DE102023001128A1 - Device and method for NOx reduction and creation of hydrogen fuel gas (NOx reducer) - Google Patents

Abstract

1. Device and method for NOx reduction and production of hydrogen fuel gas (NOx reducer).2.1. To date, exhaust gas recirculation and selective catalytic reduction have been used to reduce the nitrogen oxides produced by the use of engines, which require external energy and fuel, but which damage the engine in the long term due to increased soot accumulation and also lead to a high increase in CO levels. The device and the method for NOx reduction and production of hydrogen fuel gas make it possible to achieve a reduction in nitrogen oxides in engines without resulting in increased fuel consumption, a high increase in CO values, or the deposition of soot particles or solids.2.2. The NOx reducer captures the device for carrying out processes for NOx reduction and production of hydrogen fuel gas, which can be used in any combustion engine and in both stationary and mobile operation. The NOx reducer works independently of load and temperature as long as the engine is running and is designed for 24/7 operation. The invention uses the process heat generated during combustion. The NOx reduction occurs through synthesis gas produced from exhaust gas, which is fed to the engine as a partial flow. In the combustion chamber, the synthesis gas optimizes the combustion situation of the fuel-air mixture, with the result that the specific fuel consumption decreases, less turbulence and significantly fewer emissions occur than with known processes.2.3. Reduction of NOx and production of hydrogen fuel gas in power and heat engines derived from a variety of applications, including but not limited to industrial and power plants that use fossil fuels.

Description

To date, exhaust gas recirculation (EGR) and selective catalytic reduction have been used to reduce nitrogen oxides produced by the use of engines. Since the Euro 4 emissions standard, exhaust gas recirculation alone was no longer sufficient to reduce nitrogen oxides, which is why selective catalytic reduction has also been used since then. The operation of the EGR requires external energy and fuel and, in the long term, damages any engine. The damage is caused by increased accumulation of soot in the exhaust gas recirculation valve. The result is poor combustion, a significant loss of performance or increased consumption. Another side effect is the sooting of the air supply systems up to the valves, which requires either thorough cleaning or even replacement of these systems. For these reasons, EGR is not used, especially in large engines such as generators, marine and industrial engines. In addition, the AGR cannot guarantee secure 24/7 operation.

The invention specified in claims 1 and 2 is based on the problem of achieving a reduction in nitrogen oxides during engine operation without resulting in increased fuel consumption, a high increase in CO values, or the deposition of soot particles or solids.

This problem is solved by the invention listed in claims 1 and 2.

The present invention is a NOx reducer that can be integrated into any internal combustion engine and can be used in both stationary and mobile operation. The NOx reducer works independently of load and temperature as long as the engine is running and is designed for 24/7 operation. All power and heat machines generate large amounts of process heat, which is usually undesirable and is therefore released into nature unused. This process heat can be used sensibly, ecologically and economically by the ethanol reformer (12). The exhaust gases are filtered and cooled before entering the intake tract. The NOx reducer varies the exhaust gas recirculation rate to achieve IMO TIER III standards in the driving-specific load range and also produces fuel by vaporizing flammable fluids in the syngas generator (8) to compensate for power losses.

The device according to claim 2 is controlled by a controller (1). The NOx reduction is based on synthesis gas produced from exhaust gas, which is fed to the engine as a partial flow. The quantity is controlled by the bypass flap of the exhaust gas bypass (4) and the exhaust gas back pressure sensor (15), which monitors the exhaust gas back pressure. The partial exhaust gas stream is fed to the particle filter (10), whose operating status is monitored via differential pressure sensors (16). The temperature sensors (17) are indicators for the switch-on and operating phase as well as for the time of self-cleaning. When the pressure at the differential pressure sensors (16) drops, the exhaust gas quantity control valve (9) closes, which causes the temperature in the particle filter (10) to rise and thus starts self-cleaning. Self-cleaning occurs automatically during normal operation. The exhaust gas partial stream is then fed to the synthesis gas generator (8) and heats the synthesis gas generator (8) to approx. 180 ° C. The evaporator temperature sensor (18) then gives the release and starts the pump, which then pumps the water from the water tank (2) or a mixture consisting of water from the water tank (2) and ethanol/methanol from the ethanol tank (3) into the Synthesis gas generator (8) is injected or misted, and the water or the mixture evaporates.

The ethanol reformer (12) consists of a double-walled container, the second barrier of which is insulated from the inner container against thermal losses. The inner container is the actual catalyst (19). The area between the inner container/catalyst (19) and the outer container is heated with hot gas to a temperature of 350°C. The evaporator (13) is also heated to 350°C using hot gas and generates water and ethanol steam, which then flows through the catalyst (19) and is catalytically “cracked”, producing hydrogen and CO. By installing a Venturi tube, the fluid flow (steam) in the Venturi tube creates a negative pressure through which the ambient air is sucked in. This air supports the catalytic process. The synthesis gas is then cooled via the HD-H2 gas cooler (11) and fed through the air filter (7) to the compressor (6), which, like conventional intake air, compresses it and directs it into the combustion chamber. In the combustion chamber, the synthesis gas optimizes the combustion situation of the fuel-air mixture, with the result that the specific fuel consumption decreases, less turbulence and fewer emissions occur. With a drop size of 10 µm, the aerosol creates a large surface area that absorbs so much heat that the exhaust gas (synthesis gas) can be fed to the engine's intake tract and burned in the combustion chamber. The inlet temperature is then approx. 40°C - 50°C. The water tank (2) and the ethanol tank (3) are each monitored by a fill level sensor (14), which switches off the NOx reducer when the low level is reached. Every sensor is part of the security chain. Switching off the empty water tank (2) is safety-relevant because it prevents... Ethanol is injected into a “hot area” without water. Conversely, the injection of water without ethanol would not be critical, but would lead to significantly higher emission levels.

During combustion, the synthesis gas limits the development of temperatures that produce NOx, since the moisture in the synthesis gas removes heat from the combustion. This happens in high temperature areas from around 1000°C and at a point in time at which the thermodynamic performance has been implemented. CO increases slightly or to a negligible extent. The control (1) processes the signals from the sensors and regulates the exhaust gas partial flow quantity, the water/ethanol injection quantity, the temperatures of the particle filter and synthesis gas generator and ensures safe operation, as setpoint deviations lead to the NOx reducer being switched off.

The advantages achieved by the invention are, in particular, that a self-sufficient emissions reduction system is used, which can be integrated into any infrastructure of a combustion engine, has a modular structure, is used in both mobile and stationary operation, and is independent of load and temperature 24/7 operation enables nitrogen oxides to be reduced without a significant increase in CO, fuel generated during operation and thereby nitrogen oxides also reduced without increased fuel consumption.

The NOx reducer has a very low energy requirement of its own, which is around 100W on a Cummins 6 cylinder 160kW power plant, for example. The NOx reducer is used wherever fossil fuels are burned. It can be manufactured individually or modularly in boxes or containers and can therefore meet every performance requirement of the respective machine. The NOx reducer reduces nitrogen oxides without significantly increasing CO emissions or fuel consumption. Substitution with ethanol shows a positive effect on nitrogen oxide reduction. The associated increase in CO is eliminated by ethanol reformer (12), since hydrogen does not contain any CO.

NOx reducer stands for sustainability, as older diesel engines equipped with NOx reducers achieve the values specified in IMO TIER III and can continue to be used. Since the thermal power for the ethanol reformer (12) results from the exhaust gas mass flow and does not come from the socket, as is the case with electrolysis, the invention also has economic advantages for the user. The path from substitution to “pure” hydrogen operation would make this transition technology a future-oriented technology.

The present invention is a system for reducing emissions and fuel costs in power and heat engines, consisting of a system for generating process heat, a reformer for producing hydrogen from ethanol and an energy storage or fuel cell system for storing and using the hydrogen produced, which is at Work and heat engines can be used from a variety of applications including but not limited to industrial and power plants.

Reference symbol list

1

steering

2

water tank

3

Ethanol tank

4

Exhaust gas bypass

5

exhaust turbine

6

compressor

7

Air filter

8th

Syngas generator

9

Exhaust gas quantity control valve

10

Particulate filter

11

HD H2 gas cooler

12

Ethanol reformer

13

Evaporator

14

Level sensors

15

Exhaust back pressure sensor

16

Differential pressure sensors

17

Temperature sensors

18

Evaporator temperature sensor

19

catalyst

Claims (9)

A process for reducing nitrogen oxides that are produced when engines use fossil fuels and the associated production of hydrogen by reforming ethanol using process heat, whereby the process heat is obtained from manpower and heat machines. A device for carrying out the method according to Claim 1 , consisting of a control (1), a water tank (2), an etha noltank (3), an exhaust gas bypass (4), an exhaust gas turbine (5), a compressor (6), an air filter (7), a synthesis gas generator (8), an exhaust gas quantity control valve (9), a particle filter (10), an HP h2 gas cooler (11), an ethanol reformer (12), an evaporator (13), a fill level sensor (14) in the water and ethanol tanks, an exhaust gas back pressure sensor (15), the differential pressure sensors (16), the temperature sensors (17), the evaporator temperature sensor (18) and the catalytic converter (19). The procedure according to Claim 1 and the device according to Claim 2 to carry out the procedure in accordance with Claim 1 , whereby the hydrogen produced is stored in an energy storage or a fuel cell or internal combustion engine system and used to power fuel cells or internal combustion engines. The device according to Claim 2 , in which the ethanol reformer (12) is constructed as a double-walled container, the second barrier of the inner container/catalyst (14) is insulated against thermal losses, is operated by the process heat from workers and heat machines and converts the ethanol into hydrogen. The device according to Claim 2 , in which the evaporator (13) is heated to 350 ° C by the process heat from working power and heat machines and produces water and ethanol vapor, which flows through the ethanol reformer (12), producing hydrogen and CO. The device according to Claim 2 to carry out the procedure in accordance with Claim 1 , whereby the device can be operated in a modular, mobile and self-sufficient manner. A procedure according to Claim 1 , whereby no solids and soot particles are produced as by-products of production. The device according to Claim 2 , in which the exhaust gas partial flow is fed to the particle filter (10), the operating state of which is monitored via the differential pressure sensors (16), which send the signal to close the exhaust gas quantity control valve (9) when the pressure drops, causing the temperature in the particle filter (10) to rise and self-cleaning takes place in regular operation. The procedure according to Claim 1 , in which the values of CO emissions only increase insignificantly.

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