RU2203924C1 - Liquid hydrocarbon production process - Google Patents

Abstract

FIELD: coal-chemical and petrochemical processes. SUBSTANCE: cracking and hydrogenation of raw material are carried out in presence of hydrogen-donor solvent under conditions of nonsteady flow of double-phase system (raw material/hydrogen-donor solvent) in rotary reaction apparatus with flow modulation (interruption), said hydrogen-donor solvent being water or mixture of fraction 35-100 C with recycling fractionation residue boiling within temperature range 450-600 C and freezing at 20 C. EFFECT: simplified technology and increased yield of better-quality products suitable as motor fuel. 1 dwg, 2 ex

Description

 The invention relates to methods for producing liquid hydrocarbons from solid fuels (peat, oil shale, lignite, lignite and hard coal) and carbonaceous material of industrial waste (waste coal, oil refining, lignin, plastics, rubber, etc.) and can be used in coal chemistry and oil refining industries.

 Known methods for thermochemical processing of coal — liquefaction — consist in carrying out a hydrogenation and cracking process using various hydrogen donor solvents and catalysts by heating under pressure.

Known, for example, is a method for the hydrogenation of coal under a hydrogen pressure of 50-100 atm with an organic solvent and a hydrogenation catalyst containing Mo and Fe at a temperature of 400-425 ^o C (SU ed. St. 355867, class C 10 G 1/06) .

 A known method of liquefying coal in the presence of atomic hydrogen generated by the action of ultrasound on molecular hydrogen (JP patent 58-35247, CL 10 G 1/06).

It is known to use as a hydrogen donor solvent a light hydrocarbon fraction isolated from the obtained products of coal hydrogenation and having a boiling point in the range of 35-200 ^° C (GB application 2085913, class C 10 G 1/06, 1982).

 A known method of converting coal into liquid products by mixing coal with a solvent, which is a mixture of thermally stable hydroaromatic hydrocarbons at elevated pressure and temperature (US patent 4081351, CL 208-8, 1978).

 A known method of thermomechanical cracking and hydrogenation of coal, which requires high temperature and high pressure for its implementation (US patent 4250015, 1981).

 The disadvantages of these known methods include multi-stage, the complexity of the technology associated with the need to use specific catalysts, the use of high temperatures and pressure, significant energy consumption and increased cost of the products.

 Closest to the technical nature of the proposed method is a method of thermomechanical cracking and hydrogenation of hydrocarbons in the presence of hydrogen-releasing chemicals, carried out in a mechanically installed fluidized bed of finely ground particles. In this case, the mechanical action in the fluidized bed generates the heat involved in cracking in addition to the mechanical action on the substance, as a result of which cracking in cavitation microbubbles and hydrogenation are carried out in a reactor with a common temperature and pressure lower than in other known cracking and hydrogenation processes (RU Patent 2131903, class C 10 G 1/06, 47/30, 1995).

 The disadvantages of this method include the weak effect of friction grinding elements, in particular steel balls, on solid particles of carbon material for their ultrafine grinding, which leads to incomplete opening of grains of carbon material and, as a result, incomplete involvement of carbon in the hydrogenation process and insufficiently high yield of required fractions of liquefaction products.

 Another disadvantage of this method is the need to use a significant amount of water to release the required amount of hydrogen involved in hydrogenation, a sufficiently high vapor content in the cracked products and, as a result, a significant presence of water in the light fractions of the product.

The objective of the invention is to provide a method that allows to intensify the process of ultrafine grinding of solid particles of the processed material and heat and mass transfer processes under the conditions of the cavitation regime of the flow of the processed medium, to increase the yield of the gasoline fraction with a boiling point of 100-200 ^o C and diesel fraction with a boiling point of 200-450 ^o C.

 The problem is solved by the proposed method, in which liquid hydrocarbons are obtained from solid fuel and carbon material by thermomechanical cracking and carbon hydrogenation under conditions of unsteady flow of the two-phase system "feedstock - hydrogen donor solvent".

 In this case, apparatuses with interruption of the medium to be treated and, in particular, the most effective of them rotary apparatuses with modulation (interruption) of the flow, are used as a reaction apparatus.

As a hydrogen donor solvent, water and a mixture of a fraction with a boiling range of 35-100 ^{° C.} with a recycle residue after fractionation with a pour point of 20 ^{° C.} and having a boiling range of 450-600 ^° C. are used.

 The device and the principle of operation of the reaction rotor apparatus with modulation (interruption) of the flow of the medium being treated allow the latter to be affected by such a powerful intensifying factor as cavitation.

 Cavitation is a complex non-stationary hydromechanical process, accompanied by secondary physical and chemical processes, such as luminescence, sparking; shock waves of pressure, speed and temperature; microflows and cumulative microjets; heating and ionization of gas in a cavitation bubble.

 Such an abundance of secondary effects allows the successful use of cavitation in the process of cracking and hydrogenation.

The occurrence and development of cavitation in pores, cracks and intergranular spaces of solid particles contributes to their intensive destruction. The pressure generated by collapsing cavitation bubbles reaches values of the order of 10 ⁸ Pa. This provides a sufficiently high degree of grinding, the growth of the specific surface of solid particles and their reactivity. The process is accelerated due to the discrete distribution of energy in a large number of small volumes (cavitation centers). In this case, the energy is concentrated in volumes of the order of the size of cavitation bubbles (0.001-0.01 mm), which sharply intensifies the process.

A distinctive feature of the operation of a rotary apparatus with flow modulation (interruption) is that cavitation and numerous secondary cavitation effects occur in a highly turbulent medium: particles of a dispersed phase moving at high speeds are also exposed to tremendous accelerations reaching 10 ⁵ m / c ² , which is four orders of magnitude greater than the acceleration of gravity g. Shear stresses and vibrations complement the list of intensifying factors that favorably affect the process of thermochemical decomposition of water with the formation of atomic hydrogen and cracking processes in which heavy hydrocarbons and radicals break down into smaller, low-boiling molecules.

 The method is carried out according to the scheme shown in the drawing, as follows.

The crushed pre-solid feedstock along line 1 together with water along line 15, a fraction boiling at 35-100 ^° C, along line 11 and a recycle residue with a pour point of 20 ^° C and boiling at 450-600 ^° C along line 14 is fed to mixer 2. The prepared suspension through line 3 is fed into the reaction apparatus 4 for thermomechanical cracking and hydrogenation. Particulate matter, including ash, flows through line 5 to a storage tank (not shown). The reaction products through line 6 are fed to a separator 7, in which solid particles are separated, including ash, discharged to the accumulator via line 8. Next, the purified reaction products through line 9 are taken to a distillation column 10, from which fraction is transferred to mixer 2 via line 11 boiling at 35-100 ^o С, line 12 - gasoline fraction boiling at 100-200 ^o С, line 13 - diesel fraction with a boiling point 200-450 ^o С and line 14 - fraction boiling at 450-600 ^o C, hardening at 20 ^o C, part of which is served in the mixer 2.

 Example 1

Crude peat with a humidity of 80% and a carbon content of 49% for a completely dry substance and a hydrogen donor solvent are continuously fed through a screw mixer to a rotor reactor with a rotor speed of 2500 rpm for processing. As a result of cavitation processes, in the working chamber of the rotor there are reactions of mechanical destruction of solid particles, peat, thermochemical evolution of hydrogen from water and carbon compound (hydrogenation) with hydrogen. At the outlet of the reactor, a gaseous hydrocarbon mixture with a temperature of more than 350 ^o C is obtained, which, after separation, is sent to separation and fractionation. The output of liquid products of medium fractions 160-400 ^o With is 17% of the initial mass of the end.

As a hydrogen donor solvent, water and a mixture of a fraction with a boiling range of 35-100 ^{° C.} with a recycle residue after fractionation with a pour point of 20 ^{° C.} and having a boiling range of 450-600 ^° C. are used.

 Example 2

The method is carried out as in example 1. Brown coal with a moisture content of 55% with a carbon content of 72% on a completely dry substance is used and water is added to the screw mixer to obtain a coal moisture of about 80%. The output of liquid hydrocarbon products of medium fractions 160-400 ^o With is 22% of the initial mass of coal.

Claims (1)

A method of producing liquid hydrocarbons from solid fuels by thermomechanical cracking and hydrogenation, characterized in that thermomechanical cracking and hydrogenation are carried out under unsteady flow conditions - in reaction rotor apparatuses with modulation (interruption) of the flow of the medium being processed — a two-phase system “feedstock — hydrogen donor solvent”, wherein as the hydrogen donor solvent is a mixture of water and a fraction with b.p. 35-110 ^o C with recycled after residue fractionated Bani, with a pour point of 20 ^o C, having a boiling range 450-600 ^o C.