A Novel Approach of Retrofitting a Combined Cycle With Post Combustion CO2 Capture

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Klas Jonshagen ◽  
Nikolett Sipöcz ◽  
Magnus Genrup
Keyword(s):  
Gas Turbine ◽  
Carbon Capture ◽  
Gas Flow ◽  
Carbon Capture And Storage ◽  
Main Tool ◽  
Pressure Level ◽  
Combined Cycle ◽  
Pressurized Water ◽  
Novel Approach ◽  
Gas Turbine Exhaust

Most state-of-the-art natural gas-fired combined cycle (NGCC) plants are triple-pressure reheat cycles with efficiencies close to 60%. However, with carbon capture and storage, the efficiency will be penalized by almost 10% units. To limit the energy consumption for a carbon capture NGCC plant, exhaust gas recirculation (EGR) is necessary. Utilizing EGR increases the CO2 content in the gas turbine exhaust while it reduces the flue gas flow to be treated in the capture plant. Nevertheless, due to EGR, the gas turbine will experience a different media with different properties compared with the design case. This study looks into how the turbomachinery reacts to EGR. The work also discusses the potential of further improvements by utilizing pressurized water rather than extraction steam as the heat source for the CO2 stripper. The results show that the required low-pressure level should be elevated to a point close to the intermediate-pressure to achieve optimum efficiency, hence, one pressure level can be omitted. The main tool used for this study is an in-house off-design model based on fully dimensionless groups programmed in the commercially available heat and mass balance program IPSEPRO. The model is based on a GE 109FB machine with a triple-pressure reheat steam cycle.

Optimal Combined Cycle for CO2 Capture With EGR

2010 ◽  
Author(s):  
Klas Jonshagen ◽  
Nikolett Sipo¨cz ◽  
Magnus Genrup
Keyword(s):  
Gas Turbine ◽  
Carbon Capture ◽  
Gas Flow ◽  
Carbon Capture And Storage ◽  
Main Tool ◽  
Pressure Level ◽  
Combined Cycle ◽  
Pressurized Water ◽  
Reheat Steam ◽  
Gas Turbine Exhaust

Most state-of-the-art natural gas fired combined cycle (NGCC) plants are triple-pressure reheat cycles with efficiencies close to 60 percent. However, with carbon capture and storage, the efficiency will be penalized by almost 10 percent units. To limit the energy consumption for a carbon capture NGCC plant, exhaust gas recirculation (EGR) is necessary. Utilizing EGR increases the CO2 content in the gas turbine exhaust while it reduces the flue gas flow to be treated in the capture plant. Nevertheless, due to EGR, the gas turbine will experience a different media with different properties compared to the design case. This study looks into how the turbo machinery reacts to EGR. The work also discusses the potential of further improvements by utilizing pressurized water rather than extraction steam as the heat source for the CO2 stripper. The results show that the required low-pressure level should be elevated to a point close to the intermediate-pressure to achieve optimum efficiency; hence one pressure level can be omitted. The main tool used for this study is an in-house off-design model based on fully dimensionless groups programmed in the commercially-available heat and mass balance program IPSEpro. The model is based on a GE 109FB machine with a triple-pressure reheat steam cycle.

A Novel Intake Concept for Flue Gas Recirculation to Enhance CCS in an Industrial Gas Turbine

2014 ◽  
Author(s):  
Robin C. Payne ◽  
Manuel Arias ◽  
Vassilis Stefanis
Keyword(s):  
Gas Turbine ◽  
Flue Gas ◽  
Carbon Capture ◽  
Low Cost ◽  
Co2 Concentration ◽  
Combined Cycle ◽  
Flue Gas Recirculation ◽  
Novel Approach ◽  
Inlet Conditions ◽  
Gas Recirculation

For the next generation of combined cycles, it is essential to not only improve the performance of a gas turbine combined cycle power plant, but also reduce its environmental impact. Flue Gas Recirculation is a useful method to increase CO2 concentration in the exhaust stream, allowing a smaller and lower cost carbon capture plant than would be required without FGR. Conventional FGR methodology requires a complex mixer with long mixing section to achieve acceptable inlet conditions for the GT compressor. A novel approach is presented, where the method of introducing the flue gas to the compressor has been substantially rethought to provide a low cost and robust FGR solution for carbon capture and sequestration applications. In this paper, CFD analysis of the flow in the intake section is used to demonstrate the operating principle of such a method, and cycle modelling calculations to compare its performance with a more conventional approach.

New Possibilities for Combined Cycles Through Advanced Steam Technology

2002 ◽  
Author(s):  
Kristin Jordal ◽  
Jens Fridh ◽  
La´szlo´ Hunyadi ◽  
Mikael Jo¨nsson ◽  
Ulf Linder
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Enhancement ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Pressurized Water ◽  
Exhaust Duct ◽  
Combined Cycles ◽  
Gas Turbine Exhaust ◽  
Efficient Power

In order to improve the performance of the combined cycle, much effort has been spent over the past decade on increasing gas turbine performance. As a contrast to this, the present work focuses on possibilities for combined cycle performance enhancement through present and expected future steam cycle and boiler technology. The use of various heat recovery steam generators, (single and dual pressure) with or without supplementary firing are studied, in combination with steam turbine admission temperatures of up till 973 K. Supplementary firing is applied either in the entire gas turbine exhaust duct or in part of it, in a so-called split-stream boiler (SSB). Furthermore, the flashing of pressurized water from an overdimensioned economiser in the SSB, to produce steam for gas turbine vane cooling is studied. Many of the supplementary fired cycles studied are found to have a thermal efficiency superior of the unfired cycles, based on the same gas turbines. Hence, available steam technology and expected future development mean that most of the cycles studied are realistic concepts that merit further attention in the quest for more efficient power production.

Combined Cycles With CO2 Capture: Two Alternatives for System Integration

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Nikolett Sipöcz ◽  
Mohsen Assadi
Keyword(s):  
Co2 Capture ◽  
System Integration ◽  
Carbon Capture ◽  
Gas Flow ◽  
Carbon Capture And Storage ◽  
Combined Cycle ◽  
Plant Performance ◽  
Exhaust Gas ◽  
Steam Extraction ◽  
Two Alternatives

As carbon capture and storage technology has grown as a promising option to significantly reduce CO2 emissions, system integration and optimization claim an important and crucial role. This paper presents a comparative study of a gas turbine cycle with postcombustion CO2 separation using an amine-based absorption process with monoethanolamine. The study has been made for a triple pressure reheated 400 MWe natural gas-fuelled combined cycle with exhaust gas recirculation (EGR) to improve capture efficiency. Two different options for the energy supply to the solvent regeneration have been evaluated and compared concerning plant performance. In the first alternative heat is provided by steam extracted internally from the bottoming steam cycle, while in the second option an external biomass-fuelled boiler was utilized to generate the required heat. With this novel configuration the amount of CO2 captured can be even more than 100% if the exhaust gas from the biofuelled boiler is mixed and cleaned together with the main exhaust gas flow from the combined cycle. In order to make an unprejudiced comparison between the two alternatives, the reduced steam turbine efficiency has been taken into consideration and estimated, for the alternative with internal steam extraction. The cycles have been modeled in the commercial heat and mass balance program IPSEPRO™ using detailed component models. Utilizing EGR can double the CO2 content of the exhaust gases and reduce the energy need for the separation process by approximately 2% points. Using an external biomass-fuelled boiler as heat source for amine regeneration turns out to be an interesting option due to high CO2 capture effectiveness. However the electrical efficiency of the power plant is reduced compared with the option with internal steam extraction. Another drawback with the external boiler is the higher investment costs but nevertheless, it is flexibility due to the independency from the rest of the power generation system represents a major operational advantage.

Combined Cycles With CO2 Capture: Two Alternatives for System Integration

2009 ◽  
Author(s):  
Nikolett Sipo¨cz ◽  
Mohsen Assadi
Keyword(s):  
Co2 Capture ◽  
System Integration ◽  
Carbon Capture ◽  
Gas Flow ◽  
Carbon Capture And Storage ◽  
Combined Cycle ◽  
Plant Performance ◽  
Exhaust Gas ◽  
Steam Extraction ◽  
Two Alternatives

As Carbon Capture and Storage (CCS) technology has grown as a promising option to significantly reduce CO2 emissions, system integration and optimization claim an important and crucial role. This paper presents a comparative study of a gas turbine cycle with post-combustion CO2 separation using an amine-based absorption process with Monoethanolamine (MEA). The study has been made for a triple pressure reheated 400 MWe natural gas-fuelled combined cycle (NGCC) with exhaust gas recirculation (EGR) to improve capture efficiency. Two different options for the energy supply to the solvent regeneration have been evaluated and compared concerning plant performance. In the first alternative heat is provided by steam extracted internally from the bottoming steam cycle while in the second option an external biomass-fuelled boiler was utilized to generate the required heat. With this novel configuration the amount of CO2 captured can be even more than 100% if the exhaust gas from the bio-fuelled boiler is mixed and cleaned together with the main exhaust gas flow from the combined cycle. In order to make an unprejudiced comparison between the two alternatives, the reduced steam turbine efficiency has been taken into consideration and estimated, for the alternative with internal steam extraction. The cycles have been modelled in the commercial heat and mass balance programme IPSEpro™ using detailed component models. Utilizing EGR can double the CO2 content of the exhaust gases and reduce the energy need for the separation process by approximately 2%-points. Using an external biomass-fuelled boiler as heat source for amine regeneration, turns out to be an interesting option due to high CO2 capture effectiveness. However the electrical efficiency of the power plant is reduced compared to the option with internal steam extraction. Another drawback with the external boiler is the higher investment costs but nevertheless, it is flexibility due to the independency from the rest of the power generation system represents a major operational advantage.

scholarly journals Gas Turbine Heat Recovery Steam Generators for Combined Cycles Natural or Forced Circulation Considerations

1988 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Natural Circulation ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Steam Generators ◽  
Forced Circulation ◽  
Gas Turbine Exhaust

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.

Advanced and Transformational Hydrogen Turbines for Integrated Gasification Combined Cycles

2016 ◽  
Author(s):  
Walter W. Shelton ◽  
Robin W. Ames ◽  
Richard A. Dennis ◽  
Charles W. White ◽  
John E. Plunkett ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Carbon Capture ◽  
Combined Cycle ◽  
Plant Performance ◽  
System Level ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Reference Case ◽  
Advanced Technologies ◽  
Integrated Gasification

The U.S. Department of Energy’s (DOE) provides a worldwide leadership role in the development of advanced fossil fuel-based energy conversion technologies, with a focus on electric power generation with carbon capture and storage (CCS). As part of DOE’s Office of Fossil Energy, the National Energy Technology Laboratory (NETL) implements research, development, and demonstration (RD&D) programs that address the challenges of reducing greenhouse gas emissions. To meet these challenges, NETL evaluates advanced power cycles that will maximize system efficiency and performance, while minimizing CO2 emissions and the costs of CCS. NETL’s Hydrogen Turbine Program has sponsored numerous R&D projects in support of Advanced Hydrogen Turbines (AHT). Turbine systems and components targeted for development include combustor technology, materials research, enhanced cooling technology, coatings development, and more. The R&D builds on existing gas turbine technologies and is intended to develop and test the component technologies and subsystems needed to validate the ability to meet the Turbine Program goals. These technologies are key components of AHTs, which enable overall plant efficiency and cost of electricity (COE) improvements relative to an F-frame turbine-based Integrated Gasification Combined Cycle (IGCC) reference plant equipped with carbon capture (today’s state-of-the-art). This work has also provided the basis for estimating future IGCC plant performance based on a Transformational Hydrogen Turbine (THT) with a higher turbine inlet temperature, enhanced material capabilities, reduced air cooling and leakage, and higher pressure ratios than the AHT. IGCC cases from using system-level AHT and THT gas turbine models were developed for comparisons with an F-frame turbine-based IGCC reference case and for an IGCC pathway study. The IGCC pathway is presented in which the reference case (i.e. includes F-frame turbine) is sequentially-modified through the incorporation of advanced technologies. Advanced technologies are considered to be either 2nd Generation or Transformational, if they are anticipated to be ready for demonstration by 2025 and 2030, respectively. The current results included the THT, additional potential transformational technologies related to IGCC plant sections (e.g. air separation, gasification, gas cleanup, carbon capture, NOx reduction) are being considered by NETL and are topics for inclusion in future reports.

Sequential Combustion in Ansaldo Energia Gas Turbines: The Technology Enabler for CO2-Free, Highly Efficient Power Production Based on Hydrogen

2020 ◽  
Author(s):  
Andrea Ciani ◽  
John P. Wood ◽  
Anders Wickström ◽  
Geir J. Rørtveit ◽  
Rosetta Steeneveldt ◽  
...  
Keyword(s):  
Power Generation ◽  
Free Energy ◽  
Gas Turbines ◽  
Carbon Capture ◽  
Power Plants ◽  
Carbon Capture And Storage ◽  
Combined Cycle ◽  
Fuel Flexibility ◽  
Combustion Technology ◽  
And Storage

Abstract Today gas turbines and combined cycle power plants play an important role in power generation and in the light of increasing energy demand, their role is expected to grow alongside renewables. In addition, the volatility of renewables in generating and dispatching power entails a new focus on electricity security. This reinforces the importance of gas turbines in guaranteeing grid reliability by compensating for the intermittency of renewables. In order to achieve the Paris Agreement’s goals, power generation must be decarbonized. This is where hydrogen produced from renewables or with CCS (Carbon Capture and Storage) comes into play, allowing totally CO2-free combustion. Hydrogen features the unique capability to store energy for medium to long storage cycles and hence could be used to alleviate seasonal variations of renewable power generation. The importance of hydrogen for future power generation is expected to increase due to several factors: the push for CO2-free energy production is calling for various options, all resulting in the necessity of a broader fuel flexibility, in particular accommodating hydrogen as a future fuel feeding gas turbines and combined cycle power plants. Hydrogen from methane reforming is pursued, with particular interest within energy scenarios linked with carbon capture and storage, while the increased share of renewables requires the storage of energy for which hydrogen is the best candidate. Compared to natural gas the main challenge of hydrogen combustion is its increased reactivity resulting in a decrease of engine performance for conventional premix combustion systems. The sequential combustion technology used within Ansaldo Energia’s GT36 and GT26 gas turbines provides for extra freedom in optimizing the operation concept. This sequential combustion technology enables low emission combustion at high temperatures with particularly high fuel flexibility thanks to the complementarity between its first stage, stabilized by flame propagation and its second (sequential) stage, stabilized by auto-ignition. With this concept, gas turbines are envisaged to be able to provide reliable, dispatchable, CO2-free electric power. In this paper, an overview of hydrogen production (grey, blue, and green hydrogen), transport and storage are presented targeting a CO2-free energy system based on gas turbines. A detailed description of the test infrastructure, handling of highly reactive fuels is given with specific aspects of the large amounts of hydrogen used for the full engine pressure tests. Based on the results discussed at last year’s Turbo Expo (Bothien et al. GT2019-90798), further high pressure test results are reported, demonstrating how sequential combustion with novel operational concepts is able to achieve the lowest emissions, highest fuel and operational flexibility, for very high combustor exit temperatures (H-class) with unprecedented hydrogen contents.

The Elephant in the Room–Gas Turbine Power

2010 ◽  
Vol 132 (12) ◽  
pp. 57-57
Author(s):  
Lee S. Langston
Keyword(s):  
Power Plant ◽  
Electric Power ◽  
Gas Turbine ◽  
Power Plants ◽  
Electrical Power ◽  
Electric Power Industry ◽  
Hydrocarbon Fuel ◽  
Combined Cycle ◽  
Electrical Generator ◽  
Gas Turbine Exhaust

This article presents an overview of gas turbine combined cycle (CCGT) power plants. Modern CCGT power plants are producing electric power as high as half a gigawatt with thermal efficiencies approaching the 60% mark. In a CCGT power plant, the gas turbine is the key player, driving an electrical generator. Heat from the hot gas turbine exhaust is recovered in a heat recovery steam generator, to generate steam, which drives a steam turbine to generate more electrical power. Thus, it is a combined power plant burning one unit of fuel to supply two sources of electrical power. Most of these CCGT plants burn natural gas, which has the lowest carbon content of any other hydrocarbon fuel. Their near 60% thermal efficiencies lower fuel costs by almost half compared to other gas-fired power plants. Their installed capital cost is the lowest in the electric power industry. Moreover, environmental permits, necessary for new plant construction, are much easier to obtain for CCGT power plants.

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