Reduced carbon ammonia generation process

Abstract

A method of generating ammonia while minimizing the generation of carbon dioxide. The method uses the waste of other processes as inputs to the chemical process. It also uses the energy of other processes to catalyze the process.

Claims

1. A poly-generation method of creating ammonia comprising: A) extracting water from a high-temperature exhaust source, B) generating electricity from thermal energy in a high-temperature exhaust source, I) using generated electricity to separate hydrogen from water extracted from a high-temperature exhaust source, II) using generated electricity to extract nitrogen from air, III) using generated electricity to pressurize a reaction chamber where ammonia is created using the Haber Bosch process, C) extracting heat from a high-temperature exhaust source, and I) using extracted heat to heat a reaction chamber where ammonia is created using the Haber Bosch process.

2. The method of claim 1 further comprising: A) feeding exhaust gasses into a biological process which produces ethanol from carbon dioxide.

3. The method of claim 2 further comprising: A) using heat extracted from the high-temperature exhaust source to maintain the temperature for the ethanol producing biological process.

4. A poly-generation apparatus comprising: A) a high-temperature exhaust source, B) a means for generating electricity from the high-temperature exhaust source, C) an ammonia reaction chamber configured to generate ammonia at high temperature and pressure, and D) a means for transferring heat from the high-temperature exhaust source to the ammonia reaction chamber.

5. The poly-generation apparatus of claim 4 further comprising: A) means for extracting water from a high-temperature exhaust source.

6. The poly-generation apparatus of claim 5 further comprising: A) means for extracting hydrogen for the ammonia reaction chamber, at least in part, from water extracted from the high-temperature exhaust source.

7. The poly-generation apparatus of claim 6 further comprising: A) means for extracting nitrogen for the ammonia reaction chamber from air using, at least in part, electricity generated from the high-temperature exhaust source.

8. The poly-generation apparatus of claim 7 further comprising: A) means for creating ethanol from exhaust gasses.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0019] FIG. 1 depicts the conventional Haber-Bosch process of manufacturing ammonia.

[0020] FIG. 2 depicts a conventional natural gas pipeline compressor station.

[0021] FIG. 3 depicts one embodiment of the applicant's improved process.

DETAILED DESCRIPTION OF THE INVENTION

[0022] The applicant's invention is an improved poly-generation process preferably using gas turbine engines. In a preferred embodiment, the co-generation process 300 is used to manufacture ammonia. The process centers around harnessing the energy, and waste energy, from gas turbine (or internal combustion) compressor stations along natural gas transmission pipelines to generate ammonia through the Haber-Bosch process. Gas pipeline compressor stations are geographically dispersed throughout the country. Many are located away from urban centers, in or near agricultural areas. Although compressor stations are not particularly loud and do not generally have toxic emissions, the need to locate them at intervals along transmission lines naturally results in them being geographically dispersed. Natural gas fueled compressors are particularly desirable for gas pipeline compressor stations since the pipeline which the compressor station serves carries fuel for the compressor thereby reducing the infrastructure required to power the compressor station. Although natural gas powered gas turbine compressors are made by a variety of companies with a variety of specifications, one example gas turbine used for compressor station applications is a Siemens SGT-700. The Siemens SGT-700 is rated for a compression ratio of 18.7:1, has an exhaust gas flow of 95.0 kg/s (209.41 b/s), has an exhaust temperature: 533 C. (991 F.), and is rated to be approximately 38% efficient (depending on whether it is used to generate electricity or mechanical energy).

[0023] The chemical inputs to the Haber-Bosch process are generally methane, water, air, hydrogen, and nitrogen. Depending on the exact process used, inputs for subsequent stages may be derived from other precursor inputs (e.g. hydrogen from methane) or may be discrete inputs. The energy inputs to the Haber-Bosch process are temperature and pressure. The Haber-Bosch process is generally performed at a temperature of approximately 400-500 C. The water/gas shift step to remove water from methane also generally requires a temperature of approximately 500 C. Underutilized, or un-utilized, outputs of a conventional gas turbine compressor station include: heat 304 which is exchanged into the atmosphere, water vapor which is vented into the atmosphere, nitrogenous gasses 302 which are vented into the atmosphere, and kinetic energy (exhaust pressure) which is not captured.

[0024] The applicant's process may consume chemicals being pressurized (consumptively), or may operate only as a poly-generation process. When operating as a non-consumptive poly-generation process, energy generated in the process may be used to generate hydrogen through electrolysis of water 310 or pyrolysis of organic matter or suitable inorganic matter to produce hydrogen. This hydrogen may be used as a chemical input to the Haber-Bosch process 318, burned to release energy, or for any other beneficial operation in the process.

[0025] In an alternative process, hydrogen is generated from a sufficiently homogeneous material around which a hydrogen extraction processes may be optimized. Exemplary materials include biomasses including, but not limited to, wood fibers such as wood chips and sawdust, fibrous agricultural residuals such as straw, human and/or animal fecal biomass. Other exemplary materials include waste or recycled materials, such as plastics, which may be manually collected or otherwise harvested when they occur in sufficiently high quantities (such as cleaned from waterways or oceans).

[0026] A variety of pyrolysis processes are well known in the art including, but not limited to, microwave pyrolysis, and are suited to the applicant's novel process. Microwave pyrolysis is particularly well adapted to aspects of the applicant's process as microwave pyrolysis reactions often occur at temperatures which favor the production of gases rather than liquids. Microwave pyrolysis is well known to be suited to extracting energy from tires, plastics, and biomasses.

[0027] In the applicant's process, the heat removed from the gas in the gas cooling system and/or exhaust 304 of the compressor station is that heat 316 transmitted into the hydrogen and nitrogen being fed into the ammonia reactor 318 and/or the water/gas shift chamber. This heat transfer may be through any of a variety of heat exchange devices and processes which are well known in the art and may be direct or indirect. In a preferred embodiment, the heat exchanger is a radial flow gas/gas heat exchanger. This use of exhaust temperature to generate electricity 308 and heat to heat other processes 316 is the first use of waste energy from the compressor station (co-generation). Electricity generated from exhaust heat may be used to extract nitrogen from air 312 and/or power a compressor 314 to pressurize the Haber Bosch reaction chamber 318. In an alternative embodiment, heat from the exhaust is exchanged into either or both of the hydrogen and nitrogen being fed into the ammonia reactor 318 and/or the Water/Gas shift chamber. In an alternative embodiment additional heat may be added to the system from an additional source. In this alternative embodiment, the heat may be collected through heat transfer solar. In an agricultural, or agricultural adjacent location these heat transfer solar collectors may be installed on the corners of pivots (land not reached by center pivot irrigation systems).

[0028] In an alternative embodiment of the applicant's process, the exhaust flow from the gas turbine powers a turbocharger. However, rather than compressing gas which is input into the engine to which the turbocharger is attached, the turbocharger may be used to compress hydrogen and nitrogen which is being fed into the ammonia reactor. The turbo charger may alternatively be used to pressurize a PSA process for concentrating nitrogen from air. The turbocharger may alternatively be used to pressurize gas at the input stage of the ammonia pressure vessel. This use of exhaust flow is the second use of waste energy from the compressor station (poly-generation).

[0029] In the applicant's process, the ammonia generated through the Haber-Bosch process 320 is stored in existing nurse tanks which are already located in the area for agricultural use. In an alternative embodiment, one or more Low Pressure Storage Tanks (LPSTs) may be constructed or used to store the ammonia created through the Haber-Bosch process. When LPSTs are used, electricity generated from the improved process, or electrical power from another source, such as the electrical grid, may be used to refrigerate the LPST.

[0030] In the applicant's process the chemicals in the compressor exhaust are further used as an input to a downstream process. In one preferred embodiment, water vapor is removed from compressor exhaust 306. In a preferred embodiment, carbon-rich exhaust gasses are fed into a gas fermentation system where specific microbes generate ethanol (C.sub.2H.sub.5OH) from the exhaust gas thereby reducing the amount of greenhouse gasses released into the atmosphere from the compressor. In an alternative embodiment, the carbon rich gasses are generated by organic material (biomass) such as animal excrement or straw.

[0031] This ethanol may be used for a variety of applications. The ethanol may be sold on the open market, may be fed back into the system (to generate heat), may be used as a storage medium for precursor chemicals (particularly hydrogen) which is then separated from the ethanol for use in the process, or may be consumed locally (to power an internal combustion engine).

[0032] In another embodiment, the co-generation process is used to generate electricity 308. The majority of energy input into power generation through the Rankine cycle is to heat the liquid. Water is the most frequently used liquid since it is non-toxic, plentiful, and inexpensive. However, other liquids may be used for different temperature operating ranges. The non-idealized Rankine cycle (real power-plant cycle), when performed with water, generally operates with steam heated to approximately 400-500 C. Therefore, it is well suited to operation with the exhaust of a gas turbine engine (alternatively an organic Rankine cycle is used).

[0033] In the present process, heat from the exhaust of the gas turbine engine is transmitted into water/water vapor to power a steam engine generating electricity. This heat transfer may be through any of a variety of heat exchange devices and processes which are well known in the art and may be direct or indirect. In an alternative embodiment, heat removed from the gas in the gas cooling system of the compressor station is transmitted into water/water vapor to power a steam engine generating electricity. In a preferred embodiment, water being used for agricultural irrigation is used to chill the condenser of the steam engine providing a cool cold source providing a high temperature differential between the steam turbine entry temperature and the steam condenser temperature.

[0034] Control System

[0035] In a preferred embodiment of the applicant's invention, an electronic automatic control system is employed to manage which energy sources are used for which purpose(s). Inputs to the control system include, but are not limited to, the water requirements of various agricultural consumers (plant and/or animal), the present and/or predicted future prices of process products including water, hydrogen, nitrogen, methane and/or natural gas, ammonia, ethanol, plant and/or animal crops, and/or electricity. The control system is configured to take into account the various input and output prices and determine which sub-processes to operate based on whether and which are most profitable.

[0036] Pressure created/captured from the system is useful when creating ammonia to 1) compress gas prior to Gas Separation in the Haber-Bosch Process, 2) Compress N.sub.2 and H.sub.2 gasses prior to entry into the Ammonia Reactor, and/or 3) Compress recycled N.sub.2 and H.sub.2 prior to re-entry into the Ammonia Reactor. Pressure created/captured from the system is useful when creating ethanol to compress gas fed into the fermentation reactor.

[0037] High temperatures created/captured from the system are useful when creating ammonia to 1) Heat N.sub.2 and H.sub.2 following Gas Separation in the Haber-Bosch process and/or 2) to convert CO into CO.sub.2 in a water-gas shift process prior to Gas Separation in the Haber-Bosch process. High temperatures created/captured from the system are useful when creating electricity to heat water for a steam turbine.

[0038] Low temperatures created/captured from the system are useful when creating ammonia to condense NH.sub.3, N.sub.2, and H.sub.2 coming out of the heat exchanger attached to the ammonia reactor. Low temperatures created/captured from the system are useful when creating electricity to condense the cool side of Rankine cycle for steam turbine electrical generation.

[0039] Electrical energy created/captured from the system is useful when creating ammonia for 1) LPST refrigeration, 2) heaters for any high temperature operation, 3) compressors for any high pressure operation, 4) refrigeration for any low temperature operation, and/or 5) pumps for any fluid movement operation. Electrical energy created/captured from the system is useful when creating ethanol for 1) heaters for any high temperature operation, 2) compressors for any high pressure operation, 3) refrigeration for any low temperature operation, and/or 4) pumps for any fluid movement operation. Electrical energy created/captured from the system is useful in agricultural applications to pump water. Electrical energy created/captured from the system is also useful as a market product.

[0040] Ammonia created/captured from the system is useful when creating ethanol is useful for 1) combustion for heat for high-temperature reactions, 2) storing hydrogen. Ammonia created/captured from the system is useful when creating electricity for combustion for heat for high-temperature reactions. Ammonia created/captured from the system are useful in agricultural applications for 1) combustion for transportation and/or 2) as fertilizer. Ammonia created/captured from the system is also useful as a market product.

[0041] Ethanol created/captured from the system is useful when creating electricity to help condense steam in a turbine for the Rankine cycle. Ethanol created/captured from the system is also useful as a market product. Ethanol created/captured from the system is useful in agricultural applications for transportation. Ethanol created/captured from the system is also useful for reaction promotion for burning ammonia in an internal combustion engine.

SEQUENCE LISTING

[0042] Not Applicable