Process with operational flexibility in partial oxidation

Abstract

Disclosed is a method for adapting changes in the conditions of the partial oxidation of a hydrocarbon-containing feedstock by changing the properties of the hot oxygen used in the partial oxidation.

Description

Technical Field

[0001] This invention relates to the production of hydrocarbon products by utilizing the partial oxidation (“POx”) of hydrocarbon feedstock materials. Background Technology

[0002] Plants used to produce hydrocarbon products from hydrocarbon feedstocks typically operate under predetermined conditions based on a set of assumed properties, including the characteristics of the feedstocks, and the desired properties of the products produced. However, when there are changes in the properties of the feedstocks (including inherent properties such as their composition, but also extrinsic properties such as their feed rate), operators are often forced to interrupt operations and / or set up costly alternative methods to accommodate the changes.

[0003] This general type of method, which may be susceptible to such disruption, is described in U.S. Patent No. 9,624,440 and U.S. Patent Application Publication No. US2016 / 0102259. The applicability of this type of method is described in U.S. Patent No. 9,290,422, which discloses an apparatus for adding a device such as an autothermal reactor (“ATR”) to an apparatus already in place to produce liquid fuel from source material.

[0004] This invention increases the flexibility and operational efficiency of methods for producing hydrocarbon products that can be used to produce products such as fuels. Summary of the Invention

[0005] This invention relates to a method for the partial oxidation of carbon-containing feedstocks to produce syngas, the method comprising:

[0006] (A)(i) A feedstock having a given total hydrocarbon concentration, a given concentration of C2H2, C2H4 and tar, and a given temperature is fed into a partial oxidation reactor; (ii) The feedstock is partially oxidized in the partial oxidation reactor using a thermal oxygen jet having given values ​​of its temperature, velocity and O2 concentration, under given partial oxidation conditions of temperature, residence time, pressure, specific oxygen consumption, the ratio of oxygen in the thermal oxygen jet used in the partial oxidation to the feedstock, and the entrainment rate of the feedstock entering the thermal oxygen jet; (iii) The thermal oxygen jet is generated by the reaction of oxygen and fuel in a thermal oxygen generator at a given stoichiometric ratio (HSR) in the thermal oxygen generator and a given temperature of oxygen fed into the thermal oxygen generator; (iv) Syngas having given values ​​of temperature, soot concentration, CH4 concentration and tar concentration is produced.

[0007] (B) The total hydrocarbon concentration, C2H2 concentration, C2H4 concentration, tar concentration and temperature of the feedstock to the partial oxidation reactor are changed to form a modified feedstock, wherein the modified feedstock is partially oxidized to produce syngas using a hot oxygen jet having the given value in (A)(ii) under the given partial oxidation conditions of (A)(ii), the syngas is fed to the partial oxidation reactor and the syngas has at least one of the temperature, soot concentration, CH4 concentration and tar concentration that differs by a given increment from the given value according to (A)(iv);

[0008] (C) By altering one or more of the HSR in the thermal oxygen generator and the temperature of the oxygen fed into the thermal oxygen generator to generate a thermal oxygen jet in the thermal oxygen generator, at least one of the values ​​of the temperature, velocity, and O2 concentration of the thermal oxygen jet is changed from its value in (A)(ii) to produce a modified thermal oxygen jet, and

[0009] (D) The modified feedstock is partially oxidized in the partial oxygen reactor by the modified hot oxygen jet to produce syngas, the temperature, soot concentration, CH4 concentration or tar concentration of the syngas differing from the given values ​​in (B) according to (A)(iv) by less than the increment of the increment described in (B). Attached Figure Description

[0010] Figure 1 It is a process flow diagram for facilities used to produce hydrocarbon liquids such as fuels from raw materials such as biomass.

[0011] Figure 2 This is a cross-sectional view of an apparatus that can be used in this invention to produce a hot oxygen flow.

[0012] Figure 3 yes Figure 1 A cross-sectional view of a portion of the process flow diagram.

[0013] Figure 4 It is a graph showing the effect of HSR in the thermo-oxygen generator on the entrainment rate, oxygen feed rate and temperature of the thermo-oxygen jet generated by the thermo-oxygen generator.

[0014] As used herein, “thermal stoichiometry” and “HSR” refer to the ratio of the number of moles of oxygen in the oxidant fed into the burner to the number of moles of oxygen required for the complete combustion of the fuel fed into the burner. As used herein, “total stoichiometry” and “TSR” refer to the ratio of the number of moles of oxygen in the oxidant fed into the burner to the number of moles of oxygen required for the complete combustion of all fuel fed into the burner plus auxiliary fuel plus all combustible feed fed into the reactor. Detailed Implementation

[0015] This invention is particularly applicable to operations that convert hydrocarbon products, such as biomass, into useful hydrocarbon products, such as (but not limited to) liquid fuels. Products produced by this invention include those that can be sold and used as is, as well as those that can be used as reactants to produce other useful finished products that can be subsequently sold and used.

[0016] Figure 1 This is a process flow diagram illustrating the typical steps of this type of operation.

[0017] refer to Figure 1 The feed stream 1, also referred to herein as the raw material, is fed into the partial oxidation reactor 4. The feed stream 1 is provided by source 11, which represents the production facility or reactor in which the raw material 1 is produced.

[0018] Examples of suitable raw material 1 and its source 11 include:

[0019] Natural gas, which comes from any of its commercial sources;

[0020] A gaseous feed stream generated by a gasification reactor, in which solid hydrocarbon materials such as biomass or solid fuels such as coal or lignin are gasified at a sufficiently high temperature in a gas stream that typically contains air, steam and / or oxygen, such that at least a portion of the solid material is converted into a gaseous raw feed stream 1.

[0021] Product streams and by-product streams produced by petrochemical refineries or chemical plants are typically gaseous, but may also be liquid and / or solid.

[0022] Coke oven gas, which is the waste gas stream generated in a reactor that heat-treats coal to produce coke;

[0023] Cracking gas, which is a hydrocarbon-containing gaseous stream generated in a reactor, is used to thermally treat solid carbonaceous materials such as fossil fuels or biomass to liquefy and partially oxidize the solid materials.

[0024] Other possible feedstock streams include oils such as pyrolysis oils, as well as liquid hydrocarbons.

[0025] Raw material 1 typically contains hydrogen and carbon monoxide (CO), and usually also contains one or more hydrocarbons, such as alkanes and / or alkanols with 1 to 18 carbon atoms, and usually contains carbon dioxide (CO2) and one or more higher molecular weight hydrocarbons characterized as tar and / or soot.

[0026] If the raw material stream 1 is heated when it leaves source 11, it typically exhibits a temperature between approximately 500℉ and 1600℉.

[0027] The raw feed stream 1 is then fed into a partial oxidation reactor 4, where it reacts with oxygen supplied as a hot oxygen stream 2 (described more fully below) (under the conditions described more fully below) to produce additional amounts of hydrogen and carbon monoxide (CO) from the components present in the feed stream 1. If tar is present in the feed stream, some or all of the tar present can also be converted into lower molecular weight hydrocarbon products.

[0028] As described herein, steam, represented as feed stream 16, may optionally be added to reactor 4.

[0029] The oxidation product stream 13 generated in the partial oxidation reactor 4 is fed to stage 6, where stream 13 is preferably cooled and treated to remove substances that should not be present when the stream is fed to reactor 10 (described below). Stage 6 typically includes a unit for cooling stream 13, for example by indirectly exchanging heat with incoming feed water 61 to produce a stream 62 of heated water and / or steam. In an alternative embodiment, stage 6 may also include a shift reactor in which carbon monoxide in stream 13 reacts in a catalytically mediated water-gas shift (“WGS”) reaction (with steam in a non-limiting example) to produce hydrogen, thereby providing a way to regulate the hydrogen to carbon monoxide ratio in stream 13.

[0030] The resulting feed stream 14, cooled and / or having the hydrogen:CO ratio adjusted in stage 6, is fed into stage 8, where any impurities 81 that may be present are removed, such as particles, acidic gases including CO2, ammonia, sulfurous substances, and other inorganic substances such as alkali metal compounds. Impurities can be removed in one unit or in a series of units, each unit designed to remove different impurities present or reduce specific contaminants to a desired low level. Stage 8 represents impurity removal, whether achieved by one unit or by more than one unit. Cooling and impurity removal are preferably performed in any effective order in a series of stages or all in one unit. Details are not shown but will be familiar to those skilled in the art. Stage 8 typically includes operations for the final removal of impurities, non-limiting examples of which include particles, NH3, sulfurous substances, and CO2. CO2 removal is typically performed by a solvent-based process using physical solvents such as methanol or chemical solvents such as amines.

[0031] The resulting cooled and conditioned gaseous stream 15 is then fed to stage 10, which represents any beneficial use of one or more components present in stream 15. That is, stream 15 can be used as is as the final product. However, when stream 15 is intended to be used as feed material for production... Figure 1The present invention is particularly useful for further reactions and / or other processing of the product designated as 20.

[0032] A preferred example of such further processing is converting stream 15 into liquid fuel, such as using stream 15 as feed material for the Fischer-Tropsch process or other synthetic methods to produce liquid hydrocarbons or mixtures of liquid hydrocarbons that can be used as fuel.

[0033] Other examples of possible treatments of stream 15 include producing specific target chemical compounds, such as ethanol, straight-chain or branched or cyclic alkanes and alkanols containing 4 to 18 carbon atoms, aromatic compounds, and mixtures thereof; or producing long-chain products such as polymers.

[0034] The overall composition of feed stream 15 can vary widely depending on the composition of raw material 1, intermediate processing steps, and operating conditions. Feed stream 15 typically contains (on a dry basis) 20% to 50% by volume hydrogen and 10% to 45% by volume carbon monoxide.

[0035] However, preferably, one or more properties of the material flow 15 will consistently exhibit a value, or fall within the desired range of characteristics, in order to adapt the material flow 15 to the processing it undergoes in stage 10 to produce a repeatable and reliable supply of product 20.

[0036] In a preferred practice of the invention, the relevant property of the feed stream 15, which should be maintained within the desired ratio, is the molar ratio of hydrogen (H2) to CO.

[0037] For FT fuel production, the target range for the H2:CO molar ratio depends on the products being produced. For example, ethanol production is most efficient in the H2:CO range of 1.95 to 2.05. Synthetic gasoline production requires an H2:CO ratio in the range of 0.55 to 0.65. For fuel production via other conversion mechanisms, such as bioconversion, the target range for the H2:CO molar ratio can be very wide. According to the Wood-Ljungdahl pathway, depending on the type of bacteria used, a feed stream containing only CO, a feed stream containing only H2, or any combination of H2:CO can be utilized as needed, based on the bacteria's ability to convert H2O and CO2 into H2 and CO. Each bacterial strain will favor a specific chemical composition of syngas, at which the bacterial strain is most efficient in producing the desired products.

[0038] Refer again Figure 1 The treatment in stage 10 can produce a byproduct stream 26, which can be recycled to the partial oxidation reactor 4 as reactants and / or recycled to the thermal oxidizer 202 (hereinafter referred to as...). Figure 2(Description) Combustion is carried out in a thermal oxidizer 202 as described herein. Optionally, steam (feed stream 62) formed by water stream 61 in stage 6 may be fed into partial oxidation reactor 4.

[0039] refer to Figures 1 to 3 The hot oxygen stream 2 is fed into the partial oxidation reactor 4 to provide the oxygen required for the partial oxidation of the raw material 1, and to provide enhanced mixing, accelerated oxidation kinetics, and accelerated reforming kinetics in the reactor 4.

[0040] There are many ways to provide the required high temperature, high speed oxygen-containing flow, such as plasma heating.

[0041] Figure 2 A preferred embodiment is shown, namely a thermo-oxygen generator 202, which can provide a thermo-oxygen stream 2 at high speed. A feed stream 203 of a gaseous oxidant with an oxygen concentration of at least 30% by volume and preferably at least 85% by volume is fed into the thermo-oxygen generator 202, which is preferably a chamber or conduit having an inlet 204 for the oxidant 203 and an outlet nozzle 206 for the thermo-oxygen stream 2. Most preferably, the oxidant 203 is industrial pure oxygen with an oxygen concentration of at least 99.5% by volume. The oxidant 203 fed into the thermo-oxygen generator 202 has an initial velocity, which is typically in the range of 50 feet per second (fps) to 300 fps, and will typically be less than 200 fps.

[0042] Fuel stream 205 is supplied to the thermal-oxygen generator 202 via a suitable fuel conduit 207 terminating at nozzle 208, which can be any suitable nozzle typically used for fuel injection. The fuel can be any suitable combustible fluid, including natural gas, methane, propane, hydrogen, and coke oven gas, or it can be a process stream, such as stream 26 obtained from stage 10. Preferably, fuel 205 is a gaseous fuel. Liquid fuels, such as No. 2 fuel oil or byproduct stream 23, can also be used.

[0043] The fuel 205 and oxidant stream 203 in the feed stream should be fed into the generator 202 at a rate relative to each other, such that the amount of oxygen in the oxidant stream 203 constitutes a sufficient amount of oxygen for the intended use of the hot oxygen stream. The fuel 205 supplied to the hot oxygen generator 202 is burned with oxygen from the oxidant stream 203 in the hot oxygen generator to generate heat and combustion reaction products, which may also include carbon monoxide.

[0044] Combustion within generator 202 typically raises the temperature of the remaining oxygen within generator 202 by at least about 500℉, and preferably at least about 1000℉. The hot oxygen obtained in this manner is fed as feed stream 2 from the hot oxygen generator 202 through a suitable opening or nozzle 206 and exits the opening or nozzle as a high-speed hot oxygen stream with a temperature of at least 2000℉ and up to 4700℉ into the partial oxidation reactor 4. Typically, the velocity of the hot oxygen stream 2 as it exits the nozzle 206 will be in the range of 500 feet per second (fps) to 4500 fps, and will typically exceed the velocity of feed stream 203 by at least 300 fps. The momentum of the hot oxygen stream and the feed should be sufficiently high to achieve the desired level of mixing between the oxygen and the feedstock. The momentum flux ratio of the hot oxygen stream to the feedstock stream should be at least 3.0.

[0045] The composition of the hot oxygen stream depends on the conditions under which it is generated, but preferably it contains at least 50% by volume of O2, and more preferably at least 65% by volume of O2. The formation of a high-speed hot oxygen stream can be performed according to the description in U.S. Patent No. 5,266,024.

[0046] It should be recognized that the desired state for a system employing partial oxidation in the production of hydrocarbon products is that the characteristics of the raw material 1, the oxygen flow 2, or the flow 13, 14, and 15 are minimally or undisturbed, and the operating conditions employed in the partial oxidation reactor 4, as well as in stages 6 and 8, are also minimally or undisturbed.

[0047] However, occasionally, the characteristics of the raw material 1 fed into the POx reactor may change in such a way that, without any other changes in operating conditions, the characteristics of feed stream 13 or 15 will be altered in a manner that adversely affects the characteristics of the desired product stream 20. Of course, such a change in feed stream 20 is undesirable.

[0048] The modifiable characteristics of feedstock 1 include the total hydrocarbon concentration of the feedstock; the total concentrations of C2H2, C2H4, and tar; and the temperature. Examples of situations that could cause a change in any of these characteristics include:

[0049] Because the feed to source 11 has changed, the composition of the original raw material 1 has changed.

[0050] Raw material 1 from raw material source 11 becomes too expensive relative to other compositions from other sources, which may be useful feed materials for POx reactor 4.

[0051] The treatments provided in one or more of the stages in stages 6 and 8 have been altered, such as changes in the catalytic treatments provided in the WGS reaction.

[0052] The injector system that feeds material into the POx reactor has been damaged or fouled, reducing the material's ability to be entrained in the hot oxygen flow, resulting in excessive methane leakage, excessive tar leakage, and / or excessive soot formation.

[0053] In the past, the conventional operation to adapt to changes such as those involving changes in the properties of the raw material 1 fed into POx reactor 4 was to either shut down the entire facility or, optimally, operate it at a partial load that was detrimental to capital recovery. When this occurred, operators with more than one such facility had to rely on the output of products available from other facilities or suffer production losses.

[0054] However, it has been found that the present invention enables the operator to compensate for variations in the raw materials by adjusting one or more characteristics of the hot oxygen flow 2 (also referred to herein as a hot oxygen jet).

[0055] The “characteristics” of thermal oxygen flow 2 means any one or more of the following:

[0056] The physical properties of the thermal oxygen flow 2 include its temperature, oxygen concentration, feed rate into the POx reactor 4 and the rate at which it is fed into the POx reactor 4, as well as the conditions under which the thermal oxygen flow 2 combines with the raw materials and reacts (including stoichiometry).

[0057] The thermal oxidant generator 202 is flexible with respect to the characteristics of its processable feedstocks (such as temperature, composition, and feed rate), and because the thermal oxidant generator 202 can be used directly to produce syngas, no physical modifications to the thermal oxidant generator 202 are required to accommodate any changes in the characteristics of the feedstock fed to the partial oxidation reactor 4. Changes to the "conditions" of the thermal oxidant generator operation are implemented to maintain appropriate operating conditions in the partial oxidation reactor 4 using alternative fuels to produce a feed stream 13 with characteristics that make it suitable for further processing to produce a feed stream 15 with characteristics (unchanged relative to its characteristics prior to containing feed stream 3).

[0058] A thermo-oxidative generator (HSR) provides a way to adjust the operation of a POx system to compensate for changes in the operating environment during operation without hardware changes. The properties of the thermo-oxidative jet exiting the HSR depend on the stoichiometric ratio of oxygen and fuel inside the HSR. A low HSR value produces a jet with the highest temperature, highest entrainment rate, and higher reactivity (free radicals such as OH, H, and O). A high HSR value produces a jet with lower temperature, lower entrainment rate, and fewer free radicals, but requires less fuel and consumes less O2. Figure 4 It shows how temperature, entrainment rate, and O2 rate vary based on HSR, assuming the system requires constant total stoichiometry. Figure 4 This refers to a possible representation of the system. The HSR trend will be similar for other systems and can be estimated by those skilled in the art using standard jet theory calculations.

[0059] The HSR can be easily adjusted by controlling the relative rates of fuel and oxidant supplied to the thermo-oxidant generator. This allows the operator to optimize how the thermo-oxidant jet interacts with the feedstock. This optimization can occur during operation without any hardware changes, which is very convenient and delays or prevents the need to shut down the plant. This operational flexibility for the plant can be extremely valuable if production is required.

[0060] Typical values ​​for raw material 1 vary widely, but generally fall within the following ranges:

[0061] Total hydrocarbon content: 5%-100%

[0062] Total content of (C2H2+C2H4+tar): 0%-5%

[0063] Temperature: Ambient temperature up to 800℉-1400℉

[0064] Those skilled in the art will recognize that these values ​​will vary widely depending on the nature of the feedstock. For example, natural gas will primarily contain carbon and hydrogen, as will liquid petroleum products, however, liquid petroleum products will contain a proportionally greater amount of carbon than natural gas; and syngas derived from biomass will also contain steam, tar, carbon dioxide, heavier hydrocarbons, and therefore more oxygen than the aforementioned feedstocks, as expected for pyrolysis oils, and less for refinery tail gas.

[0065] Typical values ​​for the properties of a thermo-oxygen jet are usually within the following range:

[0066] Temperature: 2000℉-4700℉

[0067] Speed: 500ft / s-4500ft / s

[0068] O2 content: 50%-90%

[0069] Typical values ​​for partial oxidation conditions are usually within the following range:

[0070] Temperature in the POx reactor: 2550℉, but as low as 2400℉ and as high as 2650℉.

[0071] Residence time in the POx reactor: 2 seconds - 10 seconds

[0072] Pressure in the POx reactor: atmospheric pressure to 600 psig – but can be higher as required by the process. The pressure is typically set based on downstream processing requirements or limitations of the biomass gasifier feed system.

[0073] The specific oxygen consumption in partial oxidation will vary based on the properties of the feedstock (which can vary widely).

[0074] And it is highly dependent on the operating temperature.

[0075] The ratio of oxygen to feedstock in the thermal oxygen jet used in partial oxidation: this depends on the HSR, which is described below.

[0076] Entrainment rate of feedstock entering the hot oxygen jet: This depends on both the properties of the HOB and the properties of the feedstock stream entrained into the jet. For example, less dense feedstocks (those operating at higher temperatures or under lower pressures) will be entrained more slowly than denser feedstocks.

[0077] Typical values ​​for the conditions used in a thermal oxygen generator to produce a thermal oxygen flow are usually within the following range:

[0078] The HSR in the thermo-oxidative generator is preferably 3-6, but can be as high as 20.

[0079] The temperature of the oxygen fed into the thermal oxygen generator is: ambient temperature -400℉.

[0080] Typical characteristics of syngas produced by POx reactors are generally within the following range:

[0081] Temperature: 2550℉, but as low as 2400℉ and as high as 2650℉.

[0082] Smoke concentration: 0 gm / Nm3 - 0.02 gm / Nm3

[0083] CH4 concentration: 0%-1%, preferably as low as possible, but practical limitations imposed by reactor temperature will restrict how much it can be reduced. Operation typically ends at around 0.5%.

[0084] Tar content: 0 gm / Nm3 - No tar can be tolerated, as it will eventually deposit on downstream equipment and cause it to stop operating.

[0085] As noted in this article, the thermal oxygen generator provides the operator with the ability to respond to changes in one or more properties of raw material 1 by adjusting one or more characteristics of the thermal oxygen flow.

[0086] Table 1 summarizes the variations in the thermal oxygen flow, which can be used to respond to changes in feed characteristics in order to restore the product in feed stream 15 to a value that is a small increment (or no increment) from its expected value before the change in conditions.

[0087]

[0088]

[0089] This invention offers several advantages.

[0090] One advantage is that no additional unit is required to supply feedstock to POx reactor 4 to accommodate the reduction, shutdown, or other changes in raw feedstock 1. The thermal oxidant generator is already present in the overall plant and is used in conjunction with the partial oxidation reactor. Because the thermal oxidant generator is flexible in terms of the feedstock it processes, it can be used in the same plant to produce gas from an alternative feedstream 3. This alternative method of providing production gasstream 15 decouples POx reactor 4 from the downstream stages 6 and 8 and their associated equipment from a specific source 11 of feedstock fed to the POx reactor. The use of thermal oxidant generator 202 provides the plant with a more complete capacity to produce both feedstream 15 and product 20.

[0091] This advantage, in turn, enables plants designed to produce products with a desired set of characteristics (such as plants producing renewable / biomass-derived liquid fuels) to continuously produce the product at rates close to or above the plant's rated capacity. This allows operators to avoid alternatives that result in no production, reduced plant uptime, and decreased potential plant revenue.

[0092] Example

[0093] One example of how valuable this type of operational flexibility is is in situations involving slight changes in feedstock composition. Even in plants where feedstock comes from reliable sources (such as natural gas pipelines), sudden and unexpected changes in feedstock can occur. In normal practice, changes in feedstock composition should be accompanied by changes in the O2 feed rate into the POx reactor via the thermal oxidant generator to maintain the desired effluent syngas quality. If this change is not monitored (feedstock composition is typically not continuously monitored), the total POx stoichiometry will change, leading to suboptimal performance. If the fuel content decreases and the O2 rate remains constant, too much O2 will be supplied to the system, resulting in lower yields (combustion products H2 and CO) and higher POx temperatures. If the fuel content increases, insufficient O2 will be supplied, resulting in lower POx temperatures and increased soot. Both of these operating conditions are undesirable, especially the increased soot load, as this can lead to premature shutdowns to clean downstream equipment.

[0094] Table 2 presents an example where the fuel content in the feed stream is increased. A portion of the methane content is replaced by ethane. Maintaining the feed rate introduces more C and H atoms into the system, reducing the total stoichiometry from 0.310 to 0.299 in this example. This increase in fuel could result in additional soot if the system operates under optimal conditions. A typical operational response to levels above acceptable soot is to increase the total amount of oxygen supplied to the POx system. This approach requires a higher O2 dosage and can reduce the total syngas (H2+CO) yield by converting more feedstock into CO2 and H2O. For this example, to maintain the TSR at 0.310, the O2 rate needs to be increased from 66.3 lbmol / hr to 68.7 lbmol / hr, almost 4% higher (or a comparable reduction in the feed rate).

[0095] Adjusting the HSR while maintaining the total amount of O2 delivered to the system can be used to reduce additional soot formation by changing the aggressiveness of the jet's interaction with the feedstock. In this embodiment, the increase in soot formation can be attributed to the relative amounts of carbon and oxygen, but also to how the oxygen jet interacts with the feedstock. The jet may entrain too quickly, causing carbon-rich feedstock to be exposed to the hot oxygen jet too rapidly. By increasing the HSR, the operator can reduce the rate at which the jet entrains feedstock, restoring POx operation to acceptable soot levels while maintaining the design O2 rate. In this embodiment, changing the HSR from 6 to 18.7 results in the same total stoichiometry while maintaining the design O2 rate. Of course, the operator can also make standard adjustments by reducing the feedstock flow rate or increasing the O2 flow rate, but the system will not be under optimal mixing conditions. Adjusting the HSR allows the operator to restore optimal operation of the HOB jet under conditions different from the initial design.

[0096] Table 2: Changes in Raw Material Composition .

[0097]

[0098]

[0099] Another example is the degradation of refractory materials in the container or feed inlet system. This can affect the aerodynamics of the feedstock, preventing effective contact with the oxidant. For tar-containing feedstocks, this can lead to tar leaving the POx system and causing fouling in downstream equipment, or soot formation due to long residence times in the thermal reactor, also causing fouling in downstream equipment. The typical response to this is to shut down the system and perform maintenance. The operator can reduce the HSR of the thermal oxidant generator. See again. Figure 4 The reduction of HSR has the effect of increasing the entrainment rate of the hot oxygen jet, which will mix more actively with the feedstock, ensuring that all the tar contained in the introduced feedstock is converted.

[0100] Another example is when the POx system is operating at a lower productivity. Reducing production and maintaining all other operating parameters results in a slower oxidant injection, similar to an example of refractory degradation, which may lead to tar or other hydrocarbon leakage. The reduction in feedstock leads to an increase in residence time in the POx unit, which compensates for the reduced mixing. However, if the increased residence time is insufficient to offset the reduced mixing, the HSR can be adjusted downward to increase mixing intensity and continue production without tar leaving the POx.

Claims

1. A method for partially oxidizing a carbon-containing feedstock to produce syngas, the method comprising: (A)(i) A feedstock having a given total hydrocarbon concentration, a given concentration of C2H2, C2H4 and tar, and a given temperature is fed into a partial oxidation reactor; (ii) The feedstock is partially oxidized in the partial oxidation reactor using a thermal oxygen jet having given values ​​of its temperature, velocity and O2 concentration, under given partial oxidation conditions of temperature, residence time, pressure, specific oxygen consumption, the ratio of oxygen in the thermal oxygen jet used in the partial oxidation to the feedstock, and the entrainment rate of the feedstock entering the thermal oxygen jet; (iii) The thermal oxygen jet is generated by reacting oxygen and fuel in a thermal oxygen generator at a given stoichiometric ratio (HSR) of oxygen and fuel in the thermal oxygen generator and a given temperature of oxygen fed into the thermal oxygen generator; (iv) Syngas having given values ​​of temperature, soot concentration, CH4 concentration and tar concentration is generated. (B) While maintaining the given partial oxidation conditions of (A)(ii), using a thermo-oxygen jet having the given values ​​in (A)(ii), feed a modified feedstock into the partial oxidation reactor, wherein at least one of the total hydrocarbon concentration, C2H2 concentration, C2H4 concentration, tar concentration, and temperature of the feedstock fed into the partial oxidation reactor is modified to produce syngas, the syngas having at least one of the temperature, soot concentration, CH4 concentration, and tar concentration differing by a given increment from its given value according to (A)(iv); (C) In response to the changed feedstock described in step (B), at least one of the values ​​of temperature, velocity, and O2 concentration of the hot-oxygen jet is changed from its value in (A)(ii) by altering the HSR in the hot-oxygen generator to produce the changed hot-oxygen jet, and (D) The modified feedstock is partially oxidized in the partial oxidation reactor by the modified hot oxygen jet to produce syngas, the temperature, soot concentration, CH4 concentration or tar concentration of the syngas differing from the given values ​​in (B) according to (A)(iv) by an increment less than the increments described in (B).

2. The method according to claim 1, wherein the raw material comprises natural gas.

3. The method according to claim 1, wherein the raw material comprises a gaseous stream of biomass generated in a gasification reactor.

4. The method of claim 1, wherein the raw material is derived from fossil fuels.

5. The method of claim 1, wherein the partial oxidation is performed using a hot oxygen jet containing at least 50% by volume of oxygen.

6. The method of claim 1, wherein the partial oxidation is carried out by feeding a hot oxygen jet into the reactor at a rate of 500 feet per second to 4,500 feet per second.

7. The method of claim 1, wherein at least 2000 0 The partial oxidation is performed by feeding a hot oxygen jet into the reactor at a temperature of F.

8. The method of claim 1, wherein in step (B), the modified feedstock is formed by changing the total hydrocarbon concentration of the feedstock fed to the partial oxidation reactor.

9. The method of claim 1, wherein in step (B), the modified feedstock is formed by changing the C2H2 concentration of the feedstock fed into the partial oxidation reactor.

10. The method of claim 1, wherein in step (B), the modified feedstock is formed by changing the C2H4 concentration of the feedstock fed into the partial oxidation reactor.

11. The method of claim 1, wherein in step (B), the modified feedstock is formed by changing the tar concentration of the feedstock fed into the partial oxidation reactor.

12. The method of claim 1, wherein in step (B), the modified feedstock is formed by changing the temperature of the feedstock fed into the partial oxidation reactor.

Images