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EP-4121638-B1 - POWER AUGMENTATION FOR A GAS TURBINE

EP4121638B1EP 4121638 B1EP4121638 B1EP 4121638B1EP-4121638-B1

Inventors

  • LARSEN-SKAANDERUP, John
  • KING, Keith, Gaylon

Dates

Publication Date
20260506
Application Date
20210312

Claims (15)

  1. A chemical processing plant comprising: a furnace (202), a process compressor (210) configured to provide compressed air to a secondary reformer (161), a gas turbine engine (212) configured to drive the process compressor (210), wherein the gas turbine engine generates an exhaust gas, and wherein at least a portion of the exhaust gas is provided to the furnace (202) as combustion air, and characterized in that it comprises: a booster compressor (302) configured to provide compressed air to a turbo compressor (214) of the gas turbine engine (212).
  2. The chemical processing plant of claim 1, wherein the booster compressor (302) is further configured to provide compressed air to the process compressor (210), and/or to provide compressed air to the furnace (202), and/or to provide compressed air to both the process compressor (210) and to the reforming furnace (202).
  3. The chemical processing plant of claims 1 or 2, further comprising an intercooler (304) configured to cool the compressed air provided by the booster compressor (302) to the turbo compressor (214) of the gas turbine engine (212).
  4. The chemical processing plant of any of claims 1-3, wherein the booster compressor (302) is powered by an electric motor or by a steam turbine.
  5. The chemical processing plant of claim 2, further comprising an intercooler (304) configured to cool the compressed air provided by the booster compressor (302) to the turbo compressor (214) of the gas turbine engine (212) and to the process compressor (210).
  6. The chemical processing plant of any of claims 1-5, wherein the furnace (202) is a furnace of a primary reformer configured to convert hydrocarbon in the presence of steam to form syngas.
  7. The chemical processing plant of any of claims 1-6, wherein the process compressor (210) is configured to provide compressed air feed to an ammonia process.
  8. An ammonia synthesis system comprising the chemical processing plant of claim 1, further comprising: a reformer comprising the furnace (202), wherein the reformer is configured to convert natural gas in the presence of steam to form syngas, an ammonia process comprising the secondary reformer (161) configured to react hydrogen from the syngas with nitrogen from a process air feed to form ammonia, wherein the gas turbine engine (212) comprises a turbo compressor (214), a combustor (216), and a power turbine (220).
  9. The system of claim 8, wherein the booster compressor (302) is further configured to provide compressed air to the process compressor (210), and/or to provide compressed air to the furnace (202), and/or to provide compressed air to the process compressor (210) and to the furnace (202).
  10. The system of any of claims 8-9, wherein the booster compressor (302) is powered by an electric motor or by a steam turbine.
  11. The system of any of claims 8-10, further comprising an intercooler (304) configured to cool the compressed air provided by the booster compressor (302) to the turbo compressor (214) of the gas turbine engine (212).
  12. A method of increasing the capacity of an ammonia-producing system, wherein the ammonia-producing system comprises: a reformer comprising a furnace (202), wherein the reformer is configured to convert natural gas in the presence of steam to form syngas, an ammonia process comprising a secondary reformer (161) configured to react hydrogen from the syngas with nitrogen from a compressed air feed to form ammonia, a process compressor (210) configured to provide the compressed air feed to the secondary reformer (161), and a gas turbine engine (212) configured to drive the process compressor and to generate an exhaust gas, wherein the gas turbine engine comprises a turbo compressor (214) a combustor (216,) and a power turbine (218), and is configured so that at least a portion of the exhaust gas of the gas turbine engine is provided to the furnace to provide combustion air for the furnace, the method characterized in that it comprises: using a booster compressor (302) configured to provide compressed air to the turbo compressor of the gas turbine engine.
  13. The method of claim 12, further comprising using the booster compressor to provide compressed air to one or more of the process compressor and the furnace.
  14. The method of claims 12 or 13, further comprising powering the booster compressor by an electric motor or by a steam turbine.
  15. The method of any of claims 12-14, further comprising using an intercooler configured to cool the compressed air provided by the booster compressor to the turbo compressor of the gas turbine engine.

Description

FIELD OF THE INVENTION This application relates to boosting the power of a gas turbine, and more particularly, to augmenting a gas turbine used in an ammonia production plant. INTRODUCTION Gas turbines are often used for energy generation, for example, to drive an electric generator, as illustrated schematically in Figure 1A. For energy generation, compressed air and fuel are combusted and the combustion gas is used to provide rotational power that drives the electric generator. The hot turbine exhaust gas is often provided to a waste heat recovery system in an attempt to increase the efficiency of the overall system, for example, by using the heat of the exhaust to generate steam to provide further work, such as powering steam turbines or the like. This use of the exhaust can be seen as remedial, i.e., it is an attempt to mitigate the fact that the gas turbine lacks efficiency. For electric generation, the higher the efficiency of the turbine, the better. In other words, we would like to have a turbine that produces the maximum rotational power (for driving a generator) with the least amount of hot exhaust production. In a perfect (but unobtainable) world, all of the combustion energy would be converted to rotational power and no hot exhaust would be produced. That consideration has driven gas turbine development over the past decades, resulting in gas turbines that are highly efficient (e.g., about 60 %), due to advances in materials and design. Gas turbines can also be used to drive equipment, such as compressors, for example in certain petrochemical processes/plants. One example is schematically illustrated in Figure 1B. In the illustrated example, the gas turbine provides rotational power to drive a compressor, which provides reactant, such as process air to a reactor. The exhaust gas of the turbine is used to provide combustion air to a reforming furnace, which in the illustrated example, is used for a reformer. An example of such a process is a Haber-Bosch ammonia process, and specifically, the Purifier™ process owned by the assignee of the instant application, which is discussed in more detail below. Notice that in the system illustrated in Figure 1B, the exhaust gas is not simply an inefficiency that must be dealt with; it is an integral part of the process. The capacity of the furnace must be balanced with the size of the compressor, which is determined by the requirement of the reactor capacity. If the gas turbine is too efficient (i.e., it does not provide adequate exhaust to run the furnace), the overall process suffers because the furnace and the compressor are out of balance. There is a need in the art for boosting the power output of a gas turbine that is used to drive a compressor in a process, such as illustrated in Figure 1B. However, simply using a more efficient gas turbine is not the optimal solution, for the reasons discussed above. US Patent application No. 2011/100007 A1 describes to a method and apparatus for recovering power from the gaseous stream produced by an oxidation reaction. The gaseous stream from the oxidation reaction is heated and energy is recovered through a gas turbine. The compressor stage of the gas turbine compresses the oxidant feed to the reactor thereby at least partially offsetting the cost of providing the high temperature and pressure reaction conditions in the reactor. Improved control of the power recovery system is obtained by optimizing the efficiency of the gas turbine by feeding gas to the gaseous stream to modulate the flow of gas to the turbine relative to the compressor discharge flow in order to compensate for the consumption of oxidant in the reactor. WO2012/106095 A1 discloses another ammonia production plant of the prior art. SUMMARY Disclosed herein is a chemical processing plant as defined in claim 1, comprising: a furnace, a process compressor configured to provide compressed air to a secondary reformer, a gas turbine engine configured to drive the process compressor, wherein the gas turbine engine generates an exhaust gas, and wherein at least a portion of the exhaust gas is provided to the furnace as combustion air for the furnace, and a booster compressor configured to provide compressed air to the gas turbine engine (for example, to a turbo compressor of the gas turbine engine). According to some embodiments, the booster compressor is further configured to provide compressed air to the process compressor. According to some embodiments, the booster compressor is further configured to provide compressed air to the furnace. According to some embodiments, the booster compressor is further configured to provide compressed air to the process compressor and to the reforming furnace. According to some embodiments, the booster compressor is powered by an electric motor. According to some embodiments, the booster compressor is powered by a steam turbine. According to some embodiments, the chemical processing plant further comprises an intercooler