consists in its distillation as a result of which, depending on a structure of the enterprise, select so-called light (gasolines, kerosene, jet and diesel fuel) and dark (black oil, vacuum distillates, tar) mineral oil. For increase of an output and improvement of quality of light mineral oil, and also receptions of petrochemical raw material oil, direct for the secondary processing connected to change of structure of hydrocarbons included in its structure. Removal of undesirable components (sulphurous, resinous and oxygen containing connections of metals, and also polycyclic aromatic hydrocarbons) is achieved by clearing of mineral oil. For the further improvement of quality of the received mineral oil to them add special substances. For areas with high consumption of black oil are characteristic ORP a fuel structure with superficial oil refining. At these enterprises it is carried out the following technological processes:
• preparation of oil for processing;
• its atmospheric distillation at which receive gasolines, kerosene&, diesel fuel and black oil;
• fuel ennobling – catalytic reforming and isomerisation of gasolines (for reception commodity fuel with low contents S).
The output of the last on such ORP can achieve 50 % on weight and more. If necessary the part of black oil can be directed on vacuum distillation with the purpose of reception of residual bitumens or raw material for manufacture of the oxidized bitumens.
ORP a fuel structure with deep oil refining are intended for regions with a low consumption level of black oil. Sold technological processes in this case look as follows:
• preparation of oil for processing;
• its atmospheric and vacuum distillation;
• destructive processing (catalytic creaking and hydro creaking) heavy and residual raw material
• and ennobling of mineral oil (catalytic reforming, hydroclearing etc.).
There is a big number destructive processes of processing of the oil rests (black oil, tar) in light mineral oil with the purpose of increase in them ratio hydrogen / carbon in comparison with initial raw material. They are subdivided into the following processes:
• the processes providing reduction of the contents of carbon (thermal and catalytic creaking, coking, asphalt destroying);
• the processes resulting in increase of the contents of hydrogen (a
version of hydro creaking).
The last are characterized by the increased output and quality of mineral oil, however demand considerably higher capital and operational investments the charges caused by necessity of realization of processes at high pressures (15-25 MPa) in an atmosphere of hydrogen. The technological circuit of processing of the rests can include one target process or a combination of processes (for example, sulfur hydro-removing of black oil — catalytic creaking). The choice of the circuit is defined by technical and economic features of functioning ORP.
At enterprises ORP of a fuel-oil structure the following processes are carried out:
• preparation for oil refining its atmospheric distillation;
• vacuum distillation of black oil at which receive some vacuum distillates and tar.
Distillates pass consistently selective clearing, paraffin destroying and hydroclearing or additional cleaning by a sulfuric acid or with the help bleaching clays. Tars are exposed asphalt destroying, and formed product of asphalt destroying process under the same circuit, as distillate fractions, and the rest use for manufacture of bitumens or as raw material for gasification. After additional cleaning distillate and residual components direct on compoundition (mixture). Changing a ratio of components and entering various additives, receive commodity lubricant oils.
At enterprises NPZ of a fuel-oil structure with release of petrochemical production as against considered processes of pyrolysis and catalytic reforming, providing development of the basic kinds of petrochemical raw material (the lowest olefins and aromatic hydrocarbons), and also more or less long chain of processes of reception of various mineral oil (spirits, mixes olefins etc.). The basic volumes of manufacture of the important kinds of production of a oil-refining industry in Russia are given in table 5.