RU2820049C1 - System for recovery of carbon dioxide during methanation for ship power plant - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention can be used in systems for processing combustion products of internal combustion engines. Carbon dioxide recuperation system during methanation for a ship power plant comprises a unit for preliminary cleaning of exhaust gases using a "wet" method, carbon dioxide gas extraction unit, carbon dioxide preparation unit, hydrogen gas preparation unit, a unit for producing gaseous methane and a unit for preparing methane for storage and use for power supply of a ship internal combustion engine. Unit for exhaust gas pre-cleaning by "wet" method includes exhaust manifold (1) connected to internal combustion engine and connected to scrubber (2) for reception and humidification of exhaust gases. Outlet of scrubber (2) is connected to gas separation device (3), which is a part of gaseous carbon dioxide extraction unit. Gas separation device (3) is made with possibility of communication with compressor (4) and outlet of cleaned exhaust gases into atmosphere. Carbon dioxide preparation unit includes compressor (4) for creation of required pressure at inlet of additional cylinder for methanation. Hydrogen gas preparation unit includes reservoir (5) for storing compressed hydrogen and pressure reducing valve (6), which reduces the hydrogen pressure at the inlet of additional cylinder (7) for methanation to the pressure required for methanation. Gaseous methane production unit includes additional cylinder (7) for methanation driven by engine crankshaft through power takeoff flange (8) and drive device (9) and connected to condenser (10) for separation of methane from water vapour. Methane preparation unit for storage and use includes methane liquefaction system (11) and methane storage tank (12). Tank (12) for storage of methane is connected to fuel system of internal combustion engine and performs simultaneous supply of diesel fuel and methane in specified ratio.

EFFECT: elimination of carbon dioxide emissions during engine operation and use of produced methane as engine fuel.

1 cl, 1 dwg

Description

The invention relates to engine building, in particular, to systems for processing fuel combustion products and carbon dioxide included in their composition for the purpose of its release, recovery by methanation, production of methane and its further storage and use on ships as fuel or stored energy.

There are closed-cycle power plants based on heat engines operating in exhaust gas recirculation mode, in which an artificial gas mixture composed of purified exhaust gases is used as an engine fuel component. There are also devices for producing technical hydrogen for use in internal combustion engines.

BACKGROUND:

According to scientific and technical information

1. Gushchin, P.A. Plasma-catalytic transformations of carbon dioxide and methane under microwave discharge conditions: specialty 05.17.07 "Chemical technology of fuels and high-energy substances": abstract of the dissertation for the degree of candidate of technical sciences / Gushchin Pavel Aleksandrovich. - Moscow, 2008. - 26 p. - EDN MBTEZO.

This dissertation examines the plasma-chemical processes of hydrocarbon raw materials, carbon dioxide conversion on electrodes made of various metals and alloys and proposes an easy-to-manufacture design of a plasma-catalytic gas conversion reactor with low energy and material consumption and a long service life, however, does not imply carbon dioxide capture directly at the source of its emissions (hydrocarbon fuel consumer, marine internal combustion engine), and also does not consider the possibility of the reaction occurring by achieving the necessary conditions in an additional cylinder, which is provided with mechanical energy by the hydrocarbon fuel consumer in the presence of catalysts on CNTs (iron, nickel). In addition, the operation of the mentioned installation is also aimed at converting hydrocarbon fuels in order to obtain synthesis gas, which is not the main goal of the carbon dioxide recovery system during the methanation process for marine internal combustion engines, since the system achieves conditions for the renewal of hydrocarbon fuel from the products combustion (carbon dioxide).

2. Pokusaeva, Ya.A. Hydrogenation of carbon dioxide on Fe-, Co- and Ni-containing catalysts in the gas phase and supercritical conditions: specialty 02.00.15 “Kinetics and catalysis”: dissertation for the degree of candidate of chemical sciences / Pokusaeva Yana Andreevna, 2020. - 128 p. - EDN DEDLLQ.

This dissertation examines the process of catalytic hydrogenation of carbon dioxide on metals of the iron triad (Fe, Co, Ni) deposited on carbon supports: Sibunit and carbon nanotubes, the catalytic activity of iron-containing catalysts in the reaction of water gas and the synthesis of hydrocarbons C1-C12, and Co- and Ni-containing - in the direct methanation reaction (Sabatier reaction), the effect of introducing chromium into the catalyst on the selective course of the water gas reaction due to the absence of the formation of the iron carbide phase on the surface of the catalysts, the effect of carrying out the hydrogenation reaction of carbon dioxide under supercritical conditions on the selectivity of hydrocarbon formation is demonstrated ; using magnetometry, the need for the presence of a Hegg carbide phase on the surface of the catalyst for the selective hydrogenation of carbon dioxide into hydrocarbons. However, this dissertation does not assume the process of capturing carbon dioxide directly at the source of its emissions (consumer of hydrocarbon fuel, marine internal combustion engine), as well as the processes of separating methane from the resulting water vapor and a system for the preparation, storage and further use of methane with its subsequent capture and repeated recovery of carbon dioxide to produce methane, which is characterized as a renewable hydrocarbon fuel.

According to patent information

Known “Method for carbon dioxide recovery” according to RF patent No. 2402373, IPC BO1D 53/14, publ. 12.12. 2006. This patent discusses a method for the recovery of carbon dioxide from gas streams containing carbon dioxide, contains the stage of absorption with a liquid, the stage of regeneration of the absorbent liquid, represented by an amine solution. However, this patent does not provide for the conversion of carbon dioxide into methane during the methanation process in an additional cylinder, captured directly at the emission source (hydrocarbon fuel consumer, marine internal combustion engine), considering only the possibility of regenerating the liquid that absorbs it for recapture.

Known is the “Method for capturing carbon dioxide from the flue gas of a power plant and the installation for its implementation” according to RF patent No. 2015101909, IPC BO1D 53/14, publ. 10.08. 2016. This patent provides for the capture of carbon dioxide directly at the source of carbon dioxide emissions (consumer of hydrocarbon fuel) by using an amine solution, thermal decomposition of the mixed solution, returning the aqueous solution of the composite sorbent as a sorbent for recycling, cooling the separated carbon dioxide, performing separation to remove water and obtaining carbon dioxide with a purity exceeding 99%, its drying, compression and condensation. However, this patent does not consider the possibility of beneficial use of the resulting carbon dioxide during the process of methanation in an additional cylinder in the presence of temperature, pressure and a catalyst in order to obtain methane when mixed with hydrogen for its reuse as fuel, upon combustion of which in the hydrocarbon fuel consumer (marine engine internal combustion), repeated recovery of carbon dioxide is possible, which makes such hydrocarbon fuel renewable, and its use eliminates carbon dioxide emissions into the air.

Known is the “Method for producing methane from atmospheric carbon dioxide” according to RF patent No. 2533710, IPC S07S 9/04, S07S 1/12, B01J 23/60, B01J 20/04, B01J 20/06, publ. November 20, 2014. This patent examines a method for producing methane from atmospheric carbon dioxide and is characterized by the use of a mechanical mixture of thermally regenerated potassium carbonate sorbent fixed in the pores of titanium dioxide, using alternative renewable energy for the synthesis of fuels. However, this patent does not provide for the production of methane by achieving the required pressures and temperatures in the presence of a catalyst in an additional cylinder driven by a drive device from an internal combustion engine, which is a source of carbon dioxide emissions, as well as the possibility of re-recovering carbon dioxide after using the resulting methane as fuel in consumer of hydrocarbon fuel (marine internal combustion engine).

The “Method for producing methane and its derivatives” is known according to RF patent No. 2218320, IPC C07C 1/12, C10G 2/00, publ. 12/10/2003. This patent considers a method for producing hydrocarbons using an aqueous solution of heteropolyacid, lead or copper plates, subsequent reduction of the anionic complex by passing through the solution under a pressure of 700-800 mm. Hg carbon dioxide in a concentration of no more than 60% by volume to produce methane or one of the saturated hydrocarbons for their production in industrial quantities. However, this patent does not consider a method for capturing and separating carbon dioxide from the exhaust gases of a source of carbon dioxide emissions (a consumer of hydrocarbon fuel, a marine internal combustion engine), nor does it use an additional cylinder in which methane is formed in the presence of temperature, pressure and a catalyst when mixed with hydrogen with the possibility of its reuse as fuel, upon combustion of which in the consumer of hydrocarbon fuel (marine internal combustion engine), repeated recovery of carbon dioxide is possible, which makes such hydrocarbon fuel renewable, and its use eliminates emissions of carbon dioxide into the atmospheric air.

The listed patents solve the problems of capturing carbon dioxide, its recovery, increasing the efficiency of processes for producing methane from carbon dioxide, and recovering carbon dioxide; however, they do not simultaneously include a number of tasks required to solve them, including: increasing environmental friendliness by separating carbon dioxide from exhaust gases gas, recovery of carbon dioxide in the presence of temperature, pressure and a catalyst when mixed with hydrogen, formation of methane, its separation from water vapor, storage and use as fuel to power the consumer (marine internal combustion engine) with the possibility of repeated recovery, which makes this hydrocarbon renewable fuel; operation of the internal combustion engine is more environmentally friendly, energy-efficient and efficient.

The technical objective of the proposed invention is:

- increasing the environmental friendliness of the ship’s power plant by releasing carbon dioxide;

- obtaining methane from separated carbon dioxide and hydrogen and its further use as fuel;

- improving the energy, environmental and economic performance of an internal combustion engine using methane obtained during the recovery of carbon dioxide in the process of methanation.

To achieve the technical task, a carbon dioxide recovery system in the methanation process is proposed for a ship power plant, containing an exhaust gas pre-treatment unit, a carbon dioxide gas separation unit, a carbon dioxide preparation unit, a hydrogen gas preparation unit, a methane gas production unit and a methane preparation unit for storage. and used to power an internal combustion engine, wherein the exhaust gas pre-cleaning unit includes an exhaust manifold connected to the internal combustion engine, connected to a scrubber for receiving and humidifying exhaust gases, directing the pre-cleaned exhaust gases to a carbon dioxide gas separating unit, including a gas distribution device, wherein the gas distribution device is connected to the outlet to the atmosphere, which allows purified exhaust gases to be emitted, the separated carbon dioxide enters the carbon dioxide preparation unit, which includes a compressor that delivers carbon dioxide to an additional cylinder for methanation, a hydrogen gas preparation unit, which includes a reservoir for storing compressed hydrogen, a pressure reducing valve that reduces the pressure of compressed hydrogen to the required level and delivers hydrogen to an additional cylinder for methanation, the methane gas production unit includes an additional cylinder for methanation, connected to blocks for preparing gaseous hydrogen and carbon dioxide, driven by a drive a device, wherein the drive device is connected through a power take-off flange to the internal combustion engine, and a condenser that separates methane from water vapor after the methanation reaction, the methane preparation unit for storage and use includes a methane liquefaction system connected to a methane storage tank, wherein the methane from the reservoir can enter the fuel system as fuel for the internal combustion engine.

TECHNICAL RESULT

The technical result consists in producing methane from carbon dioxide, which is part of the exhaust gases of an internal combustion engine, by recovering it, which completely eliminates carbon dioxide emissions during the operation of internal combustion engines of a ship power plant and allows the resulting methane to be used as fuel with the possibility of repeated recovery of carbon dioxide gas in an additional cylinder to methane during the methanation process.

SUMMARY OF THE INVENTION

The essence of the invention lies in the fact that carbon dioxide is recovered in the process of methanation in order to obtain methane from the exhaust gases of a ship's power plant: use as a recovery process and the use of the gas component of the mixture - carbon dioxide. The design solution of the proposed system provides environmental purification of exhaust gases, separation of the gas mixture into purified exhaust gases and carbon dioxide, its transfer to the compressor and then, together with gaseous hydrogen, to an additional cylinder capable of forming methane, and its subsequent use of the resulting methane as fuel for power supply. consumers of hydrocarbon fuels (internal combustion engines) with the possibility of repeated recovery of carbon dioxide from the exhaust gases formed during the combustion of the resulting methane.

The installation includes an internal combustion engine, an exhaust manifold, a scrubber, a gas separation device, a compressor, a tank for compressed hydrogen, a pressure reducing valve, an additional cylinder for methanation, a condenser, a methane liquefaction system, and a methane storage tank.

The essence of the invention is illustrated by graphic material.

The figure shows a schematic diagram of the system.

The exhaust gas pre-cleaning unit contains an exhaust manifold 1 connected to the internal combustion engine, which directs exhaust gases to the scrubber 2 for receiving pre-cleaning exhaust gases.

The carbon dioxide gas separation unit includes a gas separation device 3 capable of separating carbon dioxide from the exhaust gases, and the purified exhaust gases are sent to the atmosphere.

The carbon dioxide preparation unit includes a compressor 4, which directs the previously obtained carbon dioxide into an additional cylinder for methanation.

The hydrogen gas preparation unit includes a compressed hydrogen storage tank 5 connected to a pressure reducing valve 6.

The methane gas production unit includes a methanation cylinder 7, communicating with a condenser 10, connected to a drive device 9, communicating with a power take-off flange 8.

The methane preparation unit for storage and use includes a methane liquefaction system 11, a methane storage tank 12 communicating with the fuel system that directs methane to the internal combustion engine.

SYSTEM OPERATION

During its operation, a marine internal combustion engine produces exhaust gases, which are sent through the exhaust manifold 1 to the scrubber 2, where they are bubbling and cleaned, after which the pre-cleaned exhaust gases are sent to the gas separation device 3, which separates carbon dioxide from the exhaust gases, after whereby exhaust gases, cleared of harmful substances and carbon dioxide, are sent to the atmosphere, and carbon dioxide enters compressor 4, from where it is sent to an additional cylinder for methanation 7. Hydrogen from the compressed hydrogen storage tank 5 is supplied to the pressure reducing valve, reducing the pressure to necessary, after which it enters an additional methanation cylinder 7 along with carbon dioxide. In the additional cylinder 7, driven by the drive device 9, which receives energy from the power take-off flange 8 of the internal combustion engine, in the presence of temperature, pressure and catalyst, methane and water are formed, separated in the condenser 10. After separating the methane from the water, it enters the system methane liquefaction 11, where it is liquefied for the purpose of subsequent storage in a methane storage tank 12, from where it can enter the engine fuel system to power it as the main or additional fuel. Carbon dioxide formed during the combustion of methane is again recovered to methane in the process of methanation.

Claims (1)

A carbon dioxide recovery system in the methanation process for a ship power plant, containing a unit for preliminary purification of exhaust gases using a “wet” method, a unit for separating carbon dioxide gas, a carbon dioxide preparation unit, a hydrogen gas preparation unit, a methane gas production unit and a methane preparation unit for storage and used for power supply of a marine internal combustion engine, wherein the unit for preliminary purification of exhaust gases using the “wet” method includes an exhaust manifold connected to the internal combustion engine, connected to a scrubber for receiving and humidifying exhaust gases, the output of which is connected to a gas separation device, a unit for releasing carbon dioxide gas includes a gas separation device installed with the possibility of communication with the compressor and the release of purified exhaust gases into the atmosphere, the carbon dioxide preparation unit includes a compressor to create the necessary pressure at the inlet into the additional cylinder for methanation, the hydrogen gas preparation unit includes a tank for storing compressed hydrogen, a pressure reducing valve, reducing the hydrogen pressure at the inlet to the additional methanation cylinder to that required for methanation, the methane gas production unit includes an additional methanation cylinder driven by the engine crankshaft through the power take-off flange and drive device and connected to a condenser for separating methane from water vapor, the block preparing methane for storage and use includes a methane liquefaction system and a methane storage tank, wherein the methane storage tank is connected to the fuel system of the internal combustion engine and simultaneously supplies diesel fuel and methane in a set ratio.

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