RU129502U1 - SYSTEM FOR SYNTHESIS OF LIQUID ENGINE FUELS - Google Patents

Abstract

1. A system for the synthesis of liquid motor fuels, comprising: a gas generator configured to gasify solid carbon fuel as a result of vapor-oxygen pyrolysis; a desulfurization unit configured to purify the gaseous reaction products obtained in said gas generator from sulfur compounds; shear, made with the possibility to carry out in the desulfurized gaseous products a substitution reaction between carbon monoxide and water to produce hydrogen and carbon dioxide; a ber configured to remove acidic gases from gaseous products obtained in said shear reactor; a Fischer-Tropsch synthesis reactor for catalytic synthesis of hydrocarbons from gaseous products purified from acidic gases; a first distillation column configured to separate products, obtained in the aforementioned Fischer-Tropsch synthesis reactor for diesel fuel and paraffins, as well as for unreacted gases; a paraffin oxidation unit configured to oxidize add the above paraffins to fatty acids; - a methanol synthesis reactor designed for the catalytic synthesis of methanol from gaseous products purified from acid gases; - a second distillation column configured to separate the methanol synthesis products into methanol, dimethyl ether and unreacted gases; - esterification reactor designed to produce diesel fuel as a result of the esterification reaction of the above-mentioned fatty acids and methanol. 2. The system according to claim 1, in which the first and second trunk are provided

Description

The technical field to which the utility model relates.

This utility model relates to the field of production of liquid hydrocarbons from solid hydrocarbon fuels and can be used to create a system for the synthesis of liquid motor fuels, intended, for example, for local production of diesel fuel in coal mining enterprises.

State of the art

A variety of systems for converting solid hydrocarbon fuels into liquid motor fuels are currently known.

For example, U.S. Patent No. 2925335 (publ. 02.16.1960) describes a system in which crushed solid fuel is mixed with steam and free oxygen in an amount sufficient to burn only part of the fuel to gasify the remainder. In US patent No. 4108759 (publ. 08.22.1978) describes a device for converting coal into liquid fuel, which gasifies the crushed coal in the presence of superheated steam in an oxygen-free atmosphere. US patents No. 4277416 (publ. 07/07/1981) and No. 8038746 (publ. 10/18/2011), as well as UK patent No. 671490 (publ. 07.05.1952) and Canadian patent No. 1083991 (publ. 04.06.2004) disclose various settings to produce liquid fuels from coal through Fischer-Tropsch synthesis. All these and other well-known documents describe rather complex plants, which ensure, however, incomplete processing of coal into liquid fuels.

The closest analogue of this utility model is described in RF patent No. 2340651 (publ. 10.12.2008). The device presented in this document carries out the pyrolysis of solid fuel in a fluidized bed reactor, the obtained semi-coke is divided into a coarse fraction sent for the manufacture of activated carbon and a fine fraction from which the generator gas is obtained in the gas generator, which is supplied together with a part of the gas mixture from the reactor to receive synthesis gas, from which liquid hydrocarbons are then synthesized. However, this system does not provide a sufficiently high yield of liquid fuels.

Utility Model Disclosure

Thus, there is a need for a system capable of more fully processing solid hydrocarbon fuels into liquid motor fuels. This will expand the arsenal of technical means, especially for the local production of diesel fuel in coal mining enterprises.

To solve the problem and achieve the technical result, this utility model proposes a system for the synthesis of liquid motor fuels, comprising: a gas generator configured to gasify solid carbon fuel as a result of vapor-oxygen pyrolysis; a desulfurization unit configured to purify the gaseous reaction products obtained in the gas generator from sulfur compounds; a shear reactor configured to carry out a substitution reaction between carbon monoxide and water in desulfurized gaseous products to produce hydrogen and carbon dioxide; a scrubber configured to remove acid gases from gaseous products obtained in the shear reactor; Fischer-Tropsch synthesis reactor for the catalytic synthesis of hydrocarbons from gaseous products purified from acid gases; the first distillation column, configured to separate the products obtained in the Fischer-Tropsch synthesis reactor into diesel fuel and paraffins, as well as unreacted gases; a paraffin oxidation apparatus configured to oxidize paraffins to fatty acids; a methanol synthesis reactor for the catalytic synthesis of methanol from gaseous products purified from acid gases; a second distillation column, configured to separate the products of methanol synthesis into methanol, dimethyl ether and unreacted gases; an esterification reactor designed to produce diesel fuel as a result of the esterification of fatty acids and methanol.

The peculiarity of the system according to this utility model is that it can be provided with the first and second lines for the return of unreacted gases and other products from the distillation columns of the same name to the gas generator.

Another feature of the system according to the present utility model is that it can further comprise an apparatus for separating oxygen from the air, configured to separate oxygen from the incoming air and supply the released oxygen to the gas generator. At the same time, the system may provide for the use of heat obtained in synthesis reactors as energy for the operation of the oxygen evolution unit.

Another feature of the system according to the present utility model is that it may further comprise a water treatment unit configured to vaporize incoming water and supply evaporated water to the gas generator. In this case, the system may provide for the use of heat obtained in synthesis reactors as energy for the operation of the water treatment plant.

Another feature of the system according to this utility model is that, as a catalyst in a Fischer-Tropsch synthesis reactor, a cobalt-magnesium-zirconium catalyst on kieselguhr — reduced (CMC-B) can be used.

Finally, another feature of the system but a true utility model is that the Severodonetsk low-temperature methanol-advanced catalyst (SNM-U) is used as a catalyst in the methanol synthesis reactor.

Brief Description of the Drawing

The system of the present utility model is further illustrated using the drawing.

Detailed description of utility model

The system for the synthesis of liquid motor fuels according to the present utility model in the preferred embodiment comprises (see drawing) a gas generator 1, a unit 3 for oxygen separation from air, a unit 5 for water treatment, a unit 7 for desulfurization, a shear reactor 8, a scrubber 9, a reactor 10 Fischer-Tropsch synthesis reactor, methanol synthesis reactor 11, a first distillation column 12, a second distillation column 13, a first line 14 for returning unreacted gases, a second line 15 for returning unreacted ha s, 16 for setting the oxidation reactor 17, the paraffins and esterification. Compounds of these elements and their implementation are disclosed below.

The gas generator 1 is configured to gasify solid carbon fuel as a result of vapor-oxygen pyrolysis. The gas generator 1 is a known device (for example, from the above analogues, a Lurgi gas generator, a Winkler gas generator) for converting solid fuel by means of its vapor-oxygen gasification into a gaseous form. To do this, crushed coal is supplied to the gas generator (bold arrow indicated by 2), as well as oxygen from an oxygen recovery unit 3, capable of releasing oxygen from the air entering it (bold arrow indicated by 4) oxygen during cryogenic distillation , and water vapor from the water treatment plant 5, which is capable of evaporating the water entering the carrier (bold arrow indicated by 6). In principle, the installation 3 for the separation of oxygen from the air is optional, because in some embodiments, air may be directly supplied to the gasifier. Similarly, water treatment plant 5 is optional, as water can be supplied to the gas generator 1 and directly.

In addition, gases that do not react in subsequent reactors of the system according to this utility model are supplied to the gas generator through the first and second lines 14 and 15.

In gas generator 1, partial combustion of coal occurs at a temperature of about 800-900 ° C in the presence of water vapor of a depleted amount of oxygen (pyrolysis). In this case, the following reactions take place:

C + O ₂ → CO ₂

2H ₂ + O ₂ → 2H ₂ O

These reactions proceed with the release of thermal energy. After which recovery reactions occur:

С + СО ₂ → 2СО

C + H ₂ O → CO + H ₂

These reactions proceed with the consumption of thermal energy.

Accordingly, the active part of the gas generator 1 consists of three flowing sections: thermal decomposition of fuel, oxidation, and reduction.

The thermal energy released in the gas generator 1 can be used for the operation of the installation 3 for the release of oxygen from the air and (or) the water treatment unit 5. Excessive heat from the gas generator 1 can also be diverted for other needs.

The gaseous reaction products obtained in the gas generator 1 must be cleaned of sulfur compounds. Therefore, these products from the gas generator 1 enter the installation 7 for desulfurization.

The sulfur compounds in the generator gas are represented by the following compounds: hydrogen sulfide H ₂ S, carbon sulfide COS, thiophene H ₂ S C ₄ H ₄ S; other harmful substances are ammonia NH ₃ and tarry substances. All these compounds are toxic, sulfur compounds in addition cause intense corrosion of the equipment and are irreversible poisons for the applied Fischer-Tropsch synthesis catalysts. The content of organosulfur compounds in the generator gas is from 3 to 10% of the total sulfur content.

The presence of organosulfur compounds in the generator gas necessitates their hydrogenation or hydrolysis, that is, the interaction of organosulfur compounds with hydrogen or water vapor to produce hydrogen sulfide as a result. Such reactions are carried out at 350 ... 400 ° C on a cobalt-molybdenum or other catalyst. Further removal of the hydrogen sulfide formed and present in the gas is carried out by one of the known methods.

Purification of H ₂ S and organosulfur compounds in industry is carried out mainly by dry (adsorption) and liquid (absorption) methods. When using absorption of hydrogen sulfide by amino alcohols, a stage of preliminary conversion of organosulfur compounds to hydrogen sulfide is necessary; when absorbed by physical solvents, organosulfur substances are absorbed together with hydrogen sulfide.

For large volumes of gases and a high concentration of hydrogen sulfide, absorption methods are preferable in them, for insignificant volumes of gas - absorption methods (physical adsorption or chemical absorption). Given that the synthesis gas after the gas generator has a high temperature, it is advisable to chemically absorb hydrogen sulfide at this temperature, which exceeds the condensation temperature of the highest boiling fractions of resinous substances. In this case, the formation of liquid effluents containing resins does not occur, and, in addition, the physical heat of the generator gas is retained.

For most chemical scavengers, organosulfur compounds are absorbed together with hydrogen sulfide. The absorption of hydrogen sulfide at high temperatures is usually carried out by chemisorbents based on oxides of calcium, iron, zinc, manganese or titanium in a fluidized, moving or stationary sorbent layer. The metal sulfides formed during purification are either disposed of without regeneration or regenerated with air or a steam-air mixture to form SO ₂ , which, depending on economic feasibility, is converted into gypsum, elemental sulfur or sulfuric acid.

Immediately before installation 7 for desulfurization, a cyclone and (or) a filter can be installed to remove dust and ash from products obtained in the gas generator 1.

Generator gas after ash removal in a metal-cloth filter is divided into two identical streams and enters the first stage of hydrogen sulfide removal. The first desulfurization stage is a four-adsorber circuit, in which gas passes through one desulfurization adsorber, and the remaining three are in reserve. After the established cycle of operation of one adsorber ends, the flow of generator gas switches to the second adsorber, then to the third adsorber, then to the fourth. After which the cycle closes.

After cleaning, in one of the adsorbers, the corresponding valves on the nitrogen line open, and the adsorber is purged with nitrogen with a purge gas discharge onto the candle, while the sorbent is cooled to 50 ° C, and then discharged into the hopper. Next, the adsorber is filled with the regenerated sorbent and the sorbent is heated through the nitrogen line using hot gases generated during the combustion of liquid fuel used as starting fuel, after which the nitrogen line is closed and the apparatus is ready for absorption of hydrogen sulfide.

After purification from H ₂ S, the generator gas enters the second stage of desulfurization, where the generator gas is cooled to 380 ° C in the heat exchanger using high-pressure cold steam, and then it is purified from organosulfur compounds that have not reacted in the first stage of desulfurization in the hydrogenation reactor on a cobalt-molybdenum catalyst . After that, the synthesis gas is fed to two second-stage desulfurization adsorbers operating according to the so-called “lead-lag” scheme, which consists of the following: two reactors connected in series, switched in a different sequence along the gas flow, and each reactor can be switched off from the chain. When the first reactor in the course of gas is operated (as judged by the fact that the sulfur content at its outlet starts to increase), it is turned off (without stopping all production), it is overloaded and the second one is turned on.

After removal of the dioxide and other sulfur compounds, the gaseous products enter the shift reactor 8 (also known in the art as a substitution reactor or shift reactor). It involves the substitution of carbon monoxide (CO) with water (H ₂ O) to produce hydrogen (H ₂ ) and carbon dioxide (CO ₂ ) to reduce the carbon monoxide (CO) content in the gaseous product stream.

After the shift reactor 8, gaseous products enter a scrubber 9, where gas cleaning is performed, which includes the removal of toxic and strongly smelling substances. For this, gaseous products are brought into intensive contact with finely distributed water droplets (or drops of another washing liquid) supplied in the oncoming flow. The larger the surface area between the washing liquid and the gas being cleaned and the smaller the size of the water droplets, the more efficient the cleaning. Typically, the cleaning fluid is recycled to save water and reduce runoff.

Using a scrubber, the following components can be removed from the exhaust gas:

- Water soluble substances will be dissolved.

- Dust will be precipitated.

- Hydrolyzable substances will be decomposed.

- Water vapor condenses.

Wet scrubbing results in decontamination, poison removal, dust removal, moisture removal, condensation, as well as the removal of strongly smelling substances to protect the environment. In particular, water pollution is very well removed from the gas. In many cases, when adsorbing substances from a gas, the flushing fluid may be contaminated. Dissolved substances are usually acidic or alkaline chemicals, such as Hcl, carbon monoxide or ammonia NH ₃ . Using a neutralizer integrated in the scrubber, it is possible to maintain neutral pH values and thus remove poisons. In addition, a low acid wash liquid for alkaline gas components is more effective, and a low alkaline wash liquid is more effective for acid gas components.

Dust will precipitate and form large amounts of sludge, which must be filtered out of the effluent. In such circumstances, filter sludge should be considered as special waste.

Hydrolyzable substances dissolve in water.

The gaseous products purified in a scrubber enter two reactors: a Fischer-Tropsch synthesis reactor 10 and a methanol synthesis reactor 11.

The design and principle of operation of the Fischer-Tropsch synthesis reactor 10 are well known to specialists. The catalytic synthesis of hydrocarbons from gaseous products takes place in it.

The synthesized hydrocarbons come from the Fischer-Tropsch synthesis reactor 10 to the first distillation column 12, in which the synthesized liquid hydrocarbons are separated into fractions. As is known (I.A. Aleksandrov. “Distillation and absorption apparatus.” - Moscow, 1971), a distillation column is an apparatus designed to separate liquid mixtures, the components of which have different boiling points. A classic column is a vertical cylinder in which the incoming vapor rises to the top of the column, is cooled and condensed in a condenser refrigerator and fed back as irrigation. Thus, in the upper part of the column, pairs (from bottom to top) move countercurrently and liquid flows (from top to bottom). When flowing down, the liquid is enriched with high-boiling components, and the vapors, the higher they rise, the more enriched in low-boiling components. In this utility model 1, the lightest fractions, in which the proportion of unreacted gases is large, are returned via the first line 14 to the gas generator 1. The heavier fractions from the first distillation column 12 are removed from the system as diesel fuel (bold arrow indicated by the reference number 18). The heaviest fractions - paraffins - enter the paraffin oxidation unit 16.

In the installation 16, the oxidation of paraffins is carried out, for example, by passing a current of oxygen or ozone through paraffins heated to a temperature of about 150 °. Catalysts have an effect on the success of the reaction. As a result, paraffins are oxidized to carboxylic acids. The specific implementation of the installation 16 oxidation of paraffins can be any - as known to specialists in the prior art, and newly developed.

The design and operation of the methanol synthesis reactor 11 are also well known to those skilled in the art (e.g., Lurga synthesis). In the methanol synthesis reactor 11, catalytic synthesis of methanol from gaseous products takes place.

The synthesized methanol comes from the methanol synthesis reactor 11 to the second distillation column 13, in which the methanol synthesis products are separated into fractions. The operation and design of the second distillation column 13 are the same as for the first distillation column 12. As in the first distillation column 12, the lightest fractions, in which there is a high proportion of unreacted gases, are returned from the second distillation column 13 along the second line 15 to the gas generator 1 Heavier fractions from the second distillation column 13 enter the esterification reactor 17, which also receives fatty acids from the paraffin oxidation unit 16.

The esterification reactor 17 is designed to produce diesel fuel as a result of the esterification of fatty acids and methanol. The result is esters that can be used as diesel fuel and which are discharged from the system (bold arrow denoted by 19).

Thus, the system according to this utility model provides a more complete processing of solid hydrocarbon fuels (coal) into liquid motor fuels. In addition, by cleaning the results of steam-oxygen gasification of coal, carbon dioxide emissions into the environment are reduced. This utility model expands the arsenal of technical means, especially for local production of diesel fuel in coal mining enterprises.

Literature:

1. Storch G., Golambik N., Anderson R., Synthesis of hydrocarbons from carbon monoxide and hydrogen, trans. from English., M., 1954.

2. G. Kheprici-Olive, S. Olive, Chemistry of Catalytic Hydrogenation CO., Translated from English. S.L.Davydova. - M .: "World", 1987.

3. Erich V.N. Chemistry of oil and artificial liquid fuel, 1955, 510 p.

4. B. Leach. Catalysis in industry, v.2. - M.: “World”, 1986.

5. Chemisorption methods for gas purification from hydrogen sulfide and organosulfur compounds / V.I. Lazarev. Industrial and sanitary gas treatment. Overview information. - M.: TSINTIHIMNEFTEMASH, 1986 - 44 p.

6. Alekseev S.Z. and other Purification of natural gas with alkanolamines from hydrogen sulfide, carbon dioxide and other impurities. Overview information. Moscow, IRC Gazprom. 1999 - 41 p.

7. Kuznetsov B.N. Motor fuels from alternative crude oil. // Soros Educational Journal, Volume 6, No. 4, 2000.

Claims (8)

1. A system for the synthesis of liquid motor fuels, containing: - a gas generator configured to gasify solid carbon fuel as a result of vapor-oxygen pyrolysis; - a desulfurization unit configured to purify the gaseous reaction products obtained in said gasifier from sulfur compounds; a shear reactor configured to carry out a substitution reaction between carbon monoxide and water in desulfurized gaseous products to produce hydrogen and carbon dioxide; - a scrubber configured to remove acid gases from gaseous products obtained in said shear reactor; - Fischer-Tropsch synthesis reactor designed for the catalytic synthesis of hydrocarbons from gaseous products purified from acid gases; - the first distillation column, configured to separate the products obtained in the aforementioned Fischer-Tropsch synthesis reactor into diesel fuel and paraffins, as well as into unreacted gases; - installation for the oxidation of paraffins, made with the possibility of oxidizing said paraffins to fatty acids; - a methanol synthesis reactor designed for the catalytic synthesis of methanol from gaseous products purified from acid gases; - a second distillation column, configured to separate the products of methanol synthesis into methanol, dimethyl ether and unreacted gases; - an esterification reactor designed to produce diesel fuel as a result of the esterification reaction of said fatty acids and methanol. 2. The system according to claim 1, in which the first and second lines are provided for returning said unreacted gases and other products from the distillation columns of the same name to said gasifier. 3. The system according to claim 1, further comprising an apparatus for separating oxygen from the air, configured to separate oxygen from the incoming air and supply the separated oxygen to said gasifier. 4. The system according to claim 3, which provides for the use of heat generated in said synthesis reactors as energy for the operation of said oxygen evolution unit. 5. The system of claim 1, further comprising a water treatment unit configured to vaporize incoming water and supply vaporized water to said gasifier. 6. The system according to claim 5, which provides for the use of heat generated in said synthesis reactors as energy for the operation of said water treatment plant. 7. The system according to claim 1, in which the catalyst used in said Fischer-Tropsch synthesis reactor uses a cobalt-magnesium-zirconium catalyst on kieselguhr — reduced (CMC-B). 8. The system according to claim 1, in which the Severodonetsk low-temperature methanol-advanced catalyst (SNM-U) is used as a catalyst in said methanol synthesis reactor.

Images