The internal combustion engine as a chemical reactor for producing synthesis gas from hydrocarbon feedstocks

Abstract

To provide a method for using an internal combustion engine as a synthetic gas generator.SOLUTION: An internal combustion engine 100 operates in fuel-rich conditions by adjusting one or more operating parameters such as a throttle 210, ignition timing, a load coupled to the engine, a fuel pressure, power to a supercharger and power to a preheater, and maintains a specific engine speed and an exhaust gas temperature. When the internal combustion engine 100 operates under these conditions, the internal combustion engine 100 can function as a reformer 200 that produces synthesis gas containing hydrogen and carbon monoxide.SELECTED DRAWING: Figure 2

Description

Related Applications

[0001] This application is a joint application of "INTERNAL COMBUSTI ON ENGINE AS A CHEMICAL REACTOR TO PRODU CE SYNTHESIS GAS FROM HYDROCARBON FEEDS” This application claims the benefit of U.S. Provisional Patent Application No. 62 / 565,844, entitled "Compounds for the Prescription of Novel Coronavirus Infections," which is hereby incorporated by reference in its entirety. FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made under grant number DE-AR0000506 awarded by the U.S. Department of Energy. This invention was made with government support. The government has certain rights in this invention. [Technical Field]

[0003] The present invention relates generally to the production of synthesis gas, and more particularly to the production of synthesis gas using an internal combustion engine as a synthesis gas generator. do. [Background technology]

[0004] Many processes and operations produce gas streams of light hydrocarbons. The gas stream is at low pressure and may contain various additional contaminants. The gas stream may have little intrinsic value and is used to remove contaminants and compress the gas ( costs (such as increasing the pressure to allow for introduction into natural gas transmission pipelines) are Given these constraints, the gas stream can be flared, incinerated, or is often disposed of by venting.

[0005] Recently, there has been growing interest in making more productive use of these low-quality hydrocarbon streams One such area is the use of hydrocarbons as feed gas in the production of synthetic gas (syngas). Syngas is a mixture of organic feedstocks (light hydrocarbons, coal, petroleum coke, etc.) It is produced from the partial combustion of fuels (fuel, biomass, oil) and produces primarily hydrogen (H2) and carbon monoxide (CO Syngas may contain contaminants (including H2S and COS) depending on the starting material. Many syngas production processes involve catalytic reforming. The catalyst increases the reaction rate and reduces the reaction temperature. However, many catalysts are made from expensive materials and are susceptible to damage by sulfur compounds present in the gas stream. are subject to poisoning and clogging by soot and other particles.

[0006] Syngas is a starting material for the production of various chemicals. It can also be used to generate electricity in a bin or engine-based generator. Syngas is a mixture of CO and water vapor. to H2 and carbon dioxide (CO2) via the water-gas shift (WGS) process. It can also be used to generate H2 by: The ratio of H2 to CO in the process gas is: It usually needs to be carefully tuned to meet the demands of downstream applications.

[0007] Recently, U.S. Patent No. 9,169,773 (Bromberg et al.) has reported that hydrogen-rich gas A reformer-liquid fuel production system is disclosed that utilizes an engine to generate The systems operate at air / fuel ratios, equivalence ratios, and φ < 4.0. ,Effective engine-based reformers, homogeneous charge compression ignition (HCCI), part Must be able to use premixed compression ignition (PCI) or reaction-controlled compression ignition (RCCI) They disclose that "in the flow burner flame and cylinder calculation, the lower the equivalence ratio, The higher the energy released in the conversion, the higher the peak cylinder temperature, and the higher the hydrogen and CO "The selectivity for the target molecule decreases..."

[0008] U.S. Patent No. 2,391,687 (Eastman et al.) describes a method for producing oxygen with over 90% pure oxygen. and producing syngas having an equivalence ratio of 2.8 to 4.0. There are. Summary of the Invention

[0009] All or part of the above problems may have been observed by those skilled in the art. To address other issues, the present disclosure is described by way of example in the implementations shown below. Methods, processes, systems, apparatus, equipment, and / or devices are provided.

[0010] According to one embodiment, a method for operating an internal combustion engine under fuel-rich conditions comprises: starting the engine using a supply gas having an equivalence ratio; increasing the fuel-air equivalence ratio while producing a fuel-rich feed gas; Acting on the throttle, ignition timing, load coupled to the engine, fuel pressure, and gas supply adjusting one or more of the power to the turbocharger and the power to the preheater acting on the feed gas to In one embodiment, the air equivalence ratio is maintained at about 1.6 to 2.4. An engine speed of 2000 revolutions per minute (RPM) and an exhaust gas temperature below approximately 900°C were maintained. It will be held.

[0011] According to another embodiment, a method for operating an internal combustion engine under fuel-rich conditions includes starting said engine. After starting, exhaust back pressure, intake manifold pressure, engine speed, ignition timing, fuel gas fuel Maintaining the initial conditions set for air equivalence ratio, and fuel gas inlet temperature; fuel gas The fuel gas inlet temperature is increased while maintaining the fuel-air equivalence ratio, and the methane and oxygen in the engine exhaust gas are reduced. monitor methane and oxygen content; adjust ignition timing according to monitored methane and oxygen content This includes adjusting the

[0012] According to another embodiment, the gas reformer system is is configured to run

[0013] According to another embodiment, the gas reformer system includes a fuel gas inlet, an exhaust gas outlet, a plurality of Includes cylinders, ignition timing system, throttle, fuel gas preheater, and turbocharger. The internal combustion engine includes an internal combustion engine having a fuel gas fuel-air equivalence ratio of about 1.6 to 2.4. It is structured as follows.

[0014] Other devices, apparatus, systems, methods, features, and advantages of the present invention are described in the following figures and drawings. It will be or become apparent to those skilled in the art upon review of the detailed description. All such additional systems, methods, features, and advantages are included within this description and are within the scope of the invention. It is intended that this invention be protected by the following claims.

[0015] The present invention can be better understood by reference to the following figures, in which: The components are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the drawings, like reference numerals designate corresponding parts throughout the different views. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic cross-sectional view of an exemplary cylinder of an internal combustion engine according to some embodiments. [Figure 2] FIG. 1 is a schematic diagram of a system for producing syngas using an internal combustion engine, according to some embodiments. [Figure 3] FIG. 1 is a schematic diagram of a system for producing syngas using an internal combustion engine, according to some embodiments. [Figure 4] FIG. 1 is a schematic diagram of a system for producing syngas using an internal combustion engine, according to some embodiments. [Figure 5] FIG. 5 is an exemplary flowchart of a method for starting an engine under fuel-rich conditions, according to some embodiments. [Figure 6] FIG. 6 is an exemplary flowchart of a method for operating an engine under fuel-rich conditions, according to some embodiments. [Figure 7] FIG. 7 is a graph of fuel air inlet temperature for various fuel air equivalence ratios according to some embodiments. [Figure 8] FIG. 8 is a graph of H2 to CO ratio for various fuel-air equivalence ratios, according to some embodiments. [Figure 9] FIG. 9 is a graph of natural gas fractionation for various fuel-air equivalence ratios, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0017] As used herein, the term "syngas" refers to synthetic gas. Syngas is a mixture of at least carbon monoxide (CO) and diatomic hydrogen gas (H2). Depending on the embodiment, the syngas may be, for example, water, air, diatomic nitrogen gas (N), diatomic Oxygen gas (O2), carbon dioxide (CO2), sulfur compounds (e.g., hydrogen sulfide (H2S) , carbonyl sulfide (COS), sulfur oxides (SO x ), nitrogen compounds (e.g., nitrogen Oxide (NO x ), metal carbonyls, hydrocarbons (e.g., methane (CH4)), Ammonia (NH3), chlorides (e.g., hydrogen chloride (HCl)), hydrogen cyanide (HCN) , trace metals and metalloids (e.g., mercury (Hg), arsenic (As), selenium (Se), cadmium It also contains other components such as cadmium (Cd) and its compounds, and particulate matter (PM). It can be seen.

[0018] As used herein, the term "lower hydrocarbons" refers to methane, ethane, propane and "Non-alcoholic" refers to low molecular weight hydrocarbons, including but not limited to toluene and butane.

[0019] As used herein, the term "load" refers to an electric heater, a dynamometer, a water bath, etc. By increasing or decreasing the load, the engine can be kept at a constant speed when input conditions change. It can be operated at different temperatures. The load can also be varied to achieve this.

[0020] As used herein, the term "natural gas" refers to gas that is a mixture of methane and smaller amounts of higher alkanes. Depending on the embodiment, natural gas may refer to a mixture of hydrocarbon (HC) gases consisting primarily of: non-HC species such as one or more of the following, as well as carbon disulfide (CS2) and / or other di- Sulfides, and methanethiol (CH3SH) and ethanethiol (C2H5SH ), and thiophenes such as thiophene (C4H4S). and other organic sulfur compounds.

[0021] The present disclosure provides a method for utilizing an internal combustion engine as a syngas generator. The process can be used in conjunction with methanol production and other chemical production processes. The disclosed method can utilize a wide variety of hydrocarbon sources distributed around the world. For example, oil and natural gas producing wells are located in many remote locations in the United States, and individual wells, comp Lessors, pneumatic equipment, and well storage vessels may produce hydrocarbon discharge streams. These hydrocarbon streams are often flared or vented due to their low volume, low pressure, and potential for contamination. These heterogeneous materials are often collected in natural gas transmission pipelines. Compressing and purifying a stream of Mass-produced internal combustion engines operated under specific conditions are used to partially convert these hydrocarbons into Oxidize to produce syngas that can have higher value, making collection of syngas economically viable Let's say.

[0022] Internal combustion engines are typically used to either propel vehicles, drive mechanical devices, or generate electricity. It has been developed and utilized for decades to produce electricity. Each of these uses In the However, internal combustion engines have other interesting properties for other applications. Controlling the heat from the coolant and radiator system, and providing high pressure in the cylinder The ability to generate, the ability to have a short residence time in the cylinder, and the control of valve pressure are all This can be used in processes of chemical conversion where the engine acts as a chemical reactor. controls engine parameters to maximize the desired chemical conversion as opposed to power generation In some cases, chemical reactions can generate electricity. In an example, power can be added by turning the shaft externally. Chemical reactions that operate between and take advantage of the above properties can be achieved by using the engine as a chemical reactor. Here, we present a novel method for converting light hydrocarbons into syngas. Such uses will be explained.

[0023] FIG. 1 illustrates a cross-sectional schematic view of one cylinder 105 of an internal combustion engine 100 according to various embodiments. The internal combustion engine 100 may further include a combustion chamber 110 within the cylinder 105. A piston 115 is disposed within the cylinder 105 and moves up and down within the cylinder 105. The combustion chamber 110 can be configured to have a variable volume, thereby defining a variable volume of the combustion chamber 110. When the cylinder 105 is at its highest point (called top dead center (TDC)), When the piston 115 reaches the lowest position (bottom dead center) in the cylinder 105, the volume becomes minimum. The piston 115 has its maximum volume when it is at its maximum displacement (BDC). 5 to the crankshaft 120. The internal combustion engine 100 includes a cylinder 105 The head 130 may further include a head 130 coupled to the top of the one or more intake valves. 135 and one or more exhaust valves 140. Each intake valve 135 may be connected to an intake port 14 5, while each exhaust valve 140 serves to open and close an exhaust port 150. The intake port 145 is in fluid communication with the combustion chamber 110 to allow the intake of fuel. The mixture of fuel and oxidizer (called the charge) flows into the combustion chamber 110. 50 is also in fluid communication with the combustion chamber 110 to allow exhaust gases to flow out of the combustion chamber 110. The rod 130 also extends at least partially into the combustion chamber 110 and provides ignition for the charge. It may include one or more spark plugs 155 that may provide a source of electricity.

[0024] Although not shown in FIG. 1, the internal combustion engine 100 may include a gas turbine engine, which may include a gas turbine engine, a power plant, and a power plant. a preheater to raise the temperature of either or both the oxidizer and the fuel, and The preheating device may further include a supercharger that increases the pressure of one or both of the fuel and the oxidizer. The device may include, for example, a heat exchanger for extracting a portion of the heat of the exhaust gases from the internal combustion engine 100. Alternatively, the preheater may be an electrically powered heater, a secondary fuel combustion, or another process Heat energy can be obtained by other processes known in the art, such as the removal of heat from a gas. The turbocharger is a device for extracting energy from exhaust gas from the internal combustion engine 100. Alternatively, the supercharger may be powered by an electric motor or by energy from another process. It may be powered by other processes known in the art such as ghee removal.

[0025] In a specific, non-limiting embodiment, the internal combustion engine 100 is configured to operate using a four-stroke process. A four-stroke process may be adapted to operate, for example, when the piston 115 is It starts at C and then starts moving downward. The intake valve 135 moves downward, This places the intake port 145 in fluid communication with the combustion chamber 110. The piston 115 moves downward. This allows the charge to enter the combustion chamber 110. When the piston 115 reaches BDC, When the intake valve 135 closes, the piston 115 then moves upward, compressing the charge. As the piston 115 approaches TDC, the spark plug 155 ignites the charge. In various embodiments, as further described below, the piston 115 A spark can be generated before the charge reaches TDC. As the charge burns, the combustion chamber 11 The pressure inside the piston 115 increases, pushing down the piston 115. The piston 115 reaches BDC. When the exhaust valve 140 is released, the exhaust port 150 is placed in fluid communication with the combustion chamber 110. As the piston 115 moves toward TDC, the combustion gases from the burned charge When the piston 115 reaches TDC, the exhaust valve 14 The 0 closes and the cycle repeats.

[0026] Although the details of each process are not described herein, various embodiments of the internal combustion engine 10 0 is 2-stroke process, 5-stroke process, 6-stroke process, compression ignition Process (e.g., diesel), jet engines, turbines, rotary engines, or configured to operate according to any other engine type known in the art Due to its widespread popularity and ready availability, this disclosure is While the present disclosure focuses on the process, no limitation on the scope of the disclosure should be inferred.

[0027] Typically, hydrocarbons and oxygen are the fuel and oxygen, respectively, that are burned in the internal combustion engine 100. It is an oxidizing agent. The general stoichiometric chemical equation for the combustion of hydrocarbons in oxygen is given by Eq. Can be: [ka] Therefore, in stoichiometric complete combustion, all hydrocarbons react with oxygen to form carbon dioxide. Therefore, for complete stoichiometric combustion, a certain ratio of fuel to air is required. One example shows how the actual air-fuel ratio compares to the stoichiometric air-fuel ratio. The measure of this is the equivalence ratio (denoted as φ). The equivalence ratio is the ratio of the actual air-fuel ratio to the stoichiometric air-fuel ratio. It is calculated by dividing by the fuel ratio. Equivalence ratio values ​​greater than 1 indicate fuel-rich conditions.

[0028] An internal combustion engine 100 operated according to stoichiometric complete combustion typically produces useful work and heat. However, various embodiments may operate the internal combustion engine 100 to extract To utilize the internal combustion engine 100 as a reactor, it is necessary to operate the engine 100 at other than stoichiometric conditions. Certain embodiments may include using fuel-rich conditions ( (i.e., less than the stoichiometric amount of oxygen burns all the hydrocarbons) Without intending to be limited to a particular mechanism of action, under some conditions, The engine 100 operates as a reformer, producing hydrogen ( A synthetic gas (syngas) containing hydrogen (H2) and carbon monoxide (CO) can be produced. [ka] When the hydrocarbon is methane (CH4), the partial oxidation reaction is given by Equation 3. CH4+ 0.5O2→ CO + 2H2 formula 3 Furthermore, complete combustion (Equation 1), reforming reactions such as Equation 4 and Equation 5 (shown for methane), and Other reactions may also occur, such as HCl and other known reforming and combustion reactions. 2CH4+ O2+ CO2→ 3CO + 3H2+ H2O Equation 4 4CH4+ O2+ 2H2O → 4CO + 10H2 formula 5

[0029] FIG. 2 illustrates, for example, a system utilizing an internal combustion engine 100 as a chemical reactor to produce syngas. 2 is a schematic diagram of a process 200 according to various embodiments that can be used to The charge to the internal combustion engine 100 may include an oxidizer and a fuel. The oxidizer may be air, a rich The oxidant may be oxidized air or a gas containing sufficient oxygen. The oxidant is passed through a filter 205 , particles and other solid contaminants, as well as liquid or gaseous contaminants such as water The flow of oxidizer can be controlled by a throttle 210. The flow regulator 210 may be equipped with any flow regulator known in the art and may be manually The oxidizer pressure can be increased by a supercharger 215. The supercharger 215 acts as a compressor to increase the pressure, This allows more oxygen to be delivered to each cylinder 105 of the internal combustion engine 100 . The supercharger 215 may be driven by an electric motor or by the exhaust stream of the internal combustion engine 100. or powered in another way, such as by utilizing residual energy in another process stream. The oxidizer may also be passed through a heater to increase the temperature of the oxidizer before entering the internal combustion engine 100. The heater 220 may be an electrically heated coil or an internal combustion engine. A heat exchanger that extracts energy from a process stream such as the exhaust stream of 100 (see, for example, Figure 4). The fuel may also be passed through a filter 225 to separate solid, liquid, or gaseous fuel. The temperature of the fuel stream may be adjusted to remove any contaminants present in the fuel stream and pass through a flow conditioner 230. The temperature can be increased by a heater 235, which operates similarly to the heater 220. 0 mixes oxidizer and fuel in a desired ratio and supplies them to each cylinder 105 of the internal combustion engine 100. The internal combustion engine 100 can then generate a charge as described above. The operation of the internal combustion engine 100 also includes partially oxidizing the oxidized carbon dioxide to produce syngas in the exhaust stream. Mechanical power and heat can be produced.

[0030] In various embodiments, the process 200 may further include a central processing unit (not shown). The central processing unit communicates with one or more of the individual components of the process 200 and The central processing unit executes computer code to activate and control the and storing and executing the monitored operating conditions of the internal combustion engine 100 and the Operation of the process 200 can be initiated in response to an analysis of the syngas produced by the process. For example, the ratio of H2 to CO in the exhaust stream of an internal combustion engine 100 can be monitored, and a central processing unit may adjust one or more of the individual components of the process 200 in response to the monitored ratio of H2 to CO. Additionally, the central processing unit may adjust the combustion temperature in one or more cylinders 105. The process is performed in response to monitored parameters of the internal combustion engine 100, such as temperature, intake pressure, and exhaust pressure. One or more individual components of the system 200 can be adjusted.

[0031] FIG. 3 illustrates a system that may utilize an internal combustion engine 100 as a chemical reactor to produce, for example, syngas. FIG. 3 is a schematic diagram of a process 300 according to various embodiments. 305 to convert the mechanical power generated by the internal combustion engine 100 into electrical power. The power may be supplied to the oxidant heater 220, the gas heater 235, or any other It can be used to provide electrical power efficiently.

[0032] FIG. 4 illustrates a process utilizing an internal combustion engine 100 as a chemical reactor for producing syngas, for example. 4 is a schematic diagram of a process 400 according to various embodiments for obtaining Residual heat in the gas can be used to heat the oxidizer and fuel. 20 and fuel heater 235 to transfer heat from the syngas to the oxidant and fuel streams. Heat exchangers may include shell and tube, plate and shell, plate and tube, and The fins may be of any type known in the art, such as parallel flow, counter flow, etc. , or can operate in a cross-flow configuration.

[0033] An internal combustion engine 100 operating under fuel-rich conditions is susceptible to detonation or knocking. Knocking can occur when the charge is pocketed. This occurs when a flame ignites outside the flame front generated by the spark, and This pressure increase can cause the piston 115 to rise above its design limit. or could tear a hole in the head 130, leading to catastrophic failure of the internal combustion engine 100. Gar.

[0034] Various embodiments may be used to start the internal combustion engine 100 to achieve fuel-rich operation, 5 includes a method for operating under steady state conditions without (or with minimal) knocking. Various implementations of method 500 for starting engine 100 and achieving fuel-rich operation 5 shows a general flow chart of the embodiment. The internal combustion engine 100 starts the initial fuel air intake in step 505. In step 510, the start-up can be performed using a supply gas having a fuel-air equivalence ratio. The equivalence ratio can be gradually increased to produce a fuel-rich feed gas. , while increasing the fuel-air equivalence ratio, maintaining the engine speed at approximately 1000-2000 RPM and maintain the exhaust gas temperature below approximately 900°C, while adjusting one or more of the following: Can: throttle 210, ignition timing, load coupled to internal combustion engine 100, fuel pressure power to the supercharger 215 acting on the feed gas, and power to the preheater 220 acting on the feed gas. , power to 235.

[0035] Before starting the internal combustion engine 100, the fuel pressure is typically below ambient pressure and the throttle The torque 210 is partially opened to a predetermined value, typically less than 50%, and the ignition timing is adjusted to a first position. By setting the initial operating conditions such that the load is coupled to the internal combustion engine 100, the load is set to a constant value. In various embodiments, ignition timing is provided by spark plug 155. Determines when a spark occurs and when the crankshaft 115 is at TDC. 20 rotational positions. Generally, ignition timing is measured when the piston 115 is at the TD The ignition timing may be advanced to produce a spark before reaching C. This allows combustion of the charge (or a desired amount of partial combustion) to occur when the piston 115 reaches TDC. The ignition timing can be completed near the point where the piston 115 reaches T The angle of rotation of the crankshaft 120° before reaching DC, or simply before top dead center ( In various embodiments, the first predetermined ignition timing value is expressed as degrees BTDC. The BDTC may be about 8 degrees, or about 5 degrees to about 15 degrees. In some embodiments, the first predetermined ignition timing value may be up to about 30 degrees BDTC.

[0036] The internal combustion engine 100 begins to start, and the internal combustion engine 100 rotates for a short time until the engine starts. After allowing the fuel pressure to increase, the fuel pressure is typically increased to near ambient pressure to power the internal combustion engine 100. After starting, it is advisable to monitor the engine speed. The timing is adjusted to maintain the engine speed between approximately 1000 and 2000 RPM. The second predetermined value can be gradually increased by adding the second predetermined value. The timing value may be approximately 16 degrees BTDC. In other embodiments, the second predetermined ignition timing The timing value is about 8 degrees to about 28 degrees BTDC, preferably about 10 degrees to about 20 degrees BTDC. The range can be:

[0037] As previously mentioned, the supercharger 215 is, in certain embodiments, powered by an electric motor. In such an embodiment, the supercharger 215 may be first powered and then approximately 10 Fuel pressure is increased in stages to maintain engine speed between 00 and 2000 RPM. In various embodiments, the output can be increased stepwise while the turbocharger 2 15 is initially set to a predetermined value, usually to provide air similar to that naturally aspirated in the engine. The power is supplied at a setting that is approximately 10% to 15% increments between the first and second predetermined values. gradually increase to a predetermined value of 2. In various embodiments, larger increments may be used. However, the fuel pressure may be increased incrementally by approximately 0.1 inches H2O.

[0038] The throttle 210 is adjusted from 1% to 90% open until it reaches its final throttle position. It can be gradually increased from the initial setting using increments up to 10%. To maintain engine speed at approximately 1000-2000 RPM while increasing throttle 210, To achieve this, the fuel pressure can be increased. If the engine performance deteriorates rapidly, the fuel-air mixture may be too rich. If the engine is running, the fuel pressure will drop and the load may be used to control the engine speed. Temperature can also be monitored, along with one or more of fuel pressure, throttle 210, and engine load. It is better to keep the temperature below 900°C by changing the above.

[0039] The preheaters 220, 235 are first powered to heat the air before it enters the intake port 145. The temperature of the fuel can be maintained at about 200°C by the preheaters 220, 235. Timing can be further advanced by BTDC. The specific ignition timing and the specific process for advancing the ignition timing may be, for example, conditions (temperature, pressure, presence of contaminants, etc.), fuel injection timing, ignition system type Many factors can affect the engine, such as engine speed, engine load, and the specific type of engine used. The power to the supercharger 215 is stepped to increase the air supply velocity. When the power output of the turbocharger increases and the preheaters 220 and 235 heat up, By adjusting fuel pressure and load, the engine speed can be adjusted to approximately 1000-2000 RPM. Once the desired engine throughput is achieved, the turbocharger power increase is discontinued. It is possible.

[0040] When the preheaters 220 and 235 reach approximately 200°C, the preheater temperature exceeds the set temperature. To avoid shoots, the setting can be increased in predetermined increments, typically no more than 15%. As is known in the art, an automatic control system can be used to automatically adjust the set temperature. Allowing for larger temperature increments without increasing the risk of overshoot The fuel pressure can be increased by increasing the engine speed to about 1000-200 while the preheater temperature is rising. Once the desired fuel-air equivalence ratio is achieved, the preheater temperature In various embodiments, the desired fuel-air equivalence ratio is , may be about 1.6 to 2.4.

[0041] If the internal combustion engine 100 suddenly loses stability while ramping up the preheater temperature, the current manifold The operating temperature in the cylinder 105 may be too high for the current fuel to air ratio at the cylinder pressure. In this situation, power to the preheaters 220, 235 may be turned off until stability is restored. Then, power is turned on to the preheaters 220, 235 to increase the preheater temperature and fuel pressure. can be resumed.

[0042] Air is often used to provide the oxidant to the charge, but enriched air (e.g., Up to about 35 volume percent O2 may be used in various embodiments. This increases engine throughput and reduces downstream costs per unit of throughput This improves the collection of liquid products and catalytic activity. Increasing humidity or adding additional steam can increase the The water vapor concentration in the catalyst increases, and the water vapor is converted by the steam reforming reaction as explained in Equation 5 above. The yield of the material increases.

[0043] Although methane is used herein to describe the primary fuel, various embodiments may A variety of hydrocarbon fuel compositions can be used. In many cases, the operation of the system is dependent on the Methane taken from natural gas pipelines, associated gas from oil wells, and waste gas that is commonly flared. The pipeline utilizes gas streams, biogas streams, and other such gaseous light hydrocarbon streams. Natural gas is composed primarily of methane, with ethane levels of 1-6% and trace amounts of other There are hydrocarbons, carbon dioxide, nitrogen, and other molecules. Similarly, associated gases from oil wells are High concentrations of ethane and natural gas liquids, commonly known as propane, butane, pentane, and hexane. In some cases, the remaining natural gas is Natural gas liquids are collected before being collected and utilized for fuel or flared. The operation of the engine to produce gas is operated in a manner that maintains conversion and avoids soot formation. By adjusting the parameters, it is possible to achieve high-performance combustion with this fuel, with or without the removal of natural gas liquids. A separate fuel stream for the engine can be generated from various chemicals, manufacturing processes, and other waste products as by-products. Such fuels may also be gas streams from fuel manufacturing or industrial processes or storage systems. These streams may contain a variety of light hydrocarbons. If these streams are sufficiently high in fuel (depending on fuel concentration), If they have a concentration or can be processed to achieve such a concentration, This is considered a potential fuel source for syngas production using the stream. There are many sources of biogas that can be used as fuel to produce syngas. For the purposes of this invention, biogas is defined as primarily methane and carbon dioxide and biogas fractions. As a gas stream produced from the decomposition of biomass materials containing other trace components known from the field Defined. Examples of sources of biogas include landfills, animal waste treatment sites, and wastewater treatment plants. Biogas is used in processing plants, etc. In order to operate engines efficiently, Pre-treatment may be required to remove carbon dioxide from the fuel (depending on concentration) However, complete removal is not required for engine operation. Engine operation is generally Tolerant of the presence of carbon. As explained in the composition of natural gas, ethane is typically present in natural gas streams. Other embodiments include using additional fuels, either as fuel or mixed with natural gas as fuel. Additional ethane can be used. The addition of hydrogen to the fuel stream is also useful in some embodiments. This hydrogen can be obtained from an external source and can provide benefits to a variety of fuel compositions. or recycled from engine operation or downstream processes. The configuration involves recycling hydrogen selectively removed from the engine exhaust gas or The goal is to recycle part of the engine exhaust.

[0044] Once the start of the internal combustion engine 100 is achieved to reach a fuel rich condition (e.g., FIG. 5 6 shows the results of the experiments under fuel-rich conditions. Another general example of various embodiments of a method 600 for continuously operating an internal combustion engine 100 is shown in FIG. In step 605, the exhaust back pressure, intake manifold pressure, engine The engine speed, ignition timing, fuel gas fuel-air equivalence ratio, and fuel gas inlet temperature were After starting the internal combustion engine 100, an initial set of operating conditions may be maintained. In step 610, the fuel gas is heated by increasing the power to the preheater while maintaining the ratio. The inlet temperature can be increased. The methane and oxygen content of the exhaust gas (methane in the fuel) The ignition timing can be adjusted based on the monitored methane and oxygen. Depending on the element content, adjustments can be made in step 615.

[0045] In various embodiments, the initial operating exhaust back pressure may be approximately ambient to 5 bar absolute. Preferably, the initial operating intake manifold pressure may be about ambient to 2 bar absolute. The initial operating engine speed may be about 1000-2000 RPM, and the initial operating ignition timing The timing may be about 25 to 35 degrees BTDC, with the initial operating fuel-air equivalence ratio being about 1.6 to 1.8. 2.4, and the initial fuel gas temperature may be about 200 to 270°C. , the approximate fuel gas temperature range for a fuel-air equivalence ratio of 1 to 2 is shown.

[0046] In various embodiments, ignition timing is adjusted in response to monitored methane and oxygen. This means that methane and oxygen slip (i.e., unreacted methane passing through the internal combustion engine 100) This includes monitoring the methane content in the exhaust gas or the oxygen content in the exhaust gas. If the element content exceeds the allowable level, the ignition timing is advanced to reduce slip. By monitoring exhaust gas temperature while advancing ignition timing, exhaust The gas temperature can be maintained within the range shown in Figure 7. In various embodiments, the internal combustion engine 1 Instead of advancing the ignition timing of all cylinders 105 equally, The exhaust gas temperature of each individual cylinder 105 can be adjusted individually. can be varied within a range of about 75°C.

[0047] Under essentially steady-state operating conditions, FIG. 8 shows the exhaust gas Therefore, the internal combustion engine 100 is able to efficiently control downstream processes. If necessary, the H2 to CO ratio may be adjusted to produce a desired ratio. 1 shows the fractional conversion of natural gas as a fuel for the internal combustion engine 100 for various fuel-air equivalence ratios. According to various embodiments, FIG. 8 can be used to determine the fuel required to produce a desired H2 to CO ratio. The air equivalence ratio can be determined and then Figure 9 can be used to determine the fuel-air equivalence ratio. The expected fractional conversion of fuels that may occur can be determined. [Example]

[0048] The engine system is powered by natural gas supplied from a local utility natural gas pipeline. The syngas was produced using a commercially available 8-cylinder, 8.8L engine. The spark ignition engine was configured for a system that produced syngas in rich operation. Air is taken in from the intake manifold and pressure is increased to approximately 2 bar using a turbocharger. The boosted natural gas is a utility that meets normal U.S. specifications for pipeline natural gas. The typical composition throughout the stated run was 95% by volume. Methane (CH4), 4% by volume of ethane (C2H6), 1% by volume of carbon dioxide (CO2) and Before mixing, the air and natural gas mixture was heated for 20 The mixed feed was heated above 0°C. It was then fed into the engine cylinder through the intake manifold. The feed was converted to syngas in the cylinder using spark ignition. The engine was operated at a speed of 1500 RPM and the exhaust gas temperature was maintained below 900°C. The gas is collected through the exhaust manifold and is adjusted to a pressure of 4-5 bar using downstream pressure regulation. maintained in force.

[0049] Table 1 shows the syngas composition (4%) from this example of operation of the internal combustion engine 100 according to the present disclosure. The average of the number of runs is shown.

[0050] [Table 1]

[0051] The above examples are for illustrative purposes only and do not limit the invention to the processes used in the examples. It is not limited to this.

[0052] Generally, terms such as "communicate" and "in communication" (e.g., when a first component is "Communicating with" or "being in communication with" two components is used herein to refer to two or more components. structural, functional, mechanical, electrical, signal, optical, magnetic, electromagnetic, or other characteristics of components or between components It shows gaseous, ionic or fluidic relationships, so that one component can interact with the second component. The fact that the first and second components communicate with each other means that additional components exist between the first and second components, and and / or operatively associated or engaged with.

[0053] Various aspects or details of the invention may be changed without departing from the scope of the invention. It is further understood that the foregoing description is by way of example only and not by way of limitation. It is not intended to be limiting, but the present invention is defined by the claims.

Claims

1. 1. A method for using an internal combustion engine as a reactor under fuel-rich conditions, comprising: starting the engine using a supply gas having an initial fuel-air equivalence ratio; increasing the fuel-air equivalence ratio in stages to produce a fuel-rich feed gas; and adjusting ignition timing while increasing the fuel-air equivalence ratio, and optionally adjusting one or more of throttle, load coupled to the engine, fuel pressure, power to a supercharger acting on the feed gas, and power to a preheater acting on the feed gas to maintain a fuel-air equivalence ratio of 1.6 to 2.4; The method further includes setting an initial condition before starting the engine at a first predetermined ignition timing value, wherein setting the first predetermined ignition timing value includes setting the ignition timing between 5 and 12 degrees before top dead center (BTDC); adjusting the ignition timing includes advancing the ignition timing to a second predetermined value while increasing engine load to maintain an engine speed between 1000 and 2000 RPM; The method wherein the second predetermined value of ignition timing is between 8 degrees BTDC and 28 degrees BTDC.

2. The method of claim 1 , wherein the feed gas comprises a hydrocarbon compound and an oxygen-containing stream.

3. 10. The method of claim 1, further comprising setting initial conditions before starting the engine as at least one of a predetermined fuel pressure, a partially open throttle, and a load coupled to the engine.

4. 4. The method of claim 3, wherein setting the partially open throttle comprises setting the throttle at a predetermined setting less than 50%.

5. 2. The method of claim 1, wherein starting the engine comprises starting the engine with the fuel pressure set below ambient pressure.

6. 10. The method of claim 1, wherein the engine speed is maintained between 1000 and 2000 revolutions per minute (RPM) and the exhaust gas temperature is below 900°C.

7. The method of claim 1 , further comprising: powering the supercharger prior to adjusting the power to the supercharger.

8. 8. The method of claim 7, further comprising increasing the power to the supercharger while increasing the fuel pressure to maintain the engine speed between 1000 and 2000 RPM.

9. 2. The method of claim 1, wherein adjusting the throttle comprises increasing the throttle while increasing the fuel pressure and the engine load to maintain the engine speed between 1000 and 2000 RPM.

10. The method of claim 1, further comprising monitoring exhaust gas temperature and varying one or more of the fuel pressure, the throttle, and the engine load to maintain the exhaust gas temperature below 900°C.

11. The method of claim 1 , further comprising providing power to the preheater prior to adjusting the power to the preheater.

12. 12. The method of claim 11, further comprising setting the preheater to an initial temperature and increasing the fuel pressure as the preheater temperature increases while maintaining the engine speed between 1000 and 2000 RPM.

13. 13. The method of claim 12, wherein the initial temperature of the preheater is 200°C.

14. 9. The method of claim 8, further comprising increasing the power to the supercharger while maintaining the engine speed between 1000 and 2000 RPM by adjusting the fuel pressure and the engine load until a desired engine volumetric throughput is reached.

15. 13. The method of claim 12, further comprising increasing the temperature of the preheater when the preheater reaches the initial temperature while adjusting the fuel pressure to maintain the engine speed between 1000 and 2000 RPM until the fuel-air equivalence ratio reaches 1.6 to 2.

4.

16. The method of claim 1 , wherein the initial fuel-air equivalence ratio is one.

17. A gas reformer system configured to carry out the method according to any of claims 1 to 16.

18. 20. The gas reformer system of claim 17, wherein the gas reformer system is configured to produce syngas.

19. The syngas is hydrogen (H ２ 20. The gas reformer system of claim 18, comprising: a) a mixture of argon and carbon monoxide (CO);

20. 1. A gas reformer system comprising: An internal combustion engine including a fuel gas inlet, an exhaust gas outlet, a plurality of cylinders, an ignition timing system, a throttle, a fuel gas preheater, and a supercharger Including, the internal combustion engine is configured to operate at a fuel gas fuel-air equivalence ratio of 1.6 to 2.4; the internal combustion engine is configured to set an initial condition before starting the engine of a first predetermined ignition timing value, and setting the first predetermined ignition timing value includes setting the ignition timing to 5 to 12 degrees before top dead center (BTDC); the internal combustion engine is configured to advance the ignition timing to a second predetermined value while increasing engine load to maintain an engine speed between 1000 and 2000 RPM; The gas reformer system, wherein the second predetermined value of ignition timing is between 8 degrees BTDC and 28 degrees BTDC.

21. 21. The gas reformer system of claim 20, wherein the internal combustion engine is configured to independently adjust a fuel gas fuel air equivalence ratio, a fuel gas inlet temperature, an intake manifold pressure, an ignition timing, an engine speed, an exhaust manifold pressure, and an exhaust gas temperature to operate at a fuel gas fuel air equivalence ratio of 1.6 to 2.

4.

22. The internal combustion engine uses hydrogen (H ２ 22. The gas reformer system of claim 21 configured to produce an exhaust gas comprising: carbon monoxide (CO);

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