Patent ID: 12252461

The T-S diagrams of these Figures, are all plotted and depicted on graphs having the same axes. The Specific Entropy axis (x axis) is in units of kJ/kg ° C., and describes the entropy per unit mass of air. The Temperature axis (y axis) is in ° C. and describes the fluid temperature, assumed to have properties similar to air. The relationship between temperature and lines of constant pressure are governed by the physical properties of the fluid.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present inventions generally relate to systems, devices and methods to recover in an economical fashion usable materials from waste gas, e.g., flare gas. In general, embodiments of the present inventions relate to systems, devices and methods, to achieve such recovery at smaller, isolated or remote locations or point sources for the waste gas.

In general, embodiments of the present inventions relate to methods, devices and systems for utilizing flare gas to produce a reprocessed gas and then utilizing that reprocessed gas to provide useful and economically viable materials. In particular, embodiments of the present inventions relate to methods, devices and system for producing, recovering and processing reprocessed gas to provide useful and economically viable materials.

Embodiments of the present inventions have a reciprocating engine, a gas turbine engine or both, to produce reprocessed gas, preferably syngas. These embodiments can be modular and can easily and readily be positioned at difficult to access locations, locations with limited area for placement of the systems, and combinations and variations of these, where flare gas typically is generated.

Systems and Processes—Generally

Generally, embodiments of the present systems and methods can be associated with a source of hydrocarbon fuel. The hydrocarbon fuel can be a solid, a liquid, a gas, a slurry and combinations and variations of these. Preferably, the hydrocarbon fuel is a waste gas, and in particular a flare gas. The system is in fluid communication with the hydrocarbon fuel source, by way of for example, pipes, conduits tubulars, hoses and the like, and in this manner the hydrocarbon fuel is provided to the system. The hydrocarbon source can be an active source, in that the hydrocarbons are actively flowing, e.g., flowing from a borehole in the earth, a producing hydrocarbon well, a refinery, or a chemical plant. The hydrocarbon source can be a static source, in that the hydrocarbons are contained in, and obtained from, a holding or collected source, e.g., a holding tank, a tank farm, a tank truck, a rail car, a barge, a container and the like. The source of hydrocarbon fuel can be combinations and variations of active sources, and static sources

Generally, the hydrocarbon fuel source, e.g., flare gas, and an oxygen source, e.g., air, are feed to a reformer unit, where the hydrocarbon fuel source is converted through preferably a controlled and predetermined combustion into reprocessed gas, e.g., syngas. This reformer stage of the general system and method, can also have equipment for handling and processing the incoming hydrocarbon fuel source, e.g., flare gas and oxygen source, e.g., air, as well as, equipment to process the reprocessed gas, e.g., syngas, such as for example, valves, controllers, compressors, sensors and monitors, temperature control systems, mixers, filters and screens, separators, equipment to remove water, guard beds, guard bed reactors, deoxo reactors, and other handling and processing equipment and methods. It being understood that some or all of the reprocessed gas, e.g., syngas, processing equipment and methods can be in stages, or located in the general system places other than the reformer stage.

Generally, the reformer, and the reformer stage, are preferably operating in a predetermined manner to optimize the composition of reprocessed gas, e.g., syngas, that is obtained, such that the reprocessed gas, e.g., syngas, has a predetermined composition that is determined for optimum performance in its conversion to a value-add product, e.g., methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals, and combination and variations of these.

Generally, the reprocessed gas, e.g., syngas, from the reformer is provided to a synthesis unit, e.g., a methanol unit, where the reprocessed gas, e.g., syngas, is converted to a value-add product, e.g., methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals, and combination and variations of these. Preferably, the value-add product is collected and stored as a liquid. It being understood that the value-add product can be gaseous, or in some other state. This synthesis stage, e.g., methanol synthesis stage, can have other equipment and methods for processing and handling the incoming reprocessed gas, e.g., syngas, as well as, for handling and processing the value-add product, e.g., methanol, including for example, valves, controllers, compressors, sensors and monitors, mixers, filters and screens, temperature control systems, separators, equipment to remove water and other handling and processing equipment and methods. The pressure of the reprocessed gas, e.g., syngas, can be, and preferably is controlled, e.g., compressed, prior to being provided to the synthesis unit, e.g., methanol unit, when forming the value-add product, e.g., methanol.

Generally, the systems and methods may have additional separation and processing equipment, for example, to remove hydrogen from the value-add product, e.g., methanol. In these embodiments, preferably the hydrogen can be used to generate electricity to operate the system, as well as, potentially other devices, e.g., excess electricity is produced by the system.

The stages can be in a single system, in a single integrated system, in separate systems, in two or more modular systems and combinations and variations of these.

Generally, the systems and methods have control systems. The control systems can include computers having possessors, memory and data storage. The control systems further can include controllers, e.g., program logic controllers (“PLC”), input/output (“I/O”), sensors, graphic user interface (GUI) and communication protocols and capabilities, e.g., web servers, cellular, satellite. In embodiments, the control system includes a blockchain for authenticating the operation of the system and method, e.g., mass balance of method and operation, and to validate, encrypt and authentic data related to carbon capture, reduction of greenhouse gases, carbon credits, and the like.

Thus, the preferred embodiments of the present systems relate to liquid-to-gas systems and methods, e.g., flare gas to methanol.

In general, the reformer can be one or more devices or assembly of devices that combusts the waste gas, e.g., flare gas, under controlled and predetermined conditions to provide a reprocessed gas. Preferably one or more of the temperature, pressure, and composition for the reprocessed gas is optimized for use in the synthesis stage, and the controlled and predetermined conditions for operation of the reformer are optimized to provide this optimized temperature, pressure, and composition of the reprocessed gas. Thus, and in general, the reformer can have one or more combustion device, a combustion box, engine, internal combustion engine, reciprocating engine, rotary engine, gasoline engine (i.e., spart ignition), diesel engine (i.e., compression ignition), jet engine, turbine engine, gas turbine engine, air-breathing engine, air breathing combustion device and combinations and variations of these, as well as other peripheral or ancillary devices and equipment.

Embodiments of the present inventions can be used to take uneconomic hydrocarbon-based fuels at a well-head and remote locations that are primarily gaseous hydrocarbons and convert them to a more valuable easily condensable or liquid compounds, such as methanol. One source of fuel could be associated gas or flare gas, which is produced as a byproduct at oil wells. Another source is flare gas produced by industrial processes, such as refinery flare gas. Another source could be biogas from landfill or anaerobic digesters.

In general, the embodiments of the present systems and methods use waste gas that is preferably flare gas. Examples of the composition of flare gas that any of the reformers of the present systems and methods can process into reprocessed gas, which is then processed by the synthesis units into a value-added product (e.g., methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals) are set forth in Table 1 and Table 2. The flare gasses can have one or more, and all of the constituents or components in one or more of the various amounts set forth in these tables.

TABLE 1Examples of flare glass compositionsGas Constituent% of ConstituentNameFormulaMin.MaxAverageMethaneCH47.1782.043.6EthaneC2H60.5513.13.66PropaneC3H82.0464.220.3n-ButaneC4H100.19928.32.78IsobutaneC4H101.3357.614.3n-PentaneC5H120.0083.390.266IsopentaneC5H1;0.0964.710.530neo-PentaneCSH120.0000.3420.017n-HexaneC6H140.0263.530.635EthyleneC2H40.0813.201.05PropyleneC3H60.00042.52.731-ButeneC4H80.00014.70.696Carbon monoxideCO0.0000.9320.186Carbon dioxideCO20.0232.850.713Hydrogen sulfideH2S0.0003.800.256HydrogenH20.00037.65.54OxygenO20.0195.430.357NitrogenN20.07332.21.30WaterH2O0.00014.71.14

TABLE 2Examples of biogas types of flare gas compositionsSource of biogas type flare gasMunicipalAgricultural/Waste fromConstituentwasteWastewaterAnimal wastefood industryLandfillCH4(vol %)50-6055-7750-7568-7535-70C02(vol %)34-3836-3837-382615-6019-3319-3330-4530-5035-4530-40N2(vol %)0-5<1<1-40<2<1-2<1<302(vol %)0-1<0.5<0.5<0.2-5H2(vol %)0-5CO (vol %)0-3H2S (ppm)70-65063-3,0003-7,000280-<21,5000-20,000Aromatic0-20030-1,900(mg/m3)Ammonia50-100 mg/m35 ppmHalogenated100-8001-2,900compounds(mg/m3)Benzene0.1-0.30.7-1.30.6-2.3(mg/m3)Toluene2.8-11.80.2-0.71.7-5.1(mg/m3)Siloxanes1.5-15<0.40.1-4(ppmv)Non-0-0.25methaneorganics (%dry weight)Volatile0-0.1organics (%dry weight)

FIGS.20A and20Balso provide the compositions of flare gas that can occur and are processed by embodiments of the present inventions.FIG.20Ashows a typical composition of a lean flare gas, andFIG.20Bshows a typical composition of a rich flare gas. The lean and rich flare gases can have methane2001, ethane2002, propane2003, butanes2004, impurities2005, the rich flare gas can also include pentanes2006and hexanes and heavier hydrocarbons2007.FIG.21is a graph showing the Wobbe number vs fuel heating value for various components and variations of flare gases that can occur and are processed by embodiments of the present inventions.

These compositions (e.g., Table 1, Table 2,FIG.20A,20B,21) represent compositions, and variations in compositions that the present systems and methods can utilize for gas-to-liquids synthesis (e.g., fare gas to liquid methanol) in embodiments of the present systems and methods in general, as well as embodiments of small modular systems.

The present inventions, including the embodiments of the Examples, can use and reprocess flare gases falling within any of the ranges of compositions and constituents set forth in Table 1, Table 2 and combinations of the compositions and ranges in these tables, as well as, other compositions and ranges of components. One of the reasons that these gases are non-economic is that the flare gas, composition is highly variable. Thus, the composition of the flare gas can change from source-to-source, from day-to-day at the same source (transients), from season-to-season (e.g., bio-gases), and over time as the source (e.g., well) ages. These variations have effects on combustion properties such as: heating value, cetane number (delay in time of ignition of fuel), and octane number (resistance to pre-ignition due to compression). Embodiments of the present reformers address these changes and provide the ability to operate in a consistent and efficient manner to process these varying flare gas compositions at a source site to provide a reprocessed gas, e.g., syngas, and preferably provide a consistent, predetermined and both syngas, with respect to the composition and temperature of the syngas.

Turning toFIG.1there is shown a generalized embodiment of a system and method for the conversion of a waste gas, e.g., flare gas, into a value-added product, e.g., methanol. The system100has a reformer stage101and a synthesis stage102. The system100has an air intake110, that feeds air through into a compressor111, which compresses the air. The compressed air is feed through heat exchanger120ainto a mixer113. The system has a waste gas, e.g., flare gas, intake114. The waste gas flows through a heat exchanger120binto the mixer113. The mixer113, provides a predetermined mix of air and waste gas, as taught and disclosed in this specification, to a reformer114.

The fuel-air mixture that is formed in mixer113is preferably rich, more preferably having an overall fuel/air equivalence ratio (0 or ER) greater than 1, greater than 1.5, greater than 2, greater than 3, from about 1.5 to about 4.0, about 1.1 to about 3.5, about 2 to about 4.5, and about 1.1 to about 3, and greater values.

It being understood that oxygen can be added to the air. And that water or steam may also be injected into the mixture of air and fuel, or to air or fuel individually. From about 1 to about 20% (molar) water can be injected, from about 10 to about 15% (molar water), from about 5 to about 17% (molar) water, more than 5% (molar) water, more than 10% (molar) water, more than 15% (molar) water, and less than 25% (molar) water, water can be injected. Following oxygen enrichment, the combustion air can have from about 21% to about 90% oxygen. “Air-breathing” reformers, and air breathing engines as used herein are understood to also include engines using air modified with the addition of water, oxygen or both.

The reformer114combusts the predetermined mixture of waste gas and air (e.g., flare gas and air) to form a reprocessed gas (e.g., syngas). The syngas flows through heat exchangers120a,120band into a filter115, e.g., a particulate filter.

After passing through the filter115, the reprocessed gas (e.g., syngas) flows to a guard bed reactor assembly116, having two guard bed reactors116a,116b. The guard bed reactor116has materials, e.g., catalysts, that remove contaminates and other materials from the syngas that would harm, inhibit or foul later apparatus and processes in the system. For example, the guard bed reactor116may contain catalyst or other materials to remove sulfur (e.g., iron sponge, zinc oxide or similar) and halogenated compounds.

After leaving the guard bed reactor116, the reprocessed gas (e.g., syngas) flows to a deoxo reactor117. The deoxo reactor117removes excess oxygen from the reprocessed gas (e.g., syngas) by oxidizing combustible compounds in the mixture such as methane, CO, and H2, where the oxygen is converted to water. Catalyst for the deoxo reaction are platinum, palladium, and other active materials supported on alumina or other catalyst support materials.

The system100has a cooling system150, which uses a cooling fluid, e.g., cooling water, that is flow through cooling lines, e.g.,151.

After leaving the deoxo reactor117, the reprocessed gas (e.g., syngas) flows to heat exchanger120c. The reprocessed gas (e.g., syngas) then flows from heat exchanger120cto a water removal unit118, e.g., a water knockout drum, demister, dryer, membrane, cyclone, desiccant or similar devices, where water is removed from the reprocessed gas (e.g., syngas). In general, the reprocessed gas (e.g., syngas) upon leaving unit118should have less than about 5% water by weight, less than about 2%, less than about 1% and less than about 0.1% water.

The overall (general) reaction for a rich fuel/air mixture to syngas is given by the equation:
ØCH4+2[O2+3.76 N2]→aCO+bH2+cCO2+dH2O+7.52 N2
Where stoichiometric coefficients a, b, c and are determined by the chemical kinetics, conservation of atomic species, and the reaction conditions.

In addition to syngas minor constituents in the gas exiting the reformer can include water vapor, CO2, and various unburned hydrocarbons.

After leaving unit118, the now dry reprocessed gas (e.g., syngas) is in the synthesis stage102. In stage102the now dry reprocessed gas (e.g., syngas) flows to an assembly130. Assembly130provides for the controlled addition of hydrogen from line131into the now dry reprocessed gas (e.g., syngas). In this manner the ratio of the syngas components can be adjusted and controlled to a predetermined ratio. The hydrogen is provided from hydrogen separate139. The ratio adjusted dry reprocessed gas (e.g., syngas) leaves assembly130and flow to compressor132. Compressor132compresses the reprocessed gas (e.g., syngas) to an optimum pressure as taught and disclosed in this specification, for use the synthesis unit133. Preferably, the synthesis unit133is a two-stage unit with a first reactor unit133aand a second reactor unit133b. Each reactor is a pressure vessel where process gas flows through a catalyst bed in an exothermic reaction. The catalyst bed tubes are typically immersed in a pool of cooling water at a controlled temperature and pressure. Synthesis unit133also has heat exchanger120e.

The synthesis unit133converts the ratio adjusted dry reprocessed gas (e.g., syngas) into a value-added product (e.g., methanol, ethanol, mixed alcohols, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals). The value-added product (e.g., methanol, etc.) flows into to heat exchanger120d. The value-added product (e.g., methanol, etc.) flows to a collection unit140. The collection unit140collects the value-added product (e.g, methanol, etc.) and flows it through line141for sale, holding, or further processing.

Generally, the syngas is compressed to a pressure of about 15 to about 100 bar and preferably 30-50 bar, and about 25 to about 80 bar, at least about 10 bar, at least about 25 bar and at least about 50 bar, and greater and lower pressures. The temperature of the pressurized syngas is adjusted to a temperature of about 150° C. to about 350° C. and preferably 250° C., about 200° C. to about 300° C., about 250° C. to about 375° C., greater than 125° C., greater than 150° C., greater than 200° C., greater than 250° C., greater than 350° C., and less than 400° C., and higher and lower temperatures. The pressure and temperature-controlled syngas is then feed to reactors for transforming the syngas into a more useful, more easily transportable, and economically viable product such as methanol, ethanol, mixed alcohols, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals. In a preferred embodiment methanol is produced using the reaction of syngas to methanol, reactions for hydrogenation of CO, hydrogenation of CO2, and reverse water-gas shift using actively cooled reactors, such as a heat-exchanged reactor or boiling water reactor, and a copper containing catalyst such as Cu/ZnO/Al2O3or the like. In general embodiments of the synthesis state can use the following reactions:
CO+2H2→CH3OH(CO hydrogenation)
CO2+3H2→CH3OH+H2O(CO2hydrogenation)
CO+H2O→CO2+H2(reverse water-gas shift)

Generally, and in preferred embodiments, the characteristic length scale of the reactors used in this system are sufficiently small (e.g., micro-channel or mini-channels) that they can be shaped into unconventional shapes and topologies using new 3D printing techniques for metals and other high-temperature materials, thus allowing compact packaging and tight control over reaction conditions. Other strategies for intensification of the downstream synthesis reactions can also be considered, such as selectively removing the product from the reactor in-situ, or in a closely coupled fashion, to shift the equilibrium-limited reaction to higher conversion. This process intensification may minimize the need for large recycle streams or allow the reaction to proceed at milder conditions (e.g., lower pressure) thereby increasing process safety margins.

Typically, in reacting the syngas to form the higher value product, unreacted H2is also produced. The H2can be collected and sold, or used to power the gas turbine or a second generator to produce additional electric power.

In general, the ratio of H2/CO in the syngas produced by the engine can be tailored to the downstream conversion process. For example, for methanol synthesis or Fischer-Tropsch (F-T) synthesis the ideal H2/CO ratio is 2-3. For ammonia synthesis or for hydrogen production, the maximum possible H2/CO ratio is desirable and can be enhanced by, for example, steam addition to promote the water-gas shift reaction. For ammonia and hydrogen production, the CO is not required by the downstream synthesis. As such, CO and CO2byproducts can be collected, sequestered, stored or utilized for other purposes.

The collection unit140also has a line that flows gas separated from the value-added product (e.g, methanol, etc.) to valve135, where it is sent to hydrogen separate139, to a recycle loop136or both. Recycle loop has compressor134and valve138to feed the value-added product (e.g, methanol, etc.) back into the synthesis unit133. Hydrogen separation can be achieved by via membrane separation or pressure swing absorption (PSA) or the like in the hydrogen separation unit139.

Turning toFIG.2there is shown a temperature-entropy (T-S) diagram for the general operation and thermodynamics for the operation of systems of the type shown inFIG.1. The overall conversion process from waste gas, e.g., flare gas, to useful product, e.g., methanol, is described using the T-S diagram ofFIG.2. This diagram uses the properties of air, in an air standard approximation of the process.FIG.2outlines the general solutions and operation of systems such as shown inFIG.1from the point of thermodynamics, temperature and pressure. The diagram shows the starting point of the process at ambient conditions, the high temperature and the pressure conditions for rich, partial oxidation, in the reformer, and for high pressure lower temperature reactions for the synthesis of methanol. Thus, there is shown temperature vs entropy dashed line201for 60 bar pressure, dashed line202for 30 bar pressure, dashed line203for 8 bar pressure, and dashed line204for 1 bar pressure. (1 atmosphere is equivalent to 1.013 bar.) The temperature and pressure for the incoming air (e.g.,FIG.1,110) and the waste gas (e.g., flare gas) is at point206(FIG.2). The operating conditions for the reformer stage (e.g.,FIG.1,101) is shown in zone210(FIG.2). Zone210has temperatures above at and above 900° C. Zone210has two sub-zones,210a,210b. Sub-zone210ais a lower pressure zone (from less than 1 bar to about 25 bar). Sub-zone210bis a higher-pressure zone (from about 20 bar to about 100 bar), and in particular, a high pressure zone for rich, partial oxidation conditions in the reformer (e.g.,FIG.1,114), which are the preferred conditions for the embodiments of the present inventions. The optimum operation for the synthesis stage (e.g.,FIG.1,131) is shown in zone211for methanal synthesis. The zone211is in a temperature of 200-300° C. and a pressure of about 20 bar to 100 bar. A preferred zone for methanol production is 200-300° C. and a pressure of 30-100 bar.

Thus,FIG.2is a graphic representation of conditions that may generally be used in a system to provide for the conversion of flare gas to an end product, in this case methanol, and to preferably do so with a neutral (i.e., provides all energy needed to operate the system and process, or positive, provides excess energy) energy balance. The Specific Entropy axis (x axis) is in units of kJ/kg C, and describes the entropy per unit mass of air. This type of diagram is a convenient way to show physical processes, such as compression and expansion (nearly vertical lines between pressure levels, and heat exchange (usually at near constant pressure). Ideal compression or expansion is isentropic, meaning no change in entropy, between two pressure levels. Compression with real equipment is non-isentropic as indicated by non-vertical lines. The Temperature axis (y axis) is in degrees C. and describes the fluid temperature, assumed to have properties similar to air. The relationship between temperature and lines of constant pressure are governed by the physical properties of the fluid. One of the benefits of the T-S diagram is that is allows a visual representation of the physical processes and the relationship between components.

The partial oxidation window210defines a region of temperature and pressure where the key partial-oxidation (POX) reactions take place to produce syngas. The region defines the reaction conditions that lead to reaction timescales that are commensurate with the combustion residence in reformers (e.g., a gas turbine, typically 5-50 ms). In general the POX reaction happens at much higher temperatures than that downstream synthesis (e.g., methanol) reactions, which means that the temperature needs to be reduced in a heat exchanger prior to the methanol reactor.

The methanol synthesis window211defines the region of temperature and pressure where the methanol synthesis reactions take place. The region defines the reaction conditions that lead to reasonable equilibrium conversion for this equilibrium-limited reaction. For this exothermic process, lower temperatures are favored for equilibrium conversion but are constrained on the low end by ensuring sufficient catalyst activity. Higher pressures yield higher equilibrium concentrations due to the net decrease in moles in the reaction but require the cost of compression and design for high pressure. While figure specifically shows a methanol synthesis window, it is understood that other possible downstream synthesis reactions, e.g. Fischer-Tropsch synthesis, require similar conditions.

In embodiments, the present systems, can be a mobile system that is contained in a shipping container frame that would fit on a single semi-truck trailer, length about 40 feet to about 60 feet, width about 6 feet to about 10 feet, and height of about 7 feet to about 15 feet. The system may also be in one, two or more separate shipping containers or open skid frames, which are then assembled into a flare gas recovery system at the location of the flare gas, e.g., an oil field, an oil well, an off-shore platform, or a floating production storage and offloading (FPSO) vessel.

In embodiments these mobile systems they are sized and configure to processes from flare gas flows of from about 250,000 scfd (standard cubic feet per day) to 30,000,000 scfd, from about 400,000 scfd to 30,000,000 scfd, from about 500,000 scfd to about 20,000,000 scfd, from about 600,000 scfd to about 15,000,000 scfd, from about 700,000 scfd to about 10,000,000 scfd, from about 1,000,000 scfd to about 25,000,000 scfd, greater than about 250,000 scfd, greater than about 500,000 scfd, greater than about 750,000 scfd, less than 10,000,000 scfd, less than 5,000,000 scfd, and less than 1,000,000 scfd, and larger and smaller flows. It further is contemplated that one, two or more of these mobile systems can be placed at a location associated with flare gas, such as an oil field, having a large number of wells, and the flare gas can be piped from several wells to these mobile systems. Thus, providing complete coverage, i.e., capture and recycling of all of the flare gas produced from the oil field.

Embodiments of the present inventions are useful in small-scale plants, using one or a plurality of syngas engines, targeting 600,000 scfd (standard cubic feet per day) of inlet gas. The size of such a plant could vary from 80,000 scfd to 3,000,000 scfd, or 20,000 scfd to 100,000 scfd.

Embodiments of the present inventions can be incorporated into one or more modular, interconnected skids or containers that are built at a central fabricator shop location and then installed at a field location. A small number of modules comprise the system and when connected at site they form an integrated system. The modular nature of the assembly enables application to remote locations under a range of inlet gas feed volumes, with a minimum of field labor.

In general, embodiments of these present systems and processes provide low carbon reprocessing of flare gas, and are preferably carbon neutral-to-negative and energy positive. In this manner embodiments of the present systems and processes capture the flare gas and convert the flare gas to an end product (e.g., methanol, ethanol, etc.) while generating sufficient energy (mechanical, electrical and both) to operate the system. In making the end product, the system is essentially carbon neutral-to-negative due to the combination of two effects: (1) Instead of being released as CO2and methane slippage, carbon from the flare gas is sequestered in the methanol thus displacing the flare gas emissions, and (2) instead of producing methanol by conventional means from natural gas or coal, that methanol is displaced by methanol produced from flare gas.

Thus, in embodiments the system and the process to produce an end product (e.g., methanol) provide a net negative CO2e for the process and the making of the end product. (As used in this specification CO2e and CO2e are synonymous.) Thus, in preferred embodiments the process and resultant end product (e.g., methanol) has from about −40 kg CO2e to −130 kg CO2e, less than −20 kg CO2e, less than −40 kg CO2e, less than −60 kg CO2e, less than −100 kg CO2e and less than −130 kg CO2e per kg of downstream product (e.g, liquid methanol). It should be noted that the typical CO2e for methanol produced from natural gas is 2.1 kg CO2e per kg methanol (based on 45 kg CO2e per MMBTU methanol, 1,040 btu/scf natural gas, and 0.8 kg natural gas per m3). CO2e (carbon dioxide equivalent) is based on a 20-year time horizon global warming potential for methane, based on the IPCC AR5 estimate for methane, and is 85× the global warming potential of CO2.

Thus, turning toFIG.23there is shown a graph showing the significant improvement, from among other things, an CO2e (and GWP) perspective, compared to conventional sources for methanol (coal, natural gas or CO2+H2or black liquor).FIG.23shows the significant reduction in CO2e for the present inventions2300, which methanol is obtained using the present systems and processes to convert flare gas into syngas into methanol.

More preferably, these reformers, the synthesis units and both can also produce sufficient energy to have excess energy available to operate other devices or for other purposes, e.g., oil field operations, computers having high electrical needs for processing complex algorithms, charging electric vehicles, battery storage, etc.

More preferably the control system (and sub-systems if any) operate the entire mobile system and processes. The mobile systems are configured for real time or near real time monitoring and control from a remote location, or on site.

In embodiments, these systems also have monitory and metering devices to monitor and control and memory devices to record the amount of flare gas processed, the amount of product produced and the amount, if any, of CO2produced. This information will be recorded in a secure manner for use or transmission to support carbon capture credits, or other regulatory or private equity or exchange transaction relating to CO2.

More preferably the control system (and sub-systems if any) operate the entire mobile system and processes. The mobile systems are configured for real time or near real time monitoring and control from a remote location, or on site.

A block-chain based record of the carbon captured or carbon offset measurement will improve the quality of the measurement system through networked, secure record keeping. A blockchain-based carbon credit may then be sold as part of a cryptocurrency or other verifiable token in a voluntary carbon market as a carbon offset.

Reciprocating Engine Based Reformers—Generally

Embodiments of the present inventions have a reciprocating engine and methods of operating those engines to handle the variable combustion properties of the waste gas, e.g., flare gas, sources. Thus, and generally, in some embodiments the reformer114ofFIG.1is a reciprocating engine. One of the reasons that these gases are non-economic is that the waste gas, e.g., flare gas, composition is highly variable. A consequence of composition variation is the resulting effect on combustion properties such as: heating value, cetane number (delay in time of ignition of fuel), and octane number (resistance to pre-ignition due to compression). These variations can occur from source-to-source, from day-to-day at the same source (transients), from season-to-season (particularly bio-gases), and over time as the source ages.

Conventional air-breathing reciprocating engines typically are designed to operate using fuels with a narrow fuel specification. For example, the compression ratio of automotive gasoline engines is selected for the quality of fuel used. The “regular’ gasoline in the United States has an octane rating of 86-87. A higher performance (e.g., higher compression ratio) engine may require premium gasoline with octane rating of 91-94.

Embodiment of the present inventions use a commercial reciprocating engine (e.g., off the shelf engine) as the reformer to produce a reprocessed gas, e.g., syngas, by operating the reciprocating engine at rich conditions with high fuel-to-air ratio (equivalence ratio in the range 1.5 to 2.5). To allow the engine to operate off-design from its intended design point, and to operate satisfactorily using fuel that varies over a wide range of octane and cetane numbers, embodiments modify the operating engine parameters including compression ratio, inlet manifold air temperature, inlet manifold air pressure, and engine speed. These modifications apply to both compression ignition engines (diesel cycle) and spark ignition engines (otto cycle). For spark ignition engines, the spark timing can also be used to adapt the engine operation to fuel variation.

In embodiment of a modular system, the system and method utilize a nominally air-breathing engine that is operated under rich conditions to produce a reprocessed gas, e.g., syngas, from a waste gas, e.g., flare gas, source. Variation in composition of the fuel results in variation in combustion properties that effect engine operability. In particular, impacted operability parameters include, for example:Engine mis-fire—inability to transition from spark discharge to propagating flame, in one or more cylinders of an engine.Pre-ignition—Premature combustion of the fuel-air mixture in one or more of the cylinders in an engine.Auto-ignition (knock)—Spontaneous ignition of the fuel-air mixture ahead of the propagating flame.Low combustion efficiency—high levels of unburned fuel in the exhaust, due to exhaust valve opening before combustion propagation across the cylinder volume is complete, or unburned fuel in crevice volumes and quenching on cold surfaces, or can be related to mis-fire.

FIGS.20A,20B, and21, as well as, Tables 1 and 2, show the range of compositions for the flare gas that can be processed by embodiments of the reciprocating engine reformers, including the embodiments of the Examples, into reprocessed gas, e.g., syngas.

These mixtures and their individual constituents represent wide range of octanes, with the heavier hydrocarbons having lower octane and hence a greater tendency to pre-ignite or auto-ignite. Specific values of octane number, a key measure of mixture reactivity, are shown in Table 3. Estimated values of octane number for the lean and rich gas inFIGS.20A and20Bare shown in Table 3.

FIG.21shows how the fuel energy per unit volume varies with gas composition. This variation affects, and is address by the sizing and control of the fuel delivery system.

TABLE 3(Octane numbers of individual constituents (OctaneNumber (research octane number = RON))OctaneOctaneAKIConstituent(research/RON)(motor/MON)(R + M)/2Methane135122128.5Ethane108Propane11297104.5Butane939091.5Pentane61.761.961.8Lean Associated126 (est)Gas (table 1)Rich Associated117 (est)Gas (table 1)

Turning toFIG.21it is shown that for gaseous fuels, changes in fuel composition also influence the energy content of the fuel, as quantified by fuel heating value per unit volume (Wobbe number). This figure shows typical ranges of Wobbe number vs fuel heating value for a range of fuel compositions.

Variation in fuel properties sets up a fundamental tension in the design of a reciprocating engine system, which embodiments of the present inventions address. On one hand, high compression ratio and high inlet air temperature are beneficial for the combustion characteristics to produce syngas with desired H2/CO ratio (typical range about 1.0 to about 2.0, preferably 1.5 to 2.0) with low emission of unburned fuel. On the other hand, high compression ratio and high inlet air temperature can result in pre-ignition, or autoignition of the fuel-air mixture if the fuel becomes more reactive. Conversely, if the fuel becomes less reactive, increased compression ratio or inlet air heating would be beneficial. Thus, setting a specific design point for the engine is not compatible with smooth engine operation with fuel, e.g., flare gas, that has variable combustion properties.

In embodiments, the solution to this problem is modify the engine operating properties while the engine is operating. In embodiments, a combination of modified critical operating engine parameters including:compression ratio (effective compression ratio or geometric compression ratio)range 8:1 to 17:1inlet manifold air temperature, range of ambient temperature to 300° C.inlet manifold air pressure, ambient to 5 bar.spark timing, TDC (top dead center, e.g. zero degrees) to MBT (minimum spark advance for best torque, e.g. 30 degrees typical, 15-45 degree range)and engine speed, 800 rpm to engine max (eg. 1800 rpm)the range of conditions above can be applied to a two-stroke or four-stroke reciprocating engine.

In embodiments, to detect if the engine is operating correctly, in a controller, and preferably an autonomous control system, a set of sensors can be used. This autonomous control system is preferable a part of, or in control communication with, the control system for the overall system (e.g., system100ofFIG.1), and can be for example a sub-system, a separate controller, and preferably is also in control communication with the general control system for the overall system. These sensors can include:Knock detection (vibration-based sensors) mounted to the block or headLambda sensor (sensor that infers air to fuel ratio from exhaust gas composition, typically mounted downstream of exhaust valves)Exhaust temperature (typically thermistor or thermocouple) mounted downstream of the exhaust valves.Intake manifold temperature or pressure.Fuel sensors including mass flow, dew point temperature, and heating value (e.g., calorimeter).

In an embodiment, of the reciprocating engine, the fuel-air mixture is rich, preferably having an overall fuel/air equivalence ratio (0 or ER) greater than 1, greater than 1.5, greater than 2, greater than 3, from about 1.5 to about 4.0, about 1.1 to about 3.5, about 2 to about 4.5, and about 1.1 to about 3, and greater values.

In embodiments of the reciprocating engine reformer, it being understood that oxygen can be added to the air. And that water or steam may also be injected into the mixture of air and fuel, or to air or fuel individually. From about 1 to about 20% (molar) water can be injected, from about 10 to about 15% (molar water), from about 5 to about 17% (molar) water, more than 5% (molar) water, more than 10% (molar) water, more than 15% (molar) water, and less than 25% (molar) water, water can be injected. Following oxygen enrichment, the combustion air can have from about 21% to about 90% oxygen. “Air-breathing engines” defined herein are understood to also include engines using air modified with the addition of water or oxygen.

The reciprocating engine produces, a reprocessed gas, e.g, syngas, (as well as heat and mechanical energy, which can be used to power and operate the entire process) which is then filtered and heat from the syngas is recovered by a heat exchanger.

The overall (general) reaction for rich fuel/air mixture to syngas in a reciprocating engine is given by the equation:
ØCH4+2[O2+3.76 N2]→aCO+bH2+cCO2+dH2O+7.52 N2
Where stoichiometric coefficients a, b, c and are determined by the chemical kinetics, conservation of atomic species, and the reaction conditions.

In addition to syngas minor constituents in the gas exiting the reciprocating engine include water vapor, CO2, and various unburned hydrocarbons.

Gas Turbine Engine Based Reformers—Generally

Embodiments of the present systems and methods, utilizing gas turbine reformers, generally relate to systems, devices and methods to convert otherwise uneconomic hydrocarbon-based fuel, e.g., flare gas to a to value-added, easily transported products (such as, methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals, and combination and variations of these). These embodiments in general have a flare gas (i.e., fuel) conditioning system, an air-breathing gas engine, and a conditioning assembly that conditions the syngas for storage, shipping, later processing and combinations and variations of these. The flare gas is conditioned to remove impurities and materials that could be detrimental to later processing steps. The flare gas (e.g., fuel gas for the system) is then mixed with air and ignited in an engine.

Embodiments of the present inventions have a turbine engine, e.g., air breathing gas turbine engine, as the reformer to produce reprocessed gas, preferably syngas. Thus, and generally, in some embodiments the reformer114ofFIG.1is a gas turbine engine. In some embodiments gas turbines are preferred under certain circumstances (such as larger magnitudes of wellhead flows), as they provide advantages over embodiments using reciprocating engines to produce syngas. The gas turbine-based systems are suitable for larger scale gas-to liquid (e.g., flare gas to methanol) applications where there are packaging limitations, e.g., on-site footprint limitations. Embodiments of the present systems are modular and can easily and readily be positioned at difficult to access locations, locations with limited area for placement of the systems, and combinations and variations of these, where for example flare gas is generated.

Further, the gas turbine-based system has the capability to handle, e.g., receive and process to an end product, flare gases having a wide and varying ranges of composition, which in some embodiments can provide an advantage over a reciprocating engine. Changes in flare gas (i.e., fuel) composition can change ignition characteristics and burning times. For a reciprocating engine with fixed compression ratio, such changes should be addressed to avoid the potential of damaging engine knocking or misfires and exhaust value over-heating, as well as other problems.

Gas turbine combustion systems can burn a wide variety of liquid and gaseous fuels, preferably provided they are suitably free of contaminants that would lead to corrosion or deposits. Also, the flame is continuously burning in a gas turbine, unlike reciprocating engines where ignition must occur in each cylinder during each power stroke. Moreover, gas turbines can operate continuously for about 8,000 hrs (up to 24,000 hrs for some models, and potentially longer), without shutdown, and extended intervals greater than 24,000 hrs for major overhaul. With more moving parts and more wear surfaces, reciprocating engines must typically be shutdown to replace lubricating fluids at about 2,000 to about 4,000 hours intervals, and major overhaul at about 8,000-12,000 hours.

One of the many advantages that a gas turbine system may have over a reciprocating engine system, in some embodiments, is that the flare gas components can vary and gas turbine performance is not affected. In general, flare gasses having compositions as set out inFIGS.20A,20B,21, as well as, Tables 1 and 2, can be processed by the embodiments of gas turbine systems of the present inventions, including the Examples. However, some factors that still may play a part in performance of gas turbine system include: 1) margin to the dew point, i.e., superheat, of the flare gas of 10° C., ensuring gaseous inlet fuel, 2) keeping the heating value of the overall fuel is >400 BTU/scf., and 3) corrosive elements, such as Vanadium, are filtered out prior to combustion.

Embodiments of the present systems and methods, utilizing gas turbine reformers, generally relate to systems, devices and methods to convert otherwise uneconomic hydrocarbon-based fuel, e.g., flare gas to a to value-added, easily transported products (such as, methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals, and combination and variations of these). These embodiments in general have a flare gas (i.e., fuel) conditioning system, an air-breathing gas turbine, and a conditioning assembly that conditions the syngas for storage, shipping, later processing and combinations and variations of these. The flare gas is conditioned to remove impurities and materials that could be detrimental to later processing steps. The flare gas is then compressed to a pressure of about 8 to about bar (typically corresponding to about 1.2× the pressure ratio of the gas turbine air compressor), about 5 to about 40 bar, at least about 10 bar, at least about 20 bar and at least about 1.1× the pressure ratio of the gas turbine air compressor, from about 1.05× to about 1.8× the pressure ratio of the gas turbine air compressor and greater and smaller values. The compressed flare gas (i.e., fuel for the system) is then mixed with air and ignited in a gas turbine. The pressure of the air when mixed with the compressed fuel gas, preferably will be the same as the fuel gas. The temperature of the compressor discharge air is a known function of the inlet air temperature, the compression ratio, and the compressor efficiency, and the temperature of the compressed discharge air should be about 150° C. to about 600° C., about 150° C. to about 500° C., about 200° C. to about 400° C., greater than about 150° C., greater than about 300° C., and greater than about 500° C. The temperature of the compressed waste gas, e.g., flare gas, should be about 100° C. to about 300° C., about 150° C. to about 300° C., about 125° C. to about 200° C., greater than about 150° C., greater than about 200° C., and greater than about 250° C., and less than 350° C. and higher and lower values.

Generally, for embodiments of the gas turbine reformers, the fuel-air mixture is rich, preferably having an overall fuel/air equivalence ratio (0 or ER) 0.98 or greater, greater than 1, greater than 1.5, greater than 2, greater than 3, from about 1.5 to about 4.0, about 1.1 to about 3.5, about 2 to about 4.5, and about 1.1 to about 3, and greater values.

In embodiments of the gas turbine reformers, it is understood that oxygen can be added to the air. And that water or steam may also be injected into the mixture of air and fuel, or to air or fuel individually. From about 1 to about 20% (molar) water can be injected, from about 10 to about 15% (molar water), from about 5 to about 17% (molar) water, more than 5% (molar) water, more than 10% (molar) water, more than 15% (molar) water, and less than 25% (molar) water, water can be injected. Following oxygen enrichment, the combustion air can have from about 21% to about 90% oxygen. “Air-breathing engines” defined herein are understood to also include engines using air modified with the addition of water or oxygen.

Preferably the gas turbines are smaller sized units, from about 200 kW to about 5000 kW, from about 200 kW to about 2000 kW, and less than 6000 kW, less than 5000 kW, less than 3000 kW and less than 2000 kW, although larger and smaller sizes may be used.

The gas turbine produces syngas, (as well as heat and mechanical energy, which can be used to power and operate the entire process) which is then filtered and heat from the syngas is recovered by a heat exchanger.

The overall (general) reaction for rich fuel/air mixture to syngas in a gas turbine is given by the equation:
└CH4+2[O2+3.76 N2]→aCO+bH2+cCO2+dH2O+7.52 N2
Where stoichiometric coefficients a, b, c and are determined by the chemical kinetics, conservation of atomic species, and the reaction conditions.

In embodiments of the systems initiation of combustion occurs at near ambient conditions in the combustion chamber of gas turbine when the shaft of the turbine is turned at low cranking speed.

An additional feature, for an embodiment of the combustion chamber is to stage the fuel addition to extend the rich limit of combustion. For example, in a forward part of the combustion chamber part of the fuel is mixed with air to produce a flame with very stable combustion (for example near stoichiometric conditions). Downstream of that stable flame zone additional fuel is added to meet the overall equivalence ratio required to achieve the H2/CO ratio of the downstream process.

In addition to syngas minor constituents in the gas exiting the gas turbine include water vapor, CO2, and various unburned hydrocarbons.

In general, embodiments of a partial-oxidation gas turbine comprise a compressor, combustor, and turbine. The compressor takes ambient air and raises the pressure. The compressor discharge air is mixed with excess fuel and partially oxidized in the combustor. The discharge of the combustor is expanded through the turbine to ambient conditions. The work produced by the turbine typically exceeds the work required to drive the compressor. A conceptual drawing of one embodiment of the partial-is shown inFIG.7.

Thus, turning toFIG.7the reformer gas turbine assembly700. The gas turbine700has a gas turbine engine710, (e.g., air breathing turbine engine) that has an air intake711, a compressor712, a turbine713, and an exhaust flow714. The gas turbine710has a shaft configured for rotation with the turbine and compressor that is connected to a motor or generator715. The gas turbine700has two part or two stage combustor740, that provides for partial oxidation combustion of the flare gas. The two stage combustor740has a first stage, which is a rich partial oxidation combustor741and a second stage, which is the gas turbine710. The flare gas is injected at742and is partially combusted in reaction zone743of first stage combustor741. The product of this partial combustion is directed into the gas turbine710where further combustion, with the incoming air from intake711occurs to provide syngas. Syngas is produced in743(inside the combustion chamber), flows up and through heat exchanger760and out line733to the synthesis stage. The post-reaction synthesis gas returns through line732from the synthesis unit. This flow is heated by the syngas produced in743, and expanded through the turbine in713. A portion of the flow of line732is unheated and flows through bypass line731. This gas may have a high N2gas flow for use on seals and secondary cavities.

The numbers in circles inFIG.7relate to a location for a process condition, e.g., state points, discussed with respect to T-S diagrams relating to specific Examples and as discussed in the Examples.

EXAMPLES

The following examples are provided to illustrate various embodiments of the present waste gas conversion processes and systems. These examples are provided to illustrate various embodiments of the present gas-to-liquid conversion processes and systems. These examples are for illustrative purposes, may be prophetic, and should not be viewed as, and do not otherwise limit the scope of the present inventions.

The embodiments of these Examples 1 to 54 can have or utilize one or more of the embodiments, processes, methods, features, functions, parameters, components, or systems disclose and taught in the “Systems and Processes —Generally”, “Reciprocating Engine Based Reformers—Generally”, and “Gas Turbine Engine Based Reformers—Generally” sections of this specification, and combinations and variations of each of these; as well as, one or more of the embodiments, processes, methods, features, functions, parameters, components, or systems provided in one or more of the other Examples and other embodiments taught and disclosed in this specification.

Example 1

A system and process to convert otherwise uneconomic hydrocarbon-based fuel such as flare gas to value-added, easily transported products (such as methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals) using an autonomous, modular system comprising the following elements: (1) a fuel conditioning system to meet requirements of downstream components; (2) an air-breathing gas turbine, modified to operate a rich, partial-oxidation reformer, to produce a syngas mixture with a H2/CO ratio suitable for synthesis of liquids; (3) a combination of integrated heat exchangers, compression system components, and heat exchangers to prepare the syngas for the downstream synthesis reactors; and (4) a downstream synthesis reactor system to produce useful liquid hydrocarbon products.

Example 2

A system and process to convert otherwise uneconomic hydrocarbon-based fuel such as flare gas to value-added, easily transported products (such as methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals) using an autonomous, modular system comprising the following elements: (1) a fuel conditioning system to meet requirements of downstream components; (2) an air-breathing gas turbine, modified to operate a rich, partial-oxidation reformer, to produce a syngas mixture with a H2/CO ratio suitable for synthesis of liquids; (3) a combination of integrated heat exchangers, compression system components, and heat exchangers to prepare the syngas for the downstream synthesis reactors; (4) a downstream synthesis reactor system to produce useful liquid hydrocarbon products; and, (5) a hydrogen recycle loop to improve overall system process performance.

Example 3

The systems and process of Examples 1 and 2 can also have one, or more, or all of the following additional features: (6) optional substantially oxygen-free gas recirculation loop to cool and protect downstream components of the combustor, such as seals, bearings, and secondary cavities; (7) optional O2enrichment of the inlet stream to the gas turbine via membrane separation or partial air separation unit; (8) a recuperator heat exchanger (from (3)) and a turbo expander to recover energy from the high pressure exhaust gas from the downstream synthesis reactor; (9) integration of a closed-loop operating system with custom instrumentation; (10) a cloud-based remote monitoring system, including AI-trained anomaly detection for dynamic preventative maintenance and operations control; (11) optional offtake pathways to utilize byproducts, such as nitrogen, water, and CO2for reinjection, well recompletions, or other purposes; (12) optional water (or steam) injection into the rich combustor to improve H2/CO ratio and reduce carbon build-up on surfaces within the combustor and turbine.

Example 4

A gas-to-liquid system takes uneconomic hydrocarbon-based fuels, e.g., flare gas, at a well-head and remote locations that are primarily gaseous hydrocarbons and convert them to a more valuable easily condensable or liquid compounds, such as methanol. One source of source fuel could be associated gas or flare gas, which is produced as a byproduct at oil wells. Another source could be biogas from landfill or anaerobic digesters.

A small-scale plant, targeting 3,000,000 scfd (standard cubic feet per day) of inlet gas. The size of such a plant could vary from 300,000 scfd to 15,000,000 scfd. The plant is incorporated into one or more modular, interconnected skids or containers that are built at a central fabricator shop location and then installed at a field location. A small number of modules comprise the system and when connected at site they form an integrated system. The modular nature of the assembly enables application to remote locations under a range of inlet gas feed volumes, with a minimum of field labor. The modular nature further improves flexibility to deploy or redeploy these assets, reduces initial capital outlay and project financial risks, allows matching of the process throughput to the flare gas supply, and reduces time-to-market by allowing module fabrication and site preparation to occur in parallel.

Example 5

Turning toFIG.3there is shown a schematic of a system and method, and preferably a modular plant and processes, for the recovery and conversion of flare gas into methane.FIG.4is a T-S graph showing a preferred operating conditions and thermodynamic state points of the process that can be used for the operation of the embodiment ofFIG.3. The reference points (numbers—31,32,33,34,35,36,37,37.5,38,39, inFIG.3) correspond to process conditions, i.e., state points, at those locations in the system ofFIG.3, and those process conditions are shown by corresponding reference points inFIG.4. The prime reference points inFIG.4(e.g.,35′,36′) indicate expected cycle points considering efficiency of the components. Reference point7.5indicates the discharge of the downstream synthesis process. And, reference points33sand35sindicates idealized isentropic processes (vertical process lines) conditions. The starting specific entropy for this process is at points31,32(6.9 kJ/kg ° C.) and the final specific entropy point for this process is39(7.04 kJ/kg ° C.). Thus, the difference between the start and final specific entropy is 0.14 kJ/kg ° C.).

Turning toFIG.3there is shown a combustion chamber system300for converting flared gas from a flare gas source (e.g., oil well, gas well, land fill, agriculture plant, waste water treatment plant, etc.) into methanol. The system300has a reformer section or stage350and a synthesis section or stage351.

The system300has an air intake301that flows the air to a filter302, where dust, sand, particulates, etc., are removed from the air, after which the air flows to compressor303, where it is compressed. The compressed air leaves compressor303and flows to an air breathing combustion box304, where the flare gas is partially oxidized. The combustion box304can be a single stage, two stages, or more.

Flare gas (e.g., raw flare gas) from a flare gas source (e.g., an oil or gas well or field) enters system300through line311and flows to a separator313, where liquids and gas are separated. The separated liquids, including liquid hydrocarbons having 3 or more carbon atoms, and flow from the separator313through line314. These liquids can flow through line315to a storage tank316, The separated liquids can flow through line317, and are pumped, by pump318into the combustion box304.

The gases components of the flare gas exit the separator313via line312and flow to a gas conditioning unit310. Gas conditioning unit310can remove harmful materials to the process, including H2S (hydrogen sulfide), as well as, any materials that would harm or poison any catalysts that are used in the system. The conditioned flare gas leaves conditioning unit310and flows to gas filter309, where further harmful or detrimental materials are removed, e.g., iron sulfides, sulfur, as well as any materials that would harm or poison any catalysts that are used in the system. The conditioned and filtered flare gas leaves filter309and flows into gas compressor306, which is driven by motor307. The compressor306, compresses the flare gas to a predetermined pressure and temperature as taught and disclosed in this specification and for example shown inFIG.4, and flows this flare gas into combustion box304. Water, steam, or oxygen may also be added to the combustion box304via line305.

The compressed flare gas can be at a pressure of about 3 to about 60 bar, about 8 to about 35 bar (typically corresponding to about 1.2× the pressure ratio of the gas turbine air compressor), about 5 to about 40 bar, at least about 10 bar, at least about 20 bar, and at least about 1.1× the pressure ratio of the air compressor, from about 1.05× to about 1.8× the pressure ratio of the gas air compressor and greater and smaller values. The compressed flare gas (i.e., fuel for the system300) is then mixed with the compressed air and ignited in the combustion box304, where it is partially oxidized. The pressure of the air when mixed with the compressed flare gas, can be any of the above ranges of pressure for the flare gas; and preferably will be the same pressure as the flare gas. In the embodiment of the operation of the process as shown inFIG.4, the pressure of the flare gas and air is 8 bar, when they are introduced into the combustion box304for partial oxidation to form syngas.

The syngas exits the combustion box304and flows into turbine320, where its pressure is reduced (see, e.g., state points34(preferred 8 bar) and35(preferred 1 bar)). The turbine320is connect to compressor303by rotation shaft329, where it turns compressor303. The turbine320is connect to motor or generator336by rotating shaft319a. Rotating shaft319bcontexts turbine337with motor or generator336.

The syngas leaves turbine320via line321and flows into filter322where particulates, e.g., soot, are removed. The syngas then flows into heat exchange323where the temperature is lowered to the methanol synthesis window, preferably 200° C.-300° C. (see, e.g.,FIG.4). The heat exchanger323is part of a heat exchanger loop324. The syngas then flows from heater exchanger323to a water separation unit325. Water is removed from the water separation unit325via line326. The syngas leaves unit325and flows via line321ainto compressor327, which is driven by motor328. The compressor compresses the syngas to about 30-100 bar. For the preferred operation shown inFIGS.3and4, by state points36(1 bar) and37(30 bar).

The syngas leaves compressor327and flows to a heat exchanger329, where the temperature is maintained for the methanol synthesis window, and flows from the heat exchanger329via line321bto the synthesis unit329. The synthesis unit has two reactors329aand329b. It is noted that a single stage or reactor can be used, and that more than two stages or reactors can be used. The synthesis unit329has a line335for discharging water, methanol or both. The synthesis unit329converts the syngas to methanol, which then flows to hold and separation unit330. Unit330separates the liquid methanol from any remaining gas. The methanol is discharged through line331for storage, further processing, use, shipping, etc. The gases flow through line332to hydrogen separator unit333. Hydrogen leaves separation unit333via line334and flows back to the synthesis unit329, where it is used to adjust the H2/CO ratio of the syngas. The remaining gases, e.g., low H2concentration stream, from the unit333, flow through line339bfor injection into the turbine320; and flow through line339ato turbine337and then to exhaust line338.

This arrangement of components in this example is an efficient way to achieve the particular state points of the process that produce methanol in an economic and effective manner. These state points include: 1) starting at ambient conditions, 2) raising temperature and pressure to achieve rich partial oxidation, and 3) cooling and pressurizing to achieve downstream synthesis. The carbon intensity and energy intensity of the process can be managed by tuning the cycle points to just match the POX and synthesis windows. Furthermore, the cycle points can be tuned to minimize the energy requirements for midstream and downstream separations processes.

The operation of the system ofFIG.3under the embodiment of the state conditions ofFIG.4revolves around a rich-burn reformer and a synthesis reactor. Unlike a traditional gas turbines and reciprocating engines, the combustor304runs at rich conditions, up to equivalence ratio of about 4 so the fuel, i.e., flare gas, experiences rich partial oxidation (POX). The system300has fuel, i.e., flare gas, conditioning system, heat exchangers, compressors, and turbines. The fuel conditioning system separates liquids from gases in the feed stream and removes compounds that can damage the gas turbine or synthesis reactor. The heat exchangers and compressors take the syngas mixture at the exit of the gas turbine and adjust the temperature and pressure to deliver the target conditions for the synthesis reactor. Within the synthesis sub-system is an optional H2recycle loop. The gas at the exit of the synthesis reactor is heated in a recuperating (e.g., counter-flow) heat exchanger to an elevated temperature and then expanded to ambient conditions.

Example 6

The system ofFIG.3, and other embodiments of the present systems, can be operated and configured in a manner that limits expansion of the gas through the turbine337, such that the work from the compressor303and turbine sections320is matched. In this way, the exhaust gas from line338is pressurized above ambient pressure and less compression work, with compressors303, and in particular329, is required to meet the pressure required by the downstream synthesis reactor329, thus reducing the compression stages and equipment complexity. For example, compressor329can be reduced in size, work required, and even eliminated.

Example 7

Turning toFIG.5there is shown a schematic of a system and method, and preferably a modular plant and processes, for the recovery and conversion of flare gas into methane.FIG.6is a T-S graph showing a preferred operating conditions and thermodynamic state points of the process that can be used for the operation of the embodiment ofFIG.5. The reference points (numbers—51,52,53,54,55,56,57,58,59, inFIG.5) correspond to process conditions, i.e., state points, at those locations in the system ofFIG.5, and those processes conditions are shown by corresponding reference points inFIG.6. And, reference points53sindicates idealized isentropic processes (vertical process lines) conditions. The starting specific entropy for this process is at points51,52(6.9 kJ/kg ° C.) and the final specific entropy point for this process is58(7.2 kJ/kg ° C.). Thus, the difference between the start and final specific entropy is 0.3 kJ/kg ° C.

Turning toFIG.5there is shown a combustion chamber system500for converting flared gas from a flare gas source (e.g., oil well, gas well, land fill, agriculture plant, waste water treatment plant, etc.) into methanol. The system500has a reformer section or stage550and a synthesis section or stage551.

The system500has an air intake501that flows the air to a filter502, where dust, sand, particulates, etc., are removed from the air, after which the air flows to compressor503, where it is compressed. The compressed air leaves compressor503and flows to an air breathing combustion box504, where the flare gas is partially oxidized. The combustion box504can be a single stage, two stages, or more.

Flare gas (e.g., raw flare gas) from a flare gas source (e.g., an oil or gas well or field) enters system500through line511and flows to a separator513, where liquids and gas are separated. The separated liquids, including liquid hydrocarbons having 3 or more carbon atoms, and flow from the separator513through line514. The separated liquids can flow through line514, and are pumped, by pump518into the combustion box504.

The gases components of the flare gas exit the separator513via line512and flow to a gas conditioning unit510. Gas conditioning unit510can remove harmful materials to the process, including H2S, as well as, any materials that would harm or poison any catalysts that are used in the system. The conditioned flare gas leases conditioning unit510and flows to gas filter509, where further harmful or detrimental materials are removed, e.g., iron sulfides, sulfur, as well as any materials that would harm or poison any catalysts that are used in the system. The conditioned and filtered flare gas leaves filter509and flows into gas compressor506. The compressor506, compresses the flare gas to a predetermined pressure and temperature as disclosed and taught in this specification and for example shown inFIG.6, and flows this flare gas into combustion box504. Water, steam, or oxygen may also be added to the combustion box.

The compressed flare gas can be at a pressure of about 3 to about 60 bar, about 8 to about 35 bar (typically corresponding to about 1.2× the pressure ratio of the gas turbine air compressor), about 5 to about 40 bar, at least about 10 bar, at least about 20 bar, and at least about 1.1× the pressure ratio of the air compressor, from about 1.05× to about 1.8× the pressure ratio of the gas air compressor and greater and smaller values. The compressed flare gas (i.e., fuel for the system500) is then mixed with the compressed air and ignited in the combustion box504, where it is partially oxidized. The pressure of the air when mixed with the compressed flare gas, can be any of the above ranges of pressure for the flare gas; and preferably will be the same pressure as the flare gas. In the embodiment of the operation of the process as shown inFIG.6, the pressure of the flare gas and air is 8 bar, when they are introduced into the combustion box504for partial oxidation to form syngas.

The compressor503is connected by rotation shaft529, to motor or generator536. Rotating shaft519bcontexts turbine537with motor or generator536.

The syngas exits the combustion box504via line521and flows into filter522where particulates, e.g., soot, are removed. The syngas then flows into heat exchange523where the temperature is lowered to the methanol synthesis window, preferably 200° C.-500° C. (see, e.g.,FIG.6). The heat exchanger523is part of a heat exchanger loop524. The syngas then flows from heater exchanger523to the synthesis unit529. The synthesis unit has two reactors529aand529b. It is noted that a single stage or reactor can be used, and that more than two stages or reactors can be used. The synthesis unit529converts the syngas to methanol, which then flows to hold and separation unit530. Unit530separates the liquid methanol from any remaining gas. The methanol is discharged through line531for storage, further processing, use, shipping, etc. The gases flow through line532to hydrogen separator unit533. Hydrogen leaves separation unit533via line534and flows back to the synthesis unit529, where it is used to adjust the H2/CO ratio of the syngas. The remaining gases, e.g., low H2concentration exhaust products stream, from the unit533, flow into the turbine537and then to exhaust line538.

The operation of the system ofFIG.5under the state conditions ofFIG.6revolves around the integration of the synthesis reactor within the gas turbine cycle. The fuel system, compressor, and rich combustor are similar to the systems of Example 5. However, instead of delivering combustion products into the turbine, in this Example 7 the syngas at the exit of the combustor504flows through a recuperating heat exchanger523until the syngas temperature is acceptable for the synthesis reactor529. At the exit of the synthesis reactor529, the spent gas is returned through the recuperating heat exchanger system524, and delivered to the turbine537to expand back to ambient pressure. An advantage of this embodiment is fewer components, but it requires a high-temperature recuperating heat exchanger and more sophisticated controls, than the embodiment of Example 5.

Example 8

An embodiment of these systems and methods includes the use of water in the waste gas, e.g., flare gas, or added directly into the POX combustor to raise the H2/CO ratio to enhance the efficiency and effectiveness of the downstream synthesis reactor. This embodiment can be used with any of the present systems, including the Examples.

Example 9

An embodiment of these systems and methods includes the addition of substantially oxygen-free gas, to the reformer, e.g., the turbine, including such as that at the exit of the high pressure side of hydrogen separator, to pressurize seals and ensure that no air is entrained into the secondary passages of the turbine. This embodiment can be used with any of the present systems, including the Examples.

Example 10

A hybrid system, consisting of reciprocating engine(s) and gas turbine(s), whereby the reciprocating engine(s) may be used for auxiliary power generation, or to supply additional synthesis gas is also contemplated. The hybrid system may contain reciprocating engines and gas turbines at scales sized to match the inlet gas feed.

Example 11

In an embodiment of the system ofFIG.1, the reformer is the gas jet turbine ofFIG.7. This system can be preferably operated as set forth in the T-S diagram ofFIG.7A. The reference points (numbers—3,4,5,6,7,8, inFIG.7) correspond to process conditions, i.e., state points, at those locations in the system ofFIG.7, and those process conditions are shown by corresponding reference points inFIG.7A. The state point1(not shown inFIG.7), is the conditions of the flare gas as it is injected at742. The starting specific entropy for this process is at points1,2(6.9 kJ/kg ° C.) and the final specific entropy point for this process is 8 (7.2 kJ/kg ° C.). Thus, the difference between the start and final specific entropy is 0.3 kJ/kg ° C.

Example 12

Turning toFIG.8there is shown an embodiment of a system and method for the conversion of flare gas into a value-added product. The system800has a reformer stage801and a synthesis stage802. The system800has an air intake810, that feeds air through into a compressor811, which compresses the air. The compressed air is feed through heat exchanger820ainto a mixer813. The system has a flare gas intake884. The flare gas flows through a heat exchanger820binto the mixer813. The mixer813, provides a predetermined mix of air and flare gas, as disclosed and taught in greater detail in this specification, to a reformer814, which is a reciprocating engine.

The fuel-air mixture that is formed in mixer813is preferably rich, more preferably having an overall fuel/air equivalence ratio (0 or ER) greater than 1, greater than 1.5, greater than 2, greater than 3, from about 1.5 to about 4.0, about 1.1 to about 3.5, about 2 to about 4.5, and about 1.1 to about 3, and greater values.

It being understood that oxygen can be added to the air. And that water or steam may also be injected into the mixture of air and fuel, or to air or fuel individually. From about 1 to about 20% (molar) water can be injected, from about 10 to about 15% (molar water), from about 5 to about 17% (molar) water, more than 5% (molar) water, more than 10% (molar) water, more than 15% (molar) water, and less than 25% (molar) water, water can be injected. Following oxygen enrichment, the combustion air can have from about 21% to about 90% oxygen. “Air-breathing” reformers, and air breathing engines as used herein are understood to also include engines using air modified with the addition of water, oxygen or both.

The reciprocating engine814combusts the predetermined mixture of flare gas and air to form syngas. The syngas flows through heat exchangers820a,820band into a filter815, e.g., a particulate filter.

After passing through the filter815, the syngas flows to a guard bed reactor assembly816, having two guard bed reactors816a,816b. The guard bed reactor816has materials, e.g., catalysts, that remove contaminates and other materials from the syngas that would harm, inhibit or foul later apparatus and processes in the system. For example, the guard bed reactor816may contain catalyst or other materials to remove sulfur (e.g., iron sponge, zinc oxide or similar) and halogenated compounds.

After leaving the guard bed reactor816, the syngas flows to a deoxo reactor817. The deoxo reactor817removes excess oxygen from the reprocessed gas (e.g., syngas) by oxidizing combustible compounds in the mixture such as methane, CO, and H2, where the oxygen is converted to water. Catalyst for the deoxo reaction are platinum, palladium, and other active materials supported on alumina or other catalyst support materials.

The system800has a cooling system850, which uses a cooling fluid, e.g., cooling water, that is flow through cooling lines, e.g.,851.

After leaving the deoxo reactor817, the syngas flows to heat exchanger820c. The reprocessed gas (e.g., syngas) then flows from heat exchanger820fand820cto a water removal unit818, e.g., a water knockout drum, demister, dryer, membrane, cyclone, desiccant or similar, where water is removed from the syngas. In general, the syngas upon leaving unit818should have less than about 5% water by weight, less than about 2%, less than about 1% and less than about 0.1% water.

After leaving unit818, the now dry syngas is in the synthesis stage802. In stage802the now dry syngas flows to an assembly830. Assembly830provides for the controlled addition of hydrogen from line831into the now dry syngas. In this manner the ratio of the syngas components can be adjusted and controlled to a predetermined ratio. The hydrogen is provided from hydrogen separate839. The ratio adjusted dry syngas leaves assembly830and flow to compressor832. Compressor832compresses the syngas to an optimum pressure as taught and disclosed in this specification, for use the synthesis unit833. Preferably, the synthesis unit833is a two-stage unit with a first reactor unit833aand a second reactor unit833b. Synthesis unit833also has heat exchanger820e.

The synthesis unit833converts the ratio adjusted dry syngas into a value-added product, methanol. The methanol flows into to heat exchanger820d. The methanol flows to a collection unit840. The collection unit840collects the methanol and flows it through line841for sale, holding, or further processing.

Generally, the syngas is compressed to a pressure of about 15 to about 100 bar and preferably 30-50 bar, and about 25 to about 80 bar, at least about 10 bar, at least about 25 bar and at least about 50 bar, and greater and lower pressures. The temperature of the pressurized syngas is adjusted to a temperature of about 150° C. to about 350° C. and preferably 250° C., about 200° C. to about 300° C., about 250° C. to about 375° C., greater than 125° C., greater than 150° C., greater than 200° C., greater than 250° C., greater than 350° C., and less than 400° C., and higher and lower temperatures. The pressure and temperature-controlled syngas is then feed to reactors for transforming the syngas into a more useful, more easily transportable, and economically viable product such as methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals. In a preferred embodiment methanol is produced using the reaction of syngas to methanol, reactions for hydrogenation of CO, hydrogenation of CO2, and reverse water-gas shift using actively cooled reactors, such as a heat-exchanged reactor or boiling water reactor, and a copper containing catalyst such as Cu/ZnO/Al2O3or the like.

Generally, and in preferred embodiments, the characteristic length scale of the reactors used in this system are sufficiently small (e.g., micro-channel or mini-channels) that they can be shaped into unconventional shapes and topologies using new 3D printing techniques for metals and other high-temperature materials, thus allowing compact packaging and tight control over reaction conditions. Other strategies for intensification of the downstream synthesis reactions can also be considered, such as selectively removing the product from the reactor in-situ, or in a closely coupled fashion, to shift the equilibrium-limited reaction to higher conversion. This process intensification may minimize the need for large recycle streams or allow the reaction to proceed at milder conditions (e.g., lower pressure) thereby increasing process safety margins.

In general, the ratio of H2/CO in the syngas produced by the engine can be tailored to the downstream conversion process. For example, for methanol synthesis or Fischer-Tropsch (F-T) synthesis the ideal H2/CO ratio is 2-3. For ammonia synthesis or for hydrogen production, the maximum possible H2/CO ratio is desirable and can be enhanced by, for example, steam addition to promote the water-gas shift reaction. For ammonia and hydrogen production, the CO is not required by the downstream synthesis. As such, CO and CO2byproducts can be collected, sequestered, stored or utilized for other purposes.

The collection unit840also has a line that flows gas separated from the methanol to tee-connector835, where it is sent to hydrogen separate839, to a recycle loop or both. Recycle loop has compressor834and valve838to feed the methanol back into the synthesis unit833. Hydrogen separation can be achieved by via membrane separation or pressure swing absorption (PSA) or the like in the hydrogen separation unit839.

The remaining gas after hydrogen separation is sent through loop890and through heat exchanger820fto turbine expander891, where the gas is then sent to exhaust.

Example 13

In an embodiment of the system ofFIG.8, the reformer814is a spark ignition (otto cycle) reciprocating engine. This system can be preferably operated as set forth in the T-S diagram ofFIG.9. The reference points (numbers—81,82,83,84,85,86,87,88,89inFIG.8) correspond to process conditions, i.e., state points, at those locations in the system ofFIG.8, and those process conditions are shown by corresponding reference points inFIG.9. The line from state point84a′ to84b′ represents a reduction in compression ratio that occurs in response to a more reactive flare gas fuel. State point85brelates to the syngas exiting the syngas reformer after the expansion of the turbocharger. The expansion from85to85boccurs within the turbocharger. The starting specific entropy for this process is at points81,82(6.9 kJ/kg ° C.) and the final specific entropy point for this process is89(6.95 kJ/kg ° C.). Thus, the difference between the start and final specific entropy is 0.05 kJ/kg ° C.

FIG.9Ais a table set out further operating conditions for the system of this Example.FIG.9Ashows the compression power (gross and net) for flare gas to methanol process using the turbo expander891under the conditions of a 3 bar backpressure and a 50 bar methanol synthesis pressure.

Example 14

In an embodiment of the system ofFIG.8, the reformer814is a compression ignition (diesel cycle) reciprocating engine. This system can be preferably operated as set forth in the T-S diagram ofFIG.11. The reference points (numbers—81,82,83,84,85,86,87,88,89inFIG.8) correspond to process conditions, i.e., state points, at those locations in the system ofFIG.8, and those process conditions are shown by corresponding reference points inFIG.11. The line from state point84a′ to84b′ represents a reduction in compression ratio that occurs in response to a more reactive flare gas fuel. State point85brelates to the syngas exiting the syngas reformer after the expansion of the turbocharger. The expansion from85to85boccurs within the turbocharger. The starting specific entropy for this process is at points81,82(6.9 kJ/kg ° C.) and the final specific entropy point for this process is89(6.95 kJ/kg ° C.). Thus, the difference between the start and final specific entropy is 0.05 kJ/kg ° C.

Example 15

Turning toFIGS.10A and10Bthere is shown an embodiment of a variable compression ratio engine that can be used as a reformer in embodiments of the present systems, including the Examples. The variable compression ration engine,1002can be one such as the Nissan VC-turbo engine, that uses a multi-link system in place of a traditional connecting rod to rotate the crankshaft, and an actuator motor changes the multi-link system endpoint in order to vary the pistons' reach to transform the compression ratio.

FIG.10Ais a cutaway view of a conventional engine1001compared to a partial cutaway view of a variable compression engine1002. The piston1010are the crank1011are the same. The conventional engine1001has a connection rod1020, and a 2ndbalancer1021. The variable compression engine1002has a U-link1030, an L-link1031, a C-link1032, a control shaft1033, an A-link1034and an actuator Motor1035.

The components of the variable compression engine1002make it possible to vary the compression ratio continuously as needed within the range of about 8:1 (for high load) to about 14:1 (for low load). For an automobile engine made by Nissan, the optimal compression ratio can be continuously set to match the operation of the accelerator pedal by the driver. A schematic of this linkage is shown onFIGS.10A and10B. The effects of this linkage on piston height is shown onFIG.10B. This approach can be applied to a two-stroke or four-stroke reciprocating engine, although an engine as described here is preferably operated as a four-stroke. Thus, using the variable compression engine as a reformer, the optimal compression ratio for producing syngas can be continuously set to accommodate combustion properties from variation in the flare gas with variable compression ratio. In this manner, in embodiments, an engine with a linkage to rotate the crankshafts to vary the compression ratio to run rich with variable flare gas compositions is utilized to produce synthetic gas.

Thus, and for illustration, turning toFIG.10B, the relative adjustments for the variable compression reciprocating engine reformer1002are shown. Piston height1010ais for 14:1 compression ratio. Piston height1010bis for 8:1 compression ratio. The adjustment of the linkages are shown by arrows1031aand1033a.

Example 16

Turning toFIGS.12, there is shown an embodiment on an engine for production of syngas from compression-ignition of rich fuel-air mixtures is preferred due to simplicity (lower part count) and better performance (high compression ratio yielding faster burn times). This engine reformer can be used in embodiments of the present systems, including the Examples. An example architecture is the opposed-piston free-piston linear internal combustion engine with integrated linear motor/generator, such as that produced by MainSpring Energy (aka Etagen). U.S. Pat. No. 2,362,151 discloses a basic engine configuration for modification in accordance with the teachings of the present specification, the entire disclosure of which is incorporated herein by reference.

Thus, turning toFIGS.12, the a free piston engine “A” is connected to two single phase generators “B” and “B”, which can be operated by the engine. When used as a reformer the generators may not be present, or can be used to power components in the system.

The free piston engine A has a cylinder61in which the pistons62-62areciprocate and which is surrounded by a second cylinder63having the annular water chamber65therein encompassing the explosion chamber64of the engine. Annular air chambers66are formed in the end portions of cylinder63as shown and are connected by a passage67whereby the air pressure in the two chambers is equalized, Intake passages68lead from chamber66ato the interior of cylinder61, and discharge passages69lead from the opposite end portion of the cylinder61to discharge into manifold10.

Inasmuch as the two ends of the device are duplicates one end only will be described in detail and similar parts on the other end will be indicated by similar characters followed by the character “a”.

Through the outer end of chamber66are formed passages11fitted with inwardly opening check valves12, the said passages leading to an annular cylinder13axially disposed relative to cylinder61and somewhat larger In diameter than said cylinder—and mounted end wise thereon as at14. This cylinder13is provided with an air intake passage at15fitted with an inwardly operating check valve as at18and disposed adjacent the inner end of said cylinder.

The piston12has an enlarged head17thereon to reciprocate in chamber13, and a stem18projects axially outwardly from said head and through the bearing19in the outer end of the chamber13and has a shoulder20formed therein as shown, exteriorly of chamber13to form a seat for the magnet21.

The magnet21is a field magnet, and in the present instance comprises a part22, circular in form, seated on the shoulder20, a second member24of smaller diameter seated on the member22, and a winding of wire on the second member as indicated at23and grounded to said second part. This second member24is also provided with a flange25extending outwardly from its outer end at right angles to its axis, and then turned backwardly in parallel relation with the axis and with a diameter slightly greater than the chamber13to encompass the magnet parts22and24as shown. The winding23is energized by means of a battery at26grounded to the engine at21and connected to a bar28mounted upon the engine at29and extending forwardly thereof as indicated, in parallel relation with its axis. A shoe630slidably engages the bar28and is in fixed contact with the coil23so that the magnet is energized at all times regardless of its position with relation to the fixed end of the device.

The armature comprises a coil of wire as631within a supporting cylinder632mounted upon the outer end of chamber I! to encompass the magnet parts22and24. Wires as633connect the armatures631and631a, and. electricity is taken off of these wires as at34.

When the device is in operation the outward movement or the piston heads17-17adraw air into the chambers13-13athrough valves16-16a, and on their inward movement push the air through valves12into chamber66-66a. The air in chamber68ais sufficiently compressed to flow forcibly into the cylinder61when the piston62auncovers the passages68. The exhaust passages69are uncovered at substantially the same time as the passages68so that the air entering the cylinder61at68will scavenge the same and carry out all of the burnt gases at69leaving the cylinder filled with fresh air.

But in the movement of pistons12-12ajust described the piston heads17-17acompress the air entrapped in the chamber13-13a, which form cushions which forcibly drive the said pistons back in cylinder61compressing the air therein. As the pistons approach each other the compressed air trapped between them, or at least a small portion thereof, is discharged through passage635and pipe637to actuate a plunger638in injector639in which the fuel oil is admitted at49and discharged through valve41into combustion chamber64. These parts are proportioned and arranged to form a combustible mixture at the moment when the pistons62-62aapproach each other most closely, the resulting explosion diving the pistons outwardly again to repeat the cycle. The valves at47-47aare inserted in chambers13-13ato permit the drawing of air into said chambers to compensate for such air as may leak out of the same past the heads17-17aor paste bearings19-19a.

In an engine of this kind the pistons62-62aare reciprocated at high speed, upwards of some ten thousand times a minute, and the magnets21-21aare, or course, reciprocated at the same high speed. In this manner the mechanical energy of the engine is converted into electrical energy, since the rapid reciprocation of the magnetic fields about the magnets21-21athrough the induction coils631-631awill rapidly alter the number of lines or force passing through the coils.

This engine is modified with digital electronic controls (sensor and control system) to achieve a practical and high efficiency engine for small-scale power generation. This approach can be applied to a two-stroke or four-stroke reciprocating engine, although a linear engine with fixed ports in the side walls is generally operated as a two-stroke. Thus, this linear engine operating under rich conditions can be a reformer in any of the Examples of systems to produce syngas. Preferably this linear engine reformer is a free-piston configuration with an electronically-control linear motor/generator that allows the compression ratio to be varied according the properties of the incoming fuel. This linear engine reformer may also have a free-piston configuration with sensors to detect the in-cylinder combustion behavior under rich conditions and automatically adjust the compression ratio.

Example 17

An embodiment of a variable compression ratio engine reformer, for use in embodiments of the present systems, including the Examples, is through a crankshaft-driven opposed-piston engine utilizing a variable phaser on the crankshafts. Combustion chamber volume in such an engine is dictated by the relative positions of the pistons. Offsetting motion of one piston to the other increases minimum volume, thereby reducing compression ratio. Turning toFIG.8there is shown a comparison of displaced volume when the opposed pistons are synchronized (left) vs offset by 40 degrees (right). The compression ratio is higher when the pistons are synchronized, and reduces when the pistons are offset. An example of an opposed-piston linear engine with crank shafts is an engine developed by Achates Engines.

In an embodiment the opposed piston engine reformer has a variable phaser on the crankshafts to run rich with variable fuel to produce synthetic gas is novel.

This approach can be applied to a two-stroke or four-stroke reciprocating engine, although a linear engine with fixed ports in the side walls is generally operated as a two-stroke.

Example 18

Turning toFIG.14there is shown a modular reformer system and process that is a portion of a liquid-to-gas system1400. This system1400has a reformer stage1401, that is placed on a transport system1490(e.g. skid, truck bed, rail car, ship deck, barge, drilling platform, drill ship, container, or other platform, base or container), that can be readily moved by rail, air, truck or ship. The stage1401has a compressor1411and an engine reformer1414, as well as other components as labeled on the drawing as taught and disclosed in this specification. It being understood that any of the engine reformers of the present systems and Examples could be used in the stage1401. The stage1401provides clean syngas.

This stage can be used, or positioned with any unit that can further process the syngas into move valuable products. For example, this stage1401can be used with the modular methanol synthesis unit of the present inventions, such as the unit of Example 19.

Example 19

Turning toFIG.15there is shown a modular methanol synthesis system and process that is a portion of a liquid-to-gas system1400. This system1400, has a synthesis stage1402, that can be placed on a transport system1491(e.g., skid, truck bed, rail car, ship deck, barge, drilling platform, drill ship, container, or other platform, base or container), that can be readily moved by rail, air, truck or ship. This stage1402is configured to receive clean, syngas. This stage1402can be used with the reformer stage1401of Example 18, as well as with other reformer stages as taught and disclosed in this specification, including the Examples. The stage1402produces an end product, e.g., methanol, from syngas.

The stage1402has a synthesis unit1433, which is a two-stage unit with a first reactor unit1433aand a second reactor unit1433b. The stage has a hydrogen separator1439, a collection unit1440, as well as, other components as labeled on the drawing and as taught and disclosed in this specification. It being understood that any of the configurations of synthesis stages of the present systems and Examples could be used in stage1402.

This stage1402can be positioned near a tank, storage container, or source of syngas and process that syngas into methanol.

Example 20

Turning toFIGS.16,17and17A.FIG.16shows an embodiment of a system and method for the conversion of flare gas into a value-added product, e.g., methanol. The system1600has a reformer stage1601and a synthesis stage1602. The system1600has an air intake, that feeds air through into a compressor1611, which compresses the air. The compressed air is feed through a heat exchanger into a mixer. The system has a flare gas intake. The flare gas flows through a heat exchanger into the mixer. The mixer provides a predetermined mix of air and waste gas, as taught and disclosed in this specification, to a reformer1614, which is a reciprocating engine.

The fuel-air mixture that is formed in mixer is preferably rich, more preferably having an overall fuel/air equivalence ratio (0 or ER) greater than 1, greater than 1.5, greater than 2, greater than 3, from about 1.5 to about 4.0, about 1.1 to about 3.5, about 2 to about 4.5, and about 1.1 to about 3, and greater values.

It being understood that oxygen can be added to the air. And that water or steam may also be injected into the mixture of air and fuel, or to air or fuel individually. From about 1 to about 20% (molar) water can be injected, from about 10 to about 15% (molar water), from about 5 to about 17% (molar) water, more than 5% (molar) water, more than 10% (molar) water, more than 15% (molar) water, and less than 25% (molar) water, water can be injected. Following oxygen enrichment, the combustion air can have from about 21% to about 90% oxygen. “Air-breathing” reformers, and air breathing engines as used herein are understood to also include engines using air modified with the addition of water, oxygen or both.

The reciprocating engine1614combusts the predetermined mixture of flare gas and air to form syngas. The syngas flows through heat exchangers and into a filter, e.g., a particulate filter.

After passing through the filter, the syngas flows to a guard bed reactor assembly, having two guard bed reactors. After leaving the guard bed reactor, the syngas flows to a deoxo reactor. The deoxo reactor removes excess oxygen from the reprocessed gas (e.g., syngas).

The system has a cooling system, which uses a cooling fluid, e.g., cooling water, that is flow through cooling lines.

After leaving the deoxo reactor, the syngas flows to heat exchanger. The reprocessed gas (e.g., syngas) then flows from the heat exchanger to a water removal unit, e.g., a water knockout drum, demister, dryer, membrane, cyclone, desiccant or similar, where water is removed from the syngas. In general, the syngas upon leaving unit the water removal unit should have less than about 5% water by weight, less than about 2%, less than about 1% and less than about 0.1% water.

After leaving the water removal unit, the now dry syngas flows into in the synthesis stage1602. In stage1602the now dry syngas flows to an assembly that provides for the controlled addition of hydrogen from line into the now dry syngas. In this manner the ratio of the syngas components can be adjusted and controlled to a predetermined ratio. The hydrogen is provided from hydrogen separate1639. The ratio adjusted dry syngas leaves the assembly and flows to compressor1632. Compressor1632compresses the syngas to an optimum pressure as taught and disclosed in this specification, for use the synthesis unit1633, which is a two-stage unit with a first reactor unit1633aand a second reactor unit1633b. Synthesis unit1633also has heat exchanger.

The synthesis unit1633converts the ratio adjusted dry syngas into a value-added product, e.g., methanol. The methanol flows into to heat exchanger and then to a collection unit1640. The collection unit1640collects the methanol and flows it through a line for sale, holding, or further processing.

The collection unit1640also has a line that flows gas separated from the methanol to tee-connector, where it is sent to hydrogen separate1639, to a recycle loop or both. Recycle loop has a compressor and a valve to feed the methanol back into the synthesis unit1633.

The system1600can be preferably operated as set forth in the T-S diagram ofFIG.17. The reference points (numbers—161,162,163,164,165,166,167,168,169inFIG.17) correspond to process conditions, i.e., state points, at those locations in the system ofFIG.16, and those process conditions are shown by corresponding reference points inFIG.17. The starting specific entropy for this process is at points161, (6.9 kJ/kg ° C.) and the final specific entropy point for this process is169(6.95 kJ/kg ° C.). Thus, the difference between the start and final specific entropy is 0.05 kJ/kg ° C.

Further, turning toFIG.17Athere is shown the predicted compressor work (total and for syngas compression only), as a function of the engine exhaust backpressure for a 50 bar downstream synthesis pressure. These data are generated using a chemical process simulation that performed the mass and energy balances for the embodiment of a liquid-to-gas system and method of the type shown inFIG.16. The syngas compressor is treated as a three-stage compressor with interstage cooling. The isentropic efficiency of the compressor is assumed to be 75%, representative of industrial centrifugal and reciprocating compressors. The syngas ratio adjustment recycle stream enters the compressor at the inlet to the second stage. Increasing the engine exhaust backpressure from 2 bar up to 3 bar decreases the compression work by 20.4%. Further increasing the backpressure from 2 bar to 4 bar decreases the compression work by 28.0%. This trend suggests a diminishing return and therefore optimal value of engine exhaust backpressure for the embodiment ofFIG.16would be in the 2-5 bar range to balance reduction in compression work with reduction in engine reformer breathing and performance.

Example 21

Turning toFIG.18there is shown an embodiment of a system and method for the conversion of flare gas into a value-added product, e.g., methanol. The system1800is configured to reduce the compression work required by raising the back pressure of the engine above ambient, to about 5 bar.

The system1800has a reformer stage1801and a synthesis stage1802. The system1800has an air intake, that feeds air through into a compressor1811, which compresses the air. The compressed air is fed through heat exchanger in to a mixer. The system has a flare gas intake. The flare gas flows through a heat exchanger1820binto the mixer1813. The mixer1813, provides a predetermined mix of air and waste gas, as taught and disclosed in this specification, to a reformer1814, which is a reciprocating engine.

The fuel-air mixture that is formed in mixer is preferably rich, more preferably having an overall fuel/air equivalence ratio (0 or ER) greater than 1, greater than 1.5, greater than 2, greater than 3, from about 1.5 to about 4.0, about 1.1 to about 3.5, about 2 to about 4.5, and about 1.1 to about 3, and greater values.

It being understood that oxygen can be added to the air. And that water or steam may also be injected into the mixture of air and fuel, or to air or fuel individually. From about 1 to about 20% (molar) water can be injected, from about 10 to about 15% (molar water), from about 5 to about 17% (molar) water, more than 5% (molar) water, more than 10% (molar) water, more than 15% (molar) water, and less than 25% (molar) water, water can be injected. Following oxygen enrichment, the combustion air can have from about 21% to about 90% oxygen. “Air-breathing” reformers, and air breathing engines as used herein are understood to also include engines using air modified with the addition of water, oxygen or both.

The reciprocating engine1814combusts the predetermined mixture of flare gas and air to form syngas. The syngas flows through heat exchangers and into a filter, e.g., a particulate filter.

After passing through the filter, the syngas flows to a guard bed reactor assembly, having two guard bed reactors. After leaving the guard bed reactor, the syngas flows to a deoxo reactor. The deoxo reactor removes excess oxygen from the reprocessed gas (e.g., syngas).

The system has a cooling system, which uses a cooling fluid, e.g., cooling water, that is flow through cooling lines.

After leaving the deoxo reactor, the syngas flows to heat exchanger. The reprocessed gas (e.g., syngas) then flows from the heat exchanger to a water removal unit, e.g., a water knockout drum, demister, dryer, membrane, cyclone, desiccant or similar, where water is removed from the syngas. In general, the syngas upon leaving unit the water removal unit should have less than about 5% water by weight, less than about 2%, less than about 1% and less than about 0.1% water.

After leaving the water removal unit, the now dry syngas is in the synthesis stage1802. In stage1802the now dry syngas flows to an assembly that provides for the controlled addition of hydrogen from line into the now dry syngas. In this manner the ratio of the syngas components can be adjusted and controlled to a predetermined ratio. The hydrogen is provided from hydrogen separate1839. The ratio adjusted dry syngas leaves the assembly and flows to compressor1832. Compressor1832compresses the syngas to an optimum pressure as taught and disclosed in this specification, for use the synthesis unit1833, which is a two-stage unit with a first reactor unit1833aand a second reactor unit1833b. Synthesis unit1833also has heat exchanger.

The synthesis unit1833converts the ratio adjusted dry syngas into a value-added product, e.g., methanol. The methanol flows into to heat exchanger and then to a collection unit1840. The collection unit1840collects the methanol and flows it through a line for sale, holding, or further processing.

The collection unit1840also has a line that flows gas separated from the methanol to tee-connector, where it is sent to hydrogen separate1839, to a recycle loop or both. Recycle loop has a compressor and a valve to feed the methanol back into the synthesis unit1833.

Stage1802has a line1883for taking depleted methanol from unit1833band sending it through heat exchanger1820d. The stage1802has a methanol desorber1880that has pump1881. Line1882for desorber1880flows methanol rich product to heat exchanger1820g.

In the operation of system1800the preferred process uses a two-stage methanol synthesis reactor with reactive separation in the second stage (Rxtr 2)1833bonly. The first stage (Rxtr 1)1833ais generally far from equilibrium and does not warrant reactive separation. The example shown in this figure is reactive absorption or membrane separation with a liquid sweep. Methanol is selectively removed from the reactor in situ resulting in a methanol-depleted gaseous stream containing primarily unreacted syngas and a methanol-rich absorbent stream. Compared to other embodiments, the primary recycle loop is not used because of the improved single-pass conversion. The methane-rich absorbent stream passes through a valve to reduce the pressure and desorb the methanol which is then condensed and sent the product stream. The absorbent, now in a regenerated state, is pumped back to the synthesis pressure and recirculated to the reactor. The pumping work for the absorbent is minimal compared to the syngas compressor work because the liquid absorbent is nearly incompressible. The reactor could be a trickle bed or a membrane reactor with the liquid absorbent (sweep) on the permeate side of the membrane. Any methanol that does not partition into the absorbent is condensed out of the gas phase in a downstream separation step and combined with the methanol product stream

Example 22

Turning toFIG.19there is shown an embodiment of a system and method for the conversion of flare gas into a value-added product, e.g., methanol. The system1900has a reformer stage1901and a synthesis stage1902. The system1900has an air intake, that feeds air through into a compressor1911, which compresses the air. The compressed air is feed through heat exchanger into a mixer. The system has a flare gas intake. The flare gas flows through a heat exchanger1920binto the mixer1913. The mixer1913, provides a predetermined mix of air and waste gas, as taught and disclosed in this specification, to a reformer1914, which is a reciprocating engine.

The fuel-air mixture that is formed in mixer is preferably rich, more preferably having an overall fuel/air equivalence ratio (0 or ER) greater than 1, greater than 1.5, greater than 2, greater than 3, from about 1.5 to about 4.0, about 1.1 to about 3.5, about 2 to about 4.5, and about 1.1 to about 3, and greater values.

It being understood that oxygen can be added to the air. And that water or steam may also be injected into the mixture of air and fuel, or to air or fuel individually. From about 1 to about 20% (molar) water can be injected, from about 10 to about 15% (molar water), from about 5 to about 17% (molar) water, more than 5% (molar) water, more than 10% (molar) water, more than 15% (molar) water, and less than 25% (molar) water, water can be injected. Following oxygen enrichment, the combustion air can have from about 21% to about 90% oxygen. “Air-breathing” reformers, and air breathing engines as used herein are understood to also include engines using air modified with the addition of water, oxygen or both.

The reciprocating engine1914combusts the predetermined mixture of flare gas and air to form syngas. The syngas flows through heat exchangers and into a filter, e.g., a particulate filter.

After passing through the filter, the syngas flows to a guard bed reactor assembly, having two guard bed reactors. After leaving the guard bed reactor, the syngas flows to a deoxo reactor. The deoxo reactor removes excess oxygen from the reprocessed gas (e.g., syngas).

The system has a cooling system, which uses a cooling fluid, e.g., cooling water, that is flow through cooling lines.

After leaving the deoxo reactor, the syngas flows to heat exchanger. The reprocessed gas (e.g., syngas) then flows from the heat exchanger to a water removal unit, e.g., a water knockout drum, demister, dryer, membrane, cyclone, desiccant or similar, where water is removed from the syngas. In general, the syngas upon leaving unit the water removal unit should have less than about 5% water by weight, less than about 2%, less than about 1% and less than about 0.1% water.

After leaving the water removal unit, the now dry syngas is in the synthesis stage1902. In stage1902the now dry syngas flows to an assembly that provides for the controlled addition of hydrogen from line into the now dry syngas. In this manner the ratio of the syngas components can be adjusted and controlled to a predetermined ratio. The hydrogen is provided from hydrogen separate1939. The ratio adjusted dry syngas leaves the assembly and flows to compressor1932. Compressor1932compresses the syngas to an optimum pressure as taught and disclosed in this specification, for use the synthesis unit1933, which is a two-stage unit with a first reactor unit1933aand a second reactor unit1933b. Synthesis unit1933also has heat exchanger1920e.

The synthesis unit1933converts the ratio adjusted dry syngas into a value-added product, e.g., methanol. The methanol flows into to heat exchanger and then to a collection unit1940. The collection unit1940collects the methanol and flows it through a line for sale, holding, or further processing.

The collection unit1940also has a line that flows gas separated from the methanol to tee-connector, where it is sent to hydrogen separate1939, to a recycle loop or both. Recycle loop has a compressor and a valve to feed the methanol back into the synthesis unit1933.

Stage1902has a line1983for taking water depleted methanol from unit1933band sending it through heat exchanger1920d. The stage1902has a line1987from unit1833bthat removes water rich product.

The system1900is for the gas-to-liquids process with reactive separation of byproducts. The process uses a two-stage methanol synthesis reactor with reactive separation in the second stage (Rxtr 2)1933bonly. The first stage (Rxtr 1)1833ais generally far from equilibrium and does not warrant reactive separation. The example shown in this figure is membrane separation with a gaseous sweep. Water (a byproduct of CO2hydrogenation to methanol) is selectively removed from the reactor1833b(via line1987) in situ resulting in a water-depleted gaseous stream containing primarily unreacted syngas and a water-rich sweep gas. In this embodiment a primary recycle loop is not use because of the improved single-pass conversion. Further, in this embodiment, regeneration of the sweep stream (e.g., air in this embodiment) is not performed. The membrane reactor could use a polymeric or ceramic membrane material that is perm-selective to water and a sweep gas (e.g., air) on the permeate side of the membrane. Removing the water shifts the equilibrium towards the products. The reverse water-gas shift reaction converts CO2to CO, and so this approach also helps convert CO2to more reactive CO. As such, this approach is especially attractive for CO2-rich syngas streams such as those produced from partial oxidation. Methanol is condensed out of the gas phase in a downstream separation step and combined with the methanol product stream.

Example 23

An embodiment of a methanol synthesis unit, for use with any of the present systems including the systems of the Examples, is a quench style methanol reactor. A cool reactor feed gas is injected between catalyst beds to quench the gas exiting each catalyst bed and control the feed temperature of reactants to each catalyst bed. The following parameters set the basis for the sizing of the Methanol Reactor.4 catalyst beds.225° C. inlet temperature to each bed, consistent with expected catalyst supplier end of life feed temperature. This sets the required quench gas flowrates.Average gas velocity within the reactor ⇐1 ft/s. This parameter sets the minimum required reactor diameter.Average gas residence time per catalyst bed ⇒2.5 seconds. This parameter sets the minimum average catalyst bed depth, which in turns sets the minimum tangent-to-tangent length of the reactor.

A parameter for methanol synthesis is the ratio of hydrogen to carbon oxides in the feed to the methanol reactor. The gas stoichiometry is defined using the S ratio as follows.

S=H⁢2-CO⁢2CO+CO⁢2

The preferred S ratio is between 2-2.3. Typical steam methane reformers produce a syngas with an S ratio of approximately 3. However, the engine reformers of the present systems can produce a syngas with an S ratio closer to 1. The target S ratio, for the embodiment of this Example, is 2.1. To achieve this S ratio at the feed to the methanol reactor it is required that a portion of the recycled loop gas is sent through a hydrogen purification step. Therefore, the target S ratio defines the sizing basis for the Hydrogen Recovery Package.

Example 23

An embodiment of a control system for the operation and monitoring of the present systems and processes, including the Examples. This control system also has components for calculation, obtaining and storing data and information about the operation of the system and process, e.g. process information and data. This process data and information can, among other things, include: mass balance data and information (e.g., kg of flare gas into system, kg of methanal produced, kg of exhaust produced, etc.), carbon capture data and information, CO2e related data and information, and combinations and variations thereof and well as other types of data and information. This data and information among other things can be used to validate or obtain carbon credits on for example a carbon exchange, or to meet environmental regulatory reporting or monitoring requirements.

A control has a control panel located on site at the system (e.g., on a skid, on one or both stages in a modular system). The control panel will house control equipment such as controllers, marshalling panels, power supplies, network switches, etc. The control panel will include the basic process control and the safety shutdown system. Preferably all information will be available for monitoring and control from the control panel.

The process information and data on the on-site control panel will preferably be available for remote monitoring and limited remote control from a remote-control room via cellular (4G/5G) network, satellite, or other hardwired or wireless communication mode.

Preferably, the level of automation provided by the control panel shall be such that under normal plant operating conditions, manual intervention of the operators is minimized. Manual intervention can be required for abnormal events and conditions that occur during module start up and shutdown. Preferably the control panel shall always be active and provide full control, monitoring, and safeguarding of the module at all times.

Preferably, the control systems shall be designed to be fail-safe such that upon the loss of power, instrument air supply, or control signal to/from instrument device shall cause the plant to move to a predetermined safe operating state.

Preferably, the control systems shall support a level of redundancy and fault tolerance such that the failure of any single component of the system shall have no significant adverse effect on the processes being controlled.

Preferably, the control panel serves as the Integrated Control & Safety System (ICSS) and thus provides basic process control and basic safety functions for the system, and preferably includes one, more than one and all of the following functions:Basic Process Control System (BPCS),Safety Instrumented System (SIS), if determined required in future phases of the project,Corresponding Human-Machine Interfaces (HMI) displays,Communications systems,Mechanical vendor system interfaces (such as Anti-Surge Control systems (ASC)).

Preferably, all field instruments shall be “smart” type device in which, for example, the HART protocol is available for instrument diagnostic. Instrument designs and selections shall follow industrial standards such as ISA (International Society of Automation) and PIP (Process Industry Practices). IEC61508 certified instruments shall be used for SIFs that are SIL 1 or above.

Example 24

Turning toFIG.24there is provided a control and communication system network2300for the use with the present systems and processes, including the Examples. Network2300includes and is control communication with a flare gas to syngas to methanol system2301, generally of the type disclosed and taught in the specification, including the Examples.

The system2300has a local, e.g., on-site control system2320. The components of the on-site control system2320can be in a box or housing located on or attached to the system2301. The components of system2320may be located in separate housings and enclosures or in a single enclosure. The system2320has a controller2321, having a processor and memory, a storage device2322, a HMI (human machine interface)2323, and an input/output (I/O)2324, and a communication module2325.

The system2300has numerous on-site communication pathways, e.g.,2341that make up local, or on-site sub-network2340. The Sub-network2340can also communicate with other sub-networks via pathway2342. These on-site communication pathways. e.g.2341, transmit communications, including control communication, data and information, to and from one, more than one, and preferably all the devices and components of the system2301. Additionally, these on-site-pathways, e.g.,2341, transmit communications, including control communications, data and information, to and from one, more than one, and preferably all of the sensors and monitoring devices and instruments in system2301. In this manner on-site sub-network2340can send and receive control communications, as well as, sensor data and information from system2301to the control system2320. In this manner the on-site control system2320is in control communications with the flare gas to syngas to methanol system2301. In this manner the on-site control system2320can operation and control the system2301, and receive data and information about the processes and operations of the system2301. The on-site control system2320can be, for example, configured along the lines of the control system in Example 23.

The on-site control system is in control communication with a remote-control system2350. In this manner, the remote-control system2350can configure, control, change, monitor the on-site control system2320, the system2300, and both. The remote-control system has The system2320has a controller, having a processor and memory, a storage device, a HMI, and a communication module.

The remote-control system2350, the control system2320and both are configured to monitor, calculate, record, store and transmit, information about any and all aspects of the operation of system2301, e.g., flow rates, mass flow, density, temperature, settings of equipment, exhaust conditions, etc. Among of things, these operation aspects would include: mass balance data and information (e.g., kg of flare gas into system, kg of methanal produced, kg of exhaust produced, etc.). This information and data can be and processed to determine and record, preferably real time, GWP information and data, carbon capture information and data, CO2e information and data, for the operation of system2301, and preferably for the real time operation of system2301. This data and information among other things can be used to validate or obtain carbon credits on for example a carbon exchange, or to meet environmental regulatory reporting or monitoring requirements. Preferably this GWP type information is encrypted using block chain, or some other encryption methodology, to insure its validity.

Thus, the control system2320, the remote-control system2350and both can be in control communication with another entity2360. For example, entity2360can be a carbon exchange, it can be a government regulatory agency, it can be a trade regulatory agency, or other entities, such as a class room. It should be noted that while the communications pathways between entity2360and the control can be two-way communication, these pathways do not send or receive any control communication. In this manner the entity2360has no capability to control the system2301. Further, the other information about system2301can be provided to entity2360, as may be needed or required.

Example 25

Turning toFIG.25there is shown a schematic of the architecture of a control communication network for use with the present systems and processes, including the Examples.

Example 26

In situations where the flare gas contains H2S, is preferably is removed prior to processing the flare gas into syngas. Batch And cyclic process technology can be used to remove the H2S, which would include a packed bed with solid adsorbent/scavenger material. Liquid solvents can be used, most commonly an amine like methyl diethanolamine (MDEA) to remove the H2S and CO2. from flare gas streams. A typical configuration is to flow the amine solution through an absorption tower countercurrent to the flare gas. The amine stays in a closed loop and is regenerated with heat.

Example 27

The present systems and processes, including the Examples are operated to convert flare gas into methanol having a purity of about 80% and greater, at least about 85%, at least about 90%, at least about 93%, at least 95%, from about 80% to 95%, and from about 85% to about 90%,

Example 28

A system and process to convert otherwise uneconomic hydrocarbon-based fuel such as flare gas to value-added, easily transported products (such as methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals) using an autonomous, modular system comprising the following elements: (1) a fuel conditioning system to meet requirements of downstream components; (2) an air-breathing gas turbine, modified to operate a rich, partial-oxidation reformer, to produce a syngas mixture with a H2/CO ratio suitable for synthesis of liquids; (3) a combination of integrated heat exchangers, compression system components, and heat exchangers to prepare the syngas for the downstream synthesis reactors; and (4) a downstream synthesis reactor system to produce useful liquid hydrocarbon products.

Example 29

A system and process to convert otherwise uneconomic hydrocarbon-based fuel such as flare gas to value-added, easily transported products (such as methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals) using an autonomous, modular system comprising the following elements: (1) a fuel conditioning system to meet requirements of downstream components; (2) an air-breathing gas turbine, modified to operate a rich, partial-oxidation reformer, to produce a syngas mixture with a H2/CO ratio suitable for synthesis of liquids; (3) a combination of integrated heat exchangers, compression system components, and heat exchangers to prepare the syngas for the downstream synthesis reactors; (4) a downstream synthesis reactor system to produce useful liquid hydrocarbon products; and, (5) a hydrogen recycle loop to improve overall system process performance.

Example 30

The systems and process of Examples 28 and 29, can also have one, or more, or all of the following additional features: (6) optional substantially oxygen-free gas recirculation loop to cool and protect downstream components of the combustor, such as seals, bearings, and secondary cavities; (7) optional O2enrichment of the inlet stream to the gas turbine via membrane separation or partial air separation unit; (8) a recuperator heat exchanger (from (3)) and a turbo expander to recover energy from the high pressure exhaust gas from the downstream synthesis reactor; (9) integration of a closed-loop operating system with custom instrumentation; (10) a cloud-based remote monitoring system, including AI-trained anomaly detection for dynamic preventative maintenance and operations control; (11) optional offtake pathways to utilize byproducts, such as nitrogen, water, and CO2for reinjection, well recompletions, or other purposes; (12) optional water (or steam) injection into the rich combustor to improve H2/CO ratio and reduce carbon build-up on surfaces within the combustor and turbine.

Example 31

Embodiments of these inventions, provide modular systems that can be positioned near sources of uneconomical hydrocarbons (e.g., flare gas), syngas, product gas, and reprocessed gas to convert these materials into higher value products. These inventions will be used to take uneconomic hydrocarbon-based fuels at a well-head (e.g, flare gas) and remote locations that are primarily gaseous hydrocarbons and convert them to a more valuable easily condensable or liquid compounds, such as methanol. One source of source fuel could be associated gas or flare gas, which is produced as a byproduct at oil wells. Another source could be biogas from landfill or anaerobic digesters.

A small-scale plant, targeting 3,000,000 scfd (standard cubic feet per day) of inlet gas. The size of such a plant could vary from 300,000 scfd to 15,000,000 scfd. The plant is incorporated into one or more modular, interconnected skids or containers that are built at a central fabricator shop location and then installed at a field location. A small number of modules comprise the system and when connected at site they form an integrated system. The modular nature of the assembly enables application to remote locations under a range of inlet gas feed volumes, with a minimum of field labor. The modular nature further improves flexibility to deploy or redeploy these assets, reduces initial capital outlay and project financial risks, allows matching of the process throughput to the flare gas supply, and reduces time-to-market by allowing module fabrication and site preparation to occur in parallel.

Example 32

A modular unit having a collection of unit-scale engine reformers and unit-scale MeOH synthesis systems, with no common BOP (balance of plant).

Example 33

A modular unit having a collection of unit-scale engine reformers and unit-scale MeOH synthesis systems, with common BOP.

Example 34

A modular unit having a collection of unit-scale engine reformers that supply a common, unitary MeOH synthesis system.

Example 35

A modular unit having 900 scfd (standard cubic feet per day) of feed gas, (e.g., flare gas).

Example 36

A modular unit having 75,000 scfd of feed gas (e.g., flare gas), scale right-sized for a single engine reformer.

Example 37

A modular reformer stage having 2 or more, 3 or more, at least 5, at least 6, or 2 to 10 reformers. The reformers can be one or more of a gas turbine engine, a combustion box, an internal combustion engine, an otto cycle reciprocating engine, a diesel cycle reciprocating engine and combinations of these. This modular reformer stage can be skid mounted, truck mounted, etc.

Example 38

In an embodiment of the present inventions have a rich-burn reciprocating engine and a synthesis reactor. Unlike a traditional reciprocating engine, the engine runs at rich conditions, up to equivalence ratio of 2.5, so the fuel experiences rich partial oxidation (POX). Additional components include the fuel conditioning system, heat exchangers, compressors, and turbines. The fuel conditioning system separates liquids from gases in the feed stream and removes compounds that can damage the reciprocating engine or synthesis reactor. The heat exchangers and compressors take the syngas mixture at the exit of the reciprocating engine and adjust the temperature and pressure to deliver the target conditions for the synthesis reactor. Within the synthesis sub-system is an optional H2recycle loop. The gas at the exit of the synthesis reactor is heated in a recuperating (e.g., counter-flow) heat exchanger to an elevated temperature and then expanded to ambient conditions.

Example 39

In this embodiment it is preferable that in configuring and operating a syngas engine for achieving preferred engine operation under conditions sufficiently rich to produce a syngas with the desired H2/CO ratio near 2. Even if acceptable operability is achieved with one fixed fuel composition, changes to the fuel composition, which will arise during operation in the field, for example at an oil well, will change the combustion properties and lead to poor engine operation. Thus, the engine has sensors and control systems that detect changes in the combustion properties of the fuel and adapt its parameters to achieve desired engine operation. An engine with a combination of sensing and variable compression ratio can overcome these challenges. A variable compression ratio engine adjusts the compression ratio of an internal combustion engine while the engine is in operation. Variable compression engines allow the volume above the piston at top dead center to be changed.

Example 40

An embodiment of a variable compression ratio engine reformer is through the use of variable valve timing, such as cam phasers. Twin Independent Variable Camshaft Timing (Ti-VCT) is the name given by Ford to engines with the ability to advance or retard the timing of both the intake and exhaust camshafts independently, unlike the original versions of VCT, which only operated on a single camshaft. This allows for improved power and torque, particularly at lower engine RPM, as well as improved fuel economy and reduced emissions

A “cam phaser” is an adjustable camshaft sprocket that can be turned by means of a computer-controlled servo. Rather than operating with a fixed amount of advance or retard, the computer can advance or retard the cam or cams continuously. An embodiment of this application is to enhance drivability at light load and low engine speed (by reducing overlap of the intake and exhaust events to minimize residual dilution), and generate more power at high engine speed (by retarding the intake valve event to increase volumetric efficiency).

For rich combustion operation to produce syngas, when the fuel composition is richer (greater fraction of low-octane constituents) the purpose of retarding the timing of the intake valve event is to retard valve closing sufficiently to shorten the effective compression stroke and thus reduce the effective compression ratio.

When the fuel composition is leaner (greater fraction of high-octane constituents) the purpose of advancing the timing of the intake valves is to advance intake valve opening sufficiently to extend the effective compression strokes and thus increase the effective compression ratio. Operating at a higher effective compression ratio increases pressure and temperature in the combustion chamber and thus extends the rich combustion limit with lean gas.

Example 41

An VVT/cam (variable valve timing/cam) phaser engine that allows, among other things, the compression ratio to be varied according the properties of the incoming fuel for rich combustion to produce syngas.

Example 42

A VVT/cam phaser engine with sensors to detect the in-cylinder combustion behavior under rich conditions and automatically adjust the compression.

This approach can be applied to a two-stroke or four-stroke reciprocating engine.

Example 43

A system and process to convert otherwise uneconomic hydrocarbon-based fuel such as flare gas to value-added, easily transported products (such as methanol, ethanol, ammonia, dimethyl-ether, F-T liquids, and other fuels or chemicals) using an autonomous, modular system comprising the following elements: (1) a fuel conditioning system to meet requirements of downstream components; (2) an air-breathing gas engine, modified to operate a rich, partial-oxidation reformer, to produce a syngas mixture with a H2/CO ratio suitable for synthesis of liquids; (3) a combination of integrated heat exchangers, compression system components, and heat exchangers to prepare the syngas for the downstream synthesis reactors; (4) a downstream synthesis reactor system to produce useful liquid hydrocarbon products; and, (5) a hydrogen recycle loop to improve overall system process performance.

Example 44

A embodiment of a variable compression ratio engine is through an opposed-piston free-piston linear internal combustion engine. A free-piston engine is linear, ‘crankless’ internal combustion engine. The power delivered by the engine is not delivered via a crankshaft, but instead through exhaust gases driving a turbine or a linear motor/generator directly coupled to the pistons to produce electric power.

Example 45

A rich-burn reciprocating engine and a synthesis reactor. Unlike a traditional reciprocating engine, the engine runs at fuel-rich conditions, up to equivalence ratio of 2.5 so the fuel experiences rich partial oxidation (POX). Additional components include the fuel conditioning system, heat exchangers, compressors, and synthesis reactor. The fuel conditioning system separates liquids from gases in the feed stream and removes compounds that can damage the reciprocating engine or synthesis reactor. The heat exchangers and compressors take the syngas mixture at the exit of the reciprocating engine and adjust the temperature and pressure to deliver the target conditions for the synthesis reactor. Within the synthesis sub-system is an H2recycle loop or CO2scrubber for syngas ratio adjustment. Optionally, the gas at the exit of the synthesis processes is heated in a recuperating (e.g., counter-flow) heat exchanger to an elevated temperature and then expanded to ambient pressure, thus providing shaft work for compression of the synthesis gas.

Example 46

The embodiments of the systems of the above Examples are operated in a carbon neutral-to-negative manner, producing and releasing less than or equal to zero CO2e from a lifecycle perspective.

Example 47

One or more of the systems of the above Examples are placed at an oil field having a large number of oil wells. The flare gas from these oil wells is captured at the wellhead of each of the oil wells and flows in a piping and manifold system to the units where it is processed into an end product, such as methanol.

Example 48

One or more of the systems of the above Examples are placed at a livestock production farm, handling or production facility. The methane-rich biogas from anaerobic digestion of the livestock manure is collected and processed by the systems into an end product, such as methanol.

Example 49

One or more of the systems of the above Examples are placed at municipal waste-water treatment facilities where anaerobic digesters produce fuel for the syngas unit, and methanol produced by the process is consumed by the denitrification process as part of the treatment process. This approach results in a local and circular process for waste water treatment.

Example 50

In an oil filed have several oil, gas or both wells, (e.g., 5 wells, 10 wells, 20 wells or more) piping and distribution headers are used to collect and transfer the flare gas from each of the wells, to one or of the present waste gas, e.g., flare gas, processing units, such as one or more of systems of the above Examples.

Example 51

Hydrocarbon production activity, e.g., exploration, drilling, workover and completion of a hydrocarbon well, e.g., an oil or gas well, can including the planning for, and use of, the present systems and methods, including the systems of the above Examples. In this manner the overall effect of the hydrocarbon production activity on global warming, e.g., GWP, can be mitigated or reduced. Thus, the use of the present systems and methods, including the Examples, can be included in the planning hydrocarbon activity, as well as, in the obtaining of regulatory approval for such activity.

Example 52

The present systems and methods, including the systems and methods of the Examples, where the source of the flare gas is one, or more than one, of a hydrocarbon well, an oil well, an unconventional oil well, a conventional oil well, an off-shore well, or an on-shore well.

Example 53

T The present systems and methods, including the systems and methods of the Examples, where the source of the flare gas is selected from the group consisting of petrochemical processing, refining, landfills, waste water treatment, and livestock.

Example 54

The embodiments of the systems of the above Examples are operated in an energy positive manner, producing more power, in the form of electricity, than is required to operate the system.

Headings and Embodiments

It should be understood that the use of headings in this specification is for the purpose of clarity, reference, and is not limiting in any way. Thus, the processes compositions, and disclosures described under a heading should be read in context with the entirely of this specification, including the various Examples. The use of headings in this specification should not limit the scope of protection afforded the present inventions.

It is noted that there is no requirement to provide or address the theory underlying the novel and groundbreaking production rates, performance or other beneficial features and properties that are the subject of, or associated with, embodiments of the present inventions. Nevertheless, various theories are provided in this specification to further advance the art in this important area, and in particular in the important area of hydrocarbon exploration and production. These theories put forth in this specification, and unless expressly stated otherwise, in no way limit, restrict or narrow the scope of protection to be afforded the claimed inventions. These theories many not be required or practiced to utilize the present inventions. It is further understood that the present inventions may lead to new, and heretofore unknown theories to explain the conductivities, fractures, drainages, resource production, and function-features of embodiments of the methods, articles, materials, devices and system of the present inventions; and such later developed theories shall not limit the scope of protection afforded the present inventions.

The various embodiments of devices, systems, activities, methods and operations set forth in this specification may be used with, in or by, various processes, industries and operations, in addition to those embodiments of the Figures and disclosed in this specification. The various embodiments of devices, systems, methods, activities, and operations set forth in this specification may be used with: other processes industries and operations that may be developed in the future: with existing processes industries and operations, which may be modified, in-part, based on the teachings of this specification; and with other types of gas recovery systems and methods. Further, the various embodiments of devices, systems, activities, methods and operations set forth in this specification may be used with each other in different and various combinations. Thus, for example, the configurations provided in the various embodiments of this specification may be used with each other. For example, the components of an embodiment having A, A′ and B and the components of an embodiment having A″, C and D can be used with each other in various combination, e.g., A, C, D, and A. A″ C and D, etc., in accordance with the teaching of this specification. Thus, the scope of protection afforded the present inventions should not be limited to a particular embodiment, configuration or arrangement that is set forth in a particular embodiment, example, or in an embodiment in a particular Figure.

The invention may be embodied in other forms than those specifically disclosed herein without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.