RU2288940C1 - Process for thermochemical processing of heavy petroleum residues - Google Patents

Abstract

FIELD: petroleum processing.

SUBSTANCE: heavy petroleum residues are subjected to thermal cracking at temperature above 400°C including preheating of feedstock. Thermal cracking is conducted at atmospheric pressure and 400-430°C in presence of 8-12% of thermally or catalytically active hydrogen-donor agents selected from following series: common or enriched shales, zeolite-containing catalysts, and mixture of common shales with zeolite-containing aluminosilicate catalysts. Duration of process ensures complete distillation of light distillate products.

EFFECT: enhanced process efficiency, increased assortment of products, simplified equipment, and avoided waste.

1 tbl

Description

The invention relates to the field of processing of natural energy carriers, and in particular to methods of thermochemical processing of heavy oil residues (TNO) into light petroleum products and heavy cracked residues.

The problem of increasing the yield of light oil products from oil is relevant for most Russian refineries, since the capacities of modern secondary processes (catalytic cracking and hydrocracking) are insufficient. These processes are characterized by huge investments, therefore, at the present stage, there is a problem of reducing capital costs. On the other hand, to increase the depth of oil refining (ideally 100%), thermal and oxidative processes for processing heavy oil residues are widely used after they have been adequately prepared by coking, thermal cracking, hydrogen donor and other types of cracking (for example, in the presence of water vapor) with obtaining light and heavy distillates, coke, pitch, bitumen.

 It is known that heavy oil residues (vacuum gas oils, fuel oils, semi-tars and tars), in contrast to light oil products (gasolines and diesel fuels), are characterized not only by a higher molecular weight, different group and fractional composition, but also by a low hydrogen content. In TNO, most of the heteroatomic components are concentrated, almost all resins and asphaltenes. The average molecular weight of TNO components is 3-5 times higher than that of light oil products. TNO molecules are characterized by the manifestation of an association with the formation of supramolecular formations. In light petroleum products, consisting almost entirely of alkanes of normal and branched structure, naphthenes and arenes and compounds of a hybrid structure, the hydrogen content is higher than in TNO. Therefore, to convert TNO molecules into light petroleum products, it is necessary to crack large TNO molecules and to the maximum extent ensure the necessary molecular structure that determines the required consumer properties of motor fuel (for gasoline - high octane characteristics, and for diesel fractions - the required cetane characteristics.

Closest to the claimed is a method for producing liquid products from heavy oil residues (RF Patent No. 2178448, BI No. 2 (II), 2002 - prototype), which consists in the preparation of a homogeneous mixture of TNO and specially dried and subjected to mechanochemical processing in a vibratory mill finely divided sapropelite (particle size 20-30 μm), followed by thermocracking the resulting mixture at 390-420 ° C and 0.2-5 MPa and separation of cracking products, characterized in that the mechanochemical treatment is carried out in an inert medium under a pressure of 0.05 atm,the vibrating mill works in a flow with a vibrating screen, and the components are continuously fed to the mixing by a screw feeder with an adjustable feed rate. As oil sapropelite, oil shale, saproximite, boghead, kennel are used. A thermal cracking unit for heavy oil residues in the presence of an organomineral catalyst, in addition to a feed mixer, a feed mixture heating furnace with a reaction chamber, includes disintegrators, remote reactors, a separator, an atmospheric column for the separation of thermal cracking products (Patents RF 2178446 and 2178447, BI No. 2 (II), 2002 g.).

However, the known method has several disadvantages (complex hardware design of the process, the need for thorough drying and very fine grinding of sapropelite, the use of sapropelite of the same genetic type (carbonate), heating of raw materials in a tube furnace with its inevitable coking, the need to carry out the process in an inert environment, including vibration grinding of sapropelite , the presence of remote reactors operating under high pressure, the need to use water vapor to isolate organomine from the reaction products cial spent catalyst).

The objective of the invention is to increase the efficiency of the method by increasing the yield of the target product while expanding the raw material base and the range of donor thermal and catalytically active additives, simplifying the hardware design of the process, its non-waste and versatility. According to this technology, not only fuel oils and tars can be processed, but also vacuum gas oils, half tars in a machine with mechanical stirring.

The problem is achieved in that in the method for thermochemical processing of heavy oil residues by thermocracking at a temperature above 400 ° C, including preheating the feedstock to a cracking temperature, according to the invention, raw materials in the form of heavy oil residues are thermocracked in the presence of thermally or catalytically active donor - hydrogen additives selected from the series: ordinary or enriched schists of various genetic types (carbonate, aluminosilicate, aluminosilicate-carbonate, sily cathodic), the mineral part of shale, zeolite-containing catalysts, a mixture of ordinary shale and zeolite-containing aluminosilicate catalysts, at atmospheric pressure in the temperature range 400-430 ° C with the content of these additives of 8-12 wt.% with a duration of the process that ensures complete distillation of light distillate products.

The proposed non-waste method allows, within certain limits, to vary the ratio between the gasoline and diesel fractions, as well as to improve the quality of the resulting light liquid products and high-boiling residue-thermal bitumen in comparison with the purely thermal process of cracking of TNO. In contrast to the prototype, the process is carried out not in remote reactors under pressure, but in an apparatus with a stirrer without using an inert medium at atmospheric pressure. It is enough to grind solid additives in a ball mill to a particle size minus 0.1 mm, and the aluminosilicate catalyst Zeocar-2 can be used without additional preparation in a commercial ready-made form. In our case, in contrast to the prototype, the contact of mineral components with the oil product and the organic mass of oil shale is provided by intensive mixing of the reaction mixture. Shales of various genetic types can be used: carbonate (for example, Baltic shale of the Leningrad or Estonian deposits), aluminosilicate-carbonate (for example, Colorado shale of the USA Green River deposit, aluminosilicate (for example, Scottish shale or Shubarkol-Komir shale from Kazakhstan) It is possible to use other shales from deposits in Russia and the CIS countries. The use of shales with an aluminosilicate mineral component (for example, high-ash menilite Carpathian shales) before more respectful, since in this case the process proceeds both in a purely thermal radical way and with a greater proportion of carbon-ion reactions characteristic of aluminosilicate catalytic cracking catalysts. It is known that catalytic cracking gasolines have improved octane characteristics and thermal stability compared to pure gasolines of thermal cracking. Note that hybrid molecules containing naphthenoaromatic fragments are excellent hydrogen donors and are introduced into systems with an organic mass of shale in relatively small amounts, and most importantly is that they saderzhatsya in TNO and actively manifest themselves in the presence of the above mineral supplements.

The method is characterized in that the thermal dissolution of TNO is carried out at atmospheric pressure in the temperature range 400-430 ° C (thermocatalytic cracking of raw materials and additives proceeds actively) with the content of these additives 8-12%. The isothermal exposure time of the reaction mixture at a final temperature in the reactor is from 30 to 180 minutes (preferably 60 minutes).

The most significant difference of the proposed method lies in the fact that it is carried out under milder conditions (at atmospheric pressure) according to a simpler hardware and technological scheme with yields of total light distillate up to 65.8% per load mixture, which is higher compared to the prototype.

The milder conditions of thermochemical processing of TNO in the presence of these additives lead to reduced gas formation and allow to obtain gasoline and diesel fractions with improved characteristics compared to the prototype (in terms of sulfur content and unsaturated mediations, which is seen from the values of iodine numbers). The reduced content of sulfur and unsaturated compounds leads to lower costs compared with the prototype for hydrotreating both diesel and gasoline fractions, that is, the proposed method is energy-saving. This goal is achieved through the use of a wider range of hydrogen donors-sapropelites (not only ordinary, but also enriched shales of various genetic types from various Russian and foreign deposits) and the use of an additional cracking additive - aluminosilicate catalysts.

Note that in the foreseeable future, oil resources will be exhausted and the problem of obtaining motor fuels and their components from alternative natural energy sources such as coal and shale will be relevant. However, according to the traditional technology of processing ordinary oil shale (for example, the Baltic field) in gas generators, to produce a ton of motor fuels, it is necessary to process at least 8 tons of oil shale with the simultaneous production of about 4 tons of coke ash residue, going mainly to the dump. Therefore, such a technology is uncompetitive and it is no coincidence that in 2003 the processing of oil shale with the conversion of gas generators to the processing of special grades of coal (for example, SS) into semi-coke and tar was stopped. Oil shales, like oil, are sapropelites. They, unlike coal, are rich in hydrogen and therefore the organic part of shale is a potential donor of hydrogen.

In the proposed method, when exposed to temperature and under the influence of catalytically active donor-hydrogen additives, large TNO molecules decompose into molecules with lower molecular weights characteristic of light distillates (components of gasoline and diesel fuel) with simultaneous saturation of the resulting fragments with hydrogen, which leads to their improvement consumer properties (decrease in sulfur content and increase in calorific values). In addition, the aluminosilicate components of the mineral part of natural shales and specially introduced into the system aluminosilicate catalysts of catalytic cracking (zeocar-2) perform a cracking-isomerizing function, which ultimately leads to the production of gasoline fractions with improved parameters, primarily in terms of octane characteristics.

During thermochemical processing of TNO by the method of their thermal dissolution in the presence of thermally or catalytically active donor-hydrogen additives introduced into the system additionally or without using the indicated operation (isomerizing cracking additives are contained in the mineral, and hydrogen donors in the organic parts of the shale), TNO can be processed with gas, water, low-boiling light liquid products, cracking residue and a small amount of coke deposited on the organomineral part of solid natural energy Carrier. It is important that the main products of this technology are light liquid products that are used as components of motor fuels (gasolines, kerosene, diesel fuel) and high-boiling cracking residues consisting of organic and mineral parts.

The peculiarity of the method is that there is no need to separate the catalytically active organomineral additive (mineral part) from the bulk of the high-boiling cracked residue. The ratio of the yields of low-boiling light distillate products to the high-boiling cracking residue of thermal dissolution varies widely; it depends on the nature of the energy carrier, process conditions (ratio of reagents, temperature and duration of the process, nature and content of the thermal and catalytically active donor-hydrogen organomineral additives). Low-boiling light distillate products are distilled off from the reactor and, after condensation, pass through a separator, where water and liquid organic products are separated. The latter are dried and further in the distillation column are separated by boiling points with the release of gasoline, kerosene and diesel fractions. From the cube of the distillation column, a medium distillate residue is taken, which serves as a low-viscosity additive in the preparation of commercial fuel oils of the M40, M-100 and F-5 types. High-boiling heavy cracked residues of the thermochemical processing of TNO without additional operations are discharged from the reactor and used as thermal bitumen as binders for asphalt mixtures for road and building materials, rubber softeners, antiseptics (sleeper impregnation material), anticorrosion and waterproofing coatings, binders for coal briquetting.

The following are examples of the proposed method.

Example 1. In a reactor with a capacity of 0.5 l, equipped with electric heating, a mechanical stirrer and a refrigerator for cooling and removing liquid thermal dissolution products of TNO, 300 g of Arlan oil fuel oil, 36 g of ordinary Baltic shale of the Leningrad field containing 54.2 wt.% Of the mineral part are loaded (SiO ₂ - 27.9%, Al ₂ O ₃ - 8.6%, Fe ₂ O ₃ - 5.5%, CaO - 50.4%, MgO - 2.5%, SO ₃ - 4.2% , Na ₂ O - 0.5%, K ₂ O - 3.4%). The specified mixture with stirring for 40 minutes is heated to a temperature of 420 ° C and then, while continuing stirring, maintained at the specified temperature for 1 hour. A gas of composition C ₁ -C _{4 is} obtained with a yield of 2.8%, water with a yield of 1.1% and light liquid distillate products with a yield of 65.3% for loaded feed and a heavy ash residue with a yield of 30.8%. The ash residue has a pour point of 16.5 ° C and can be used as a component of liquid bitumen, as a corrosion-resistant coating for ferrous and non-ferrous metals, as a rubber softener, i.e. has multi-purpose application. Of the light liquid distillate products, the gasoline fraction was distilled off with a yield of 41.5%, boiling in the range of n.a. -180 ° C and diesel fraction 180-360 ° C with a yield of 23.8%. The gasoline fraction contains 0.53% sulfur, and the diesel fraction 0.60% sulfur. The iodine number of 7.1, and 26 g I _2/100 g product respectively. After hydrotreating at 370 ° С under a hydrogen pressure of 4.0 MPa at a volumetric feed rate of 1.5 h ^-1 on an industrial alumina-cobalt-molybdenum catalyst at a hydrogen flow rate of 1000 l / l of raw material, stable gasoline and diesel fractions with an iodine number of zero were obtained, and sulfur content of 0.008 and 0.08 wt.%. The remaining examples 2-12 are carried out similarly to the above example and are tabulated.

Thus, during thermochemical processing of TNO according to the proposed method, the yield of low-boiling light liquid products reached 65.8% using solid donor additives of sapropelites or mixtures thereof with aluminosilicate catalysts.

Other examples are given in the table.

Table No. p / p Raw materials Additive The content of the additive. wt.% Temperature ° C t min Gas output,% The yield of light distillate,% The output of the cracking residue,% one 2 3 four 5 6 7 8 9 2 Fuel oil of the West Siberian oil (straight run) LLC "KINEF" Kerogen-70 Baltic shale-Kukersita 8 430 thirty 2.6 64 30.5 3 I vacuum gas oil of West Siberian oil (327-454 ° С) LLC "KINEF" Private Volga Kashpirsky slate (5%) + 3% zeocar-2 8 410 60 3 62.4 32.7 four I vacuum gas oil of West Siberian oil (327-454 ° С) LLC "KINEF" Kerogen-70 Baltic shale-kukersita 12 430 60 2.9 65.8 30.2 5 II vacuum gas oil of West Siberian oil (440-495 ° С) LLC "KINEF" Ordinary Baltic slate-kukersit (6% + 6% zeocar-2) 12 420 60 2.3 64.7 31.7 6 II vacuum gas oil of West Siberian oil (440-495 ° С) LLC "KINEF" Private Baltic Slate-Kukersit 12 420 60 2.5 62.6 33.3 7 ** Tar of the West Siberian oil of LLC KINEF Zeocar-2 12 430 60 3.9 53.2 42.1 8 Tar of Arlan oil of the Novo-Ufa refinery Colorado Private Slate (USA) 10 425 90 3.7 52.8 42.4 9 Tar of Yareg oil of LLC "Lukoil-Ukhta-Oil Refining" Scottish Private Slate 8 415 180 4.1 44 49.8 10 Fuel oil F-5 LLC "KINEF" Ash of an ordinary Baltic shale-kukersita 8 410 60 2 59.3 33.4 eleven Fuel oil M-40 LLC "KINEF" Ordinary pan-Syrt oil shale (Volga) 10 410 60 2.4 62.9 35.1 12 Fuel oil M-100 LLC "KINEF" Private Kenderlyksky slate (Kazakhstan) 12 430 90 2.1 59.7 33.7 13 Fuel oil of the West Siberian oil (straight run) LLC "KINEF" Slate LLC Shubarkol-Komir (Kazakhstan) 8 400 90 3.1 63.8 31 * - the divergence of the balance due to the formation of water and coke.
** - an example at a pressure of 3 MPa

Claims (1)

A method for thermochemical processing of heavy oil residues by thermocracking at a temperature above 400 ° C, including preheating the feedstock, characterized in that the raw materials in the form of heavy oil residues are thermocracked in the presence of thermally or catalytically active hydrogen donor additives selected from the series: or enriched schists of various genetic types, the mineral part of schists, zeolite-containing catalysts, a mixture of ordinary slate and zeolite-containing aluminosilicate catalysts at atmospheric pressure in the temperature range 400-430 ° C, with the content of these additives in the amount of 8-12 wt.% and with the duration of the process, providing a complete distillation of light distillate products.